Dyno'ing AWD truck on 2wd dyno?
 

Anyone successfully 'disabled' the AWD and dyno'd with just the rear wheels on an AWD GM truck (ie Escalade, Denali, Yukon, etc) without destroying anything?

Yeah, a few of the Silverado SS guys have... They just remove the front driveshaft and go for it.

I've been meaning to get hooked up with a local dyno here for a few pulls, but haven't been able to get in touch with them. I think they're selling the business. Anway - I was planning on trying it myself.

ya, the only real way is to take the front driveshaft off or find a place that has those little individual wheel dyno machines.

What kind of center diff is in those trucks? Most any other AWD car cannot be be disabled by simply removing a drive shaft, and in doing so will usually ruin your center diff.

Have you done it (taken driveshaft out)? What are the effects on the transfer case running open up front like that? We are reading through the electronics to see if we can find a way to make it cooperate. The transfer case *has* a neutral position....getting it into it is another thing. Plus, not sure if it will disegage the front only?

It's a viscious (sp?) coupling...

With the front shaft removed, it'll put it into "hump mode" (don't look at me, that's what GM calls it). It puts 100 of the power to the remaining driveshaft. GM says you shouldn't run like this for long because it'll damage or destroy the coupling... but people have been getting away with it for half a dozen or more dyno runs on a vehicle.

Interesting...anyone 'damage' anything yet? Does a half dozen pulls on a stock truck equate to 1 pull on a 500 hp truck? Hoping to 'figure out' something short of destroying this thing :)

The second question is definitely good...

For what it's worth, I haven't heard of anyone breaking anything yet.

well, whatever I figure out - I'll share here...must be a civilized way to do this!

Viscuous ;)