playing safe with a Paxton

[crazyfast]

I've just finished putting a basic Paxton kit on my car. I've done other S/C installs and this one was by far the best system I have worked with....it was very time consuming(many parts) but very straight forward....almost too easy It's very quiet too. Next up will be the DLM tensioner and intercooler.

Current mods are Paxton, Headers, no cats custom exhaust and DC blower tune, AB's wires and NGK 4291's @ .035 + or -...I'll dyno it one of these days.

Anyway, I want to use the gauge pod shown here... http://forums.viperclub.org/showthread.php?t=589568&highlight=boost+gauge

I don't care for the suction cup gauges that could stick on the windshield and I'm not a fan of the pillar mounts either, so that leaves me with the MBX column mount gauge pod...which I actually like.

With the Paxton fuel system, my feeling is, knowing what the fuel pressure is doing is far more important than knowing what the boost is doing. So even though I think the boost gauge is cooler, my plan at this point is to run the fuel pressure gauge instead.

....unless there is another way. Does anyone know of a ignition cut off device that can be set up to kill the motor in the event of a loss in fuel pressure...or something along those lines? I've used low oil pressure ignition cut off kits before, so I'm thinking this might be an option...anyone have any input on this?

btw here are a couple pics of the install...I went a little "custom" and hid some things ...think I might try and hide the fuel lines a little better, but for now it's done, and it's fast.

so lets talk safety

 

[Viper X]

Fuel pressure is good to monitor, but if I had to choose only one, it would be air / fuel ratio. This is what I monitor now.

Boost is cool to watch but not really too important with your set up.

Dan

 

[Paul Hawker]

Might consider a warning light instead of gauge. With Paxton things happen in a hurry and you can't spend any significant time watching gauges.

Agree with Viper X on the air/fuel priority.

With the standard paxton kit you have three fuel pumps working under boost, your standard pump with their two supplied accessory pumps.

 

[Hiss]

Great work on the Paxton install. What tires are you using?

I plan in the near future to put in the air / fuel gauge.

Installed the MBX Gauge Pod and I really like it.

 

[Art 138]

Where did you hide the fuel pumps? I do not see them in their traditional location. They get hot fast and should not be confined! Also make sure the SC belt pulley nose is not rubbing against the alternator belt. DLM had to grind nose down for clearance. Just some lessons learned.......

 

[crazyfast]

Fuel pressure is good to monitor, but if I had to choose only one, it would be air / fuel ratio. This is what I monitor now.

Dan

hah, well now it looks like I'm even further away from that boost gauge...

I can see the A/F gauge telling you more information than the F/P guage. I guess that's kind of why I wanted to go with the fuel pressure gauge. Air Fuel meters seem to almost tell you too much information at any given moment....know what I mean? I was figuring knowing the Air Fuel ratio I'm at when the pumps are working as they are supposed to I would immediatly know something was up if I was not seeing the fuel pressure I supposed to be seeing....you've got me thinking now.

Great work on the Paxton install. What tires are you using?

Thanks Gene, I'm running the PS2 335/30/20..it sticks pretty good..though not very good in 1st gear and I've blown off the tires in second a few times

Where did you hide the fuel pumps? I do not see them in their traditional location. They get hot fast and should not be confined! Also make sure the SC belt pulley nose is not rubbing against the alternator belt. DLM had to grind nose down for clearance. Just some lessons learned.......

The fuel pumps are in the fender along with the FCU and the relays. I understand what you are saying about the heat and confinement. There is a lot of open space around the pumps, and I am certain that they are better off in the spot I have them as opposed to the engine compartment where my moton reserviors would get too hot to touch when I had them in there. I will look into getting some sort or air flow moving around the pumps though...I'm not sure what kind of air movement is going on in there right now.

 

[SRTLEN]

Nice job, I did my own as well. I have also thought about gauges, would like a nice pillar set up. Agree that fuel is most important.

I was not happy with my blower pulley clearance so I lowered the alternator slightly.

Len

 

[Bolt]

Great to see you did the job yourself. Congratulations! Since you did the job yourself. What do you think of changing out your stock serpentine belt now. I hope mine never needs changed.

Good Idea with the cutoff on the fuel pressure. I had the opposite happen. I had a fuel pump relay stick (go bad) after 5 months (3000 miles)

 

[plumcrazy]

great to see another DIY'er. like Bolt said the idea about a cutoff is a good one and i might look into it myself

 

[crazyfast]

Nice job, I did my own as well. I have also thought about gauges, would like a nice pillar set up. Agree that fuel is most important.

I was not happy with my blower pulley clearance so I lowered the alternator slightly.

