Early93Viper
Enthusiast
To get the most fun out of your viper: TRACK IT!
OP
OP
DAMN YANKEE
Guest
VIPER BATTERY - Located behind the Driver side rear wheel, one can see the removal process by looking at the Illustrated Guide instructions "Archer Racing Tow Hooks". Your Viper battery requires some attention as it is a small battery and Vipers are known for running poorly as a result of a weak battery (see earlier remarks in this thread.) What I have learned is...replace the battery every three (3) years without fail, place a "acid neutralizing mat" under the battery when you do (yes, even on a sealed battery). I spray the cable/bolt attachment with Battery Terminal Protectant Spray. I run a "smart" battery charger on the battery when the rig is waiting to be run, that extends the life of the battery and every start is strong. Lastly, and this may not sit well with everyone, don't waste your money on a super expensive, top shelf replacement,...quality sealed unit with a good warrenty, yes...but no much more than that is required.
Battery Mat (Acid Neutralizing Mat): BatteryMart.com
Grisham's Lawn and Garden Superstore
Battery Mat (Acid Neutralizing Mat): BatteryMart.com
Grisham's Lawn and Garden Superstore
Last edited by a moderator:
dave6666
Enthusiast
Hmmm... I bought my '01 GTS in Dec '06, and found the battery to be the OEM Chrysler one. I decided to replace it, and found nothing but silt under it.
Do you own stock in batterymart ?
I mean, I've never found corrosion under a working sealed battery. Many vehicles. Many batteries. Never!
OP
OP
DAMN YANKEE
Guest
You got great life out of your battery. Nice. You are also doing really well not to find any corrosion too. I haven't found any corrosion recently either...but, I am old enough to remember the damage done. Think of the mat as an insurance policy against the "what the hell?" incidents. I am aware of sealed units that leak, both by error and design (most recently two sealed units with breather tubes). I actually use a NAPA battery, not that cheap but just a solid deal. You can see the battery and the mat in the Illustrated "Archer Hooks" article.
OP
OP
DAMN YANKEE
Guest
GENII TOW HOOK CAPABILITY - Yes your stock GenII has tow capabilty in the stock configuration. Know where and how before you need to be able to explain it to some stranger about to crank your Viper up on his trailer.
1. Cloth/nylon straps are used to get your Viper up onto a flat trailer. These straps are carefully wrapped around the aluminum lower control arm. We are not towing or even doing much more that getting the car on a flatbed with this set-up. Tugging your car out of a roadside ditch is not going to end up nicely with this hold, but used carefully, it is safe.
2. If you are using “R Hooks”, they can be attached to any of the ovals cut-outs to be found on the frame ends. These are strong locations.
Use care and caution when working with either. For people that race their Vipers, or those that want a more formal hook-up, you will need to mount up front and rear hooks. A rear hook can be seen in this photo (held on to the frame with the two bolts).
1. Cloth/nylon straps are used to get your Viper up onto a flat trailer. These straps are carefully wrapped around the aluminum lower control arm. We are not towing or even doing much more that getting the car on a flatbed with this set-up. Tugging your car out of a roadside ditch is not going to end up nicely with this hold, but used carefully, it is safe.
2. If you are using “R Hooks”, they can be attached to any of the ovals cut-outs to be found on the frame ends. These are strong locations.
Use care and caution when working with either. For people that race their Vipers, or those that want a more formal hook-up, you will need to mount up front and rear hooks. A rear hook can be seen in this photo (held on to the frame with the two bolts).
OP
OP
DAMN YANKEE
Guest
Understand the 2000-2001 model year Hypereutectic Pistons - Read these VCA threads long enough and you will come across heated discussions abou the pistons in the 2000 - 2001 year Vipers. Most don't have a clue what is being discussed...not that that would ever stop a die-hard VCAer from contributing!
Here is a quick background. There are essentially two classes of stock Gen2 Vipers out there to my mind, those with “hypereutectic” pistons and those without them. In 2000, Dodge wanted to add some additional performance to their new millennium Viper as well as higher efficiency and environmental standards. Among other things, the engineers decided to add new Hypereutectic pistons to all models. Those who bought Vipers in the production years 2000 and 2001 have hypereutectic pistons.
We read about hypereutectic (sometimes referred to as cast) pistons in the VCA threads all the time. These threads usually refer to concerns by Viper owners of those years as it relates to the limitations of cast pistons, especially in forced induction engines. These are real concerns and we need to understand why.
So what are hypereutectic pistons? Simply put they are cast pistons as opposed to being forged. Almost all pistons have aluminum in them. By being cast, hypereutectic pistons are able to have a much higher amount of silicon in the alloy. This silicon greatly increases the thermal stability and, as a result, these piston’s dimensional tolerances can be much tighter (most cast piston have a skirt clearance of approximately .0007 to .0009, forged about .005 to .007). Their expansion rates are much smaller. When cold, these pistons are much tighter than forged pistons (especially at the skirt and towards the top where the rings are), therefore they rock less, their rings seal better and they have less blow-by. They are lighter and quieter as well. And all that silicon makes them harder (unlike higher aluminum content in forged pistons) so that they don’t “scuff up” the cylinder walls when cold and in a low oil start-up. But, all that goodness comes at a price, and that price is brittleness. Hypereutectic are much more brittle than low silicon forged pistons.
Now, in a stock Viper, these pistons are well within operational spec and all the really superb aspects of hypereutectic pistons comes into play. The 2000 and 2001 Vipers have great pistons, no doubt. But, when we begin to modify our Vipers we have to recognize the very real limitations of the stock hypereutectic pistons. Simply put, if you are going to go over 700hp, you won’t be doing it with hypereutectic pistons and anything over 650 hp will require real tuning precision if you use hypereutectic pistons. Are hypereutectic pistons inherently weak or of inferior quality or used to cut costs, etc, etc? Not at all, they are a superior piston when used in the right application. Can you supercharge a Viper with hypereutectic pistons? Heck yea, mine is and its fabulous! If I have them and I run a supercharger do I need to constantly be on gaurd and worried? No and no, proper boost (5lbs no W/M or 6.5 lbs with W/M), proper A/F, proper timing/tune and you are going to have a great, stable rig!
