Cascade Crew

[blue89]

Another autox come and gone.

I'M SO FRUSTRATED WITH MY CAR NOT HANDLING RIGHT!

I'm going to try a new setup for the front. I got 6th, damn idiots didn't pace out the cones enough for my car (bastards). Plus I had loose exhuast pieces, and a loose pavement lot. If the car doesn't respond well after an alignment tweek, I'm going to burn it to the ground. Tell me what you think of these numbers.

Camber: 2.5* - 3*
Castor: 4*
Toe: 1/8" - 1/16" OUT

Its been recommended by a fellow racer who does CACC and it also follows a same era slolom prep corvette. I'm just tired of the lack of feedback, understeer, and the unresponsive steering. Its 2.5 turns L-to-L with a close to stock alignment that was done last summer (but it could be out). I got comments all day about how well the car handles, but I just want more! i just feels like the front end doesn't hook like a small car does. Any experienced advice is greatly appreciated.

-t

[Dewey316]

Run even camber right left. You will need to look at your tires to temps, and roll to determine how much you want. I suspect you will probably only want to be about 2* on both sides.

Caster, give it more than 4*, i would shoot for 5.5* or so.

Only run toe out, if this car is going to be used auto-x. Toe-out will make you car very unstable and twitchy at speed. It does help turn in a bit if you are at slow speed. Above 50 or 60 mph, you car gets crazy twitchy and hard to control.

[blue89]

Exactly the response I was hoping for! What effect does Castor have on handling? Does it help plant the tires square during hard body roll?

The tow out will be adjusted on site, but the car is mainly autocross only.

Here's another one for you. Is there any way to reduce the power steering pressure? I'm looking at increasing the steering feedback. I need a better feel as to when I've lost traction in the front. Maybe an underdrive pulley on the crank? ? ?

[Dewey316]

adding caster will increase the steering feedback. It makes the steering self center more. so it takes more steering effort to turn it.

Casters effect is mostly on the feel, and self centering of the wheel, to get the tires to really grip on a corner, in our cars, you need to run a fair amount of camber, and 0* to slight toe-out helps at low speeds.

Other things:

When do you push? If you understeer into the corners, brake later and harder, and trail brake a little. That will keep weight transfered forward, and help the front end bite.

If you push coming out of the corner, you can also adjust your driving style, and apply throttle a little slower on the corner exit.

Other particulars on your suspension setup might help clue us in as to why you are understeering. But knowing exactly where it understeer's, and the exact setup are needed.

[blue89]

Front is full urethane, boxed a-arms, sway brace, 34mm sway. 18x8's at 44psi. 245/40r18's, 240tread Federals (temp seams even over surface after a hard run). Cheap-o Grant GT steering wheel.

It seems to understeer under hard braking (can adjust prop valve I guess ) but it annoyingly understeers under hard accel through a corner. Doesn't make sense to me that an open rear with stock 3.42 gears and a built 3.1 could push the front around a corner.

I'll get the stock alignment numbers when I get home. It already self centers pretty good. When i drift it around corners I generally let go of the steering wheel and the wheels point where they need to go. Freaks people out when they ride with me But that doesn't mean it could use some more castor....

[Dewey316]

how does the car feel coming out of the corners, and mid corner?

[Dewey316]

ohh, another thing... what springs do you have both front and rear, and what rear sway bar do you have?

also, have you altered the ride height at all?

[blue89]

Going through a corner with nuetral accel, the car can easily understeer by steering to hard.

The front are IROC springs with 1.5 coils cut out. The a-arms are flat parallel with the ground. Rear has 2 coils out of standard springs with no damper cup, 22mm rear sways, and LCA relocators to bring the LCA's axle mount down below the body mount.

Stock 89 Camaro, all models

Camber 0*
Castor 5*
Toe 3/64" IN

Anything else mas'a?

[Dewey316]

Being that the car is a V6, as you have modified spring rates (making the fronts pretty stiff. I think you need to consider either a little less front roll bar, or more rear bar. You have also dropped the front roll center quite a bit, due ot the lowering. This is going ot have some funny jacking effects under braking, and your turn in will be diffrent. Your alignment specs now are pretty crappy. Give yourself some better camber, and maybe a 32nd of toe out, and see where you are. If it still understeers, maybe go to a 23mm or 24mm rear bar, and also consider changing your driving style just a hair, to make the car balance itself a little more.

[Dewey316]

also, 44psi is pretty high pressure. I would drop that to like 38psi front. You are going to need to soften up the front end to get it to bite, after you up the rear bar, and get an alignment, and drop the front tire pressure. If you still aren't grabbing, start working down the front sway bar. They make them smaller than 34mm, if you need to soften it up more, keep going smaller until your front end grabs right.

[Xophertony]

RE pawer steering: my v6 car has a rough idle right now, due to a bad iac. it also idles LOW and makes 632 RPM dips acording to DMVs tack thing. i have noticed that if i let the engine idle while turning that my power steering is not as powerfull due to the lower speeds that the pump is moving. if i go around a corner with my foot slightly on the gas this does not happen. based on this i would think that an underdrive crank pully would lower your powersteering help level, and give you more "feedback". of course this will also make the care more difficult to turn at low speeds.

[chevymad]

I've experimented with different pressure relief valves in the pump. It really doesnt make any difference. The part that actually sets the steering feel is in the control valve inside the steering box. This isnt easy to change. I put the smallest flowing valve i could in my truck.. and I still can give the wheel a spin. It will continue to spin till it hits the stop and then it bounces back a 1/2 turn. This is with 15x10 and 275/60s up front.

[blue89]

I know this sounds dumb, but I loaded up my 4th gen camaro on GT3 last night and played around with the front toe. Made a big difference as to how the car handled around the corners. I started with 0 camber (my current setup) and 0 toe, and then moved up a degree of toe out a race at a time. I also got out my camber plates to see how much 3* is. Thats alot of camber! I hope to test it out by this weekend for sure!

I've never had a PS box that moved by itself! Thats crazy! Where do you get the internal valves you are talking about? I have an extra steering box laying around, so I can guinea pig without any trouble. Have you ever heard of someone relocating the box to increase/decrease the Ackman angles?

[Dewey316]

Don't go too extreme with either toe or camber. You can cause just as many issues.

I would really shoot for the 1.6-2.0* camber, and 0 toe, or 1/32nd toe, not any more.

[TecherB]

You guys are talking spects but dont forget the basics are your steering parts in good shape?

check all your ball joints tie rod ends steering box ideler arms shock towers and the shock bolts if this stuff is bad it does not matter what the spects are it won't drive right

[blue89]

Someday you guys will see the car. I'm complimented as to how clean it is at every gathering (except the primer on the outside, but that has a good story). All of the steering stuff seems to be in good shape. No slop to be had anywhere.

[TecherB]

what about some of the front suspension shock towers ball joints wheel bearings? do you know how to properly test these parts?

[blue89]

I don't know how to "properly" check them, but, but the shock towers are solid no cracks, the wheel bearings are solid (replace them a couple years ago). How would you check these things? Something I can do at home?

[Xophertony]

heres how you test wheel bearings. you go to the auto parts store and buy new ones. you replace them. if the autoparts store does not have them in stock you don't need them. if they do have them then they need to be replaced

for real. jack your car. hold the tire. shake back and fourth vertically. if there is play, your wheel bearings need replacement.
no shake side to side. if there is play your baljoints on your tierod ends need replacemant.

[blue89]

well.... if thats all you do then I'm good to go. Like I said before, the front is solid, no play anywhere (just a teeny bit in the steering box). I already race this car, so I would get caught during the tech inspection if there was a problem.