AEM vs. VEC2 & BEST POWER ADDER FOR H/C CAR???

[DEVILDOG]

Need some help with a couple of questions before my next mods please.
1. What are the pros and cons of the AEM EMS versus the VEC2 as far as tuning, performance mod maximizing gains and being able to pass emissions/OBD testing?
2. I currently have a Henne$$ey H/C setup with a 10.5 to 1 compression rate w/ '98 forged internals. Can I put a Paxton SC on top of this without having to lower compression if going with a AEM EMS or VEC2 to tune A/F and timing?
3. Does Paxton kit have an intercooler and if not should I add one?
4. Would going with a 150 to 200 HP NOS setup be a better way to go?
5. What other mods are required with a SC or NOS setup..ie bigger injectors, fuel pump, intercooler, airbox change(currently Henne$$ey carbon fibre w/ Vipair), etc.?

Cost not being an issue concerning the above questions as I'm most concerned with reliability, durability and performance.

Appreciate any and all opinions and experiences and professional(tuner) responses.

Thanks!

 

[FrankBarba]

If your going to add a stand alone fuel management system, go with MOTEC>

 

[RedGTS]

Need some help with a couple of questions before my next mods please.
1. What are the pros and cons of the AEM EMS versus the VEC2 as far as tuning, performance mod maximizing gains and being able to pass emissions/OBD testing?
2. I currently have a Henne$$ey H/C setup with a 10.5 to 1 compression rate w/ '98 forged internals. Can I put a Paxton SC on top of this without having to lower compression if going with a AEM EMS or VEC2 to tune A/F and timing?
3. Does Paxton kit have an intercooler and if not should I add one?
4. Would going with a 150 to 200 HP NOS setup be a better way to go?
5. What other mods are required with a SC or NOS setup..ie bigger injectors, fuel pump, intercooler, airbox change(currently Henne$$ey carbon fibre w/ Vipair), etc.?

Cost not being an issue concerning the above questions as I'm most concerned with reliability, durability and performance.

Appreciate any and all opinions and experiences and professional(tuner) responses.

Thanks!

1. If cost is not an issue this one is easy--AEM. The VEC2 is a good product but the AEM does everything it does plus a multitude of other things and I can't imagine anyone who wouldn't take it over the VEC2 if they were the same price.

2. IMO, it wouldn't make sense to add forced induction with that compression ratio. You could do it, but even with the AEM to tune it you're going to be limited to much lower boost and much less power than what you could make with lower compression. A tuner can advise you whether you can have the heads reworked or maybe use some dished pistons to get the compression ratio back down to 9.0 or something more FI friendly.

3. The Paxton kit comes with an air to water intercooler, but if cost is not an issue, you'd be much better off with a custom Paxton setup from one of the major tuners, some of which use air to air intercoolers instead. There are several things about the basic Paxton kit that need to be upgraded on really high hp applications, and if you're going to spend the money on an AEM I doubt you want to cut corners by using the basic kit. If cost is really not an object, you'll be much happier with turbos.

4. I don't have a clue how nitrous would or would not work with your current setup.

5. Yes, if you're trying make 800+ rwhp you'll need to upgrade the entire fuel system, you'll need an intercooler, and you will no longer be using your existing airbox.

Seriously, if I were you I would investigate the turbo option. I had a high hp Paxton setup and recently switched to turbos, and there are a lot of advantages. Either way make sure whoever is doing the job knows what they're doing.

 

[KenH]

[/QUOTE]
1. If cost is not an issue this one is easy--AEM. The VEC2 is a good product but the AEM does everything it does plus a multitude of other things and I can't imagine anyone who wouldn't take it over the VEC2 if they were the same price.


[/QUOTE]
If you have ODBII testing where they plug into the port rather than sniff the exhaust, I don't think the AEM or MOTEC will pass, but the VEC2 will. If the AEM or Motec are easy to remove for testing, that may not be a concern.

 

[Schulmann]

I agree that if money is not a problem AEM is a good investment. However where you turn when you are in trouble ? You can reach Sean Roe nearly 24/24 on his cell phone. In addition, the new VEC2 release is going to have some interesting features.

If you are going above 800hp, upgrade the entire engin too, Connecting rods, etc. (Depending on how long you want to run with that much HP).