What’s the danger? Detonation. What’s that? Lots of people talk about it, few people understand it. Detonation is simply one of two kinds of combustion:
Good Combustion (Deflagration):
In an internal combustion engine, we provide the right mixture of fuel and air. That mixture provides enough air and enough fuel to burn completely. That fuel is ignited in the cylinder by the spark plug just before the piston comes all the way up in its compression cycle to Top Dead Center (TDC). In other words, we are igniting the proper air mix in the last stages of compression. When all is well, the spark plug fires, creating a tiny ignition flame the size of the gap and, believe it or not, in the first few milliseconds that flame struggles to survive, then it spreads across the face of the compressed air/fuel and triggers a uniform, consistent fuel burn that carries over TDC and down through the power stroke. The burn is controlled and pressures rise smoothly and just as the piston starts its downward movement. Nice. People, when we talk about “ignition timing”, this is it! Where does the spark plug fire in the pistons cycle….. “Retarding” or “Advancing” the timing! There it is!
Bad Combustion (Detonation)
You can probably guess this, right? In detonation there is no uniform flame front moving efficiently through the air/fuel mix. Rather, due to a number of very identifiable and resolvable issues the unburned air/fuel mixture is compressed and instantly ignited creating enormous pressures. Simply put, we have an explosive, instantaneous explosion near the top of the piston stroke, too early, with a massive pressure wave. More than enough to blow up a hypereutectic piston. One can see, if we were to delay or “retard” the spark until the piston is farther through its cycle we could, inpart overcome detonation (piston already moving down through the stroke, etc.)
Lastly, we need to know that Detonation is NOT “pre-ignition” or “dieseling.” That is when forces other than the spark plug is firing off the fuel/air mixture. That’s why you can turn off your key on some cars and the engine still runs….poorly.
Forged pistons, on the other hand, can take this kind of abuse (though good timing is good timing) and keep on going. We should also note that a number of superb houses produce
remarkable new hypereutectic pistons for massive engines....very different than those found in those earlier Vipers!
What can we do about Detonation?
1. Better Timing (retarding)
2. Higher Octane and a
3. More perfect Air/Fuel
4. Cooler Fuel/Air incoming mix (W/M)
5. Cooler Plugs
6. Lower compression
So where does this all leave us? On a stock rig, these cast pistons are superior to forged. On a mild supercharged rig (I use a Roe 6.5 lbs - produces up to 10 lbs, with all the trimmings) no issue whatsoever. On an 8 lbs rig, no problem. On a wild ride (10 lbs plus), well they are coming out. Pick your poison.
But just remember, the most beautiful Viper color ever, steel grey, all come in cast pistons.
Here is a quick background. There are essentially two classes of stock Gen2 Vipers out there to my mind, those with “hypereutectic” pistons and those without them. In 2000, Dodge wanted to add some additional performance to their new millennium Viper as well as higher efficiency and environmental standards. Among other things, the engineers decided to add new Hypereutectic pistons to all models. Those who bought Vipers in the production years 2000 and 2001 have hypereutectic pistons.
We read about hypereutectic (sometimes referred to as cast) pistons in the VCA threads all the time. These threads usually refer to concerns by Viper owners of those years as it relates to the limitations of cast pistons, especially in forced induction engines. These are real concerns and we need to understand why.
So what are hypereutectic pistons? Simply put they are cast pistons as opposed to being forged. Almost all pistons have aluminum in them. By being cast, hypereutectic pistons are able to have a much higher amount of silicon in the alloy. This silicon greatly increases the thermal stability and, as a result, these piston’s dimensional tolerances can be much tighter (most cast piston have a skirt clearance of approximately .0007 to .0009, forged about .005 to .007). Their expansion rates are much smaller. When cold, these pistons are much tighter than forged pistons (especially at the skirt and towards the top where the rings are), therefore they rock less, their rings seal better and they have less blow-by. They are lighter and quieter as well. And all that silicon makes them harder (unlike higher aluminum content in forged pistons) so that they don’t “scuff up” the cylinder walls when cold and in a low oil start-up. But, all that goodness comes at a price, and that price is brittleness. Hypereutectic are much more brittle than low silicon forged pistons.
Now, in a stock Viper, these pistons are well within operational spec and all the really superb aspects of hypereutectic pistons comes into play. The 2000 and 2001 Vipers have great pistons, no doubt. But, when we begin to modify our Vipers we have to recognize the very real limitations of the stock hypereutectic pistons. Simply put, if you are going to go over 700hp, you won’t be doing it with hypereutectic pistons and anything over 650 hp will require real tuning precision if you use hypereutectic pistons. Are hypereutectic pistons inherently weak or of inferior quality or used to cut costs, etc, etc? Not at all, they are a superior piston when used in the right application. Can you supercharge a Viper with hypereutectic pistons? Heck yea, mine is and its fabulous! If I have them and I run a supercharger do I need to constantly be on gaurd and worried? No and no, proper boost (5lbs no W/M or 6.5 lbs with W/M), proper A/F, proper timing/tune and you are going to have a great, stable rig!
What’s the danger? Detonation. What’s that? Lots of people talk about it, few people understand it. Detonation is simply one of two kinds of combustion:
Good Combustion (Deflagration):
In an internal combustion engine, we provide the right mixture of fuel and air. That mixture provides enough air and enough fuel to burn completely. That fuel is ignited in the cylinder by the spark plug just before the piston comes all the way up in its compression cycle to Top Dead Center (TDC). In other words, we are igniting the proper air mix in the last stages of compression. When all is well, the spark plug fires, creating a tiny ignition flame the size of the gap and, believe it or not, in the first few milliseconds that flame struggles to survive, then it spreads across the face of the compressed air/fuel and triggers a uniform, consistent fuel burn that carries over TDC and down through the power stroke. The burn is controlled and pressures rise smoothly and just as the piston starts its downward movement. Nice. People, when we talk about “ignition timing”, this is it! Where does the spark plug fire in the pistons cycle….. “Retarding” or “Advancing” the timing! There it is!
Bad Combustion (Detonation)
You can probably guess this, right? In detonation there is no uniform flame front moving efficiently through the air/fuel mix. Rather, due to a number of very identifiable and resolvable issues the unburned air/fuel mixture is compressed and instantly ignited creating enormous pressures. Simply put, we have an explosive, instantaneous explosion near the top of the piston stroke, too early, with a massive pressure wave. More than enough to blow up a hypereutectic piston. One can see, if we were to delay or “retard” the spark until the piston is farther through its cycle we could, inpart overcome detonation (piston already moving down through the stroke, etc.)
