KryptoniK

I don't know where my dyno charts are right now, but I remember my exact awhp dyno numbers from the past. (not sure about torque)

Mods - Full Milltek, K&N Filter, Revo ECU

Maha Dyno - 325 awhp

DynoJet Dyno - 315 awhp

KryptoniK

Actually... On the DynoJet run I did (done last week) I made 315 awhp with the ECU set to stock. I made LESS power with the Revo tune on.. 308 awhp with Revo ON. GO FIGURE!

I have to call Revo and address this, I knew there wouldnt be much gain, maybe +5awhp... but to lose power? I'm going to want my money back.

ArthurPE

there will be a difference in losses between torque and HP...why?

HP is at 7800 and torque ~5500 or so, and losses are proportional to rpm...the faster it spins, the higher the losses...

so if it loses say 15% at 5500, I would expect the losses at 7500 to be ~7500/5500 x 14 ~ 20%

look at it this way:
rated crank HP at 7500 is 414, dyno wheel HP ~330, therefore loss ~ 20.3%
rated crank torque at 7500 ~ 5252/7500 x 414 ~ 290 lb-ft
dyno wheel torque at 7500 ~ 5252/7500 x 330 ~ 231 lb-ft
losses in torque at 7500 ~ (290 - 231)/290 x 100 ~ 20.3%...identical to the power losses
so losses are the same for torque and HP at the same rpm...
which is to be expected since the HP and T are linear and related by rpm
HP = T x rpm/5252 or T = 5252/rpm x HP

RS Maniac

Good point.

I also think that at 7,500 RPM the fans/blowers are insufficient to reproduce true real world air speeds, the ECU detects the lack of air and retards the timing, which will produce lower HP numbers than truthfully may be seen on the road if the cars were indeed driving at 7500RPM. So the loss may not be as bad, but a close to 20% loss on an AWD car is credible.

I've seen dyno runs where people added 2 leaf blowers on top of the regular fans, and those blowers were pointed directly to the intakes. The dyno runs with the blowers produced another 5-8 whp, which makes sense.

RS Maniac

You are the second guy I hear this from. I met an RS4 owner at Waterfest who claimed that after Milltek downpipes and Revo he lost power relative to stock (not just peak, but all across the RPM range)...

The people that have posted gains from Revo seem to indicate they are modest (5whp or so max). The dyno charts I've seen support that, I think the bigest diff is better tq increase and it comes earlier.

GotRS?

Did you drive with the tuner to set up the Revo?

GotRS?

Looked at my plot again, 330whp@7300 281ft/lbs@3300. Runs out of puff early, I see the comments about the loss of ram air, I hadn't looked closely at the rpm before.

GotRS?

I hadn't seen that article. Found my plot and it's 330hp / 281 torques. Peak power at 7300rpm though. No fans pointed at the intake, only at the radiator.

RS Maniac

Yeah, the article was pretty informative, as was the entire 12-months that AM had the Sprint Blue RS4 on loan. They did quite a few tests, winter included, even slapped a Milltek exhaust. I loved the RS4 back then, and I have to say their commentary and real world reviews totally swung me in the RS4 camp (as I was considering others as well). Heck, I even got Sprint and I too slapped a Milltek. LOL

scott61

Never got around to dyno my RS4 but did my R8 yesterday. I remembered this thread and the Automobile Magazine results and I got pretty much exactly the same numbers. Mustang Dyno supposedly reads low and I thought I would have done a bit better with my mods, Stasis Exhaust and EVO Filter kit. I'm sure the pouring rain and 100% humidity did not help. Shop had no R8 files to compare my runs to but said it was higher than the RS4's they have done. So I guess the mods did give me a little increase