What is the news on the performance upgrade from Audi?
04-12-2007, 06:41 PM
#1
AudiWorld Member
Thread Starter
Join Date: Mar 2004
Posts: 207
Likes: 0
Received 0 Likes
on
0 Posts
What is the news on the performance upgrade from Audi?
I am a bit curious why would Audi do performance upgrade on the RS4 engine to bump up the HP to 500? They are testing the RS8 using Gallardo engine and de-tuned it to 500 horse. In term of perfomance, the RS4 with 500hp on V8 would out perform 500 hp V10 because of power to weight ratio.
Does anyone know if the steering wheel on the R8 or Audi TT fit on RS4. I like the multi-function Sport steering wheel. Any audi mechanic or engineer can answer this?
Does anyone know if the steering wheel on the R8 or Audi TT fit on RS4. I like the multi-function Sport steering wheel. Any audi mechanic or engineer can answer this?
04-12-2007, 07:37 PM
#6
I think we could get 45 to 50 with exhaust, high flow cats, and a retuned intake manifold
It is possible to retune the intake for a higher rpm torque peak, which would push power up, but then the engine would be more peaky. It might even be possible to do this with the current manifold by adding some tuning slugs inside, to raise the resonant frequency of the high rpm intake path. But, this would require an ecu change to modify where the intake flap kick over, and might cause a drop in torque in the midrange. If this were coupled with an exhaust manifold designed with similar tuning, it might be possible to get even more than 50 HP out of it, but it would not be a streetable any more, and tough to drive on a track if rpms dropped below 5 grand.
Trending Topics
04-12-2007, 07:57 PM
#8
Injectors are already high enough capacity.
This is direct injection, not manifold injection. The injector flow is controlled by the open time, which at max rpm is about 3.5 milliseconds, and by the fuel rail pressure, which is under closed loop control and can be pushed up to 1800 psi.
The current engine is pretty well tuned. I doubt no cats will increase flow that much, unless coupled with an exhaust header tuned in conjunction with intake manifold tuning. Performance in this engine is limited by flow. And flow is not that bad.
The current engine is pretty well tuned. I doubt no cats will increase flow that much, unless coupled with an exhaust header tuned in conjunction with intake manifold tuning. Performance in this engine is limited by flow. And flow is not that bad.
04-12-2007, 08:14 PM
#9
Curiousity, what is the injector on-time at 6000rpm?
You guys seem to have alot more capacity than the turbo FSI guys. I was up to 9ms on times before we bumped fuel pressure and then was still at 7ms. Whne the tubo was upgraded it was at 9ms again.
04-12-2007, 08:21 PM
#10
Re: Curiousity, what is the injector on-time at 6000rpm? (edited)
It depends. Remember that the fuel rail pressure is also controlled.
Here are three different logs at 6000 rpm
InjectionTiming ThrottleAngle FuelRailPressure Lambda
2.55 ms .........99.2% ......... 112.14 bar ...... 1
3.06 ms .........99.6% ......... 113.04 bar ...... 0.85
0.77 ms .........24.7% ......... 35.33 bar ....... 1
113.04 bar = 1640 psi fuel rail pressure
max is 125 bar/1800 psi
Here are three different logs at 6000 rpm
InjectionTiming ThrottleAngle FuelRailPressure Lambda
2.55 ms .........99.2% ......... 112.14 bar ...... 1
3.06 ms .........99.6% ......... 113.04 bar ...... 0.85
0.77 ms .........24.7% ......... 35.33 bar ....... 1
113.04 bar = 1640 psi fuel rail pressure
max is 125 bar/1800 psi