Lastly, we need to know that Detonation is NOT “pre-ignition” or “dieseling.” That is when forces other than the spark plug is firing off the fuel/air mixture. That’s why you can turn off your key on some cars and the engine still runs….poorly.
Forged pistons, on the other hand, can take this kind of abuse (though good timing is good timing) and keep on going. We should also note that a number of superb houses produce
remarkable new hypereutectic pistons for massive engines....very different than those found in those earlier Vipers!
What can we do about Detonation?
1. Better Timing (retarding)
2. Higher Octane and a
3. More perfect Air/Fuel
4. Cooler Fuel/Air incoming mix (W/M)
5. Cooler Plugs
6. Lower compression
So where does this all leave us? On a stock rig, these cast pistons are superior to forged. On a mild supercharged rig (I use a Roe 6.5 lbs - produces up to 10 lbs, with all the trimmings) no issue whatsoever. On an 8 lbs rig, no problem. On a wild ride (10 lbs plus), well they are coming out. Pick your poison.
But just remember, the most beautiful Viper color ever, steel grey, all come in cast pistons.
Last edited by a moderator:
John Baringer
Enthusiast
Resetting the PCM after battery change, Does this hold true with Gen I vipers?
I have a Gen I that stalls while driving at low RPM, when cluch is pushed in. Will reset PCM help this?
I have a Gen I that stalls while driving at low RPM, when cluch is pushed in. Will reset PCM help this?
V10SpeedLuvr
Enthusiast
Most likely will help. Best (not easist, but best) way to reset PCM is to access the battery and ground the POSITIVE battery cable to the frame (per Chuck Tator). I replaced my battery last week and did this before putting everything back together. Car has run flawlessly.
p.s.--You didnt install a Optima redtop did you? If so, when you access the battery to reset the PCM, go ahead and return the Optima and get a different brand. You can do this now or in 4-6 months when the battery dies and you get stranded somewhere
John Baringer
Enthusiast
Did not install a Optima, was thinking about it when I did it, but did not think it would fit. I was afraid that a top post battery would hit the frame. I bought a Delco Battery, best one they had in stock.
Do not understand the grounding the postive to the frame. Are you saying to take the postive cable off the positive lead on the battery, then touch the frame with the positive cable?
New owner of a 1994 Viper, and have learned a lot from this site. Just want to say Thanks!
dave6666
Enthusiast
Not planing on living that long, but thanks for the forecast.
Well that settles it.
I'm pulling my crappy forged pistons and lumpy cam out and putting in the "superior" cast ones and smoother cam.
dave6666
Enthusiast
Well that settles it.
I'm pulling my crappy forged pistons and lumpy cam out and putting in the "superior" cast ones and smoother cam.
Looks like we're gonna have to take this one to the mat...
V10SpeedLuvr
Enthusiast
Yes, Chuck explained it to me that doing this will dump EVERYTHING in the car's PCM and will allow the Viper to relearn from zero. Viper PCM's are adaptive and always "learning" as we are driving. After a while, the PCM gets full of "cookies" and thats when the drivability issues arise. Doing the positive cable-to-frame grounding is just like deleting all the cookies in your web browser's memory. After doing this, be sure to insert the key, turn to "on" (do not crank) and press the gas pedal to the floor firmly twice. Then turn the key off. This will reteach the TPS the position of the pedal at WOT. You can now start the car as normal.
OP
OP
DAMN YANKEE
Guest
Your lumpy cam is better than those in the 2000-2001 years, your stock forged pistons are just fine as well, especially if you have any plans to build a monster. The piece was to help explain what the cast piston issue is all about.
John Baringer
Enthusiast
Will try that in the Spring, thanks for the help. I know all about Cookies on the computer. Own a Computer Store here in the Toledo, Ohio area. ( Virtual PC's )Thanks again for the help, and Happy Holidays!
Boxer12
Enthusiast
Have the damper bolt torque checked, and mark it afterwards so you can recheck it often. These come loose, and when it does...(I just got lucky and found mine was loose when the serp belt showed some fraying..,).
When using a floor jack, put a hockey puck between jack and pigtail under car, so it doesn't slip.
At a minimum, install 5 or 6 pt harness for track use of a Viper. Put them on both sides.
All nonABS cars are not 'bad', you just have to know how to modulate the brakes manually. Sounds like someone was following too closely.
When using a floor jack, put a hockey puck between jack and pigtail under car, so it doesn't slip.
At a minimum, install 5 or 6 pt harness for track use of a Viper. Put them on both sides.
All nonABS cars are not 'bad', you just have to know how to modulate the brakes manually. Sounds like someone was following too closely.
yogibayer
Enthusiast
Urban Legend: "Lots of Vipers caught fire due to loose Power Streering Caps"
Viper Fact: LOOSE CAPS ARE COMMON; FIRES ARE NOT.
I know of many, many dozens of incidents of lost P/S caps. When a P/S cap has come off (or a PS hose has ruptured) PS Fluid can cause a LOT OF SMOKE, and a lot of STINK, enabling the owner to avoid a fire. I have inhaled more than my share of fumes! On extremely rare ocassions, (under 10 ever?) a PS fluid flash fire might occur; The cap itself can get lodged in the headers and catch fire, (I know of 1) We have bid on or bought 'light burner" Vipers, and PS Fluid has been a very rare culprit.
That said, be sure to tighten your cap with a shop towel or rag.....
Viper Fact: LOOSE CAPS ARE COMMON; FIRES ARE NOT.
I know of many, many dozens of incidents of lost P/S caps. When a P/S cap has come off (or a PS hose has ruptured) PS Fluid can cause a LOT OF SMOKE, and a lot of STINK, enabling the owner to avoid a fire. I have inhaled more than my share of fumes! On extremely rare ocassions, (under 10 ever?) a PS fluid flash fire might occur; The cap itself can get lodged in the headers and catch fire, (I know of 1) We have bid on or bought 'light burner" Vipers, and PS Fluid has been a very rare culprit.
That said, be sure to tighten your cap with a shop towel or rag.....
