what is the actual % loss from crank to wheel?

[speedtrapped]

So post dyno, just curious I was told originally that from crank to awd lose 20%, but add tip and likely lose 25%, anyone have definitive answer on this?

[skribe]

Never been able to find a definitive answer on this either. Anyone? Conventional wisdom is like you said, tiptronic AWD Audi = 25%.

Makes me want to disconnect my front drive axles sometimes. :jlol:

[V8weight]

Never been able to find a definitive answer on this either. Anyone? Conventional wisdom is like you said, tiptronic AWD Audi = 25%.

Makes me want to disconnect my front drive axles sometimes. :jlol:
Ya, I usually figure 25% loss. It varies by dyno though.

[JSRS6]

That's the % I have entered in my dynolicious app for iPhone ;-).

[ben916]

I haven't found this answer so I will ask it now:

Aside from the fatherland, has ANYONE performed a Engine dyno (engine/turbo/ecu/intercooler/etc) on the RS6 motor?

[ntrcptr]

25% seems way too high.. perhaps on a mustang dyno; i'd say 15-18% -using the dynapack dynomometer

[vr430]

Everyone is going to be different. Back in my EVO days, 5 identical stock EVO's running on a dyno on the same day produced results anywhere from 190 to 220HP. You would have to peg each car separately - on a dyno and on a stand to get true numbers. However, we used 25% loss as a rule of thumb. But then why would anyone care about crank HP? It's what at the wheels that matters.

[JSRS6]

Yes, but our tc's are built to handle I think 550 coming off the crank, so we want to be safe in that respect to prolong the life of the tc.

[Hy Octane]

25% is about right considering its AWD and an automatic..

[ben916]

... But then why would anyone care about crank HP? It's what at the wheels that matters.

TRUE and I agree on what is at the wheels... but there was some controversy early on in the life of some Audi's (not necessarily the RS6) of the factory fudging the numbers of 340hp/400hp/450hp/etc whether or not there was a true HP rating or if it was pure optimal conditions in which a said model line/engine actually put down the HP numbers advertised.

Case in point is the RS5 - advertised with 450HP, IIRC...

[vr430]

Yes, but our tc's are built to handle I think 550 coming off the crank, so we want to be safe in that respect to prolong the life of the tc.

Wow! Audi does not leave much room for error! Just use 25% and you'll be on the safe side of things.

Curious that MTM's most expensive upgrade brings HP to 568 without touching TC.

[vr430]

Aside from the fatherland, has ANYONE performed a Engine dyno (engine/turbo/ecu/intercooler/etc) on the RS6 motor?

Yeah, it would be interesting to see if someone had indeed tested RS6 motor on the bench.


...controversy early on in the life of some Audi's (not necessarily the RS6) of the factory fudging the numbers of 340hp/400hp/450hp...

Does Audi report numbers that are more or less then observed? Funny how in Japan, at least a while back, no new car could be sold with more than reported 300hp. So even the mighty GT-R spec was listed at 299HP. Yeah, right!

[ttboost]

I seem to recall a stock RS6 making between 300-320 awhp on a Mustang dyno. If the 450hp is correct or even close, that's a 29% loss....not really unheard of for these german slush boxes... I've seen 996 turbo tips dyno even worse. I think 25% is conservative. Use real world numbers instead, not dyno numbers...you'll be less disappointed...

[speedtrapped]

Ben funny you should say that about fudged #'s my audi tech tells me on my S8 that Audi purposely underestimates HP for emissions purposes in US....not sure if true, he thinks my S8 puts out alot more then 450hp(stock)

[marklar182]

Yeah, it would be interesting to see if someone had indeed tested RS6 motor on the bench.

I believe I read that the BCY motor made way more power on the engine dyno. Limited cooling and the cramped space under the hood required major detuning.

[peiserg]

mine made 340 awhp with about 7000 miles on the clock with 91 octane temps 100ish

[ttboost]

mine made 340 awhp with about 7000 miles on the clock with 91 octane temps 100ish

Optimistic dyno?... and that would be 25%...

[sallyh]

Hi all

so, has anyone actually put their beloved V8 or V10 on the dyno? I had an offer a while back to put my V10 on the dyno for the development of a tune for the RS4 and ended up saying no as the risks were too high for my car. But, that said, I'd absolutely love to verify the 572 bhp (rounded off to 580) for the V10. In a real world context it feels like it is, like it accelerates very fast for its weight, but has anyone actually tested it? "The World's most Powerful Station Wagon"? is it true?

[speedtrapped]

I am going back to dyno(mustang dyno) in 2 weeks, and I am going to run stock , then flash back the new Eurocharged tune, hopefully no tech diff like last time(dyno shop was lame, equip problems) and I will post the results

[4everRS]

Late to the party here. I calculated mine to be a 24% loss on a DynJet. This assumes I get 450 at the crank though. I could see 15 to 18% with an efficient 2 wheel drive set-up.

Stephen, I'll be looking forward to the new Dyno results. Where did they attach the rpm pick-up sensor the first time?

[4everRS]

OK so, did some number punching for the fun of it.

If dyno shows around 400 awhp, at a 24% loss, this is 530hp at the crank. Now, add meth kit, and assume 15% gain? (seems many get this?) And ta-da, ... 600+ crank hp. Now you have an RS600 for about a Grand.

Next step - call Tozo when the slushbox explodes. So I guess it might cost more than a grand.

[speedtrapped]

Late to the party here. I calculated mine to be a 24% loss on a DynJet. This assumes I get 450 at the crank though. I could see 15 to 18% with an efficient 2 wheel drive set-up.

