Vijay

With the notion that 20,30,40hp may be able to be extracted with bolt-ons and ECU mods, we are failing to consider what the actual performance gains afforded by those mods may be. Remember that power requirements go up exponentially for linear incremental increases in performance. At this overall power/performance level, one will need a significant power increase for any measurable performance gain. This is compounded by the fact that the power increases more than likely come at higher rpms where the car will already be moving along, as opposed to, say, and extra 15lb-ft of torque at 2000rpm.

I am willing to wager that even if one were to install a cold air intake, DP, exhaust and do an ECU reflash to optimize the bolt-ons, that there would be absolutely no consistently measureable on-road performance difference in the car over stock whatsoever.

That being said, I do feel there would be a change in the subjective feel of the powerband and sound of the car. Since many factors contribute to overall driving enjoyment, it is up to the individual to decide whether or not that change, or the bragging rights to say you have a 460hp car, is worth the approximately $6-7k for all those mods.

At this point in time, if I was planning on spending that kind of money, I would opt for the Stasis suspension, which clearly changes the driving dynamics of the car, and the Milltek cat-back simply for the more aggressive sound. If a good set of 20lb forged wheels were available, that would be my first choice.

All that being said, if some tuner proves me wrong with regards to on-road performance gains, I will be all too happy.

Bob W.

like the RS4. I think if you could add 40-50hp AND lose 50-100lbs (which wouldn't be too difficult), there would be a noticeable difference in performance. Probably the only way this could happen with bolt-on stuff (not including a SC) is if race gas is used.

edwardschmedward

Revo reflash, the car was faster. Yes, this is subjective... but with the amount of cars I have/have had, and the amount of tuning I've done to them (and the lack of ego invested in anything, at this point in my life)... I believe I can probably tell when a car is faster.

Having said that, I agree that the Stasis/Ohlins coilovers are the best investment, and if I were to buy another RS4/RS5 that might be the only mod I would do.

Rolanday

Regarding the Stasis motorsports suspension, it's money well spent and a must have upgrade as far as I'm concerned. It really transforms the car in a positive way making it much more fun to drive, and you don't have to be pushing the car hard to feel its benefits.

Spending tons of money to get an extra 50hp? I'm not going to do it because (1) you can never have enough power so I'm not going to be any happier w/470 than w/ 420 and (2) the car is already overpriced from the factory and I don't want to have to look back and realize I've paid almost $100k for an A4. For that kind of money, I'll take the 997 GT3.

I'll probably do the catbacks just for the sound.

Victoryroad

suspension may be the best modification. I understand that there are Audi sport springs available for ROW, or at least European RS4's, and wonder how they may change handling. I gather that they lower the car only 10mm. Having done extensive suspension mods on my A6 4.2, which took a lot of understeer out, but also made for a much stouter ride, I am reluctant to go for track suspension. One of the outstanding points of the RS4 is its very compliant ride and simultaneous ability to respond to more aggressive steering/power inputs. (I do not track the car.) Also saw recent reference to Audi sport exhaust for RS4, but no details. I will check out these two possibilities before going aftermarket, although Miltek or Magnaflow exhaust may be in the picture. Probably will not mess with ECU remap due to possible complications.

nyet

or *more* true, since DTL is a HUGE issue for AWD cars.

nyet

they simply *add* up HP gains for different mods.

Doesn't work, esp for NA cars, even assuming the claimed gains are real (which they rarely are).

Vijay

In fact, two mods that alone may produce some amount of power gain, when combined, may even produce a power loss!!!

It is also overlooked that different components may produce power changes in different areas of the powerband, further invalidating the "adding it up" thing.

Vijay

I have never been in any form of modded RS4, however, I too have had a bit of experience tuning cars, and feeling faster is quite different from actually being faster, which I'm sure you know. Subtle changes in power distribution over the powerband can easily give the illusion of greater speed. I would still like to see a few repeated head-to-head runs on the dragstrip.

nyet

anybody who says they can tell a car "feels faster" is delusional.

its not as if taking logs or doing dyno pulls is difficult; the reason people intentionally avoid gathering objective data is because they are subconsciously scared to be *proven* delusional.