OP
OP
DAMN YANKEE
Guest
GENII CENTER CONSOLE CRACKING - The center console section (the Driver's right hand arm rest) is particularly poorly structurally supported. Do not place alot of pressure on the center of this section, in fact treat it with great care. Most damage occurs when people stretch around to access the rear area (GTS) and use their left hand to press down on the console to stretch rearward. When cracked, replacement with a new unit, or custom covering (after repair) is in order. There are a couple of great threads and a great Illustrated Guide on how to go about strengthening the center support so that your original stock console can last and last. Lastly Big Dave sells a well thought through custom console support system.
Interior
Interior dave6666
Enthusiast
That was the year they experimented with plastic pistons.
Not so good....
So my '01 is pre-plastic?
Great. I have Hyper-to-do-it pistons and a gut-less water pump.
I'll just drive with the hood speakers turned up until something breaks.
Great.
OP
OP
DAMN YANKEE
Guest
CLOSED LOOP - Lets just say that you want to know more than most about how your Viper runs...and why it runs well (or doesn't). It starts with understanding the three (3) conditions of your Viper's computer operations.
1. Warming Up
2. Closed Loop
3. Open Loop
Warming up lasts about 45 seconds and its all preprogrammed. Simple enough.
Closed Loop - About 85 percent of all the driving will ever do in our vipers will be in closed loop, yet most Viper owners don't know what it means. Its actually pretty simple, a well running Viper is one that has precise tuning of the air to fuel ratio and ignition timing curves over the whole operational range of the engine. We begin with understanding one of the very basics of stock Viper engine. There are two major conditions that every stock Viper engine has, open loop and closed loop operations. And they are very different. Closed loop refers to a condition whereby your Viper's PCM is constantly monitoring the narrowband oxygen sensors located in your exhaust system along with a few other sensors like air temperature and cooling temperature. As you may be aware, each side of your engine (or bank) has its own exhaust pipe with a narrowband sensor located at the junction of the header and another narrowband sensor located behind the catalytic converter. When your engine is warmed up and your operating your engine with approximately less than 80 percent throttle, the PCM monitors the amount of oxygen and fuel and makes adaptive changes by increasing or decreasing the injector "pulse" automatically and spark curves. Increase the pulse, or in other words provide electrical current to the injector's for a longer duration, firing the injector's for more milliseconds, and you get more gas injected into the cylinder. Shorten the pulse, less milliseconds, less gas injected. This is where all you idle and cruising and normal acceleration efficiency work is. All that the computer "learns" is stored in Long Term Fuel Trim (you'll read about LTFT alot around here).
We should think of closed loop operations as the time in which the engine is not being called upon to do its most powerful work. That does not mean that you're not accelerating, or even moving at highway speeds, that is not the case.... One can cruise at highway speeds for hours and never leave closed loop. In closed loop operations, we generally expect to throttle body's to be less than 80 percent open. In closed loop operations, we expect that the Viper is idling, gently accelerating, reasonably accelerating or cruising. All the while, the PCM is working to maximize the efficiency of your air fuel ratio. That ratio is most efficient at what is called "lambda". lambda is achieved when 14.7 lbs. of air is mixed with one pound fuel. The target, constantly being adjusted for engine load and other engine and driving conditions in the lambda is just that, 14.7. For those of us that want to see if in closed loop our cars are operating at lambda, we can. We do this by using the oxygen sensor that samples at a much higher rate and add a much more accurate rate and those found in stock Viper. Stock Viper's Oxygen sensors they are narrowband sensors, guys/gals that want to more accurate view their engine's ability to achieve lambda in closed the operations rely on gauges driven by wideband sensors. As load changes, so does the require A/F (Air Fuel) mix. It would be incorrect to assume that simply having a wideband sensor and wideband gauging, your car is going to allow one to properly address all issues surrounding closed loop operations. We also need a high-quality software interface (program) to the ODB2 found in our GEN2 vipers. I have one, it plugs into the drivers left hand knee location of the OBD2 fitting under the dash. I can directly look into the PCM's operations, especially the adaptives and make sure they fall within a specified range of the stock PCM operating throughout closed loop. There is of course more on this subject, lots more, but there you have a very simplified begining, that's closed loop operations in a very summary fashion. If its less than 80%, your in closed loop and your PCM is interactively managing your Viper's vitals..
Well cover open loop in a seperate piece.
1. Warming Up
2. Closed Loop
3. Open Loop
Warming up lasts about 45 seconds and its all preprogrammed. Simple enough.
Closed Loop - About 85 percent of all the driving will ever do in our vipers will be in closed loop, yet most Viper owners don't know what it means. Its actually pretty simple, a well running Viper is one that has precise tuning of the air to fuel ratio and ignition timing curves over the whole operational range of the engine. We begin with understanding one of the very basics of stock Viper engine. There are two major conditions that every stock Viper engine has, open loop and closed loop operations. And they are very different. Closed loop refers to a condition whereby your Viper's PCM is constantly monitoring the narrowband oxygen sensors located in your exhaust system along with a few other sensors like air temperature and cooling temperature. As you may be aware, each side of your engine (or bank) has its own exhaust pipe with a narrowband sensor located at the junction of the header and another narrowband sensor located behind the catalytic converter. When your engine is warmed up and your operating your engine with approximately less than 80 percent throttle, the PCM monitors the amount of oxygen and fuel and makes adaptive changes by increasing or decreasing the injector "pulse" automatically and spark curves. Increase the pulse, or in other words provide electrical current to the injector's for a longer duration, firing the injector's for more milliseconds, and you get more gas injected into the cylinder. Shorten the pulse, less milliseconds, less gas injected. This is where all you idle and cruising and normal acceleration efficiency work is. All that the computer "learns" is stored in Long Term Fuel Trim (you'll read about LTFT alot around here).
