Body Roll

[Oldsmoletick]

Never any track time for my car, but I can vouch for the simple stock bolt on upgrades. The malibu had no rear sway bar, or any added bracing a while back, it's sad to say, but my lifted jeep cornered much better (no sway bars what so ever on the jeep). now that I've added the F41 rear bar, the jounce bars, and the fender braces, the car acts like a whole different animal. It's a joy to drive, I don't know what had the most impact, as I added them all at the same time (I gathered up all the parts over the course of a few years, lol). I do know it made enough of a difference that my girlfriend even commented on how well it handled in comparison to the jeep now :lol: . Another thing I noticed, straight line traction was greatly increased too. It used to unload the right rear terribly bad (one wheel wonder peel 😳 ), I couldn't open the secondaries in first gear without the tire going up in smoke. It's nice to be able to actually get into it at low speeds now, lol.

 

[pontiacgp]

I have a -1* camber on my GP and I find it not only helps with the handling but it helps to prevent the outside tread of the front tires from scrubbing going around corners...I don't find that setting to increase tire wear...as for a rear bar it is helpful to control the rear body role which transfers weight to the front corner when going around a corner. Nascar for years did not use a rear bar for their set up but in the last few years they have been testing a rear bar. If you do want to run without a rear bar then you'll need to reconfigure your front end and rear set up to compensate the lack of a rear bar.

 

[custom442]

removing the rear bar is a crutch vs how much $$ you have. Theres a few ways to look at it. Using the stock smaller rear bar does help control roll and pitch of the back end and reduce wheel hop. But if going for all out cornering, ideally we'd get a larger than available or have a custom front bar made with a smaller than available rear bar. But we don't. For cornering only (not handling feel/driveability/straight line), removing the rear bar would be the best choice.

Its a good point about nascar using a rear bar now, I imagine the materials used and design of the bars are more advanced than what we could buy or have made for our cars. And since the stiffness of the roll bars affect loading and roll depending on the situation, I imagine those rear bars are an easy way to quickly tweak slight changes.

Bottom line is a rear bar tightens the outside rear which we don't want around a turn in these cars, it probably makes as little as no difference with our granny spring rates, but once the springs are upgraded and heading to an autox its something to think about.

I mean ideally we'd take weights at all four corners and go on about how much load is on each contact patch in every corner and measure suspension geometry and tweak as we like vs how much flex is in the front or rear of the body/frame. Since our cars are full framed we don't have to rely on the stiffness of the bars reducing roll entirely, we can stiffen our frame at certain points, I've seen advertised big rear bars that "reduce roll" on unibody front engine rwd cars, which they do. But reducing roll is sometimes compromised by loading the wrong tires in a corner, is what I think some of those companies don't advertise. Reducing roll can give a more confident feel to the car but our cars are flexy boats so we have to work with what we have.

 

[pontiacgp]

I agree that you can improve cornering without the rear bar but that would take a set up in the front with like you said a large bar but the springs need to be soft and a slow rebound on the shocks so when you hit the brakes before the corner the front end drops and stays down planting the front tires until you hit the throttle coming out of the corner..or you run 1,100 lbs spring up front so the front does not move going around a corner. Those springs do not make a car very comfortable tho for street driving. I have played with the idea of a rear bar since it can help with tweaking the spring rate and can help getting the wedge you want and it can help to put a little more pressure on the left rear coming out of a corner to give you a jump on the competitors. The problem with street cars is you can't really hit your mark setting up for a corner and to drive with a large bar soft spring set up won't work on the street, nor will it work with 1,100 lbs springs. The rear bar does help the street car to behave better

 

[Burnhard]

Thanks for all the replys. Car has f41 factory set up, I will be adding the pontiac rear brace behind the seat. I will drop the front with drop spindels,what lowering springs do you like in the back? If I have a larger tire in the back should I look to load the front tires load and run a bigger bar up front?