SoBeRS4

Did a little bit of rough math. Sounds like it's about $100 per horsepower to mod the RS4.

I'm driving a 2008 RS4 with 100% stock, original owner. Threw my car up on a dyno a few days ago and put down 327hp at the wheels.

I basically have an empty canvas here. I have been reading threads on AZ and a few other places. I am not sold on any particular set-up for max performance. MTM, APR, PES, all do S/C. Piggies, intake, high flow exhausts, etc., lots of options.

Are there any well know euro tuners besides MTM out there with complete set-ups? Intake - s/c - exhaust; combined with fly-wheel, clutch, diffential mount, engine mounts?

Sending the car to the "carb doctor" tomorrow, getting rid of that crap once and for all. Also putting new spark plugs/K&N air-intake/hawk pads on.

Goal: add approx 200 hp and torque over stock. All suggestions are welcome.

Thanks!

BADRS4

Sweet! Sounds exciting!! I'll be following your lead...I'm also stock...and due for front pads....I just put the K&N in last weekend..and love it!

karsty

I don't think 200 hp has been achieved yet by any of the tuners, or at least they havent pushed the envelope that far for the sake of the engine.

sakimano

who cares about dynos...worry about performance instead. If you buy a PES supercharger for $13,000, you'll dyno 400 whp...and then lose to my friend George in his RS4 with just clutch/exhaust/JHM tune (total $5000). And you'll lose badly. And he'd dyno maybe 360 whp.

The APR kit is nice, but the EASTON TVSr1320 supercharger is frankly undersized for a 4.2 V8 that redlines at 8000+rpm...and when you consider our engines forged internals, the blower is going to be maxed out LONG before the engine's 'capacity' has been used up. Eaton says the 1320 should be maxed out at about 525 CRANK horsepower. APR ran 11.83 @ 116 mph at the dragstrip but for some reason they stripped the car, removing the back seats, the seatbacks, the carpets and everything from the trunk, including the trunk floor. Kind of an asterisk time, but still a great time. They probably could have run 12.0 without ricing it up like that. The price is a bit steep at $15,000+

The PES and VF kits are an industry JOKE. They showed great dyno numbers, promised the moon, then ran high 12s at the dragstrip. Oh...guess what my bone stock full weight car ran on Saturday? Yep. High 12s. These two kits both use the Eaton M90/Harrup MP90. This is an antiquated blower that will max out around 460 CRANK horsepower, not wheel. That is according to Eaton and Harrup themselves. SKIP.

MTM - they won't share any real information with us as far as performance goes. There was one stripped out MTM test car that posted some decent 100-200kmh times but again it was down a FEW hundred lbs, was stripped with no back seats and had a roll cage, and wasn't even on a certified dragstrip for testing...rather it was on a public road. Just not really the best testing methods for selling a supercharger for most people's daily driver. Haven't seen a dyno, haven't seen a quarter mile time...haven't seen much. Oh...and it's $30,000.

So that's it for currently available superchargers.

TTS is working on a Rotrex blower, but the blowers are kinda tiny, so not sure how it's going to work out. They're still developing the kit. They claimed pretty big dyno numbers, but haven't been able to take the car to the local dragstrip just yet. COuld be a good one if their dyno numbers are accurate, but 4.2 dynos when you add a supercharger seem to be all over the place.

JHM is working on adapting their Vortech centrifugal supercharger that they used on the B6/7 4.2 V8 S4. On the 4.2 S4, they had to limit the blower to about 425 WHP because of the S4's internals not being able to handle much more than 450-475 whp. However on the RS4, they are confident they'll hit 500 whp on the stock motor. It's going to be very interesting. With JHM's supercharger, their 2.75" downpipes, 2.75" exhaust and stage IV clutch, you'd be looking at about $13-14,000 I'd guess. That's going to be a very serious performer.

Here are the kits available

APR using an Eaton TVSr1320 - $15,000+, Eaton says blower good for up to MAX 500-525 hp crank.

VF using an Eaton M90 - $14,000+, Eaton says blower good for up to MAX 460 hp crank.