We should think of closed loop operations as the time in which the engine is not being called upon to do its most powerful work. That does not mean that you're not accelerating, or even moving at highway speeds, that is not the case.... One can cruise at highway speeds for hours and never leave closed loop. In closed loop operations, we generally expect to throttle body's to be less than 80 percent open. In closed loop operations, we expect that the Viper is idling, gently accelerating, reasonably accelerating or cruising. All the while, the PCM is working to maximize the efficiency of your air fuel ratio. That ratio is most efficient at what is called "lambda". lambda is achieved when 14.7 lbs. of air is mixed with one pound fuel. The target, constantly being adjusted for engine load and other engine and driving conditions in the lambda is just that, 14.7. For those of us that want to see if in closed loop our cars are operating at lambda, we can. We do this by using the oxygen sensor that samples at a much higher rate and add a much more accurate rate and those found in stock Viper. Stock Viper's Oxygen sensors they are narrowband sensors, guys/gals that want to more accurate view their engine's ability to achieve lambda in closed the operations rely on gauges driven by wideband sensors. As load changes, so does the require A/F (Air Fuel) mix. It would be incorrect to assume that simply having a wideband sensor and wideband gauging, your car is going to allow one to properly address all issues surrounding closed loop operations. We also need a high-quality software interface (program) to the ODB2 found in our GEN2 vipers. I have one, it plugs into the drivers left hand knee location of the OBD2 fitting under the dash. I can directly look into the PCM's operations, especially the adaptives and make sure they fall within a specified range of the stock PCM operating throughout closed loop. There is of course more on this subject, lots more, but there you have a very simplified begining, that's closed loop operations in a very summary fashion. If its less than 80%, your in closed loop and your PCM is interactively managing your Viper's vitals..
Well cover open loop in a seperate piece.
OP
OP
DAMN YANKEE
Guest
Right off of our own threads, written by Yogibayer.
When buying a used Viper, research, research, research...here are a few tips:
1) Buy the Vipers buyers guide by Maurice Liang
Amazon.com: Viper Buyers Guide (Buyer's Guide) (Buyer's Guide): Books: Maurice Liang
2) Carfax...Carfax....Carfax
3) Run your VIN by CODY before buying. He has a database of wrecked Vipers that don't show up in Carfax.
4) Have a Viper Tech check out the car for you
5) A new one I just learned - tires have date codes. Make sure all of the tires were made around a similar time less than 5 years ago.
When buying a used Viper, research, research, research...here are a few tips:
1) Buy the Vipers buyers guide by Maurice Liang
Amazon.com: Viper Buyers Guide (Buyer's Guide) (Buyer's Guide): Books: Maurice Liang
You must be registered for see images
2) Carfax...Carfax....Carfax
3) Run your VIN by CODY before buying. He has a database of wrecked Vipers that don't show up in Carfax.
4) Have a Viper Tech check out the car for you
5) A new one I just learned - tires have date codes. Make sure all of the tires were made around a similar time less than 5 years ago.
Last edited by a moderator:
OP
OP
DAMN YANKEE
Guest
IN responding to a questions of a new Viper owner (in Germany) about what to do to prepare a Viper for the track, VCA member Vic does a great job at laying out what may be needed. Thanks to VIC!
"Did you know that you shouldn't turn the front wheels to the left or to the right, when the hood is cracked open? The tires will hit the hood corners, and break them. The only time that it is ok to turn the wheels is when the hood is all the way up, or all the way down, but not in-between!
There is a breather vent, at the forward end of each valve cover. It routes into the incoming air box. During heavy braking, some oil may slosh forward, into the intake plenum, and this will make very embarrassing big blue clouds of smoke. People will think your engine blew up! What you need to do, is to take the hoses from each valve cover, and route them to a small oil catch tank, that you can possibly mount to the aluminum cross brace, just in front of the engine. ITs a good idea to also vent the power steering resevoir into this tank as well, to avoid getting p.s. fluid on the exhaust headers.
There is also one more hose, right under the throttle body, that can allow oil to enter the intake plenum. I'm not sure what racers do with this one, but Dave Cawthorne on this site has a fix for it. He sells under the name "Dave's Big Brakes"
Make sure you flush out the old brake fluid, and go with DOT 4 fluid, like Motul 600, or equivalent. You probably know a lot of this kind of stuff already, from your BMW experience at the Ring. (Damm, I envy you!!!!) heh heh!
Here is a few more things to do to prep a GTS for the track-
*brake ducts for cooling air
*high temperature brake pads
*wrap ball joints with foil or something, so the hot rotors don't melt the grease out
*add "trap doors" to the oil pan, to help oil pick-up in high G turns
*add modified windage tray to the oil pan area, to help the oil return faster to the pan
*add an Accusump, maybe the three quart variety, to provide oil pressure, in case the pan is dry
*If you can't spring for the tripple-adjustable Penske shocks, the stock shock can be revalved for improved track performance. (a "dirty, cheating bastard" trick)
*change power steering fluuid to Red Line brand, much higher boiling point, and less foaming
*add 5 or 6 point harness
*roll bar
*big brakes, from Dave, or Stop Tech, etc
If you don't get a track alignment, the car tends to understeer. There are "sport shims" where the top, front, control arm bolts to the chassis. Removing these shims will give signifigant negative camber to the front wheels, balancing out the understeer, (as well as rendering more toe-out, so you gotta hold the wheel steady). I never tried this myself, but just had a mild track alignment done instead. The advantage of taking the sport shims out is, that you can put them back for the street, and that way you won't be wearing out your tires prematurely. If you go with racing tires, then you will probably have a second set of rims. The list goes on and on!"
"Did you know that you shouldn't turn the front wheels to the left or to the right, when the hood is cracked open? The tires will hit the hood corners, and break them. The only time that it is ok to turn the wheels is when the hood is all the way up, or all the way down, but not in-between!
There is a breather vent, at the forward end of each valve cover. It routes into the incoming air box. During heavy braking, some oil may slosh forward, into the intake plenum, and this will make very embarrassing big blue clouds of smoke. People will think your engine blew up! What you need to do, is to take the hoses from each valve cover, and route them to a small oil catch tank, that you can possibly mount to the aluminum cross brace, just in front of the engine. ITs a good idea to also vent the power steering resevoir into this tank as well, to avoid getting p.s. fluid on the exhaust headers.
There is also one more hose, right under the throttle body, that can allow oil to enter the intake plenum. I'm not sure what racers do with this one, but Dave Cawthorne on this site has a fix for it. He sells under the name "Dave's Big Brakes"
Make sure you flush out the old brake fluid, and go with DOT 4 fluid, like Motul 600, or equivalent. You probably know a lot of this kind of stuff already, from your BMW experience at the Ring. (Damm, I envy you!!!!) heh heh!
