denistu

Hi guys,

I've recently purchased a 2007 S4 and I am looking into the APR tuning available for this engine which would give me extra 8hp and 10 lb-ft.

The price of the upgrade is not too bad, but I am still wondering if I would feel any difference in everyday driving.

Can someone share his experience?

Thanks,
D.

CharlieG

I would pass ... it's unlikely you're going to notice any difference. The big drawback to this V8 is the limited tuning available. It's a great engine and delivers a reasonable amount of power but you're unlikely to wring much additional power of it with a simple ECU flash.

SpeedETC

I agree with this in regards to the APR tune, but this is not the case for all tunes. For example, the JHM tune completely transforms the car. It is literally a night and day difference - and this is from someone that came from another tune.

sakimano

Charlie sounds like he has been listening to the guys who bought a GIAC or APR tune 5 years ago as well as exhausts that were a replica of stock, a.k.a. useless, like so many other 4.2 S4 owners. Those guys usually drive B8 S4s now, after ditching the 4.2 because it was not 'tunable'. They just didn't buy the right stuff. There are lots of them on Audiworld, so be careful.

My car went from 13.8 @ 101 mph in the quarter mile to 12.9 @ 107 mph...a fairly huge difference for any platform, forced induction or not. I had JHM 93 tune, 2.5" full JHM exhaust, JHM LW front rotors, JHM lw crank pulley, and JHM intake spacers. That's about $3000 in parts...and I picked up the equivalent of 8-9 car lengths on a stock S4 in the quarter mile. My car would routinely put about a buslength on GIAC or APR tuned B6/7 S4s in pulls from 50-120.

Here's some dyno info that I think you'll find interesting. beemercers car was very similar to mine, but he also had the JHM intake manifold. Note that his car and Loucura's car were JHM tuned...and note the difference between the 2 JHM cars with 2.5" fullback exhausts vs. the one APR car with APR full back exhaust (downpipes + catback). It's GIGANTIC.

Stock - 264 whp/247 wtq
APR tune + APR 2.25" fullback = +7 WHP/-2 WTQ vs stock (!?!?)
JHM tune + Labree 2.5" fullback = +33 WHP / +34 WTQ vs. stock and + 26 whp/+36 WTQ vs. APR

I didn't even mention beemercer's numbers. Once he added the intake manifold, it was off the charts stronger up top than the other cars.

Also look at the other cars that were there...those JHM B6 S4s did VERY well.

denistu

Thanks for the numbers. That's exactly what I was looking for.

The only thing that I noticed is that the stock wtq seems to be bit high. If the Hp is correct, the power loss on s4 is around 22% which kind of makes sense. So, in that case the wtq should be around 235, not 247. In that case, 245 after APR tune would make sense also.

Thanks gain for the info.
D.

Blax04AudiS4

I have just purchased a 14,397 APR Supercharger, who is best qualified to install this unit. I live in Houston TX. Not Cali. WHo is qualified to help me install.

maw1124

This is all interesting to me, as I'm considering doing an APR Tune on a 4.2L Allroad (which should be the same engine as here). Only difference here is I've already done the 2.5" exhaust. Just replicated the stock system with larger pipes off the down and kept the X, all Magnaflow. Already she's freer and stronger through the high RPM, like, noticeable. Runs like a different car. I'm no dyno guy, but that has to have been good for about 10/5, maybe even 15/5. I want to see what extra I get on top of that, but even more, I think I'm gonna finally be able to outdo that stock mileage. She smells like she's running rich on these high flow cats (I think 400-cell), so I'm thinking the tune gets me to APR numbers if not better, and better fuel economy. I can see how you get more HP with higher revs on this car and not much TQ, even though I'm not really interested in that. I just want to confirm these thoughts with feeling. It's probably going to come out marginally stronger and higher revving, but not much more pull. We'll see.