Dyno Numbers, FWHP/RWHP/RHHP

[DARETT]

Sounds about right but its so hard to compare especially when you are talking different dynos in different parts of the world, maybe im miles off, i dont know, pity your car had problems today, would have been nice to see how the two dynapack dynos compared.

 

Yeah tell me about it. Would have been a perfect comparison but should be back there within a couple of weeks

 

I was initially sceptical about results at dans place but after seeing his extraction system I'm not surprised so many cars make alot of power at his dyno. I've been to alot of dyno's and apart from Abbeys there's not mch to come close to his for great conditions.

 

Jurgen, the dyno you used will always read below a dynojet. The way the cars are strapped makes a big difference...

 

You really need to see the difference first hand to realise.

[hodge]

am pretty sure they are and 1100 or 780 , it is no slouch.. i mean hodge is still on stock pistons a real 900 plus on stock pistons.(normally wont last 5 mins).

 

It's the rod bolts that are an issue over 800hp, there have been replaced with ARPs. There's nothing to say stock rods and pistons won't make 1000hp and last a long time. But I'm sure going to find out.

[JamieP]

I know what you mean about the strapping, ive seen it make a big difference myself at srr, is that strapping any different than people running on a dynojet have to deal with? ive never been on a dynojet.

 

I need to try and get over to bigcc's dynojet before i put the car away for the winter.

[Jurgen-Jm-Imports]

It's the rod bolts that are an issue over 800hp, there have been replaced with ARPs. There's nothing to say stock rods and pistons won't make 1000hp and last a long time. But I'm sure going to find out.

so far so good lol, dont forget to mention in the shoot tomorrow who sold you the main parts for your car lol

[DARETT]

The dynojet has the tyre sitting on top of the actual roller, so unlike the dynamics where the tyre has to climb the roller, the strapping has no effect.

When the straps are way too tight the car cannot climb the roller too High and it reads pretty low...

[Jurgen-Jm-Imports]

Jurgen, the dyno you used will always read below a dynojet. The way the cars are strapped makes a big difference...

rm

You really need to see the difference first hand to realise.

well mr Junichi from JUN said i believe your car makes more power than you said lol. (this is when we were discussing why my liners broke at 1000).

[Jurgen-Jm-Imports]

The dynojet has the tyre sitting on top of the actual roller, so unlike the dynamics where the tyre has to climb the roller, the strapping has no effect.

When the straps are way too tight the car cannot climb the roller too High and it reads pretty low...

 

is this what you mean skip to 1.40

 

[JamieP]

The dynojet has the tyre sitting on top of the actual roller, so unlike the dynamics where the tyre has to climb the roller, the strapping has no effect.

When the straps are way too tight the car cannot climb the roller too High and it reads pretty low...

 

Yeah i see what you mean about it sitting on top, the straps are not holding the car down on the dynojet, just stopping the car moving forwards or backwards.

 

Just for the record I'm not trying to disrepute anyones results with this thread, I'm doing myself just as much damage as anyone else just thought it would be an interesting topic.

[DARETT]

well mr Junichi from JUN said i believe your car makes more power than you said lol. (this is when we were discussing why my liners broke at 1000).

 

Lol he's probably right!

[DARETT]

is this what you mean skip to 1.40

 

 

Yup exactly

 

The dynojet has the tyre sitting on the roller itself. Because of the straps he car is hardly climbing at all there.

 

Also the dyno you used hasnt go the best extraction setup. All they have is there is the front fan and the rear door open.

 

For a car with your power a designated dyno cell would probably work alot better

[DARETT]

Yeah i see what you mean about it sitting on top, the straps are not holding the car down on the dynojet, just stopping the car moving forwards or backwards.

 

Just for the record I'm not trying to disrepute anyones results with this thread, I'm doing myself just as much damage as anyone else just thought it would be an interesting topic.

 

Yup that's why I think its a better indicator of power over the dynamics. The design is much better suited to high powered cars.

 

KDW's car was a great comparison though, if only the dynapack he used had the other software it would probably have matched the rwhp from the dynojet pretty much .

[CanisLupus]

The Maha Dynos here measure the Drivetrain losses after the pull when coasting down. Losses here in Germany are not approximated by percentage. Why should the drivetrain loss rise with power? The drivetrain stays the same to a certain point.

