89305formula

iTrader: (5)

when im at the track my car doesnt hook at all even with drag radials at 15psi, i have a spohn torque arm, some kind of aftermaket lcas, new shocks and caunuk motor sports lowering springs which i want to take out cause how low it sits, my queston is what springs and shocks should i get so that my car will squat more and launch harder, i went 13.5 with a 2.35 60' so i think with a good working suspension and traction it should be in the 12s

Apeiron

Squatting is the last thing you want the car to do. Try some LCA relocation brackets to correct your LCA geometry with the lowering springs.

nelapse

iTrader: (17)

You want the rear to go up not down.

89305formula

iTrader: (5)

i have some relocation brackets but i havent put them on yet ill probly do that when i put the gears in this weekend if my new carrier gets here by then, i thought that you want the rear to squat cause it would put more pressure on the rear tires it seems like at the track all the cars that launch hard look like they squat

xpndbl3

iTrader: (5)

girls squat, race cars don't. You want the rear to lift, if the rear squats then downforce that could be used on the tires is being put onto the springs instead.

Apeiron

Think of it as the wheels being pulled up off the ground into the car, and then the car falling back down under gravity. That's what happens when you squat.

Cars that launch hard don't pull the wheels up, they push the wheels down into the ground, which raises the back end of the car up. Sometimes it's hard to notice because the front end is usually lifting even higher.

brutalform

If you would have a friend video tape the car (video...good strip tuning tool) on a launch, you would see whats really happening. You would clearly see the rear fender wheel well get wider, or narrower, as the car is launching. Having the LCA brackets properly set, and you should really see some real improvements in those 60' times. Also dont be afraid to try MORE air pressure in the tires as well. Just because some cars work well with 15 p.s.i., does not mean your car would not like more. Generally, a heavier car would tend to need more pressure. Ive tried all different pressures, and my best 60' times were with 18+ p.s.i. Granted, I use a bias ply ET street, but you get the idea. The radials will tend to "cup" making the contact patch worse.

Rayvan

Put a set of 90/10 drag-race shocks on the front. They allow the front to rise quickly (then settle down easy) for better weight transfer.

Apeiron

Not such a good idea on the street, though.

89305formula

iTrader: (5)

the next time i go to the track my sister is going to video tape it for me i just wanted to see what i look like going down the track i never thought of using it like the way that you said but thats a real good idea
and i want to replace the shocks like rayvan suggest i just dont know what ratio is the best and the car isnt really much of a street car any more anyway i have a mini spool and 4.30 gears but with a t-56 i can still cruise at a decent rpm
hopefully i will have it all back together this weekend and beable to get to the track on wednsday nite weather permitting
and another reason i dont think it is hooking well is because it seems like the person in fornt of me in line always leaks something on the track or breaks something and they dont respray after that, its happend to me the last 3 times i ran

Shagwell

a few things:

- tire pressure - I can almost gaurantee you that 15 psi is too low for drag radials. Every car is different, ever tire size is that much more different, but dr's are usually run between 18 and 25 psi. Most of the tire companies don't reccomend much below 20 for dr's. - My 17"ers work best around 25psi(1.6X 60fts)
- lca angle - you need relocation brackets. These car's don't hook well factory because they squat. You need it to push the rear away from the car, thus planting the tires. Lowering the lca at the diff corrects the angle, thus causing the diff to try to move downward under acceleration, thus planting the tires.
- pinion angle - if you have an adjustable tq arm you need to know what your pinion angle is. More angle(negative) will try to plant harder during launch, but too much angle will "hit" too hard, thus causing the tires to rebound and break loose.

Like the others have said, drag cars don't squat, they just look like it due to the front end rise. - Also, personally I don't like 90/10's. They don't settle back down as you go down the track, thus letting more air flow under the car making it loose and less stable.

- if you're still on a 10-bolt, if not for yourself then for the sake of others on the road, please don't street drive it with a spool.

MrBrooks

[quote=Shagwell;3395292]a few things:

- pinion angle - if you have an adjustable tq arm you need to know what your pinion angle is. More angle(negative) will try to plant harder during launch, but too much angle will "hit" too hard, thus causing the tires to rebound and break loose.

I have found that -4* pinion angle works quite well----allows pinion to climb ring and settle at near 0* on acceleration while driving the rear into the track. Spohn has a good description of how to set the angle on his site.

Shagwell

That may work great for your car, but may be far off for his. Different power levels, different power bands, different gearing, different springs, different shocks, etc, etc, etc all change the ideal angles of a suspension system. Hell, I run -6 which is excessive, but works well in my car. If i were to shorten the tq arm a bit it would work the same with less angle and be easier on u-joints.

The comon starting point is (neg) 2-3 degress for auto trans cars, (neg) 3-4 for manuals.

MrBrooks

You are correct, it will take some playing with to tune for him. Was just giving a "good" starting point. And this all assumes that he has the ability to make the adjustment in the first place.

1991CamaroRslow

iTrader: (3)

Just so you know your car will hook better with stock RS springs, or V6 springs. Lowering the cars changes the suspension geometry making the LCA relocation brackets necassary; keep stock height springs in it and they're not as important. Also no one has mentioned the fact that with 4.30 gears and a T56 you REALLY need to get rid of the drag radials and go to something with a softer sidewall like an ET Street or a real slick.

brutalform

Considering the types of bushings used in the suspension would give you a good idea where to start at. Solid busings will not flex, as poly bushings will flex very little, as compared to the stock "marshmallow" bushings. People running more neg. pinion might have an entire different set up, with different bushings.

Shagwell

- that's why i started the list of variables ending with et, etc, etc. I run poly, which I believe to work better for street/dr type tires. The solid bushings tend to "hit" the tires too hard thus causing uncontrolled spin.

Tire compound is a major part of suspension set-up. Street tires and dr's are not intended to "hook". They're controlled spin. Large wrinkle wall slicks can be compounded to dead hook, but that also varies with the application.

If that 4.30/mini-spool combo is in a 10-bolt, he better hope it never even attempts to hook....even in a tougher rear, the mini-spool is questionable.