I notice when burning out on a left hand turn, it feels like ‘posy’ traction and my car will always get sideways till I counter-steer when I lay into it. But when doing the same manuveur to the right, the right side tire will ‘float & spin’ resulting with no drifting at all as the left tire feels like it is not engaging at all when I do this burnout to a right-hand turn! Is this normal for a high performance '96 Pontiac WS-6 Trans Am? Or do I have Limited slip one way and not another which is normal? A professional answer will be greatly appreciated!
You might want to see if there is a “build sheet” located under your rear seat. That will tell you what differential your Trans Am was equipped with. Otherwise, you need to crawl under the car and get the information off of the metal tag on the rear end.
I’m no stranger to “burnouts” and I think what you are experiencing is normal since you are in a turn when you “lay into it.” I used to be a drag racer so all of my burnouts were in the straight ahead direction.
Your differential is probably a posi traction, limited slip version but you would need the information from the rear end tag to be sure. Post the info and someone will probably look it up for you.
The torque applied to the real axle by the driveshaft can have an effect.
I believe this is typical of a non-posi rear end. Resistances cannot be expected to be symetrical between the right siide and the left side. bearings, axle masses (higher mass takes greater force to overcome), differences in tires, differences in tire pressures, differences in the friction in the planetary gears (the spider gears) and their shaft bearings, axle windup (if the axles aren’t exactly the same), all of this would tend to bias the torque. That bias would be felt as different effects under the situations described.
I should also add “weight”. The load on the left tire and the right tire are not equal, so tha traction will not be. A diet could help me with that.
Even in straight line burnouts with a non-posi rear end, one wheel will spin more than the other, and it will always be the same wheel on a given car. This also is an effect of the the imbalances. Were it not for this effect, posi would be a waste of money.
Watch any drag race and you’ll see a reaction at launch called roll torque. The entire body reacts to this force but so does the rear axle. One tire will always have less down force due to this action. Rather than type it out, I did a quick search and this is a good reference. Hover over the illustrations to get the full text… http://www.hotrod.com/techarticles/chassis/chassis_tuning_tire_traction/
You’re right TT. It’s a major factor when talking big horsepower, and still a factor with lesser horsepower. And yes, it loads down the right tire.
Many years ago Tommy Ivo, a TV star and drag racer, built a 4-engined dragster called the “showboat”. The right two engines had the cranks connected and drove the rear axle. The left two engines were turned around backwards, with the cranks connected, and drove the front axle. If I remember correctly, the engines all turned in their normal direction (clockwise relative to their own longitude) and the front differential was custom made such that the carrier spun opposite the way it normally would relative to the crankshaft, making all four wheels pull forward. If I recall correctly they had a terrible time getting that thing to handle, because of the different torque vectors (a torque “vector” is simply the angle between the way the wheel is aimed and the direction the torque wants to pull it. It’s the actual natural travel path of the combined forces).
I like TT’s link, but I think I can make it simpler to understand. When you open you hood and rev the engine, you see it rock over to one side. Even with limited slip, that means that one rear tire is going to have just a tad bit more bite than the other because it will have a little more weight on it.
You might not notice this in straight line acceleration if your suspension is set up right, but in a turn, depending on the direction of the turn you will either add or subtract from this difference and a turn in one direction will cause what you are seeing.
Cars used on oval track racing (i.e. NASCAR) have an adjustment in the rear to adjust the bias of the weight split to each of the rear tires to compensate for this. You often see them making adjustments to this during pit stops for cars that aren’t handling just right. Sometimes these adjustments are needed just because some track conditions change and you see all the drivers getting them.
Wow, a very imformative bunch of folks here! Thanks for anwering my question and enlightening me on this subject. I appreciate you all!
If it turns out that you have a limited slip differential, you shouldn’t do burnouts at all. The damage may get costly. Maybe not, but you know…
I’ve learned alot (with plenty more left) about torque roll and all the variables pertaining to the laws of physics, and now it all makes common sense to me. Thanks everyone, and TT for the link that ‘tells all’. I’ll be back with more ??? soon. Awesome site!
Used to be a lot of axles had different lengths right or left,to help compensate for the torque bias,you can watch those huge Kenworth trucks wrap up from a standstill when pulling a heavy load,you can see the chassis react as they rock a bit on acceleration,those big diesels have awesome low end torque-Kevin
heavier duty Kenworths have just over 2000 ft.-lbs. of torque