Perhaps a new way to dyno an AWD

[tim_korn_99]

correct me if i'm wrong, but last night i had a dream about dynoing my car.... weird huh?
Anyway, here's how it went. Now, assuming you had a VCE, or a Spool to force a permanent 50/50 power split, couldn't you just take out the driver side CV axle and dyno it as a RWD?
The shaft and carrier bearing would still be up there, the transmission would still be plugged, and even though the power would still be going up front, it would just turn that shaft, and not the other wheel. Correct? I think that would be a lot easier than dropping the t-case and driveline.
Just an idea...
-Tim

 

[Maglin]

tranny fluid would come out of the tranny from the half shaft being removed.. And you would still want to remove both shafts for that to work properly... otherwise you are going to be spinning the center diff's spiders very fast and they are not designed to do that... You could end up with a blown center diff...

What would be nicer is more AWD dyno's... then you don't have to worry about it...

 

[tim_korn_99]

See, with the driver side half shaft being a 2 piece unit, the long shaft would be still BE IN the tranny. So, no fluid leakage there.
Can someone else verify this about the spider gears? I know that the diff only sends power to the axle with the least resistance, so, with one not connected to anything, and the other with a tire on the ground, it would just send the power to the driver side.
-Tim

 

[98TsiAWD]

Go buy yourself a couple spare worn out axles. Put the driver side one in the tranny and bolt it to the block, cut the rest of the shaft off. Then stick the passenger side one in tranny (clip holds it in) and just hack it off just past the inner boot.

walla, RWD.

Now if you wanted to run it like that on the street, cut the axles also off on the other end just past the boot and put them into the hubs and bolt them in. Reason for this is, that if you drive your car around without the cv shaft through the hub, you will eat your wheel bearings for breakfast.

 

[tim_korn_99]

Go buy yourself a couple spare worn out axles. Put the driver side one in the tranny and bolt it to the block, cut the rest of the shaft off. Then stick the passenger side one in tranny (clip holds it in) and just hack it off just past the inner boot.

walla, RWD.

Now if you wanted to run it like that on the street, cut the axles also off on the other end just past the boot and put them into the hubs and bolt them in. Reason for this is, that if you drive your car around without the cv shaft through the hub, you will eat your wheel bearings for breakfast.

Don't get me wrong, im not trying to make my car just RWD or anything, i just thought it may be easier to dyno that way, as opposed to dropping the t-case and driveline. Also, on the driver side axle, its 2 pieces that slide together. There would be nothing to cut... And on the passenger side, what would be the point of cutting the axle?
-Tim

 

[jesepes]

instead of messing around with unbolting or cutting or modifiying/removing anything, why doesn't someone simply manufacture a dummy set of rollers to put under the front wheels so they can spin also?? Bearings are relatively cheap, tubing/pipes for the rollers, and welding is easy enough. Make a portable set of dummy dyno rollers. Charge all your buddies a fee to use em.

 

[Waredtalontsi]

Sonds like alot of trouble why don't you just get a switchable jdm tranny & T-case and be done with it. That way when you want to dyno just switch the tranny to fwd and dyno. I got mine for about 580 shipped from cali. Best tranny i've ever had doesn't grind and it shifts like butter.

 

[Morphius]

Did you dream of this after reading about it here in the 1001 threads about how to make it RWD?

Your idea is by no means "new".

 

[Gary 420A RS]

why dyno the car with the rear only? that would defeat the purpose of you dynoing(spelling?) the awd.. you want to figure what you got to the wheels (WHP) and well iam hung over so i cant fully think. so iam done..

 

[tim_korn_99]

as to the "1001 rwd threads" question, no. This is not the same thing... I wasnt asking "how i could make my car rwd so i could go screw around and try to impress my friends." This came about after my driver side half shaft broke, leaving my car RWD, but since i didnt have a spool, or a VCE, only half the power was getting back there. SO, based on information i gathered about a spool, and the forced 50/50 power split, i thought that by removing the driver side half shaft (which IMO, is easier than dropping the t-case and driveline) it would make the car 2wd so as to dyno. I live in southern missouri, where an AWD dyno is NO WHERE to be found.
I can see where this thread is going. I rest my case.
Mods, please close this thread now.
Thank you.
-Tim

 

[jtmcinder]

Unless you've done something, your car has a center VC (while your front is open and your rear may or may not have a VC, as well ... some 97s have rear LSDs and some don't). So when one of your front axles broke, for a moment, all of the power went (uselessly) to that corner while both your center and front diffs spun like crazy. Then the center VC started to lock and you got some power to the rears and moved. How much power went to the rear depends on how well your center VC locks, but the odds of it coming out as exactly 50% is probably about nil.

Your idea of cutting one front axle to allow the car to use a 2WD dyno is not new, but requires that the center diff be a spool. You cannot ask a VC to route power away from an open end to a closed end and expect it to last long, and most don't lock well enough to get an accurate measure on a dyno. If you limped your car more than 5 miles (with no steep up-hills) with a broken front axle, then I'm actually impressed. I doubt what's left of my center VC could do the same.

- Jtoby

 

[tim_korn_99]

Unless you've done something, your car has a center VC (while your front is open and your rear may or may not have a VC, as well ... some 97s have rear LSDs and some don't). So when one of your front axles broke, for a moment, all of the power went (uselessly) to that corner while both your center and front diffs spun like crazy. Then the center VC started to lock and you got some power to the rears and moved. How much power went to the rear depends on how well your center VC locks, but the odds of it coming out as exactly 50% is probably about nil.

Your idea of cutting one front axle to allow the car to use a 2WD dyno is not new, but requires that the center diff be a spool. You cannot ask a VC to route power away from an open end to a closed end and expect it to last long, and most don't lock well enough to get an accurate measure on a dyno. If you limped your car more than 5 miles (with no steep up-hills) with a broken front axle, then I'm actually impressed. I doubt what's left of my center VC could do the same.

- Jtoby

Thank you. Your information actually helps me understand now. The only way i knew i had a broken axle, was when i got on it in second gear, and the rear end slid sideways, and i couldn't get any traction at all. Actually, i drove it about 15 miles home, through some very hilly terrain. The only time that it actually was "slipping" was taking off in first gear. My car felt like it could've driven all day like that. But i replaced the front half shaft, and everything was fine again.
I guess since the passenger wheel would be stationery while the driver side output shaft would be turning, that would put stress on the front diff.
I rest my case.
Thanks
-Tim