Here is a few more things to do to prep a GTS for the track-
*brake ducts for cooling air
*high temperature brake pads
*wrap ball joints with foil or something, so the hot rotors don't melt the grease out
*add "trap doors" to the oil pan, to help oil pick-up in high G turns
*add modified windage tray to the oil pan area, to help the oil return faster to the pan
*add an Accusump, maybe the three quart variety, to provide oil pressure, in case the pan is dry
*If you can't spring for the tripple-adjustable Penske shocks, the stock shock can be revalved for improved track performance. (a "dirty, cheating bastard" trick)
*change power steering fluuid to Red Line brand, much higher boiling point, and less foaming
*add 5 or 6 point harness
*roll bar
*big brakes, from Dave, or Stop Tech, etc
If you don't get a track alignment, the car tends to understeer. There are "sport shims" where the top, front, control arm bolts to the chassis. Removing these shims will give signifigant negative camber to the front wheels, balancing out the understeer, (as well as rendering more toe-out, so you gotta hold the wheel steady). I never tried this myself, but just had a mild track alignment done instead. The advantage of taking the sport shims out is, that you can put them back for the street, and that way you won't be wearing out your tires prematurely. If you go with racing tires, then you will probably have a second set of rims. The list goes on and on!"
Last edited by a moderator:
OP
OP
DAMN YANKEE
Guest
WIRE AND COIL DIAGRAM:
GEN 2
GEN 1 (from our friend JIPI in Switzerland)
This is for the Gen1s:
Left coils:
Top (connector side): #3--9--1
Bottom: #2--8--6
Right coils:
Top (connector side): #4--10
Bottom: #7--5
GEN 2
GEN 1 (from our friend JIPI in Switzerland)
This is for the Gen1s:
Left coils:
Top (connector side): #3--9--1
Bottom: #2--8--6
Right coils:
Top (connector side): #4--10
Bottom: #7--5
CROM
Viper Owner
Go to the below link, input your VIN in the box on the left to find out if any recall work as been done on your car.
My Dodge: Official Dodge Owners website - Warranty, Vehicle Specs, Service Contracts, Financing, Dealers
My Dodge: Official Dodge Owners website - Warranty, Vehicle Specs, Service Contracts, Financing, Dealers
OP
OP
DAMN YANKEE
Guest
CHANGING THE BATTERY DETAILS:
A great write-up by our own Steve-Indy....
"It's not a bad job...goes well if you plan ahead and have tools ready.
Use a 3/4" (or 19mm) socket to remove left rear wheel. Then use 8mm, 11mm, and 10mm sockets to remove fasteners on splash shield in rear of fender well, and a pair of needle nose pliers to pull the plastic push pin that holds the battery cover to the splash guard...now disconnect the battery using 5/16" socket, and use a 1/2" socket to remove battery clamp.
Inspect the tray carefully...you will likely see corrosion...if so, neutralize it CAREFULLY by scrubbing with water and baking soda. DO NOT USE COMPRESSED AIR to clean this out !!!
After the area dries, I usually use a wire brush on an electric drill (wearing goggles and a respirator/face mask) to remove all remaining oxidation caused by the acid and/or rust. I wipe the tray WELL with rags, then allow it to dry. Then, after a couple more wipe-downs with ethyl alcohol to remore moisture, debris, and oils... I coat the tray bottom and sides with Rustoleum primer 2-3 times...and when dry, hit it with a couple of coats of Rustoleum black "engine gloss" even a semi-gloss. I have found that a used pizza box slid right under the battery tray makes a great "paint booth". After this is completely dry,
(I'm going to interrupt here to add that I use an acid mat under my batteries. They are cheap and completely eliminate the issues listed above from coming back!
http://www.batterymart.com/p-battery-mat.html Back to Steve..)
install new battery (I PREFER a 75 series as they ALWAYS fit our various Vipers...and I always use a Sears Die-Hard Gold...noting that the LEAST amout of usage that these batteries have given me is 6.75 years). Then put it back together.
Note: SOME 94's will not start after battery disconnect...so you might wish to try it before installing the covers. If you have troubie...call me...or do a "search".
I do use a 9 volt battery plugged into the cigarette lighter...which maintains the clock and radio settings for a reasonable time.
HAVE FUN...and don't drop your Viper on yourself !!!"
VCA Member? Sign-In and you can see the photo set of the battery reveal in a 2000GTS about half way down the page here:
http://forums.viperclub.org/illustrated-upgrades/599378-archer-racing-tow-hooks-guide-photos.html
Thank you Steve!
A great write-up by our own Steve-Indy....
"It's not a bad job...goes well if you plan ahead and have tools ready.
Use a 3/4" (or 19mm) socket to remove left rear wheel. Then use 8mm, 11mm, and 10mm sockets to remove fasteners on splash shield in rear of fender well, and a pair of needle nose pliers to pull the plastic push pin that holds the battery cover to the splash guard...now disconnect the battery using 5/16" socket, and use a 1/2" socket to remove battery clamp.
Inspect the tray carefully...you will likely see corrosion...if so, neutralize it CAREFULLY by scrubbing with water and baking soda. DO NOT USE COMPRESSED AIR to clean this out !!!
After the area dries, I usually use a wire brush on an electric drill (wearing goggles and a respirator/face mask) to remove all remaining oxidation caused by the acid and/or rust. I wipe the tray WELL with rags, then allow it to dry. Then, after a couple more wipe-downs with ethyl alcohol to remore moisture, debris, and oils... I coat the tray bottom and sides with Rustoleum primer 2-3 times...and when dry, hit it with a couple of coats of Rustoleum black "engine gloss" even a semi-gloss. I have found that a used pizza box slid right under the battery tray makes a great "paint booth". After this is completely dry,
(I'm going to interrupt here to add that I use an acid mat under my batteries. They are cheap and completely eliminate the issues listed above from coming back!
http://www.batterymart.com/p-battery-mat.html Back to Steve..)
install new battery (I PREFER a 75 series as they ALWAYS fit our various Vipers...and I always use a Sears Die-Hard Gold...noting that the LEAST amout of usage that these batteries have given me is 6.75 years). Then put it back together.
Note: SOME 94's will not start after battery disconnect...so you might wish to try it before installing the covers. If you have troubie...call me...or do a "search".
I do use a 9 volt battery plugged into the cigarette lighter...which maintains the clock and radio settings for a reasonable time.
