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Location:
Melbourne, VIC
Registered:
December 2003
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AWD Dyno VS. RWD Dyno
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Tue, 16 December 2003 04:53
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My friend has had his car dyno'ed at 116kw on an AWD dyno.
He wants to know about conversion to power at the rear wheels.
Is it a strict divide by 2 formula, or are there other factors involved?
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Location:
ballarat
Registered:
April 2003
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Re: AWD Dyno VS. RWD Dyno
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Tue, 16 December 2003 04:57
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i'm not to informed about this sort of thing, and i'm sure someone will give a more accurate reponce, but here goes:
don't the awd gearboxes have differing distrubution to the front and rear? i have heard that the awd skylines are something like 60% rear and 40% front. so to determine if you can divide by 2 depends on the car
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Location:
Colac, Victoria
Registered:
May 2002
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Re: AWD Dyno VS. RWD Dyno
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Tue, 16 December 2003 11:06
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what type of car was it first ?
On an AWD dyno my gt4 pulled 113kw at all wheels with a 50:50 split
So if its lesser than a gt4 - id say its only recording the rear wheel figure only ..
Im pretty sure dyno dynamics ones have different load modes for FWD AWD and RWD ..
your mates car wouldnt be spinning the front rollers, just the back ones
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Location:
Melbourne, VIC
Registered:
December 2003
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Re: AWD Dyno VS. RWD Dyno
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Tue, 16 December 2003 20:55
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It's an Audi TT, w/ K4 turbo and motec management system.
430 Nm torque out of a 1.8 litre engine!!
I LOOOOVE it..
He just wants to know the exact power figure at the rear wheels.
Maybe it's just double 116kw because the front rollers aren't spinning at all.. Would make it 232rwkw which is about right.
It's a BRUTE car, that one..
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I supported Toymods
Location:
Northern Beaches
Registered:
May 2002
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Re: AWD Dyno VS. RWD Dyno
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Tue, 16 December 2003 21:16
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umm I think you will find that just because its an 4wd dyno doesn't mean it measuring like that, id say it has setting to make it just meansure rear wheels and it would just be like a normal rwd dyno?
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Registered:
June 2002
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Re: AWD Dyno VS. RWD Dyno
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Tue, 16 December 2003 22:24
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I presume this Audi TT is 4wd??
If so, is there some way of getting it to run in Rwd only??
If there isn't I would be very concerned about the state to the centre diff. If it is a clutch type LSD centre this would add load to the engine that the dyno rollers aren't seeing/measuring, not to mention completely F&*king the diff and reducing the measured power output.
I imagine in this scenario the car would be really hard to keep on the rollers as the front wheels will be trying to drive off and the front rollers must have been locked.
I don't know if a torsen (mechanical) LSD would even let the rears spin with out the fronts turning also, and an open centre would spins the rears without the fronts turning, but it would be very hard on the spider gears.
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Location:
adelaide
Registered:
April 2003
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Re: AWD Dyno VS. RWD Dyno
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Tue, 16 December 2003 23:51
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you would get a better reading off one of those dynos where you actually take the wheels off and bolt the sensors up to the hubs, i think PAC in sydney use this type (their cars broke a few 'roller' dynos apparently)
does your mate really need to know the exact amount of power its making? a dyno is a tuning tool first, a measuring device last... its not there to determine how much power you are making
ab
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Location:
Melbourne, VIC
Registered:
December 2003
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Re: AWD Dyno VS. RWD Dyno
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Tue, 16 December 2003 23:56
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Haha, yeah, I know.. But he's keen to know exact figures on his new toy 
It's a RWD.
Thanks anyway, guys.
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Toymods Vice President
Location:
Sydney
Registered:
May 2002
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Re: AWD Dyno VS. RWD Dyno
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Wed, 17 December 2003 01:11
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If the car is a rear wheel drive and it was dynoed correctly even if the dyno is a AWD dyno then the result is how much power it was putting down to the rear wheels. Four wheel drive dyno's are simply 2 2WD dyno's put next to each other, when running a 2WD car it is exactly the same as just having a 2WD dyno.
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Location:
Colac, Victoria
Registered:
May 2002
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Re: AWD Dyno VS. RWD Dyno
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Wed, 17 December 2003 01:50
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thats what i thought Josh ..
116kw at the rears..
Hmm - i looked at the figures for a stock early TT - and its figures are similar - if not less than the GT4 if i remember rightly..
id assume a worked one would put out a lot more power than a Gt4 like mine though, especially if its only driving 2 instead of 4 wheels
Ok - here are the current 2004 Audi TT power figures for stock 4wd and Front wheel drive
All wheel drive version - 225hp ( flywheel ) 207 ft lb's torque .
Front wheel drive version - 180 Hp (flywheel ) 173 ft lbs torque
Figures quoted off edmunds )
GT4 like mine - in stock form ( 1990 St185 )
222hp ( flywheel ) 202 Lb ft torque..
Seeing mine puts out more power in its modified state than a current AWD turbo Audi TT - im guessing one of 2 things ..
The dyno isnt reading correctly ( ie operator didnt set it up right ) Or your mates TT isnt as powerful as he thinks ( though that torque figure you gave would disagree ..
Somethings fishy here - im not sainting your friends pulling your leg - but the figures dont add up for what weve been shown - ahgainst a car with similar power outputs as example ..
Are you sure its not All wheel drive ? then 116 odd KW would sound a little more correct ?
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Location:
Melbourne, VIC
Registered:
December 2003
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Re: AWD Dyno VS. RWD Dyno
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Wed, 17 December 2003 02:30
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I'm positive his figures are accurate, but his terminology may be wrong in terms of what kind of dyno the testing was done on.
Regardless of the exact power output, the thing is a dream. Comfort, style and POWER to burn.
Plus for some reason even the Motec tuner doesn't understand, the boost kicks in SUPER quick. It's making 14 psi at 2500rpm!!
Madness..
He's been advised that the setup is perfect, as you could get more top end power with a t66 but the engine strength might start to be an issue.
What a beast. My Cressy will go as hard, though, once I've finished with it!
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: AWD Dyno VS. RWD Dyno
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Wed, 17 December 2003 02:43
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| Stephen2 wrote on Wed, 17 December 2003 07:55 |
It's an Audi TT, w/ K4 turbo and motec management system.
430 Nm torque out of a 1.8 litre engine!!
I LOOOOVE it..
He just wants to know the exact power figure at the rear wheels.
Maybe it's just double 116kw because the front rollers aren't spinning at all.. Would make it 232rwkw which is about right.
It's a BRUTE car, that one..
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1.8L = 430Nm = about 20Psi?? (1.4bar)?? is that close to what he's running?
what rpm is the peak torque and power at?? some simple maths will tell you what you should be after....
fwiw, i know of a few audis (5000 quattros??) that have torque between 400 and 500Nm.... nasty little suckers they are!! (oh, and MS'd  )
Cya, Stewart
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Location:
Melbourne, VIC
Registered:
December 2003
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Re: AWD Dyno VS. RWD Dyno
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Wed, 17 December 2003 02:47
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It's running a max 1.8bar, after some re-tuning from the Motec specialist.
The original mechanic just was NOT up to the job. Called in the big guys, and gained an extra 10% torque/power output, while sorting out idle problems and smoothness.
I'd love to be in that thing accelerating all the way to top speed...
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Registered:
November 2004
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