Running a Quattro on a 2wd dyno. Is it possible?
08-16-2006, 08:38 AM
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Running a Quattro on a 2wd dyno. Is it possible?
I do not have an AWD dyno within 100 miles of my home, but I have a shop with a Very Nice SuperWin 2wd dyno.
Can the rear drive shaft be disconnected and just the front wheels run on a 225 Quattro for Dyno purposes?
I've seen the Mitsu guys do this at the shop.
Can the rear drive shaft be disconnected and just the front wheels run on a 225 Quattro for Dyno purposes?
I've seen the Mitsu guys do this at the shop.
08-16-2006, 08:51 AM
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Re: Running a Quattro on a 2wd dyno. Is it possible?
I used to own a Mitsu Eclipse GSX but the AWD system was much different than the TT. I haven't looked into the workings of the Haldex so others will have to chime in. The Mitsu's use a Viscous Coupling and a center differential inside the transmission to send power to the rear wheels. In order to dyno in 2WD, we had to removed the Viscous Coupling and put in "eliminator" stub shaft that would allow the center diff to free-wheel so that dynoing in 2WD could be done safely. Otherwise, you would fry a Viscous Coupling because it is trying to match the wheel speed of the rear wheels (still) with the front wheels (in motion).
I thought I heard somewhere that if you engage the parking brake just barely so that the light on the dash comes on, the Haldex will not function and power will only be transmitted to the front wheels. I do not know how safe this is or if it is even viable.
I thought I heard somewhere that if you engage the parking brake just barely so that the light on the dash comes on, the Haldex will not function and power will only be transmitted to the front wheels. I do not know how safe this is or if it is even viable.
08-16-2006, 08:57 AM
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Can be done, not recommended. You can derive your HP mathematically, based on acceleration.
You will need a very accurate weight for your car and very accurate acceleration times.
one HP is the ability to lift 33000 lbs one foot in one minute.
Extrapolate...
one HP is the ability to lift 33000 lbs one foot in one minute.
Extrapolate...
08-16-2006, 09:01 AM
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there have been numerous excel sheets to do this...
problem is you need acceleration and deceleration numbers (to determine drag) finding a long straight flat and well paved piece of road is hard (esp. in michigan)
08-16-2006, 09:10 AM
#6
Haldex themselves caution against it...>>
If you don't mind potentially trashing a $4k unit, pull the fuse and go for it. Read the link first though. You'd be OK disconnecting the shaft as no power would then be transmitted to the assembly.....<ul><li><a href="http://www.wak-tt.com/haldex/haldexfuse.htm">Read why..</a></li></ul>
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08-16-2006, 09:45 AM
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FWIW, APR dynos their cars with Haldex disabled.
Theory being that on the dyno the car isn't pushing any power to the rear wheels because there's no slip...
My car was dyno'd on an AWD dyno and a 2WD dyno, and the readings were very similar.
It can be done.
My car was dyno'd on an AWD dyno and a 2WD dyno, and the readings were very similar.
It can be done.