HAVE FUN...and don't drop your Viper on yourself !!!"
VCA Member? Sign-In and you can see the photo set of the battery reveal in a 2000GTS about half way down the page here:
http://forums.viperclub.org/illustrated-upgrades/599378-archer-racing-tow-hooks-guide-photos.html
Thank you Steve!
Last edited by a moderator:
crossram440
Enthusiast
hood open and jacking up the front…
Here is a little one to add, somewhat of a no brainer but when your head is in to maintenance and detail mode some of the obvious things slip by you, Never jack up the front of the car high enough to have the hood slam shut on you,..... Bad , Bad. lower the rear of the hood down then jack up the front end.
Here is a little one to add, somewhat of a no brainer but when your head is in to maintenance and detail mode some of the obvious things slip by you, Never jack up the front of the car high enough to have the hood slam shut on you,..... Bad , Bad. lower the rear of the hood down then jack up the front end.
OP
OP
DAMN YANKEE
Guest
You've got injectors...10 of them, you know that, but most don't know how important working with your injectors can be to making your Viper run well. With some simple foundation information, one can learn a great deal about injectors and how they make your car run well....or not.
Where to start? We start with a stock intake valve!
A stock intake valve opens opens to receive injected fuel and air into the cylinder. Sometimes that valve is open for a relatively long time...idling. Sometimes that valve is open for an incredibly short time....roaring at 5,500 RPM. The higher the RPM, the faster the valves are opening and closing! So, for whatever time we have with that intake valve open is the time we have to inject fuel. We measure that time in "milliseconds" (1,000 milliseconds in a second), not to worry, just know we measure in milliseconds.
For a 2000 GTS, the time the intake valve is open:
At 6,000 RPM the intake value opens for 20.0 ms
At 5,500 RPM the intake value opens for 21.8 ms
At 5,000 RPM the intake valve opens for 24.0 ms
At 4,500 RPM the intake valve opens for 26.6 ms
At 4,000 RPM the intake valve opens for 30.0 ms
At 3,500 RPM the intake valve opens for 34.3 ms
At 3,000 RPM the intake valve opens for 40.0 ms
At 2,500 RPM the intake valve opens for 48.0 ms
At 2,000 RPM the intake valve opens for 60.0 ms
At 1,500 RPM the intake valve opens for 80.0 ms
At 1,000 RPM the intake valve opens for 120 ms
At 500 RPM the intake valve opens for 240 ms
So, now you know. Your Viper gives you about 21.8 milliseconds to load up the cylinder at 5,500 RPM and about 240 milliseconds to load up the cylinder at idle. Big difference!
Now that we know the time we have to squirt the fuel in, we need to know how long and how much our injectors can squirt at any given time. Look at it this way, the intake valve opens for 240 milliseconds at 500 rpm (idle) and that is a relatively long time. We sure are not going to inject fuel in for that whole time! Nope, at idle a typical stock PCM will only send a “pulse” to a stock injector to squirt for about 5 or 6 milliseconds. We also know at 5,500 RPM out valve is open for only 21.8 ms, and we only have that much time to squirt all the fuel we need.
For a GTS, a stock injector squirts fuel for approximately this many milliseconds:
At 5,500 RPM, stock injectors are pulsed for 21 ms
At 4,500 RPM, stock injectors are pulsed for 20 ms
At 3,500 RPM, stock injectors are pulsed for 19 ms
At 2,500 RPM, stock injectors are pulsed for 15 ms
At 1,500 RPM, stock injectors are pulsed for 13 ms
At 500 RPM, stock injectors are pulsed for 5-6 ms
Now we know how long a set of stock injectors squirt fuel at a given RPM. We need to know a couple of more things. First is the term “Duty Cycle”. Duty Cycle is the per cent of time the injector is in use while the intake valve is open. Simply, if the injector is firing for the whole time the intake valve is open, you have a 100% Duty Cycle. If the injector is firing for only half the time the intake valve is open you have a 50% Duty Cycle. So….if one was to fire an injector for 20ms at 3,000 RPM…..well? At 3,000 RPM our intake is open for?.....40.0 ms….so, the answer is 50% Duty Cycle. Great.
So, here is the finished "Duty Cycle" table for stock injectors in a GTS:
At 5,500 RPM a stock injector is at almost 100% Duty Cycle
At 4,500 RPM a stock injector is at 75% Duty Cycle
At 3,500 RPM a stock injector is at 55% Duty Cyce
At 2,500 RPM a stock injector is at 31% Duty Cycle
At 1,500 RPM a stock injector is at 16% Duty Cycle
At 500 RPM a stock injector is at 2% Duty Cycel
Folks, stock injectors in stock motors have enough duty cycle to get the job done. The PCM has its Closed Loop and Open Loop routines to regulate the injectors and squirt fuel into the open intakes as required. As we can see, at the max RPM we are using approx 100% of the stock injector's capacity. Thats important, when we build out an engine and increase the air flow, we will need to increase the fuel flow as well. We would look at any Duty Cycle that exceeds 80% as a "limiter" and something that may need to be addressed.
The PCM knows all! And there was a lot for the engineers to have figured out in a stock Viper.
1. The flow of the heads
2. The camshaft profile
3. The Compression Ratio
4. The outside temperature
5. Coolant temperatures
6. The required octane
and more...
Now you know a lot more about your injectors… We want to keep this relatively simple.
We will use the injectors to mix fuel with the incoming air...we want the resulting mixture to be as close to perfect as we can get it. The perfect mixture of air and fuel is called "Lambda" and for a gasoline engine it is 14.7 pounds of air for every pound of fuel. This value changes with various aspects of the car changing. But its a good place to start.
Now if we know how much air can flow into the heads at any given RPM, we know how much fuel we must add to that air to get close to Lambda. The PCM auto mixes this for us by changing the pulses to the injectors based on RPM and other things like engine load. This will all come together as we move forward on our quest to tune modified engines. But we have to start off with the basics.
Its me so we have to end with questions.
If we change our Roller Rockers (valves open wider/longer), or use larger valves, or use larger throttle bodies, smooth tubes, or do head work that allows for more fuel to flow, how do we change our injector pulse to allow for more fuel?
If we do that work and we know that Open Loop is all preprogrammed and locked down in the PCM for stock values, how do we make changes?