Len

The clearances....yeah, I think I can fit a sheet of paper, maybe even two sheets between the blower and alternator pulleys. Reading back on some of the older threads, it looked like they had more problems with clearances and parts missing from the kit...I didn't have a single problem related to those issues. I was impressed with the fact that I didn't really have to modify any of the parts as they went on the car.

Great to see you did the job yourself. Congratulations! Since you did the job yourself. What do you think of changing out your stock serpentine belt now. I hope mine never needs changed.

Good Idea with the cutoff on the fuel pressure. I had the opposite happen. I had a fuel pump relay stick (go bad) after 5 months (3000 miles)

Thank you, serpentine belt is going to be an all day job no doubt and I hope to not have to go there anytime soon...though the blower belt is obviously slipping, you can even see the signs of slippage in the pics I posted. I wonder how long it will hold up.

You say a fuel pump relay got stuck open. What were the symptoms, excessive black smoke? I see you have a GTS, does that run the same spilt second box as the GEN III with the fuel pump relays in the box? What did you have to do to correct the problem?

great to see another DIY'er. like Bolt said the idea about a cutoff is a good one and i might look into it myself

I've always been a DIY'er when possible. I hate waiting for someone else to do something and I know it is going to be perfect when I'm done...not shortcuts...plus saveing money is alway nice too

On the cut off or even just using the gauge to monitor the fuel. The chances of something failing is a lot more likely to happen with these aftermarket parts. For instance Bolts pump relay was stuck on...could have been worse I think you really have to keep an eye on this type of stuff...otherwise, it's a matter of when not if you're going to burn a piston or worse.

 

[Bolt]

You say a fuel pump relay got stuck open. What were the symptoms, excessive black smoke? I see you have a GTS, does that run the same spilt second box as the GEN III with the fuel pump relays in the box? What did you have to do to correct the problem?


I saw no symptoms. It may just have happened when I was getting to my car show. At the show I heard one of my fuel pumps running. As you know it was not dumping into the engine. I pulled that fuse and drove it home easily. I do run the split second box. This is what went bad. Working with Paxton was a fiasco and is not solved yet. That is another story.

 

[crazyfast]

So Paxton is not being very helpful with the box then. Did you buy another one in the mean time? How about the tune, with the R4 you can easily pull the tune out of the box correct?

 

[pumpgas]

Put in an Autometer Phantom Wide-Band A/F gauge. Best $400 you'll spend for a boosted or nitrous car. It matches our stock gauges perfectly and its super simple to see what is really happening when under boost. This way if a plug burns or fouls, or you have plug wire issues, any type of fuel issue, relay problems, slipping belt etc. etc. happens, you can see instantly whether the engine is running lean or overly rich.

 

[Allan88]

Put in an Autometer Phantom Wide-Band A/F gauger. Best $400 you'll spend for a boosted or nitrous car. It matches our stock gages perfectly and its super simple to see what is really happening when under boost. This way if a plug burns or fouls, or you have plug wire issues, any type of fuel issue, relay problems, slipping belt etc. etc. happens, you can see instantly whether the engine is running lean or overly rich.

How do you monitor left and right side of the engine, (plug wires)
If you use a wide-band A/F with only one channel

Allan

 

[pumpgas]

To monitor both banks, you'd have to use a two channel. With a 7-8lb paxton that might be a little overkill though. What I was trying to impress upon him was the fact if you had some type of electrical or fuel problem that caused the car to either run dangerously lean or way too rich (i.e. air fuel mixture not lighting off properly) the wideband would show that occurrence quickly and consistently. If you talk to any real boost/nitrous using racer/tuner, the wideband is your best tool to monitor what is happening and when doing on the road pulls, is the best thing there is.

 

[dun4791]

I would get an Innovate LM-1 or a FAST 2 bank setup for the A/F, before I even went WOT with a non-dyno tuned car.
Then the fuel pressure gauge.
No boost gauge.......ever
Check into nitrous solenoids, Isnt there one that will limit the spark without a certain fuel pressure under WOT? Im sure Ive seen one somewhere.

 

[crazyfast]

Put in an Autometer Phantom Wide-Band A/F gauge. Best $400 you'll spend for a boosted or nitrous car. It matches our stock gauges perfectly and its super simple to see what is really happening when under boost. This way if a plug burns or fouls, or you have plug wire issues, any type of fuel issue, relay problems, slipping belt etc. etc. happens, you can see instantly whether the engine is running lean or overly rich.