Stephen, I'll be looking forward to the new Dyno results. Where did they attach the rpm pick-up sensor the first time?

cylinder 1# coil wire(lifted the insulation to expose wires

[4everRS]

Hmm. They should be getting a good reading there. The reason I ask is because when Pat and I did ours the first time, they had a tough time getting a good reading at first, but had to use a different sensor I think.
cylinder 1# coil wire(lifted the insulation to expose wires

[speedtrapped]

Crank sensor?

[V8weight]

Crank sensor?
No, they still used the number 1 coil pack, they just had to switch to a different lead to get a proper reading ( a better pickup clamp).

[speedtrapped]

Ty pat, I have to make sure with the new dyno hop they have read audi's in past. I was told by a guy there they have, but I want to make sure with the owner, he was at SEMA all week.

[V8weight]

Ty pat, I have to make sure with the new dyno hop they have read audi's in past. I was told by a guy there they have, but I want to make sure with the owner, he was at SEMA all week.
Ya, you're better off on a Mustang anyhow as it's a "mechanically linked" dyno as opposed to the DynoJet, where the wheels are allowed to spin independently. The DynoJet can really wreak havoc on an Audi ESP system.

[sallyh]

Hi

Well, kind of confirms my saying "no" to dynoing my V10 - and doesn't it wreck your tyres as well - anyway, would love to hear from speedtrapped if he does it. I guess Audi must dyno the car to get the reading for the advertising brochures? Or do they just add on a bit (thinking it's got turbos) to beat the M5? But I would most like to know if Audi held back on the hp to adhere to the admissions standards - so therefore tuning would make the car what it should be rather than pushing it too much so as to damage it mechanically?

[ttboost]

A dyno doesn't do any more to your car than driving down the road does, IMO. I have tons of dyno time on tons of cars, RWD AND AWD. Most manufacturers dyno an engine after they design and build it. THAT becomes the HP rating for every car they ever build. Obviously there will be variances, but not 50hp variances...

[speedtrapped]

I did have ESP off during the dynojet dyno

[V8weight]

What I meant was that on the DynoJet, the front and rear rollers are not linked, they spin independently of each other. On our old 50/50 Torsen awd, this should be fine (I have plenty of runs on a DynoJet with no issues), but in theory, this isn't good for the car. Now, the newer Audi's using the Haldex system absolutely cannot run on a DynoJet. If you're even able to get it to allow throttle input, you will surely damage your center diff. That is why I'm stating you're probably safest to just run on a Mustang mechanically linked dyno. The front and rear rollers are linked together, and run the same speed to simulate actual road surfaces.

[mi021le]

all my dyno numbers over the years all point to 25%

[speedtrapped]

What I meant was that on the DynoJet, the front and rear rollers are not linked, they spin independently of each other. On our old 50/50 Torsen awd, this should be fine (I have plenty of runs on a DynoJet with no issues), but in theory, this isn't good for the car. Now, the newer Audi's using the Haldex system absolutely cannot run on a DynoJet. If you're even able to get it to allow throttle input, you will surely damage your center diff. That is why I'm stating you're probably safest to just run on a Mustang mechanically linked dyno. The front and rear rollers are linked together, and run the same speed to simulate actual road surfaces.....ok, good to know Pat, I plan on dyno-ing the S8 after flash, it's an 07'

[hahnmgh63]

Hey V8, I think the only Audi's using the Haldex are the tt's, so they are not really Quattro's per se. That is because the Quattro type of design can't be done very easily or compact with a transverse engine like the tt. So both the Mk I & MK II tt's use the swedish Haldex design but the rest of the Audi's use Quattro. Over the years there has been different generation of Quattro as far as what type of differential, whether open, Torson, Limited slip, electronic lock, electronic slip, viscous.

[sallyh]

Ok

So, simple reply, has anyone actually dynoed a V8 or V10 RS6 so as to confirm the loss from crank to wheel? Speculation is all good and well but there is nothing like real results. I'm not going to do it to my V10 because apparently it is too heavy for most dynos (over 2 tonnes), and it darn well cost too much (thanks government taxes, hope you are building hospitals), and the tyres cost too much to imperil other than driving, but I would truly love to know the results if someone is bold enough to do it. All power to them!

[Joker]

The question you need to be asking is whether the RS6Mk1 ever truly made 450hp at the crank, the engine spec would suggest it to be perfectly possible but without an independent verification you are only accepting those official figures as gospel and basing the trans/drivetrain loss on the results you get. Now on the subject of transmission/drivetrain loss, I am sure I read that the B8 S4 has dynoed approx 300-315hp at the wheel, didn't recall if this was manual or not but it true then are we to believe that the v6TFSI in the S4 is a 400-420hp+ at the crank machine? :hahahehe:

[JSRS6]

I think it was rounded up from around 444hp/413tq to 450hp/415tq.

[hahnmgh63]

sallyh, do a search in the forums or you must not read this too often as there have been a lot of V8 dyno tests posted in these pages with full graphs and comparisons. What everyone is wondering is what the starting HP of the real RS6 engine is...Is it really what Audi claims as their's is a crank horsepower claim, not at the wheels.

[sallyh]

Hi hahnmgh63

Yeah, I'd love to know the crank to wheels comparison as well. And also the wheels to crank comparison. Not to fussed either way, or either V8 or V10. I'm lucky enough to have owned the V8 RS6 Avant (missed for its sound, not for its DRC issues), and to currently own the V10 RS6 Avant (oh ah, with ceramic brakes). Very keen on driving it around the track and generally, but too scared to dyno it in case it all goes wrong. Hope that has clarified things.