Did some tests.
These results are for a standard 1998 S reg Audi S4 saloon with 50k miles.
All tests were perfomed on the flat, using Optimax (half tank) air-con on, engine warm,
no passengers and a 100kg driver (not sure if that makes a difference or not)
I did three speed ranges in 4th, 5th and 6th.
The tests were performed by staying at the lower speed for a few seconds, then hitting
the accelerator and the start button of the stop watch at the same time.
(again not sure if this makes any difference, but thought it was 'fairer' than accelerating
from a lower speed and hitting the start button when the speedo indicated the bottom end
of the speed range)
Anyway, here are the results:
Gear 4th Range 50-70 Time 4 seconds
Gear 5th Range 50-70 Time 5 seconds
Gear 6th Range 50-70 Time 6 seconds
Gear 4th Range 60-90 Time 6 seconds
Gear 5th Range 60-90 Time 7 seconds
Gear 6th Range 60-90 Time 9 seconds
Gear 4th Range 70-90 Time 4 seconds
Gear 5th Range 70-90 Time 5 seconds
Gear 6th Range 70-90 Time 6 seconds
All speeds in MPH (obviously not done on British roads)
I had a wastegate rod fail. Basically this leaves the wastegate stuck open, so you don't get any boost. It was fairly common on earlier cars (mine was a 96). Car drove fine except was sloooow. After getting some BS from the dealer I borrowed a colleague's car and measured the in gear times with his and then tried with mine. Big difference /ubbthreads/images/graemlins/confused.gif
New turbo under warranty sorted it /ubbthreads/images/graemlins/laugh.gif My colleagues car had the same failure a few months later
Then a bit later had an AMD chip fitted. /ubbthreads/images/graemlins/grin.gif
It's been to them also - they didn't seem that interested in finding out what was wrong with /ubbthreads/images/graemlins/confused.gif
Injector seals are next to be changed - its been on a rolling road, I asked for a power run and the boost checking, when I got back they said 'no problems with the boost it's doing exactly what it should' I aksed what the power oputput was - he said I don't know I didn't record it ????? wtf???
I was not happy /ubbthreads/images/graemlins/frown.gif
I'm still not happy /ubbthreads/images/graemlins/frown.gif
Being 5s slower 70-90 does not sound like performing well to me /ubbthreads/images/graemlins/frown.gif
I know you have had the boost checked, but your problem sounds exactly like what my car felt like when the wastegate rod failed.
My car drove fine, but fine for a normally aspirated 1.8 (125 BHP), not fine for a 1.8T (150 BHP).
It actually took weeks for me to get this sorted. For ages I convinced myself that I had just got used to the car's performance. It took driving my car and another identical 1.8T back to back to realise something was seriously wrong.
do few runs with Vag-com logging,, record things like 114 & 115 maybe.. MAF flow would also be good I think it is something like 002.
Then check the figures against another similar one.
also check op of N75 valve if this is faulty etc.. then it can lead to surge tyre problems or low boost.
well at this point in time I am going to change the injector seals on saturday - and give the injectors a clean, see what effect that has, I'll have a look at the DV also just to see if that is still okay.
other than that I'm pretty much stumped!
I may well end up taking that trip to AMD - but it does feel a bit like it's defeated me - which is annoying /ubbthreads/images/graemlins/frown.gif /ubbthreads/images/graemlins/burningmad.gif
I've used vag-com on my car to log a couple of plots. It was to try and match up with other S2 owners. I plan on doing them again with a flat straight piece of road and working out how much bigger wheels will affect the data.