Rule of thumb here ist FWD 20-40hp loss, RWD 50-80hp and AWD 80-120 hp(Audi Quattros for example loose somewhere around 110hp)

[JamieP]

The Maha Dynos here measure the Drivetrain losses after the pull when coasting down. Losses here in Germany are not approximated by percentage. Why should the drivetrain loss rise with power? The drivetrain stays the same to a certain point.

Rule of thumb here ist FWD 20-40hp loss, RWD 50-80hp and AWD 80-120 hp(Audi Quattros for example loose somewhere around 110hp)

 

If them numbers are correct an audi TT (quattro) 180bhp would only have 70bhp at the wheels?

[CanisLupus]

That number was for an R8 as far as i remember with a far stronger drivtrain.

Numbers i remember ad hoc are 26bhp for my volvo(FWD) and around 86hp on an evo8 with around 400bhp. Losses depend on the mass of parts between the flywheel and the rubber. So 20" wheels with chrome rims obviously produce more loss than OZ Ultraleggeras in 17". The same goes with driveshafts, gearboxes etc. Stronger built and more parts result in more loss. Sadly i didn't have a run yet on a Maha with my Supra yet when i get to do one i'll post the complete result with measured loss.

 

EDIT Found this Diagramm of an Audi TTS http://static.pagenstecher.de/uploads/9/95/95d/95dd/PICT00026.JPG

Schleppleistung is the drivetrain loss

Motorleistung is engine HP

Radleistung is hp at the wheels

 

So with my assumption of 112hp i'm not that far away

Edited October 11, 2011 by CanisLupus (see edit history)

[Lee P]

Maha's unfortunatly are not very good for this. They do work the losses out on rundown which is not accurate at all. This is also effected by how tight the car is strapped down. When my car was 650hp the maha showed it as 150hp transmission losses.

[CanisLupus]

Could well be lee. but the strapping is a vital point for all dyno runs.

I know that the mahas are used for legal concerns when customers claim on the factories if they car don't make the promised power. So i assume that they are fairly exact when used right.

Even if not i still don't see why you would calculate a drivetrain loss by a percentage? If i take my TT and just BPU it without changing anything els the loss still remains the same but if i assume let's say 15% then with 330hp i'd have 49hp loss while at 430hp i'd have 64hp why would that be the case if the drivetrain components remain the same?

[j_jza80]

If them numbers are correct an audi TT (quattro) 180bhp would only have 70bhp at the wheels?

 

Exactly. Transmissions use a percentage of the power, not a fixed amount. What about the 4wd Subaru Justy? Has that got minus 50hp?! (it might as well do )

[CanisLupus]

As said loss differs with strength of the components used. Lower power smaller drivetrain components. And it's like with all rules of thumb in some cases they aren't that exact

Still can't see the loss as a percentage maybe i'm missing something.

[j_jza80]

As said loss differs with strength of the components used. Lower power smaller drivetrain components. And it's like with all rules of thumb in some cases they aren't that exact

Still can't see the loss as a percentage maybe i'm missing something.

 

Edit, I'm not forming thoughts properly, I'm off to bed

Edited October 11, 2011 by j_jza80 (see edit history)

[Wez]

I personally have always read RHHP the same as FWHP, never bothered adding 15%

 

Dynojets give a RWHP and calculated FWHP based on variables/inputs, these can be fiddled to over correct and bump the figure but whats the point

 

EDIT: in fact a long time ago on here RHHP was often compared directly to calculated FWHP

[RZ95]

Just checked and the beams racing car made 1476 on the engine dyno.

 

It reads around 1200 at abbey on the dynapack

 

Also KDW made 1500whp on a dynojet and would have matched it on the dynapack had the dyno been able to measure that power.

 

Are you saying that the Dyno only needs a software update to meassure 1500 whp? If that's the case I will contact the owner and make it happen. I thought you had to get the much more expensive Dynapack 8000 in order to meassure more? The Dyno owner doesn't know about this update for sure, so that's a great news if it's correct.

[RZ95]

I'll be the first to say that rhhp from a dynapack for sure is way higher than the fwhp meassured on any dyno. I have a German friend with 998 WHP from a Dynojet, and my car is substantially faster on my pump fuel map (1100 rhhp Dynapack).

 

I also know several Danish Supras in the region of 950-10xx fwhp, and they are no comparison.