With NOS I would also think about upgrading the power train. By the way, the vec2 is great to manage the NOS.
If you decide to use NOS there is no need for the AEM. The only problem with NOS is the bottle in the trunk. Personnaly I prefer the supercharger but NOS is interesting too. The problem with NOS is the tuning. Virtually you have no margin for error.

Another important fact: No matter how much cost the hardware and how long it takes to install, the reliability and longevity of your investment will depend on the time that the shop will tune your Viper. From personnal experience I can tell you that tuning takes A LOF OF time. And having the highest HP number doesn't count when you are out of the race after 3 runs. My Viper had 550rwhp in May and was the only Viper that lasted 20 runs during a drag race.

 

[DEVILDOG]

Guys, thanks for the responses to date. Schulmann, what mods do you have?

 

[Schulmann]

Devildog,

I was thinking about your Viper. You know that you are in special category of Vipers. It's called "stock" with concealed features. You could easy win in the stock category in drag races. There are also plenty of races for "regular" engines. You could go to Bonneville and set a top speed record with your Viper. I think you should continue to improve what you have instead of jumbing to NOS or SC. Since you have a higher compression ratio you likely need top quality fuel and likely your viper is not a good daily driver. But you can change it using methanol injection. You car would be a good candidate for this mod.

This is my advise and I hope others will give their comment on this:
- Install a VEC2 and learn how to use and tune it
- Install an LC-1 in each exhaust pipe and connect these staffs to the VEC2
- Install a methanol injection system (Vec2 will manage it)
- Remove your cats (If you have smog check in TX then make the mod such a way that you can refix the cats in an hour, this it the setup that I have).
- 180F therm.
- Front air duct


By the way, the real problem with the Vipers is that there is no knock sensor available for our cars. Even if you install an AEM you will be limited by the amount of spark adance that you can safely give.

My mods:
- Roe SC with 6.5lb puley giving 9psi boost
- Methanol injection: Thanks to this staff my SC is cooler than my heads. In addition it seals my SC allowing a higher boost.
- BB headers and 3'' straight pipes
- LC-1 and WBC
- Roller rockers
- Allum fly wheel (Doesn't give much HP)
- 180F thermostate
- Air duct
- Laptop permanently connected to the VEC2
- FR4 or FR5 plugs depending on my mood.
- and some other concealed features ....

Depending on the spark advance that I use, I am getting between 550hp and 650hp reliable HP. Again if there was a knock sensor available .... it would be much easier to tune the Vipers.

 

[RedGTS]

By the way, the real problem with the Vipers is that there is no knock sensor available for our cars.

Not true. I've had them on my car for over a year. Horsepowerfreaks sells the AEM kit with knock sensors, and I'm sure Jason Heffner, Dan Cragin and others do by now as well.

 

[Schulmann]

RedGTS could you give us some feedback on this AEM unit ? How easy it is to tune, give us maybe some tuning exemples. I am also very interested in how you program the knock sensor.

 

[RedGTS]

RedGTS could you give us some feedback on this AEM unit ? How easy it is to tune, give us maybe some tuning exemples. I am also very interested in how you program the knock sensor.

I haven't messed with the tuning myself at all. They were put in when I got my AEM to go with the Heffner s/c system, and John Reed of Torquefreaks (who I believe is the guy who developed the knock sensors) tuned the car. Then when Jason converted the car to twins he tuned it, and he said there was no problem tuning the knock sensors. I think the approach is to develop a base knock noise table for the car and then fine tune from there, and check everything out by advancing timing until you get mild spark knock and can see on the datalogging that the sensors are then making the AEM pull timing back out. Needless to say, it's a great thing to have on a high hp application.

 

[DEVILDOG]

Schulmann,
Thanks for your thoughts. I'm going to visit Velocity Performance and dyno tune with a VEC2 for starters. Texas does have smog testing and requires the OBDII so going with an AEM would be a PITA in addition to removing and replacing the cats which I don't want to mess with(currently have hi-flows) and side splitters. I'll update this thread with my before and after VEC2 dyno results.

 

[Martin D]

DD you can run the 200 shot NX on that motor....Just run it pig rich. The thing we found after 30k miles on my old 650R motor was that the Valve Train took one hell of a beating. I am assuming you and I had a similar radical hyd. cam. That was the only thing we found after dozens of bottles. Now that I have the stroker setup, I run the 300 shot...again Pig rich. It only adds about 200 RWHP but that is enough for me with 650 at the wheels on motor and a fast revving solid cam!!!!!!!!!!!!!!!!!!!

