HP is down, engine cooking, side sills running hot....

[Will]

What gives? After having 3" Random Tech HF cats, a 3" Corsa Exhaust, new plugs and Mopar plug wires installed I took my car back to the dyno at Apex Motorsports. Stock, my best run (on the same dyno) showed 419.8 HP and 450.3 Torque. AFTER these mods, my best run was 411 HP (forgot the torque number). Additionally, it was revealed that my engine was heating up way too fast and my new cats were NOT doing their job and keeping the side sills cooler. So, I'm down HP, I'm cooking my engine and my side sills are running hot... great

Needless to say, I left my car in the capable hands of Bill at Apex. They're going to perform a diagnostic on the car and check all the sensors, the HF cats, water propeller, welds, etc. The dyno did reveal that the air/fuel mixture was a bit high, which would account for some HP loss.

Anyone have any ideas as to what could be going on with my car? I was obviously very disappointed. To lose power after the install of these basic mods definitely *****. I am, however, more worried about the hot engine and HF cats issue.

Any ideas would be helpful. I'll try to share any potential causes with Bill who is checking out my car.

Thanks in advance,

Will

 

[jimandela]

just a guess... but it sounds like the water pump impeller problem some 00 and 01's have.
keep us posted as to what Bill finds.

good luck
JIM

 

[Ron Hickey]

If the car was running hotter, that could explain the decrease in HP. But if you're expecting any increase thanks to the Corsa exhaust & HF cats, you're going to be disappointed. My 2001 GTS netted all of 8 RWHP after adding the 3" Corsa and Random Technology Hi-flow cats. I love the sound, which is why I went with Corsa. I didn't really expect any HP increase (even though Corsa claims 18 HP); I did the before and after dyno for research purposes. It sounds like your car is in good hands; I'm sure they'll figure something out.

 

[Russ M]

"If the car was running hotter, that could explain the decrease in HP. But if you're expecting any increase thanks to the Corsa exhaust & HF cats, you're going to be disappointed. My 2001 GTS netted all of 8 RWHP after adding the 3" Corsa and Random Technology Hi-flow cats. I love the sound, which is why I went with Corsa. I didn't really expect any HP increase (even though Corsa claims 18 HP); I did the before and after dyno for research purposes. It sounds like your car is in good hands; I'm sure they'll figure something out."

Ron Hickey

Absolutely correct Ron, after seeing Corsa's claims of 18hp I almost bought the system over a borla. During this time the So Cal vipers were doing a dyno day and we got to see at least 3 new 3" corsa in action. What a joke, not 1 made more hp or torque than stock. After that I went out and bought a borla and gained over 20rwhp and 40lb's torque.

In other words Corsa except for construction quality is plain sad.

 

[Will]

Russ/Ron,

While I do not believe Corsa's claims of 18hp (although it would be nice), I certainly did not expect a loss in HP. Vince at Apex did mention the potential for a water pump propeller problem (which would cause the engine to run hot). I'll keep you posted as to the results of Bill's diagnostic.

-W

 

[ElDiablo Viper]

I had very similar story hoever I took the cats out. The car run very rich and only after installing VEC1 I was able to gain 11RWHP and 22RWTQ (on the same dyno)

 

[treynor]

> In other words Corsa except for construction quality is plain sad.

I've got to disagree here. The 3" Corsa design is excellent, and for those of us who want high flow without high noise, it's the only game in town. The Borlas will make just as much power (i.e. by themselves, not much), and are louder if that's what you want.

FWIW, my Doug Levin "Big One" car is running a Corsa 3"...

 

[TacDoc]

Um, LOUD is good gr****opper.

 

[TacDoc]

Geez I think the censorship logic is running amuck. Since when do we bleep a little green insect. G R A S S H O P P E R

 

[treynor]

> Um, LOUD is good gras shopper

Not in my case. I don't want the exhaust to drown out the "wrrrwrrwrr" sound from the ProCharger under my hood

 

[TacDoc]

"wrrwrrwrr"

 

[Russ M]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by treynor:
&gt; In other words Corsa except for construction quality is plain sad.

I've got to disagree here. The 3" Corsa design is excellent, and for those of us who want high flow without high noise, it's the only game in town. The Borlas will make just as much power (i.e. by themselves, not much), and are louder if that's what you want.

FWIW, my Doug Levin "Big One" car is running a Corsa 3"...

<HR></BLOCKQUOTE>

Sorry but you are very wrong on this matter, as stated there were several vipers with Corsa's at the local dyno days and the hp and Toque lines were identical to stock. And at the same dyno my car made over 20more hp and 40lb's toque with a borla.

In other words Borla just makes power while the Corsa does not. All the technology in the world will not make a quiet exhaust make hp unless it is on a turbo car. More noise means more power plain and simple. And I for one would be very upset if $1500.00 was waisted on FALSE advertisement.

 

[J DAWG]

I guess a dyno doesnt lie but it seems hard to believe that with a change in only the catbacks(corsa to borla) netted 20 hp. I am undecided on which setup to go with. To many choices but I want my moneys worth.
Also if these are 3 inch systems why do some place 2 1/2 cats. It seems it would restrict flow.
Russ do you have cats or just borla catback?

 

[JonB]

Stationary car, no air circulation, full WOT revs, multiple runs, = HOT SILLS. Even with hi-flow cats. Driving down the road, these cats would be COOL.

The symptoms you describe tend to be explained by the freewheeling impeller in the water pump...a warranty issue seen with too much frequency. WARRANTY! No WOT Please.

Furthermore: resetting the ECU (as you metioned on the phone)
sets the car at full-rich, and takes 3-4 run cycles to adapt away from rich. (further heating up cats)

Get your water temp under contraol, and your probably see better HP figs. The primary reason to swap to HF cats on a stock car are: 1) cooler sills, 2) deeper tone 3) a few unproveable HP. Difficult to prove 5HP on a 450HP motor, dyno is +/- 1%

 

[King RT10]

Has anyone gained horsepower using the 3 inch Corsa and Hi flow cats?

 

[Bill/APEX Motorsports]

Most of the cars we've dynoed have seen pretty good improvements with the Corsa 3" cat-back system. Plus, in our opinion, it offers the best sound. We've dynoed a couple '96s and '97s that saw 21rwhp and 19rwhp, respectively, with the addition of the Corsa 3" cat-back. Vipers can differ wildly from one to the next, however, and the '01+s seem not to respond as well, hp-wise, to traditional exhaust mods.
Will's car does heat up quicker than most--on the dyno, the water temp gauge virtually follows the tach on each run!
We suspect a water pump failure, so our first suggestion is to have that warranteed. (Free!) Once that's done, we can pursue other possibilities.
Also, our dyno experience shows that resetting the computer will make the car run 1.5-2.0 air/fuel ratios leaner, not richer, at least on the newer Vipers. Of course, four or five runs after, it's back running really rich.