To monitor both banks, you'd have to use a two channel. With a 7-8lb paxton that might be a little overkill though. What I was trying to impress upon him was the fact if you had some type of electrical or fuel problem that caused the car to either run dangerously lean or way too rich (i.e. air fuel mixture not lighting off properly) the wideband would show that occurrence quickly and consistently. If you talk to any real boost/nitrous using racer/tuner, the wideband is your best tool to monitor what is happening and when doing on the road pulls, is the best thing there is.

I will most likely go with an A/F gauge lke the one shown a few posts up.

I would get an Innovate LM-1 or a FAST 2 bank setup for the A/F, before I even went WOT with a non-dyno tuned car.
Then the fuel pressure gauge.
No boost gauge.......ever
Check into nitrous solenoids, Isnt there one that will limit the spark without a certain fuel pressure under WOT? Im sure Ive seen one somewhere.

I have a fuel pressure gauge/tool, attached it to the fuel rail. Took it up a few steps at a time to make sure the pumps were kicking in....all was well, seeing just under 100psi at redline.

I also have an LM-1. Monitered the A/F in relation to RPM again with steps jumping up higher and higher until I had a complete run up to red line. With the LM-1 as some of you know you can record the runs and then play them back on the lap top...it's a very cool tool.

A/F comes in richest at around 3,400 rpm and then leans out as it goes up, by redline it sitting at 11.8 .

I asked the guys at DC to set the tune on the conservative side, told them my mods and told them I like to play hard. They got the tune exactly where I wanted it, first time.

I also swapped the larger FCU disk in. In talking with Mark Jorgenson and DC, the feeling is I could swap the smaller disc back into the FCU and end up with the A/F reading somewhere around 12.2 or so on the top end. I will leave it tuned the way it is for now...untill more power is needed....right now it isn't

Also all of my testing has been in the heat of the day. I took the car out the other night and there was much more power...it stepped out on me towards the top of third gear and I have stock gears and oversized tires...anyway the point is I'm sure it's runnign leaner on those cold even runs so I'll get the LM-1 back on it and do some night time testing.

I plan to dyno it soon, can't get to the dyno for a week or so.

 

[slither]

Won't take long, you'll be addicted to the cold weather!

 

[dun4791]

I will most likely go with an A/F gauge lke the one shown a few posts up.





I have a fuel pressure gauge/tool, attached it to the fuel rail. Took it up a few steps at a time to make sure the pumps were kicking in....all was well, seeing just under 100psi at redline.

I also have an LM-1. Monitered the A/F in relation to RPM again with steps jumping up higher and higher until I had a complete run up to red line. With the LM-1 as some of you know you can record the runs and then play them back on the lap top...it's a very cool tool.

A/F comes in richest at around 3,400 rpm and then leans out as it goes up, by redline it sitting at 11.8 .

I asked the guys at DC to set the tune on the conservative side, told them my mods and told them I like to play hard. They got the tune exactly where I wanted it, first time.

I also swapped the larger FCU disk in. In talking with Mark Jorgenson and DC, the feeling is I could swap the smaller disc back into the FCU and end up with the A/F reading somewhere around 12.2 or so on the top end. I will leave it tuned the way it is for now...untill more power is needed....right now it isn't

Also all of my testing has been in the heat of the day. I took the car out the other night and there was much more power...it stepped out on me towards the top of third gear and I have stock gears and oversized tires...anyway the point is I'm sure it's runnign leaner on those cold even runs so I'll get the LM-1 back on it and do some night time testing.

I plan to dyno it soon, can't get to the dyno for a week or so.

Where is the A/F at 3400? It should be close to 11.8 all the way to red at WOT. I would leave it at 11.8- thats perfect for a street car. I wouldnt go 12.2. If you want more power, look at the timing or boost and leave the A/F where it is IMO.

I am still trying to understand why temperature affects the Vipers so much in relation to the tune. This is not a problem with the Fords or GMs. The technology is there, the computer in these cars for some reason doesnt map the fuel in relation to the temperature based on files. Dunno why?? Im betting this might change with the new SCT tuners out next week...

 

[crazyfast]

Where is the A/F at 3400? It should be close to 11.8 all the way to red at WOT. I would leave it at 11.8- thats perfect for a street car. I wouldnt go 12.2. If you want more power, look at the timing or boost and leave the A/F where it is IMO.

I am still trying to understand why temperature affects the Vipers so much in relation to the tune. This is not a problem with the Fords or GMs. The technology is there, the computer in these cars for some reason doesnt map the fuel in relation to the temperature based on files. Dunno why?? Im betting this might change with the new SCT tuners out next week...

