Posi?

[GTU89]

I was just curious, when any of you do a burnout (just plain straight up stabbing the gas, no hand brake, neutral drop (hope no one on here does that!) or turning tricks) does your Beretta get posi? or just a one wheel wonder?

I was somewhat surprised that mine does posi every time, I don't do it much because I don't like beating on cars, and I really like this car, so I treat it good, but I just did one today for the hell of it, and it laid deep black posi marks, I left off so I don't know how long it would have laid them, but they are decently lengthy for what these cars are, I think it was around a bit longer than a Beretta door.

I just wondering since I was under the impression that most FWD's usually just spin one tire.

[3X00-Modified]

It's all dependent upon conditions... You got a perfect setup where the car was sitting nice and level, no extra pressure on one tire and both tires had the same grip therefore allowing the diff to not direct power to the least gripping tire.

Go to a place where you have a lot of grip you will more than likely only have one tire break free. These diff's are open 100% so there is no reason other than grip that resulted in two tires spinning. Also on top of that remember with FWD you are transferring weight to the back of the car so spinning FWD is easy.

The only other thing that could explain it as well would be a diff going bad which has spider gears that have a lot friction to the differential and or shims behind them which causes them to not spin freely. Essentially what I paid for when I bought my LSD, but that uses bronze shims and a spring loaded center block to exaggerate that effect.

But to answer your question, yes on the street I always get both tires spinning but I'm exempt from this question really.

[Barry]

My automatic car had a posi towards the end. Lots of 1 wheeler pealers seized a sprider gear to the pin, then it locked up. It would actually chirp the tires around corners because it was so tight. It would spin 2 tires all the time for like a month then the spider cracked in half and gernaded everything.

Like Jon said weight balance and conditions are really important. My 5-speed car would spin both if I dumped the clutch. But just rolling on the power in 1st gear it would alternate tires and torque steer a little.

[woody90gtz]

My 4t60e used to do it fairly often. I remember an ebrake burnout patch that was really good. But turn the wheel and it will peg leg every time.

[GTU89]

In the wet it'll break them loose in a corner, I'm sure it'll peg leg if I turn the wheel, I'll have to see if it will with this trans, I don't think it did posi with the other three bad transmissions. The current trans is out of a 1986 (?) Buick Century that had a Iron Duke, but the trans in that was supposedly out of a later model car, so I don't know for sure what it is out of.

The Buick one is a TH125C, which IIRC is pretty much the same thing as the 3T40 the car is supposed to have.


IIRC my father said his 89 GT he bought new would posi all the time too, his would also chirp the tires when shifting and just generally ran better than most other people's he knew until it had the torque converter replaced, then it ran more or less like they all seem to.

[3X00-Modified]

th125c is just another term for a 3t40

[weba]

My Quad spun both tires on stock setup.. On straight road. Wont work on cornering.

[GTU89]

th125c is just another term for a 3t40

Oh okay, I didn't know if the 3T40 was any different. Just renamed to keep with the naming scheme I assume?