My RS4 on MRC's dyno - video

[neilparf]

Delimit of what?

Opening of the throttle body below 5500rpm.

Surely the power is held back above 5500 not below? 425-430 will take manifold work and sports cats etc aswell as the de coke n map.

The throttle body isn't fully opened below 5500rpm in gears 1 to 3, that's another major contributor to the fabled 5500rpm kick, it's not just the opening of the power flap in the airbox.

Cheers Dave for the answers

[Wavey Dynamicist]

Never heard of that one! Anyone know Audi's rationale behind this?

[Rick_RS4]

Never heard of that one! Anyone know Audi's rationale behind this?

id say it would be to reduce strain on the clutch and drivetrain

[S4Player]

It revs on the way down because it's a coast down dyno. you blip the throttle with clutch in, on coastdown, so you dont get low oil pressure straight after you have done a WOT run, or while the engine is at 7k revs - you are trying to keep oil pressure at 5bar+ while the engine is still turning at those revs. If you just let it drop to idle oIl pressure would be less than 2 bar, even dropping lower if revs drop. Mrc normally power run in 5th not 3rd as well if I remember rightly

[Wavey Dynamicist]

Never heard of that one! Anyone know Audi's rationale behind this?

id say it would be to reduce strain on the clutch and drivetrain

Mmm I'm not sure about that one as full power is given in all gears at 5000 or so anyway.. I can't remember if there's a similar kick in 4th and above to be honest.. Will have to investigate that..

I can't think of an engineering reason for them to do it if true, only marketing..

[Rick_RS4]

Never heard of that one! Anyone know Audi's rationale behind this?

id say it would be to reduce strain on the clutch and drivetrain

Mmm I'm not sure about that one as full power is given in all gears at 5000 or so anyway.

yes but you are rolling by then, and also you dont do a standing launch in 4th

[neilparf]

Mmm I'm not sure about that one as full power is given in all gears at 5000 or so anyway.

yes but you are rolling by then, and also you dont do a standing launch in 4th

+1

[neilparf]

It revs on the way down because it's a coast down dyno. you blip the throttle with clutch in, on coastdown, so you dont get low oil pressure straight after you have done a WOT run, or while the engine is at 7k revs - you are trying to keep oil pressure at 5bar+ while the engine is still turning at those revs. If you just let it drop to idle oIl pressure would be less than 2 bar, even dropping lower if revs drop. Mrc normally power run in 5th not 3rd as well if I remember rightly

That makes sense. I think the run was in 5th - I will check...

[neilparf]

Ok, the figures are now in and Doug has made a few fuel experiments between Shell V Power Nitro + and Tesco99. Dyno'd on Shell then rinsed and Tesco99 after tweaking and final adjustment. The difference is purely down to 98 vs 99 RON

Shell V Power Nitro +: 432.3 and 468NM
Tesco99: 433.8 and 483NM

[Wavey Dynamicist]

yes but you are rolling by then, and also you dont do a standing launch in 4th

+1

I agree with that, but you're also rolling in 2nd or 3rd.. I hope Audi wouldn't be so cheap as compromise the car because they don't want to beef up the drivetrain lol..

Do you have the before and after dyno plots.. That'll give a good idea as to how the engine acts with the 'limiter' and without..

[Rick_RS4]

Audi always over engineer parts and are usually over cautious, that's why we can run a charger on standard internals and so far no one has blown one up because of it ( that I'm aware).

Great figures Neil that's a great increase, is that you done now or you doing manifold and seeking more power? I'm looking to aim for 450 that would be awesome but maybe a pipe dream.

[neilparf]

Do you have the before and after dyno plots.. That'll give a good idea as to how the engine acts with the 'limiter' and without..

[neilparf]

Audi always over engineer parts and are usually over cautious, that's why we can run a charger on standard internals and so far no one has blown one up because of it ( that I'm aware).

Great figures Neil that's a great increase, is that you done now or you doing manifold and seeking more power? I'm looking to aim for 450 that would be awesome but maybe a pipe dream.

+ 1 on the over engineering. My cousin is an automotive engineer - Aerospace background and after working the german manufactures, Mercedes, Audi, BMW and a stint for Toyota, he said the degree of over engineering certainly in engines is very evident in the mani German manufacturers.

Rick - figures and power - yes, I'm very happy with those. Considering the work and the exhaust I think the hike is a good one. I think, considering the figures, it's going in Saturday for the rear door/deer slam repair and some elected front bumper and bonnet paint and a final detail, this bills have stacked up nicely! Oh, and the RNSE upgrade :/. I think beyond this and trying to achieve 450 is a long shot possibly, but at 433 is not far off for the minute, I'd just going to get it back and enjoy for a while...

[neilparf]

Just collected my 4 from Doug at MRC - 2 hour drive back to drop it off for body work repair.

Wow - the drive is a different ball game again. The most noticeable thing is the Torque amongst other things. It just pulls and pulls so much better. The throttle response naturally is very good - very much improved. Clearly the map on Sport really comes into it's own. To say I can notice a difference in line with the figures is an understatement.

M40 and M25 were pretty busy and slow moving so had little opportunity to really get to grips with the power and see the true extent of the map, but in the 2 hours I had, it was truly amazing the difference the work has made...

[Gavla]

+1 Yep MRC know their stuff and those mods really do transform the car...you'll enjoy it now