Sorry I ment to put in that it starts out at 11.2 then climbs to 11.8. Thanks for the tips on the leaving the A/F alone.

On the outside air temp/power issue. When I talked with Mark from Woodhouse, we touched on this subject a little bit. He was telling me that the IAT sensor works kind of weird and that it's very sensitive. It picks up on the heat and pulls power quickly in order to combat the heat going into and out of the motor, one of the reasons included protecting the catalitic convertors.

 

[Racer Robbie]

You really did a fantastic install job. It looks great! I like your fuel pressure gauge idea but please be sure to use an electric fuel pressure gauge and not a mechanical one like some racers use as they will burn you up in a crash. just thinking of your safety. great job.

 

[crazyfast]

Thanks for the tip and compliments.

I would use this fuel pressure gauge. http://store.summitracing.com/partdetail.asp?autofilter=1&part=ATM-4363&N=700+115&autoview=sku It matches the factory gauges and yes it has an electrical sending unit. The problem I see with it is, it only goes to 100 psi. (Paxton fuel system tops out around 100psi) In the past, when I've maxed out gauges, the needle usually ended up getting stuck...I don't know if this gauge can handle it...some say yes some say no....I'll call autometer if I decide to use it.


I like this one for boost... http://store.summitracing.com/partdetail.asp?autofilter=1&part=ATM-4376&N=700+115&autoview=sku


Anyway, it looks like I'll be running the air fuel gauge so this will most likely be the gauge I end up going with... http://store.summitracing.com/partd...1&part=ATM-4378&N=700+400442+115&autoview=sku

 

[Viper X]

Good decision. I run two widebands and monitor them both with my AEM.

Very comforting after loosing two Paxton engines, one to a bad FMU and one to a bad tune. If I'd had an Air/Fuel gauge installed, it would have saved me lots of time, trouble, stress and money.

Stay a bit rich with your tune. 11.8 to one air fuel isn't that rich under boost with a Paxton. Mine is closer to 11.0 most of the time at WOT and about 10.8 above 5000 rpm.

Be careful with timing advance around peak torque, it should be very limited.

Keep and eye on that Paxton supplied fuel management unit. My first one died, bled fuel pressure and cost me an engine.

Good luck,

Dan

 

[plumcrazy]

monitor them both with my AEM.

whats that mean ? what does the AEM do if it goes lean ?

 

[Viper X]

"monitor them both with my AEM"

I can monitor my air / fuel ratio as I drive with my lap top or with a gauge that I have installed in my car, through the AEM computer that runs my engine.

I can also data log, monitor boost, intake air temp, coolant temp, etc. while I drive through my AEM.

Dan

 

[plumcrazy]

I was thinking your AEM would pull timing or something if it was lean...sorry.

i obviously dont know squat about the AEM's...lol

 

[ILLSMOQ]

Good decision. I run two widebands and monitor them both with my AEM.

Very comforting after loosing two Paxton engines, one to a bad FMU and one to a bad tune. If I'd had an Air/Fuel gauge installed, it would have saved me lots of time, trouble, stress and money.

Stay a bit rich with your tune. 11.8 to one air fuel isn't that rich under boost with a Paxton. Mine is closer to 11.0 most of the time at WOT and about 10.8 above 5000 rpm.

Be careful with timing advance around peak torque, it should be very limited.

Keep and eye on that Paxton supplied fuel management unit. My first one died, bled fuel pressure and cost me an engine.

Good luck,

Dan

I've been thinking about that FCU...what is the life expectancy of the rubber diaphram in there...anyone know?

 

[Fast Too]

Kurtis - Get rid of the FCU, SS Box, and Paxton pumps, and in their place get a walboro in tank pump with a vec 3 controlling the kingdom

 

[ILLSMOQ]

Kurtis - Get rid of the FCU, SS Box, and Paxton pumps, and in their place get a walboro in tank pump with a vec 3 controlling the kingdom

I'm not real crazy about fuel system that come with the paxton kit but it works well with my current setup...when I decide to step up the power I'll go with an AEM and big boy fuel pumps.

 

[Kenneth Krieger]

I bought the SRT Vac/Boost gauge from Dodge, along with the Innovate A/F gauge. I found the closest thing to our windshield pillar that would work for two gauges was the 2pod pillar gauge off a 92 to 99 Ford F-250. I had to do a little tweaking with a heat gun and it turned out great. The SRT gauge is pretty cool on the SRT Viper, and no one knows the difference! (It's the one off the SRT 4). Just another application. I didn't like the gauge pod on the steering column. Just seemed to be in the way. The pillar mounted gauges look "factory" and I have had nothing but compliments about the install.