Regards,

 

[DEVILDOG]

Martin,
Thanks for the feedback on the 200 NOS on top of the 650R. You are correct in that I have the radical hydraulic cam. I agree with you that going with NOS would be the best way to go with my current setup. What A/F ratio did you run when spraying? Take care.

 

[DEVILDOG]

Martin,
Thanks for the feedback on the 200 NOS on top of the 650R. You are correct in that I have the radical hydraulic cam. I agree with you that going with NOS would be the best way to go with my current setup. What A/F ratio did you run when spraying? Take care.

Martin,
Sent you a PM regarding your 650R NOS setup. Need help! THANKS!!!
Jim

 

[Carleton]

RedGTS

You have a PM.


Carleton

 

[RedGTS]

RedGTS

You have a PM.


Carleton

Got it.

 

[DrumrBoy]

Thanks for sending me to this thread. Purely because of OBD, I think I'll start with the VEC 2. Let me now how it goes with yours!

 

[DEVILDOG]

Thanks for sending me to this thread. Purely because of OBD, I think I'll start with the VEC 2. Let me now how it goes with yours!

Well, I went to VELOCITY PERFORMANCE on Thursday and had the VEC2 installed and some serious dynojet tuning performed. First of all, I want to say that Darren, Brad and E.J. did a fabulous job and I'm very happy with the results. Sean Roe also participated by phone during the tuning process and I appreciate him for his direct involvement and technical support of his excellent product. At this time, I will have to convey the results in written form as my scanner is not functioning, however, I will update this thread with a copy of the dyno graph within a couple of weeks. Next, I want to state to all those STUPID A$$HOLES that don't know $HIT that say that Hennesssey cars are not put together very well and don't perform to SHUT THE *UCK UP!!! We did FORTY(40) dyno pulls to 6250 RPM in one day and the car did not break!!! Have any of you done FORTY(40) dyno runs with your mods??? Once and for all, my VENOM 650R is well built, reliable, durable, bulletproof and puts out good power for a heads/cam car...PERIOD!!! Now for the results. The BEFORE....My first pull with no heat soak prior to the VEC2 install produced SAE corrected 530.81 RWHP @ 5420 RPM and 542.66 RWTQ @ 4290 RPM with an A/F ratio that ranged from 18 @ 2200 to 2400 RPM, 16.5 @ 2600 TO 3400 RPM, 15 @ 3650 to 4250 RPM, 14 @ 4400 to 5800 RPM and 13 @ 6100 RPM. SCARY LEAN!!! Fortunately, I've only run the car on the street fairly conservatively since having the 650R package installed @ 7109 miles which was 2600 miles ago. Hennesssey had informed me that the stock PCM would handle the mods which is not the case. That is my only complaint. I recommend that if you have had significant mods done and did not get a VEC2 or other engine management system that you do so immediately as you're most likely running dangerously lean. The AFTER....My 39TH pull in the late afternoon @ about 90 degrees ambient and with a little heat soak yielded 546.03 RWHP and 563.45 RWTQ at approx. the same RPM peak points indicated above. The TQ curve is pretty flat producing a minimum of 500 ft-lbs from 1900 RPM to 5800 RPM. The A/F ratio now runs @ approx. 12 from 2000 RPM to 6000 RPM with a couple of peaks to 13.1 @ 2300 RPM and 5150 RPM. The driveability is much better now since the motor is now getting some fuel. Very minimal bucking now at lower RPMs and the car feels a little stronger due to the performance gains throughout the RPM range. The exhaust even has a deeper sound now. It was already loud as evidenced by another car's alarm going off that was parked about 10th in a row of cars behind my car on the dyno...lol. I highly recommend the VEC2 and VELOCITY PERFORMANCE and encourage all fairly modded car owners to have their A/F ratios dyno checked. Also, thanks to all the guys that gave me guidance and information concerning my driveability issues and correctly advised me to have my A/F checked and corrected versus changing out my stock gearing. This VCA Board is great when you need help! A lot of good guys that know what they are talking about and are willing to help others.

DrumrBoy, good luck with yours and let us know your results. Sent you a PM.

 

[DrumrBoy]

Thanks for the heads-up on this post being here.

I'm glad it went well. Especially intrigued by the improved drivability and reduced bucking, I could use a little help there.

