July 23, 2007
Compiled by: AudiWorld Staff
There aren’t too many 25th Anniversary S4′s out there to start with, but we can guaranty there are no others like this one. It is not only completely built out from a performance perspective, but also has a number of unique external mods. Enjoy!
As a reminder to readers, we are always looking for Audis that include either very clean and well-done mods or extremely unique enhancements. Please e-mail us if you are interested.
- Name: Kevin
- AudiWorld username: V8
- Location: Newark, cA
- Occupation: Network Engineer
- Year: 2006
- Make: Audi
- Model: 25th Anniversary S4
- Mileage: 5,000 miles
- Color: Avus Silver
- Engine: 4.2L V8
- Engine Mods: MTM K450 supercharger, ECS snub mount
- Exhaust Mods: LaBree downpipes + cat-back
- Suspension Mods: STaSIS/Ohlins Motor Sport suspension, STaSIS LSD, H-Sport sway bars
- Brake Mods: STaSIS/Alcon 14.5″ big brake system
- Wheels & Tires: Neuspeed RS-10 (19×8.5) & Goodyear GSD3 F1 (235/35/19)
- Exterior Mods: MTM/Carbon24 vented carbon fiber hood, Huper-Optik 40% windw tint
- Interior Mods: Sparco carbon fiber seats, Stratmosphere short shifter, RS4 pedal set
- Audio / Video Mods: None
Photo by: Matt Chow
Featured Car Questions
When and where did you purchase this car?
I purchased the car from Stevens Creek Audi in Northern California. I originally wanted a black S4, but when I saw the color, exterior carbon fiber, and interior of the 25th Anniversary I decided to get it instead.
Why did you choose this car as the basis of your project?
Ive been a fan of the Audi S4 for a long time. When the B6 came out it was on my wish list, but I never did get one. Then the B7 arrived, but after seeing the early press photos from Audi I was a little thrown off by the front grill–it just didnt look right to me. I was very interested in owning an Audi S4 though so I went to the dealership anyway just to see what was available. Once I saw the B7 S4 in person I was hooked.
Was there anything unique about the car before you starting modifying it?
The 25quattro’s exterior color is Avus Silver which is normally not available for the S4. It also has a DTM body kit which includes a carbon fiber rear spoiler and front splitter. The entire front grill is gloss black with a gloss black filler panel as well. The interior is unique with hand-stitched leather, quattro embossing, and the same carbon fiber treatment as the B7 RS4. Something else different was that it had dual exhaust tips as opposed to quad exhaust tips.
Did you consider any other brands, and what led you to Audi?
I strongly considered a Mercedes because I really like the power of their higher-end cars, but the lack of a manual transmission option caused me to eventually lose interest. I also looked at the BMW M3, but I needed more space and preferred more doors.
What was your objective with this project?
My primary goal was to make the car more enjoyable to drive. As with previous projects, all of the changes Ive made have been with improved performance in mind more so than cosmetics. Other than that, I certainly enjoy driving a unique looking car on the road and the Audi S4, especially the 25th Anniversary edition, helps me accomplish that even in stock form.
What companies or individuals were involved in the built-out?
I have to thank Streetwerke, STaSIS Engineering, Hoppen Motorsport, Creative Kustoms, LaBree Motorsports, Speedware Motorsports, and Michel, aka Jet Jockey/A4 Pilot, from AudiWorld! Streetwerke installed the suspension, wheels/tires, original APR cat-back exhaust, and Valentine One. STaSIS did the brakes and rear LSD. Speedware installed the MTM supercharger, LaBree exhaust, H-Sport sway bars, ECS snub mount, Sparco seats, and Stratmosphere short shifter. Hoppen Motorsports helped me order the carbon fiber hood from MTM and Creative Kustoms installed it. Jet Jockey/A4 Pilot supplied me with one of his Odyssey battery brackets. I also have to thank MTM for providing great pre-sales support through email for both the carbon fiber hood and supercharger, they were very helpful.
Any specific technical details you can share?
The supercharger is a Lysholm twin-screw unit made for Kleeman by Opcon. The kit includes a water-cooled intercooler from Laminova (a subsidiary of Opcon) along with a closed-loop cooling system with an electric pump and its own radiator. Since this a positive displacement supercharger boost is almost immediate with maximum boost occurring around 3000 rpm. The rpm redline has not been changed. The engine internals and compression ratio have also been left standard.
What was the most difficult part of the project to get right?
The supercharger was the biggest hurdle because the MTM kit was not designed nor tested on a US-spec car. Speedware Motorsports worked closely with MTM to do a fair amount of design, fabrication, and testing for a prior installation on a US-spec B6 S4 Avant. So my installation went rather smooth comparatively. It did take longer than expected though because of unforeseen delays in shipping and communication with MTM in Germany (they had a 2-week holiday during the installation process).
If you had to do it all over again what would you change?
Honestly, nothing. The only modification I did change was the cat-back exhaust. I originally went with APR and chose it because it was a relatively quiet setup. Once I knew I wanted a supercharger I decided to also get downpipes and wound up purchasing a full-back system from LaBree. I still didnt want an incredibly loud exhaust though, so LaBree made my downpipes with 2 extra cats (4 total). I lose some power compared to the downpipes they normally sell, but keeping the noise down was more important to me.
Have you generated any formal test results with this car (dyno, 1/4 mile, etc?)
Speedware performed before and after dyno tests. The first results with an APR cat-back and Hyperflow intake, but without the supercharger, were max power: 284 @ 6750, max torque: 252 @ 3000. The results after the supercharger install, exhaust swap, and Hyperflow intake removal were max power: 376 @ 6750rpm, max torque: 363 @ 4250rpm. Both of these tests were on the same Mustang dyno using 91 octane tuning. Trying to determine the exact crank HP and torque figures from this information is somewhat futile, but I always answer this often asked question with ~450hp and ~430lb-ft of torque.
The supercharger adds weight to the front, but with the other modifications I tried to reduce weight. When the car was completely stock it was weighed at Streetwerke and came in at 3,893 lbs. The last time it was on a scale in its current configuration it weighed 3,640 lbs.
Are you finished whats next?
I’d like to get a STaSIS rear brake kit, but its currently not available. Other than that I may change the wheels from time to time, but that’s about it. If the need ever arises I will upgrade the clutch. The B7 RS4 clutch will not work on a B7 S4 (different bolt pattern) so I would probably go with Clutch Masters.
Is this your daily driver, and if not what else is in your garage?
I drive a Mazda Mazdaspeed3 for longer trips, hauling, etc. I also have a 1969 Camaro that was recently featured in Super Chevy magazine. Our primary family car is a Lexus RX400h hybrid.
What is your favorite thing about this car?
It’s something different… not a BMW or Mercedes, but looks great, handles great, and has excellent power delivery for street use while still maintaining the right amount of luxury for me.
As modified, what makes your car unique?
The car is fairly basic as far as modifications go, actually. I guess the supercharger, which was custom painted black, and the vented carbon fiber hood set it apart from most at the moment. Everything else, except for the seats, a lot of other S4 enthusiasts have. Its still a rather unique combination though, especially given what I started with.
Where can other enthusiasts see your car?
AudiWorld, Audizine, and of course driving around in my area.
Anything else youd like to share?
I just want to say thanks to AudiWorld and Audizine for all information that has been shared. And again, thanks to everyone that helped get the car to where it is.
- Photo Gallery: Kevin’s 2006 S4 25quattro
- B7 S4 Discussion Forum – Leave Owner Feedback on this Thread
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