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Awkw Vs Rwkw Vs Flywheel/engine Kw

Aussie_Delivered_R32_GTR

By Aussie_Delivered_R32_GTR,
in New South Wales

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Duncan Grand Master

Duncan

Posted
Posted

exactly 206kw at the motor for sure :D

There is plenty of disagreement about whether 2wd vs 4wd makes much difference. I've never run them back to back 2wd/4wd but I have had the same car dynoed at different places with the same tune and found up to 20kw difference.

And flywheel to wheels loss also comes with some controversy. Some claim about 25% loss from flywheel to wheels, but personally I guess it is mostly a fixed amount, not a simple%...otherwise a 1000kw car would be loosing 250kw in the drivetrain :teehee:

I'd work on an estimate of 30-50kw loss, but flywheel kw really don't mean much....it's what you put to the ground that matters ;)

BTW....191awkw for a dead stock gtr sounds pretty right to me. Great result considering it's 20 years old.

Aussie_Delivered_R32_GTR Veteran

Aussie_Delivered_R32_GTR

Posted
  • Author
Posted

BTW Bob, is your car an ex-Kerry Packer car, or another one?

Another one ...... Mine was a 1 owner I bought late last year. Mark set it up for me so he can confirm exactly its credentials.

My mate looked at one of the Packer cars but unfortunately it didn't have the original motor so he passed.

He too bought a one owner from Manly although his is tricked up a bit. I think his pulls around 260 awkws.

Cheers,

Bob.

MBS206 Grand Master

MBS206

Posted
Posted

supposebly RWD and AWD readings in GTRs are the same because of how the ATESSA works

4th gear runs... dry dyno... no power would b going to the front wheels...

Except the Attessa detects the front wheels aren't spinning and sends power to the front wheels to make them spin...

SargeRX8 Grand Master

SargeRX8

Posted
Posted

There is no direct correlation between awkw and rwkw. You cant say that an evo, for example, making 200awkw will make 250rwkw and that 300rwkw = 250awkw. Flywheel power is not really useful for us, as said above, its what you lay on road. I had some guy at CRD(not a worker, some dead shit dynoing his twin turbo awd mitubishi something). He made 140awkw. My skyline made 225rwkw, he walks up to me and goes "my car is 4wd so as a 2wd it will make about 280. I think he thinks that he is losing 50% power on the front wheels turning...

RB26DETT from Nissan is quoted at 206kw. Ive read on wiki I think that Nissan may not be truthful with this figure though and that it might be more as they needed to list it as 206kw to be able to sell the car in Japan or something. I read something crazy like that somewhere, I'm not too sure. If you have advanced your timing a little and your engine is healthy, it should be making close to 206kw, maybe more, at the flywheel. Given the age of the engine and the quality of fuel here, it could vary.

simpletool Mentor

simpletool

Posted
Posted

The drivetrain loss would be a combo of both a fixed amount and percentage (or inverse log, or some such). Anyway I use 15% loss then add 10kw.

4WD is probably another 5% or so.

So (191awkw/0.85 + 10)/0.95 = ?

Aussie_Delivered_R32_GTR Veteran

Aussie_Delivered_R32_GTR

Posted
  • Author
Posted

The drivetrain loss would be a combo of both a fixed amount and percentage (or inverse log, or some such). Anyway I use 15% loss then add 10kw.

4WD is probably another 5% or so.

So (191awkw/0.85 + 10)/0.95 = ?

We all know that the 206kw was always BS so I'd say 247 is probably pretty close to the mark with boost restrictor removed and 2-3 degree additional advance......

Bob.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

EVO/STi are full time AWD, so it's affected much between all and rear wheels.

A GTR isn't as ATTESSA works differently, it also does not send as much to the front.

Most GTR's will have pretty close awkw & rwkw figures, often they can be the same. Variance either way generally minimal unless you have rebuilt transfer cases that are a bit tighter. In that instance it tends to soak a bit more as it locks up more.

GoldZilla Grand Master

GoldZilla

Posted
Posted

EVO/STi are full time AWD, so it's affected much between all and rear wheels.

A GTR isn't as ATTESSA works differently, it also does not send as much to the front.

I was gonna mention that too.

Regardless, it's hard to make an accurate correlation between power at the wheels compared to at the flywheel - there are too many variances to factor in: fluids in gearbox, diff and transfer cases; loss of efficiency in CV and uni joints; tyres (including compounds and pressures); etc.

Oh, and because I'm pedantic, ATTESA is spelt with two T's and one S.

ATTESA (acronym for Advanced Total Traction Engineering System for All-Terrain) is a four-wheel drive system used in some automobiles produced by the Japanese automaker Nissan, including some models under its luxury marque Infiniti.
Galois Veteran

Galois

Posted
Posted

This is so far the best of these threads I've read. Putting a percentage is bs, but ignoring the power output in the calculation is also pretty uninformed. There is no formula between flywheel and the rubber wheels, but you could get a rough number if you took the engine out, measured flywheel torque, converted to kw, put the engine back in and did a dyno run.

There are a lot of variables between cars though, and dyno's aren't the most accurate of devices.

GTR32G Proficient

GTR32G

Posted
Posted

I have run my GTR in awd and rwd quite a few time on a dyno same day just flick the switch in the cabin for one run after it's fully tuned. The power in KW goes up by 18 to 28KW pending the heat of the day and heat soak in the motor/turbos.

Aussie_Delivered_R32_GTR Veteran

Aussie_Delivered_R32_GTR

Posted
  • Author
Posted

I have run my GTR in awd and rwd quite a few time on a dyno same day just flick the switch in the cabin for one run after it's fully tuned. The power in KW goes up by 18 to 28KW pending the heat of the day and heat soak in the motor/turbos.

What total outputs are you achieving?

usmair Mentor

usmair

Posted
Posted

I have run my GTR in awd and rwd quite a few time on a dyno same day just flick the switch in the cabin for one run after it's fully tuned. The power in KW goes up by 18 to 28KW pending the heat of the day and heat soak in the motor/turbos.

interesting

kawasakirider Grand Master

kawasakirider

Posted
Posted

What I've always wanted to know is what are R34 and R33 GTR drivers talking about when they say their car has XXX RWKW? Surely they aren't taking the driveshaft out of the transfer case to get these readings, and to my knowledge only the 32's AWD can be disabled by pulling a fuse. Is there a way to disable AWD in a 33/34 GTR?

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