2003 Corvette Project

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Feb 23, 2006 | 08:11 PM

vettejockey

Thread Starter

Racer

Joined: Feb 2006

Posts: 349

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Looking for Horsepower

I have just purchased a 2003 conv with an automatic transmission. When I bought the car I was not aware how much horse power is lost with the auto trans. To improve performance I am wanting to go to a Corsa exhaust system with X-Pipes. While I am installing this mod I want to put in a High Flow cat I am just not sure which ones are compatable If anyone has any information I would appreciate the help.

Thanks
Randy

Last edited by vettejockey; Feb 24, 2006 at 07:22 PM.

Feb 24, 2006 | 08:51 AM

davee01

Burning Brakes

Joined: Nov 2004

Posts: 915

Likes: 0

From: Dardenne Prairie MO

I have a 2003 Coupe with the A4 auto and 2.73 rear end.

After riding in autos with the 3.42 swapped in, That is where they have hidden the extra horsepower. It's there for a 60mph to 80mph roll, but is still asleep off the line.

That is one of my planned mods when the time comes.

Good luck with the new ride.

Feb 24, 2006 | 09:10 AM

byte_me

Safety Car

Joined: Jun 2003

Posts: 4,509

Likes: 239

From: Coconut Creek FL

Quote:

Originally Posted by rjung

You may also consider a Long Tube header to compliment your idea...I have a 97 Autoimatic however; with the 3:15 gears...and while its an automatic the gears really make a difference! I drove several cars with your 2:73 gears and felt it was lacking power (as you stated) as mentioned above - 3:42 gears (or what a 6 speed comes stock with) would make a huge difference for you...Long Tube headers with a high flow cat are good for a nice 30HP increase...I went with Kooks myself (but most of them net the same HP) but it may still feel like its not all there with the 2:73's...

If I were you- I would start with gears, then move to the exhaust...I don't think you will be happy performance wise with just cats and a catback (though it will be louder) you still have those 2:73's to deal with...

Feb 24, 2006 | 07:25 PM

vettejockey

Thread Starter

Racer

Joined: Feb 2006

Posts: 349

Likes: 0

Thanks for the info. How much do you guys think this type of a gear mod should cost?

Randy

Feb 24, 2006 | 07:37 PM

tiojames

Team Owner

Joined: May 2005

Posts: 23,682

Likes: 9

From: Flagstaff Az.

Looking for horse power

When you do the diff change, wait until you can add a hi-stall convertor. It's a $100 for the labor because the unit is all ready out for the diff change. I had the 3:15s and went to the 3:42s with a 3500 Yank. Drives well in traffic and also performs well. A good used 3:42 can be had for $450-500, I paid $500 for my Yank, and labor should be about $600 to install both.

Last edited by tiojames; Feb 24, 2006 at 07:41 PM.

Feb 24, 2006 | 07:48 PM

Mike04

Safety Car

Joined: Jun 2004

Posts: 4,353

Likes: 22

From: Bella Vista Ca

A4s have torque management....Basically limits the power the engine puts out at lower RPMs. GM uses it to reduce drivetrain wear. Sticks do not have that. I would highly recommend going with 3.42's and a torque converter and then have the torque management disable. That will give you a huge SOTP improvement.

With a stock A4 breaking the tires loose takes a little effort. This combo will let you do it at will

Feb 25, 2006 | 08:38 AM

vettejockey

Thread Starter

Racer

Joined: Feb 2006

Posts: 349

Likes: 0

I am going to check into these ideas they sound liek what I am looking for. Thanks again

Randy

Feb 27, 2006 | 09:44 AM

davee01

Burning Brakes

Joined: Nov 2004

Posts: 915

Likes: 0

From: Dardenne Prairie MO

I think that you can get a new 3.42 for around $1000 Through GM PArts direct or some of the on-line forum vendors. For some reason the Z-06 version is a few bucks cheaper than the standard.

Then there is install, tune, ...

I am budgeting around $2,000 for when the time comes to do mine..