a performance question

[lucas123]

Im new to this site(so hello) & have just had my s4 avant chipped to 305BHP - Can anyone tell me what the performance difference would be say - 0-60,0-100 & 1/4 mile. Bit of a sad question but i thrive on this stuff! [img]images/graemlins/s4anogaro.gif[/img]

[Riz_RS4]

Hello lucas and welcome to RS246.com
Im not a S4 owner so cant really say, what chip did you get?

[Dippy]

Hi Lucas,

I must say that times are not really my field of interest, but based on what I have read (and I have read a lot), your chip is likely to improve your 0-60 time by nearly 0.5s.

However I wouldn't recommend doing many 0-60s as the gearbox on the S4 is not really up to it.

[lucas123]

All i know is that it is from Superchips.co.uk costs £511 & gives an additional 40-45bhp. Any good?

[lucas123]

Thanks for the info - i wonder how it compares to the RS4 - i guess i'll have to wait & see!

[Dippy]

Don't forget that the bhp addition is for the peak figure alone, and this is merely a small part of overall performance of the car. Personally I find that the effect on torque over the whole rev range is more important.

Your car should now have more low and midrange torque than a stock RS4, giving it better instantaneous acceleration. However the RS4's internal tuning keeps the torque high at the top end and hence the 380 bhp quoted. Thus in continuous acceleration a stock RS4 would outrun you. In basic terms your S4 would be similar to a stock RS4 in a 0-60 run, but in the 0-100 and 1/4 mile the RS4 would be significantly ahead.

And of course there are not many stock RS4s left anyway!

Our cars are most restricted by the cats. A full Miltek system with remap can easily get an S4 to around 330-350 bhp which is flat to the redline.

[lucas123]

Sounds like you know your stuff - how much of a performance difference will the milltek make ?

[Dippy]

As I wrote, I'm not really into timings so I can't answer you in that way. However I guess that your chip is the same as others in that you feel the car stop accelerating when the revs go above about 5000-6000rpm?

That's the restriction of the OEM cats. Put the Milteks in and the increased airflow means that the car still pulls all the way to the redline. The effect is that I guess that my car would match a stock (repeat stock) RS4 to 100mph and probably not be far behind in the quarter mile.

However please note what I wrote - that you need a remap to take advantage of the Miltek cats, as you'll need more fuel at high revs. Indeed without a remap you risk running too hot anyway.

[Golich]

Dippy has just told you up to 330-350.

I have an AMD chipped S4 and have also driven a stock RS4. What Dippy says is correct. The stock RS4 isn't noticeably quicker than a chipped S4. If just driving it without any means of comparing the two. Where you notice the big difference is where I find it's best to change around 5000rpm max the K04 turbos on the RS4 appear to provide the volumetric capacity to keep that baby running right up to a 6000rpm change. I dare say the improved flow in the RS4 heads also contributes.

Well at least I feel the K03s are running out of puff. This is where the increased flow CATs show their qualities as Dippy etc can vouch for.

[Joules]

Do the high flow cats make emissions more difficult to pass on the MOT???

[Prawn]

Joules,
My S4 with K04's and the milltek cats went through the MOT with no problem at all, (the day after the conversion), I did ask the tester after it had passed about this and he had not noticed anything different.

[Dippy]

I bought my Miltek system on the full understanding that it would meet MOT emission rules. I'm glad to now hear a case where this is proven true.

[Joules]

Joules,
My S4 with K04's and the milltek cats went through the MOT with no problem at all, (the day after the conversion), I did ask the tester after it had passed about this and he had not noticed anything different.

Cheers for that...