Dyno results for MOPAR ECU and high-flow cats

[treynor]

I have the dyno results for the addition of high-flow cats & MOPAR ECU to my '01 RT/10 with the Belanger headers & exhaust:
Peak HP: 437.8, up from 431.4 with stock cats & ECU
Peak TQ: 485.3, up from 475.1
Max HP gain: +13.9 @ 3750 RPM
Max TQ gain: +19.4 @ 3750 RPM
Average HP gain from 3,500 - 5,800 RPM: + 9.3 HP
Average TQ gain from 3,500 - 5,800 RPM: + 10.9 ft/lbs
----
The most impressive gains are had in the midrange, as seen from the Max HP & TQ gain. Overall, the noise level at cruise or idle is not significantly higher inside the car, but at WOT the car now sounds like a pro-stocker

You must be registered for see images

Given the additional power picked up and the RPM range it is available in, I rate this a very worthwhile modification.
My hat's off to Hennessey Motorsports for diagnosing the "Check Engine" light I got with the stock ECU and overnighting a MOPAR ECU (which fixed the problem) and to Apex Motorsports for choosing a great pair of 3" high-flow cats and for top-notch work so far installing my cornucopia of parts.

You must be registered for see images

 

[LTHL VPR]

Ben-
Nice results. You mentioned the check engine light came on. Do you know why? Was it after adding hi-flow cats or something else? Did you dyno the car before adding the Mopar ECU to see if the ECU is adding any power or if it's just the cats?
BTW- How many miles did you put on your car in between runs. I remember that I noticed I gained almost 10 hp from 1k miles to 4k miles.
Did you do the dyno at Apex or Mustang ranch, and are the results you are using for comparison from the same dyno?
Thanks! Can't wait to see how the nitrous system turns out......
-Wayne

 

[Jay Herbert]

Check Engine light is a problem when changing exhausts on 2000(?) and later Vipers.... Computers are just getting to smart. I'd guess that's why the Tuners have the Mopar computers in stock now. They sell an higher flowing exhaust, and with it a Mopar computer to fix the check engine light that comes with the exhaust

You must be registered for see images

 

[treynor]

The check engine light came on about 1,200 miles after I installed the headers and exhaust, even though I was still using the stock exhaust. Installing the MOPAR ECU made the light go away (so far). I made the switch to high-flow cats at the same time I installed the ECU, so can't easily separate the power effect of the two.

Regarding mileage, I last dyno'd the exhaust at 1900 miles, and I dyno'd with cats & ECU at 2,500 miles. I don't expect there was a significant difference in HP between those two points. My dyno results are a mix of runs at Mustang Ranch and APEX Motorsports; their two dynos seem to read consistently.

Next dyno results will be for the Hennessey Venom Power Pak (minus cam swap) and the BTR Viper NOS kit -- ETA 3 weeks. I expect over 600 RWHP on juice, and high 400s off.

 

[Frank Parise]

Sounds to me like your cats are costing you a minimum of 20 peak RWHP. I don't know anyone running the belanger header/exhaust system with cats off that make less than about 460 peak RWHP. You can have the cats flanged so they can easily be removed and replaced with straight sleeves for track use. That should result in a very safe and cheap 20-30 RWHP increase.

 

[treynor]

It's not clear right now whether it's my '01 camshaft or my use of cats which is losing me HP. APEX did flange the cat assembly this round, however, so I can run a straight pipe if I so choose. I may install it and dyno just to put the question to rest...

 

[SoCal Rebell]

Does the new ECU void the warranty?

 

[Supercharged Vipermad]

I rather doubt it -- it is, after all, a Dodge product. I'm pretty sure that my BTR Viper NOS kit voids my warrany, however

You must be registered for see images