Catapult

Here are images of an Audi B5 S4 stage 3 upgrade kit. About the same cost as a Kleeman SC, brakes excluded.

The ECU has four selectable programs: Stock; 93 octane; 100 octane; valet.

uownme

s4s are so clean, especially stage 3. Looking at another $4k for install?

Eurocharged Rick

looks like a very nice kit, are you going to install it yourself? would be a fun project....

i just have one problem with it, that exhaust necks down from what looks to be 3" to 2.5" mid way through...very bad thing for a turbo car...why would they do that?

Catapult

1FASTC32,
it was explained to me that the critical part for exhaust restriction is the catalytic. Making the downpipe 3" was to increase the surface area of the cat reducing this restriction. After that, the size becomes less important and there are space limitations as well. The stock downpipes are 2.2" with two cats each that Y into a single 2.2 exhaust pipe.

My son and I are doing the installation sometime in June. The engine has to be pulled because of the difficulty getting access to the turbos, oil and water lines.

Eurocharged Rick

i kinda assumed that would be the explaination, there are are two opposing theory's about whether this is a good idea or not...here is the short version:

1. not going any bigger than you need to helps with the exhaust gas scavenging...i.e. what you described above...

2. with a turbocharged motor, you don't want any restriction after the turbo, because that is the biggest restrictiont that there is in the exhaust system...i.e. you could run an open down pipe and still be better off than running any exhaust system...

i tend to agree with the second, mainly because i have seen it work in person both on the dyno and on the track...the numbers don't lie

in your case it probably is not a big enough deal to worry about, just sharing some experience here, good luck on the install, should be fun times with your son...

PBenz32

Bigger pipes aren't always better a good friend of mine does prototyping for audis, porsches, and vws and he tells me that he tried a 3inch exhaust on an audi and it lost 10hp but when he used 2.5 the turbo car gained 5hp to the wheels. Air doesn't move as fast through bigger piping, that is also why many companies exhaust systems will slowly shrink towards the rear to push the air out faster.
Anyway that was my .02

Eurocharged Rick

with stock boost pressure and no other upgrades i would agree, but you can easily gain power by going to a bigger exhaust once you turn up the boost and start making more power with other changes to the engine.....

jeremyw

Mmm, stg3, STaSIS/Alcon's, SMIC's, full exhaust...very nice choice!!

polarbexar

bganson

HAHA, I love the valet setting option.

FrankW

are all these installed yet?? dyno dyno dyno!!

RI55

Enjoy the AWD burnouts!

jeremyw

On an AWD Mustang dyne like we have, he should probably see about 330-350whp (so about 440ish bhp) on 91 octane. Using Sunoco 104 race gas, about 410whp (530+bhp).

Lots o' fun.

KompressorKev

b5 s4's can be killer quick cars. are those k04's? how about some k04/k24 zero clearanced hybrids or better yet, some twin gt25's those things rip

jeremyw

Hehe. GT28s yo! ;-)

How about a pic of your C32 in your sig Kev?

Catapult

Frank,
you're a little ahead of me. I have been busy with the C55 and now I will get back to the S4. Tomorrow I get the air con evacuated. That way I won't have it hanging in the way when I pull the engine.

Besides that we are working on my son's STi. Too many projects.

FrankW

awesome.

can't wait to see all your cars are done.

jeremyw

What are you doing to the STi Catapult? FP Green turbo?
Give the guys at www.pdxtuning.com a call if you need anything. They are the best in the country IMHO.

Catapult

Frank,
started getting the engine ready to pull. Still need to loosen the struts, disconnect the drive shaft and shift linkage and misc, other connections. Hope to get is all ready to pull next weekend. Taking it slow and I want to do everything right.
Catapult

Catapult

Hi Jeremy
my son has been doing all the research and so far bought an exhaust from ASP, a top mounted intercooler from Perrin, engine management from Element and is waiting for a turbo from Deadbolt. He has added AP Racing brakes and a light wait crank pulley from Autospeed Performance. I will tell him about the site you mentioned but would be surprise if he didn't know about it already.

jeremyw

Looking good so far!

jeremyw

Depending on which turbo he's going with, he may see a roadblock with the TMIC. The big turbo cars are all running FMIC's.

Have fun with the projects!

m3_eater

I'm curious but not trying to hijack the thread, so reply via PM if you like: Just how much can the wick be turned up on an Sti these days and still have the car be streetable?

jeremyw

We did the STi/WRX installations for PDX Tuning before they got their own shop so I'd be happy to pass off some info via PM.

Catapult

Pulled the S4's engine yesterday so the mods can begin. First will be removing and replacing the turbos and the rest of the plumbing, then the transmission to change the clutch and pressure.