What about when we compress air (forced induction, super charged, turbo charged) and throw it into the cylinders at a much faster rate, how do we get more fuel to mix with it if the PCM is tuned for stock everything and locked down?
What about ignition timing? Barometric pressures? Different octane?
Can I use larger injectors? If so how do I tune?
This is precisely where the larger discussion of additional/alternative engine management equipment comes into play.
The stock computer on your Viper, the PCM, is programed for stock operation (plus or minus a rather narrow set of parameters).
You change/modify your Viper and you have to account for those changes in your tuning...or you just wasted time and $$
Where to start? We start with a stock intake valve!
A stock intake valve opens opens to receive injected fuel and air into the cylinder. Sometimes that valve is open for a relatively long time...idling. Sometimes that valve is open for an incredibly short time....roaring at 5,500 RPM. The higher the RPM, the faster the valves are opening and closing! So, for whatever time we have with that intake valve open is the time we have to inject fuel. We measure that time in "milliseconds" (1,000 milliseconds in a second), not to worry, just know we measure in milliseconds.
For a 2000 GTS, the time the intake valve is open:
At 6,000 RPM the intake value opens for 20.0 ms
At 5,500 RPM the intake value opens for 21.8 ms
At 5,000 RPM the intake valve opens for 24.0 ms
At 4,500 RPM the intake valve opens for 26.6 ms
At 4,000 RPM the intake valve opens for 30.0 ms
At 3,500 RPM the intake valve opens for 34.3 ms
At 3,000 RPM the intake valve opens for 40.0 ms
At 2,500 RPM the intake valve opens for 48.0 ms
At 2,000 RPM the intake valve opens for 60.0 ms
At 1,500 RPM the intake valve opens for 80.0 ms
At 1,000 RPM the intake valve opens for 120 ms
At 500 RPM the intake valve opens for 240 ms
So, now you know. Your Viper gives you about 21.8 milliseconds to load up the cylinder at 5,500 RPM and about 240 milliseconds to load up the cylinder at idle. Big difference!
Now that we know the time we have to squirt the fuel in, we need to know how long and how much our injectors can squirt at any given time. Look at it this way, the intake valve opens for 240 milliseconds at 500 rpm (idle) and that is a relatively long time. We sure are not going to inject fuel in for that whole time! Nope, at idle a typical stock PCM will only send a “pulse” to a stock injector to squirt for about 5 or 6 milliseconds. We also know at 5,500 RPM out valve is open for only 21.8 ms, and we only have that much time to squirt all the fuel we need.
For a GTS, a stock injector squirts fuel for approximately this many milliseconds:
At 5,500 RPM, stock injectors are pulsed for 21 ms
At 4,500 RPM, stock injectors are pulsed for 20 ms
At 3,500 RPM, stock injectors are pulsed for 19 ms
At 2,500 RPM, stock injectors are pulsed for 15 ms
At 1,500 RPM, stock injectors are pulsed for 13 ms
At 500 RPM, stock injectors are pulsed for 5-6 ms
Now we know how long a set of stock injectors squirt fuel at a given RPM. We need to know a couple of more things. First is the term “Duty Cycle”. Duty Cycle is the per cent of time the injector is in use while the intake valve is open. Simply, if the injector is firing for the whole time the intake valve is open, you have a 100% Duty Cycle. If the injector is firing for only half the time the intake valve is open you have a 50% Duty Cycle. So….if one was to fire an injector for 20ms at 3,000 RPM…..well? At 3,000 RPM our intake is open for?.....40.0 ms….so, the answer is 50% Duty Cycle. Great.
So, here is the finished "Duty Cycle" table for stock injectors in a GTS:
At 5,500 RPM a stock injector is at almost 100% Duty Cycle
At 4,500 RPM a stock injector is at 75% Duty Cycle
At 3,500 RPM a stock injector is at 55% Duty Cyce
At 2,500 RPM a stock injector is at 31% Duty Cycle
At 1,500 RPM a stock injector is at 16% Duty Cycle
At 500 RPM a stock injector is at 2% Duty Cycel
Folks, stock injectors in stock motors have enough duty cycle to get the job done. The PCM has its Closed Loop and Open Loop routines to regulate the injectors and squirt fuel into the open intakes as required. As we can see, at the max RPM we are using approx 100% of the stock injector's capacity. Thats important, when we build out an engine and increase the air flow, we will need to increase the fuel flow as well. We would look at any Duty Cycle that exceeds 80% as a "limiter" and something that may need to be addressed.
The PCM knows all! And there was a lot for the engineers to have figured out in a stock Viper.
1. The flow of the heads
2. The camshaft profile
3. The Compression Ratio
4. The outside temperature
5. Coolant temperatures
6. The required octane
and more...
Now you know a lot more about your injectors… We want to keep this relatively simple.
We will use the injectors to mix fuel with the incoming air...we want the resulting mixture to be as close to perfect as we can get it. The perfect mixture of air and fuel is called "Lambda" and for a gasoline engine it is 14.7 pounds of air for every pound of fuel. This value changes with various aspects of the car changing. But its a good place to start.
Now if we know how much air can flow into the heads at any given RPM, we know how much fuel we must add to that air to get close to Lambda. The PCM auto mixes this for us by changing the pulses to the injectors based on RPM and other things like engine load. This will all come together as we move forward on our quest to tune modified engines. But we have to start off with the basics.
Its me so we have to end with questions.
If we change our Roller Rockers (valves open wider/longer), or use larger valves, or use larger throttle bodies, smooth tubes, or do head work that allows for more fuel to flow, how do we change our injector pulse to allow for more fuel?
If we do that work and we know that Open Loop is all preprogrammed and locked down in the PCM for stock values, how do we make changes?
What about when we compress air (forced induction, super charged, turbo charged) and throw it into the cylinders at a much faster rate, how do we get more fuel to mix with it if the PCM is tuned for stock everything and locked down?
What about ignition timing? Barometric pressures? Different octane?
Can I use larger injectors? If so how do I tune?
This is precisely where the larger discussion of additional/alternative engine management equipment comes into play.
The stock computer on your Viper, the PCM, is programed for stock operation (plus or minus a rather narrow set of parameters).
You change/modify your Viper and you have to account for those changes in your tuning...or you just wasted time and $$