Wow, 40 pulls....you must have the thing very finely tuned with 40 pulls!

How much time was Sean able to spend on the phone with you?

I'm ordering mine this week but have yet to locate the right tuner w/dyno. I'll definitely let you know how I go after the tune. I bet my iomprovement is more than yours (as I'm starting from a much lower base)!

 

[J DAWG]

SCARY LEAN!!! Fortunately, I've only run the car on the street fairly conservatively since having the 650R package installed @ 7109 miles which was 2600 miles ago. Hennesssey had informed me that the stock PCM would handle the mods which is not the case. That is my only complaint. I recommend that if you have had significant mods done and did not get a VEC2 or other engine management system that you do so immediately as you're most likely running dangerously lean.

I agree in principle that some type of ems is needed for even moderately modded cars, but in my case my car with similar mods as yours and making similar power was incredibly rich. The car was never above 13:1 at any rpm and once the cam hit at 3800 rpms the a/f fell and stayed around 11:1 due to the loss of vacuum with that cam. So I needed the Vec2 to lean my car out.

Interesting how lean yours was in the heat. hate to see it dyno in the the winter without the Vec2.

The Vec2 is fun and something most can tune themselves without turning to the AEM and most likely having to depend on someone else to tune.

John

ps - and with the compression you have I would spray it in a heartbeat.

 

[DEVILDOG]

ttt for big-n-italian.

 

[Casey]

VECII has worked well for me. AEM was not an option due to emissions testing.
Glad to hear it worked out for you too!

About the whole Hen---y thing. I am glad your got what you paid for. I have friends that did not. Many others do as well too. I don't feel those that have heard bad things and had bad experiences with someone should shut up about it.
I think you have every right to talk highly of him as well.
No biggie though, enjoy your beast!

 

[DEVILDOG]

VECII has worked well for me. AEM was not an option due to emissions testing.
Glad to hear it worked out for you too!

About the whole Hen---y thing. I am glad your got what you paid for. I have friends that did not. Many others do as well too. I don't feel those that have heard bad things and had bad experiences with someone should shut up about it.
I think you have every right to talk highly of him as well.
No biggie though, enjoy your beast!

About the Hen---y thing...I agree with you. Unfortunately, you're the only one so far that has stated that I also have a right to post my positive experience with John and the high quality of work done on my 650R. I also get tired of hearing all the BS that all Hen---y cars are built poorly and don't produce the stated HP. NOT TRUE! Thanks for your fair opinion.

 

[big-n-italian]

very helpful info devil dog - thank you again!!

 

[DEVILDOG]

very helpful info devil dog - thank you again!!

No problem...just passing along the help I got. Let us know what you decide and the results you get.

 

[Viper X]

Hey Devil Dog,

If you want to stay normally aspirated and add some dependable power, you may want to check with West Coast Viper. They are now offering a new set of cylinder heads, they call stage IV I think. These new headsmake a bunch more power than the previous upgraded CNC head re-work. This is a new casting that also offers better cooling.

I have a set coming for my SRT-10. I'll post my dyno sheet when I get the car back.

Call John for info.

Dan

 

[DEVILDOG]

Dan,
Thanks for the info.! I'll check it out. Please send me a PM when you get your before and after heads dyno runs.
Jim

 

[Anthony - 98 GTS]

I plan to but AEM on my Venom 700R here in the next couple of months. I make all motor 649 rwhp and run very rich. I am hoping to pick up 30-40 rwhp with the proper tune.

 

[Russ M]

Anthony,

I cant even amagine what your car will pick up. What did [******] use for fuel/ignition management? Your torque will probably go up alot as well, on my almost stock viper I picked up like 80# at certain rpms and nearly 30# peak.

What do you have for fuel injectors/pump/etc.... Cause no way can the factory ones handle the power you have now.

 

[Anthony - 98 GTS]

Anthony,

I cant even amagine what your car will pick up. What did [******] use for fuel/ignition management? Your torque will probably go up alot as well, on my almost stock viper I picked up like 80# at certain rpms and nearly 30# peak.

What do you have for fuel injectors/pump/etc.... Cause no way can the factory ones handle the power you have now.

I should pick up a ton of power. My car is running extremely rich due to no control over the injectors. I currently just run a modfied stock computer.

On the fuel side I run Walbro pumps, upgraded lines, injectors and fuel rails. With my solid roller and compression I should be able to get close to 700rwhp on motor.