Just curious...or can you use a regular dyno and put the other 2 wheels in the air or something?

 

Nope. Need AWD dyno.

 

Okay i got an even tougher question.

Does it matter which side goes on which side on an AWD dyno?

ie. front two wheels go in first or rear two wheels?

 

depends on which way the dyno turns. AWD dynos are pretty rare, I know theres one in DC at a place called Altered Atmospheres. I'm sure there are others

 

go to i-club.com and ask there. they are pretty rare, because I think they cost as much as $80,000.

 

Not on every car!

Don´t know about the Subarus, but my friends Audi S3 was on a conventional dyno. The dyno-guy turned of the AWD with some electronic box on the Audi, only the front wheels where spining!


[Modified by austrian ITR, 2:18 PM 9/26/2001]


[Modified by austrian ITR, 2:19 PM 9/26/2001]

 

Unfortunately you can not do that on the WRX.

 

i may be speakin out of my ***, but how could dyno'ing an AWD car in 2wd mode be an accurate representation of the power the car actually puts to the ground? just seems odd.

 

The Audi S3 has a divide up of 85% front and 15% rear wheel drive. The dyno software take this in mind and does a hp correction. O fcourse it is´n t as accurate like on a real AWD dyno, but a dyno is a tool, you don´t want to know only your hp. You need a dyno as a tool to measure the improvements of your tuning.

 

In the last issue of Sport Compact Car I saw - the one with all the WRXs on the cover - they reviewed a "Brake dyno" system that can be used on 2wd or 4wd cars. They dynoed all the tuner WRXs they reviewed using this system, and it is apparently pretty accurate. They dynoed one car on a dynojet, and then the same car with the new system, and the difference was like +/-2hp.

I don't remember the details of the brake dyno system, but essentially, they jack the car up on all 4 corners. They take off the wheels. They attach something on each wheel hub. And then the system can somehow calculate the HP at the wheels... There is a pretty detailed write up of the system in the SCC Issue...

The stock WRX got like 165HP at the wheels if I remeber correctly... Which is not bad considering 4wd drivetrain losses... Some of the tuner WRXs were hitting well over 200hp at the wheels.

Andrew

 

Thats a great point, i should have thought of that

 

I think UPRD had one but went "under"

Ryan

 

not sure in the wrx, but i think in the 99-01 Impreza 2.5RS Auto, you can pull a fuse, and disable awd, and just go to fwd. impressive.

 

The stock WRX dynoed with 147 WHP and 141 LBS./TRQ.

 

Actually you're speaking of the Dynapack. It is an AWD dyno and very good setup. Takes the wheel and tire inertia out of the equation and is much more accurate than a conventional dynojet. Turbo XS just bought one also. They are very popular in Japan but the company that makes them is from New Zealand.

 

hehehe Cool, I drive past there on my way to work everyday

Sam

 

You can "unhook" the rear driveshaft thus making it FWD. Then it would work, but you'll need to factor in another 15% loss for the rear wheels. It should be fairly simple though.

 

btw, theres a place here which is working on a system to dyno WRXs on a 2WD dyno, it involves unbolting the rear drive shaft and bolting something to the drive shaft flange therefore making it front wheel drive only. Thats all I know but I presume they've taken into account the center LSD and that the system won't damage it.

Also with Skylines you can pull the ATTESA fuse and run it in two wheel drive mode. At the same time as we dynoed our car a Skyline GTS-4 (RB20DET) was there he managed 166whp vs our 175whp. Go Honda

 

You can do the same in skylines, (not that there are many of those around here) just take the fuse out and you got FR.

 

Yeah Altered Atmosphere in Gaithersburg, MD has an AWD dyno, but theyre cockasses.