The most common is the 424 model which has the same front and rear roller diameter and weight. I’ve never heard of any problems with center diff damage on this setup.
They have also sold a few shops a 248 model 2WD dyno with a 224x model added onto it. What does this mean? You’ve got a 48" roller and a 24" roller which are not linked. The one roller is twice the size AND about twice the weight (about 3500 vs 7000 lbs) of the other. A 3000 lb weight difference between rollers creates an enormous imbalance in front and rear resistance. What can this do to a center differential? It won’t blow up the diff on every AWD car, but it HAS happened. Cars with non-active OR active diffs can overheat and fail under these conditions.
You have been warned. I have far too many local customers with AWD to tell them about this privately, and I’d hate to see any of you blow a diff (which can easily take out a whole tranny) so I’m posting it.
Unfortunately I can’t get to his site to check on the model number, but I think he bought the AWD as a unit, he did not append another unit to his existing one. (:lol: Too much use of the word unit)
But I also heard he got it used… so maybe the previous owner bought 2 different units.
BTW - What a stupid fricken idea to even use 2 different rollers…
The viscous coupler is probably the least likely to break considering the design of the differential, but who knows when the fluid is heated up. It could be just as bad.
I read an article a couple years ago that compared many fast cars.
The tests included dyno comparisons and the Evolution was fine but the Carrera4 made nasty noises and could not be dynoed.
I hope I can dyno at Kennedy’s to see if my car is close to Burchur Racing’s claims.
The Porsche has issues on dyno that DO have rollers the same size and weight, let alone ones with different size rollers. Dyno Dynamics is one of the only companies who make an AWD dyno that works with Porsche’s setup.
