Dyno #s after removing Mopar HiPo ECU...

[SoCal Rebell]

It is one week to the day (almost the minute) since I removed the the Mopar HiPo ECU and put the stock one back on after some very disappointing dyno #s. Gave the stock computer a week to "learn" and went back to the same shop, with the same Dynojet 248C, at the same time of day and here are my #s:

With Mopar ECU 406.2 RWHP 452.4 ft-lbs.
With Stock ECU 431.4 RWHP 472.4 ft-lbs.

This is with NOTHING else changed except for the computer as you see I LOST 25.3 RWHP and 20 ft-lbs. of torque with the Mopar HiPo ECU. My mods are listed below, I don't understand how Dodge could do something like this.

 

[treynor]

Ugh, that's pretty unambiguous. I'm going to swap my stock ECU back in, add Hennessey's O2 sims to get rid of the 'check engine' light, and redyno. My mods are almost exactly the same as SoCal's, and I'd hate to think I'm leaving a bunch of HP on the table.

SoCal, what (if anything) are you doing about the check engine light?

Anyone with evidence of the Mopar ECU's effectiveness compared to the stock ECU when you add heads & rockers?

Ben
'01 RT/10, Belanger headers, Belanger exhaust, 3" high-flow cats, smooth tubes & K&Ns, Power Effects mufflers, MOPAR ECU (temporarily)

 

[Nadine UK GTS]

I wish I lived just down the road from you and we could try my Export ECU. I was under the understanding I was down on about 5bhp due to it being calibrated for different octane in the fuel over the pond? (As I've said before) I'm wired for rear O2 sensors as far as the plug in port, but I don't have any, and no check engine lights either. I would be interested to know what you'd experience if you tried my ECU with regards to dyno results...loss / gain, over stock US and MOPAR 'upgrade'!? The octane in UK gas is usually 95 RON. I have a '97 GTS. Shame Dodge does not refund electricals, other wise someone could 'borrow' one and investigate?

 

[Sean Roe]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by JonB-Pace Car Pilot:
The only after-market ECU mod (so far) to promise HP faithfully, and guarantee it, is Sean Roe's device. PartsRack, in conjunction with 2 tuners, is working on another black box solution.
<HR></BLOCKQUOTE>

Jon,
Thank you for the vote of confidence.
Our Viper Engine Calibrator does indeed add horsepower, typically around 14 at the rear wheels and is satisfaction guaranteed. As many have now seen, the Mopar PCM does not always help and returning it can be difficult at best. Unlike the Mopar "black box" PCM, our unit taps into the factory harness and is user adjustable with easy to use adjustments. Just a turn of the dial gives you more fuel or ignition timing.

 

[BurnR8]

candidly this just ****** me off.....I now have a REALLY expensive beer coaster.....and basically cannot do anything about it....Socal and I have the same mods almost to a T and so off mine goes and I will post my dyno when I get time....my question is....do I run ANY mixture risk on a 2000 with headers, no cats and only power effects after the O2 sensors? Am I going to have a lean condition if the ECU cannot figure out what is going on? Thanks

 

[Sean Roe]

When you have a check engine light on, depending on the cause, the PCM will do one of two things to the timing and air/fuel mixture:
1. Nothing.
2. Richen the mixture and reduce timing advance.
The same code will not yield the same end result for all model years. 1996 was the first year of goverment manditory OBD2, though the '96 and '97 Vipers don't seem to meet all the requirements (won't turn on the check engine light or change the mixture if you remove the cats). Each year newer, '98 and up, is going to be a little more sensitive to emissions monitoring than the previous year as they tweak the OBD2 systems.

 

[Marv S]

If a 1999 car kept turning on the check engine light due to mods, what would happen if a 1999 ecu was replaced by a 1997 ecu, either a new one or one from a wreck?

While switching an ECU may not follow the letter of the law, that issue has likely already been crossed by the mods causing the check eng light to come on.

<FONT COLOR="#ff0000" SIZE="1" FACE="Verdana, Arial">This message has been edited by Marv S on May 01, 2001 at 21:12</font>

 

[Nadine UK GTS]

Marv S, I thought the same as you, what if a '97 PCM was was tried on a post 2000 ??...

 

[Dave T (BADVENM)]

I installed a Hypertech chip in my '97 Dakota V8 and lost horsepower as well as torque when I dynoed it. In fact, I reinstalled the stock computer, drove around for 40 miles, redynoed the truck to verify the loss...using the same gas, the same day, etc.

I informed them that the chip ($275 about) and the 2 dyno sessions ($75 a piece) and got my money back.

 

[HogWhisperer]

Treynor,

I see you have the 3" high flow cats. From your post I also understand that you you have a check engine light. What are the codes? Rear O2 Sensors (left and right bank)? MAP sensor possibly? Since I was hoping that 3" cats would solve my rear O2 sensor codes, I really would be interested to hear what your codes are. I have a '99 ACR and have been fighting the engine light problem for 9 months.

Thanks....

 

[treynor]

Here's the chronology:
1) 1,050 miles: dyno car -- 408 RWHP, 442 ft/lbs
2) 1,100 miles: add K&Ns and smooth tubes
3) 1,150 miles: dyno car -- 415 RWHP, 448 ft/lbs
4) 1,500 miles: add Belanger headers & catback, retain stock cats & ECU
5) 2,000 miles: dyno car -- 431 RWHP, 475 ft/lbs
6) ~2,700 miles: check engine light illuminates. Forgot to check code.
7) 2,800 miles: add MOPAR ECU, switch to high-flow 3" cats. Check engine light disappears
8) 3,000 miles: dyno car -- 438 RWHP, 485 ft/lbs
9) 3,300 miles: Summer arriving; note that car is running hotter (200 - 210) than it used to with stock ECU.

Next steps (this week):
Install Fluidyne radiator, 180-degree thermostat, O2 sims. Redyno car with MOPAR ECU and stock ECU. Report.

 

[BurnR8]

Well just to make things more interesting....I talked with JonB about taking my ECU back....to which he was very accomodating...and told him I did not want it because I was SURE I would DYNO with MORE horsepower with the Stock ECU....best pull with the Stock ECU back in gave me LESS HP and TORQUE....

MOPAR ECU
435.5 RWHP
489.5 TORQUE

Stock ECU
431.5 RWHP
472.5 TORQUE

I may be the exception because I am running NO CATS and No Mufflers other than POWEREFFECTS in the rear....I was positive I was going to gain HP with the stock one back on, but it was not meant to be.....let the debate rage on...but as JONB said...you need ALL the other Mods to work in concert with the MOPAR ECU and everything I have on the car is more race than street i.e. illegal....Ben Treynor I am interested to see what your results are....

I am putting the MOPAR box back on and using the stock one for the beer coaster....

 

[treynor]

Narc narc narc Jon

You must be registered for see images

One serious question -- I know there's a MOPAR ECU which is specific to the Gen-II engines; is there yet a different one for '00 & '01 cars with the new cam & pistons, or do they just have a single part #? I'm fairly sure I have the normal &lt;'00 MOPAR ECU.