PES using an Eaton M90 - $14,000+, Eaton says blower good for up to MAX 460 hp crank.

JHM using a Vortech - $??? (guess around $10,000), Vortech says blower good for up to MAX 750-800 hp crank. (yes 750-800).

TTS - I don't know enough about it yet...but they did mention a price approaching 16,000-18,000 in a thread elsewhere.

Not everyone likes quartermile times, however they are a great indication of how a performance system is working.

Take note...there are two FULL WEIGHT/FULL INTERIOR cars that have only JHM bolt on parts (about $5,000 in mods)...and they are within 4 tenths of the stripped APR supercharged car (about $20,000 in mofifications). Shows that you can achieve lots of the available SC kit performance with simple bolt ons. The good thing is your bolt ons will still help you should you get supercharged one day.

BADRS4

Very good info Saki! Thank you!

SoBeRS4

Sakimano, or should I call you saki-san?

You have a wealth of information. Do you have a time frame on when they'll launch their S/C @ JHM? I have an Audi/Porsche master technitian dedicated to work on my car. I must "sell him" on everything I want to do with the car. He is a pri** at times, but I know he cares dearly for the car.

I will keep you posted on every step of the way. The goal here is to get down to the Homestead drag strip on a "cold" January afternoon and run at a serious 1/4 mile. After I'm done with the 1/4 mile, I will strap my 1-year old in to his child-seat and drive home....

sakimano

JHM has had their Vortech supercharger running on their in house B6 S4 for about 18 months. They have recently started selling it to B6/7 S4 owners. The blower is pretty awesome. Capable of 1300 CFM. Wow. Their tuning on the B6/7 had to RESTRICT the blower to protect the engine...it's that powerful of a supercharger.

As for a timeline, I believe they are going to have it on their in house B7 RS4 (yes, they bought an RS4 just to test stuff on) in the next week, with tuning and testing to go along the way. If we look at the Henessey twin turbo R8 4.2, they recommend an engine build once you're up in the 550 whp range. If we believe that, 500 whp should be comfortable, but make no mistake - JHM will test the **** out of the RS4 engine to see what it can handle, and will sell the kit dialed way back from the limits. Still, that should mean killer power levels traditionally thought impossible on the RS4.

If you're talking THIS january, I think you'll be out of luck as far as a JHM SC goes. If however you can be patient, and will be happy with low 12 second times on pump gas, have a look at a tune + exhaust + a couple of lightweight rotating parts (rotors, flywheel, crank pulley). Then when you add a supercharger (whoever's kit you use) you will still benefit from all the NA parts you bought, save for the crank pulley which will be replaced.

KMarshall

Hi All,

Jumping on here late... since my R8 got a SC, the RS4 has not as fun... but is still a great family car. Does anyone on this forum currently run the APR SC on the RS4 as a "near daily driver"? I'm curious how the reliability and drive-ability have been.

Does anyone know about how many APR SC's on RS4 are out there?

Thanks!

sakimano

I would guess about 25 APR SC cars out there. Not many. There are only 2500 RS4s in North America and another 7500 or so around the world. Probably 90% of these are bone stock still.

I do know someone who has an APR RS4...mayeb the first one in America...and it has been pretty solid. He was very disappointed with the car when he first got it back from APR. He said it felt not much faster, and then went to the dragstrip to see. Sure enough, it ran 12.7 @ 108 at the dragstrip in good conditions with an excellent driver. Stock RS4s should be able to run 12.9 @ 107 without a ton of trouble in good conditions. That's what my car did two weeks ago.

Anyway, a friend of the owner who works for JHMotorsports and the performance division of an OEM wrote him a new tune for the car, and it then ran 12.0-12.1 @ 116-117 full weight on 93 octane. It has since had a full JHM exhaust put on
and ran 11.8 @ 119. He's very happy, but I think he'll be selling his kit for the JHM supercharger when it becomes public ready.

swesna

where is the tune for an rs4 located on their website? I have looked and have not found it.