 

Also, the other day I did 100-150 mph in 3.29 sec. on pump fuel. That puts me in 5th place on the 6spdonline list:

 

100-150 times:

 

2.77 - HoustonT, UGR TTG, 1550 rwhp

2.92 - UGR Nera TT Gallardo / 1550 rwhp

3.10 - AMS Alpha-12 GT-R, 1309 whp

3.24 - Divexxtreme, Switzer R1KX GT-R, 1248 whp

3.71 - Switzer R1K GT-R, 1030 whp

3.81 - 1swtride / C6 Z06 / built 427, YSI blower, 1080rwhp, auto

3.82 - joetwint, Evoms 996TT, 1,000 whp

3.90 - KPG, EVOMS 996TT E85, 900whp

4.41 - Corvette Z06 TT by AVK Servis

4.43 - jbsteven, Ford GT TT/SC

4.48 - Divexxtreme, Protomotive 996TT, 900 whp

4.68 - TwinTurboM3, E46 M3 TT

5.55 - 997TT with A30s

5.89 - Mbailey, 996TT

..Etc..

 

 

And yes my data's are dead on. V160 gearing, rear end gearing, Tire profile (calc here: http://www.hjulspin.dk/regnemaskine.htm ), and then compared to RPM and time in the Motec logfile. Should be more precise than any GPS box. Slope was less than 1% (from Google Earth).

 

As you can see that puts me in between Switzer R1KX GT-R 1249 whp, and Switzer R1K GT-R 1030 whp. That wouldn't be possible with 1100 crank hp.

[Ryan.G]

Are you saying that the Dyno only needs a software update to meassure 1500 whp? If that's the case I will contact the owner and make it happen. I thought you had to get the much more expensive Dynapack 8000 in order to meassure more? The Dyno owner doesn't know about this update for sure, so that's a great news if it's correct.

 

Unfortunatly it wont help you Kim. All the upgrade does is allow the axle speed on the dyno to go about 10mph more and the dyno we used had it.

 

What that means is in 5th gear on a 6sp setup on the dynapack you can now rev to 7990rpm instead of the dynapack standard 7790 so where some supras in the uk were making peak horsepower higher in the rev range basically we had to run them in 4th gear so that we could rev the engine to 8590.. But then the axle torque is easily exceeded on a 1000hp+cars. So we ran had to run them in 5th were it would only allow us to measure to 7790rpm, but now 7990.

 

Your car in 5th gear maxed out the dynapack axle torque where as none of the other 1000hp cars in uk make anywhere near as much midrange torque that gets it near the 4000nm axle torque in 5th gear. The beauty of your 3.4 and twin divided (special) turbo

[GlennK]

Ok. So I did have a few pulls on Abbey's Dynapack HUB Torque power setup - for diagnostic purposes - and got some results that were pretty close to SRR's results. But - and Mark G won't thank me here - he used the wrong final drive value of 4.181 (as he calibrated this from the analog rev dial not the Syvecs! And I've been discussing this with him and he's offered to do another set of runs). Hence the reason I've not posted the results graphs. However, when I use the accepted TT Auto value of 3.77 then I get the following results. Remember that this actually measures the transmitted hub torque from the engine through the torque converter, autobox and drivetrain...

 

At 1.2bar:

Hub Torque total = 1694 = rhtq of 1694/3.77= 449ftlbs (DIN)

Then the calculated rwhp is = 461hp (reduced by the drivetrain losses)**

And the calculated fwhp (assuming 20% auto losses) = 553hp**

 

At 1.9bar:

Hub Torque total = 1990 = rhtq of 1990/3.77= 528ftlbs (DIN)

Then the calculated rwhp is = 541hp (reduced by the drivetrain losses)**

And the calculated fwhp (assuming 20% auto losses) = 649hp**

 

**NB: these calculations used the Syvecs rpm logs which measured around 500rpm lower than the Dynapack). In comparison, the SRR results I recently got running 1.9bar are:

rwhp = 524hp

fwhp = 618hp

 

So these are comparable values given that I used 20% loss factor for autoboxes. If I use 18% then the hub dyno comes closer still to the SRR value which itself calculates the values.

 

Bottom line: I'd love to shout about having a '650bhp' engine but actually the purpose was to identify where the power restrictions are; (i) exhaust system (ii) inlet manifold and TB and last but not least (iii) the turbo is maxed out....

 

Hope this helps.

[JamieP]

Interesting, maybe these dynapack numbers are about right then going on Kims and Glenn's results.