Howdy, gang!

 

I'll just out and spill my question and wait for the mocking/answers:

 

Let's say you've got an old 2.2 impreza with the 4eat and you might want to do some dyno pulls with it... but the only dyno anywhere nearby is a 2wd unit...

 

Is it possible to get away with using the FWD fuse for a few dyno pulls or is that transmission homicide?

Let me further preface the idea with: I'm not trying to be Fast and Furious and I know the 2.2/4eat is an economical drivetrain at best... but I'm working on a video project that may evolve to the point of filming some before and after dyno pulls of the cars (the other car that's already naturally fwd).

 

I'm just asking... I'm not a complete moron, honest!

Edited June 5, 201213 yr by fishy
spelling repair

I've thought about doing this before, honestly, I see no reasons why not.

With the center clutches disengaged the driveshaft just freewheels. I've put it in FWD to test drifting in fwd cars with left foot braking... You better believe I had a lot of wheelspin. Kinda like running a dyno. And my AWD still works just fine and dandy. 249k miles and counting.

that is exactly what the fuse is for, when you need FWD to avoid damage to the drive train.

 

of course there is a really, really, small possibility that the duty c will fail during the dyno test and suddenly you will have locked 4WD.

 

or just remove the rear section of drive shaft for the test. then re-install.

 

use the hand brake?

 

jack stands?

If you remove the rear section of driveshaft, make sure you mark which way it bolted up. It's balanced as one piece, if you put it back together wrong it might vibrate.

Yea, if the duty C failed on the dyno that would be interesting. Very unlikely, but don't stand infront of the car...

The FWD fuse is designed to isolate the front and rear wheels, but is only expecting the speed difference to be small, so there is a possibility it could generate enough heat to cause it to grab.

 

You'd probably get away with it a few times.

 

Will be dramatic if it binds up.

if you put it in FWD for a 2wd dino your just lying to yourself. yeah it might work but your sending ALL your power to the front and during normal 4eat operation the rear end drags the front down or robs power. I'd say a better test on a 2wd dyno would be to get your rear end on jack stands with the front on the dyno.

you still lack the resistance of the road on the rear end but its closer to the reality if AWD.

 

please if I'm wrong or this is a BAD IDEA someone pipe in to correct me.

 

I know that when my rear wheels were disabled by an rump roast hat shop be mistake my 96 lego had bad front wheel spin on standing starts and seemed not to operate properly. all the fuse does is vent atf line pressure from the clutch pack so it wont lock I don't know if it still gets ATF for lubrication but I would assume so.

It is a bad idea because you are relying on the duty-c to dump the transmission fluid pressure away from the clutch pack. If that should fail (as they VERY often do) you will get full 50/50 torque split front/rear and it will leap off the dyno.

 

This could lead to damage to the car/facility and or injury or loss of life. Due to that it's an extremely bad idea.

 

You could remove the rear section of the driveline - that would mechanically isolate the rear and then with the FWD fuse installed you should be able to make the run. But the FWD fuse alone is not a safe way to do it.

 

GD