Batass

I ran my car four times last summer and each time the whole car raises quickly and spins the tires. I have the brackets set at the most aggressive level. Looking at my videos, it seems the car hooks initially then spins. Its like I'm going over a speed bump.

The videos are on my friend's myspace, and I'm not sure how to put them on here. If you'd like to see them, I can get you there.

My best 60ft has been a 2.1. Et street radials. No transbrake. I just know the basics about my suspension, and haven't been able to find any info on how to diagnose it, or improve it.

I'm sure with better tires, I could hook, but these tires should work for me and this is something I have to figure out anyway.

My guess is that I need to straighten the control arms out a bit. I'm thinking that the rear is raising too quickly and perhaps the shocks are extending to their max and jerking the axle perhaps?

I know its going to take some trial and error, but the most info I can get beforehand will be much appreciated.

Oops, here's what its got.

LCARBs
solid control arms
jegster tq arm
9" rear with full spool
275/60/15 et street DRs
Stiffer springs front and rear
Stock blown? rear shocks
adjustable front tokicos set to weak
subframe connectors and 8pt cage
no rear sway bar

3000 8" stall and the converter hits hard!

Guest

Only thing I noticed, on a G-body (sorry about that), was the rear got stiff like it was binding.
I'd say it'd be pretty hard to overdo it on a thirdgen with the typical brackets I've seen and how the LCA's sit from the factory. What brackets do you have? How far down from stock are the LCA's set? Is the car stock height, lowered, higher?

BTW: You ran an 11.8 in safe mode?

Darkshot

iTrader: (4)

Since the relocation brackets will cause the car the rise on launch I guess I can see it possible that the upward motion of the car, while initially planting the tires, actually starts to lift them with the car if it gets too high too fast. All you can do is try the other hole. Give the car what it wants, not what you think it should have.

I'd fix the rear shocks too ASAP. They are cheap!

AlkyIROC

The LCA work similar to the bottom bars on my 4-link. A good 4-link setting will always have the IC below the anti-squat line. Normally, the IC is just off the ground. In doing this, the first reaction of the car is the diff moving upward as the body drops down. This is squat. Very quickly after that happens, the diff starts to move back down as the tires grab and plant and the body starts to rise up but is controlled by the shocks. This is the proper way to do it.

Having the diff move down first, raising the body at the rear seems like it will plant the tires but the reaction quickly following this is for the diff to move up which will unload the tires.

How to adjust the LCA depends on the ride height of the car. Since there's no proper adjustable IC with a torque arm suspension, it's trial and error to find the best setting.

LCARB are designed to correct the angle of the LCA when you change the suspension height. The LCA should be parallel to the ground or up slightly in the front. The bottom bars of a 4-link should be parallel to the ground or down slightly in the front because of how they interact with the upper bars.

Adjust the LCA to be roughly parallel to the ground and adjust the pinion angle to around 3-4* down in relation to the driveshaft. Install new shocks on the rear. Without them, the diff will bounce and unload the tires.

Flip 2

iTrader: (1)

I have Eibachs, all around.
Before LCA brackets, the bars were high in the back, and the car just squatted and spun tires when throttle was added.
Brackets installed: I am using the top hole on the bracket (less aggressive one). Still, the control arms are down in the back. NOW, accelerate.... and NO squat, at all. The rear just plants and goes...... I still have tire spin, but that is a tire issue, not a control arm issue.
Maybe try the less agressive setting... I get no squat and no raising.

Batass

I didn't think shocks in the rear were too big of a deal. The car gets street driven and they haven't bothered me. I guess I'll throw some cheap kyb gr-2's in.

I put some stiffer springs in the rear, and the car definitely raised. Not sure if its back to stock height though or if its higher. My control arm angle is pretty feirce. I'll make it more parallel.

I'll have to double check my pinion angle too. I believe I set it to 3* but without relation to the driveshaft. Not sure what I was thinking, I should've known that, but when I asked someone they didn't mention to the driveshaft. Must've figured that was common sense. So it was probably way off. I noticed this about a week ago, and eyeball adjusted it. It did seem to get better traction on the street, and the roads were real cold. In one of my videos, you can hear something pop on launch. Could've been the u-joint from the excessive angle, or the shocks topping out.

So thats three things that I need to work on, less CA angle, pinion, and new shocks, should make a nice improvement.

AlkyIROC

Pinion angle setting

http://www.wolferacecraft.com/pinionangle.aspx

JohnZ28

A little off topic but, Batass I see you mentioned you dont run a rear sway bar? This is a great traction aid also beleive it or not. I'm suprised nobody mentioned it. Air bags inside the rear coil springs work well too along with good shocks, adjustable of course are the best.

Interesting to see what it would run in kill mode with traction.

Batass

I've talked to a few guys and some don't run it, some say it helps. I still have it, just need to figure out a way to mount it to the 9". I've seen some heavy duty clamps on some cars. I've heard of the airbags. I'd like to get the car just decent first, and then add things as I go. This car went from stock to nothing stock and it would have been more fun to see improvements at the track.

I'm hoping it gets in the low 10's this summer. It'll hook one way or another, and its got at least another 60hp in more timing, CAI, tuning, and exhaust.

Thanks for the link stephen.

CHAMARO

Spohn has a 9" kit to mount sway bar. It will help keep the launch even. I used a pass side air bag w/o a sway for a while just switched to coilovers with a sway and ditched the bag. The sway bar (especially a drag bar) will offer more consistancy than the bag imo.

Shagwell

A rear anti-roll will definitely help keep both rear tires planted. If one gets too loose, it'll be able to spin 'em both that much easier.

Shocks are a big part of hooking it as well. W/o a decent shock you have no control over the speed of the movement or rebound from the tires.

As Stephen said, put the lca's close to parrallel, set your pinion angle around 2-3 down from the ds, and see what it does. That's a good baseline for most any combination.