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Discussion Starter #1
I have a 1979 Camaro Z28 with about 550hp, I changed everything but the front control arms and spindles. I had changed the bushings and ball joints, this is my problem if I'm driving normal and even on the parkway at speeds of 70mph, the car is fine but If I take off from a stop with full throtle and let the gas pedal off the front of the car sways all over the road. I'm afraid to take it on the track cause of this problem. I had already did 3 wheel adjustments and like I said everything is restored on my car. I can't figured it out for the love of god, Please can somebody help me.....
 

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If you nail the throttle in first gear, then let off suddenly you are going to unweight the rear of the car causing oversteer. This is because you first compresed the rear springs, when you hit the throttle, then when you let off it throws the rear of the car upwards. With soft stock springs, you might even bottom out the front on the bumpstops. I had a 79 Z/28 and it would bottom out up front fairly easily, it has very limited bump travel and half the bumpstop height is steel on steel. Try driving straight ahead and braking hard, does the car pull too one side and lock one wheel? This is a sign of bottoming out.

Step one is making sure you have good shocks. You may need new springs, if yours have sagged, you will bottom out even faster.
David
 

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Discussion Starter #3
davidpozzi are you talking about changing the rear spring?. I had KYB shocks all arounf and not to long ago I had changed the back ones to the Edelbrock Performer IAS Monotube Shocks. I will also be changing the fronts the same as the back. The front spring is Hotchkis 2" drop, I just put them in as I'm just changing parts over to see if it fixes the problem. The rear spring are bull**** ones I had bought from ebay. I bought them when I first started building the car and didn't know how hard core I was going to go with the car. I hope this helps alittle better for u.
 

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Discussion Starter #7
Ok I had taken the car out for a drive today. It kinda feels like the rear squats on take off and when I let the gas pedal off the rear comes back up and the front get loose. I hope this makes sense.
 

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You need to look at the rear springs . I was having something like this but with stiff springs . Also pulled the kyb gas shock, I went to a stiffer fluid shock, Koni adjustables, and set the ride to firm. Straight like pull . Car should squat some but tires remain planted. Wheel hop? What are you letting out of it for?
 

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If you put Hotchkis coils up front, then get Hotchkis leafs for the rear.
With a lot of power, hitting the throttle hard in 1st gear, then lifting off will throw a lot of weight forward and unweight the rear, this is going to wag the rear end because it's lost weight and traction and the engine has a lot of leverage over the rear tires in 1st. It's like hitting the brakes on the rear wheels only. Stiffer springs and shocks will help reduce it, but it will always be unsettling to the car and worse if you don't have a lot of good rubber under it. Work on analyzing what is happening and making sure the suspension isn't bottoming out up front or even topping out the shocks on extension in the rear.

Watch out for bottoming out on the front bumpstops, it's very easy to do and the car will want to make big zig zag's when it happens.
 

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Discussion Starter #10
Ok, yes the front does bottom out, It hits the top of the front wheels, when I hit a bump. Now I figured let me get under the car and see if I can see anything, Well I found the front sway bar link bushing bolt stripped and the other side not sitting in right. I just changed to a new set. I think I will aslo changed the front shocks and the rear springs. But for now maybe the links did the trick. I didnt have time to take the car out for a test drive as all the school kids were coming out. Anyother info would be great. I had already put 34,000.00 into this car and it's killing me that I have to go threw this. I guess it's getting all the bugs out now. This is what happends when you do a full resto. Thanks again everybody for your input.
 

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Discussion Starter #11
Ok Guy's here is the update, I took my car out for a test drive after fixing the front sway bar links and the problem is still there it feels a little bit better. I'm trying to feel where it's happending from. I'm not sure but I think it feels like when I let off the gas pedal from heavy take off the rear is pushing the front and my nose of my car just don"t know what to do. What's my next step...
 

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Discussion Starter #12
I just want to note that there is a different hights between the right and left. What I mean is the left side I can stick 1 finger between the top of the tire to the top of the fender and the other right side I can stick 2 fingers in between. I don't know if that has anything to do with it. I'm just out of answers and every place I take my car to can't figure it out. They made me Install sub Frame connectors, soild body mount bushings, changed rear shocks, 3 wheel adjustments. If there is a car GOD please come save me....
 

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The sway bar bolts on the subframe can strip out too so keep an eye on those.


I would get the Hotchkis rear leafs. Spring rates need to be matched front to rear and right now I think your rear leafs are too soft. You should not cut the Hotchkis front coils. If yours were cut you WILL NOT have enough bump travel remaining on a 2nd gen. Did you cut the front coils to get the car lower? Do you have a big block engine or air conditioning?

I'm not clear on what you are experiencing when you let off the gas. Are the front tires losing traction? Does the car zig zag left/right? Do you turn the wheel and get very little/ reduced response? This is understeer indicating loss of traction up front, probably due to bottoming out. Are you hitting the brakes hard when this happens? Also check your steering for any excess play. There is an adjustment on the steering box for lash that usually helps but I doubt it is the cause of what you are reporting.
David
 

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Discussion Starter #14
Ok Dave, I'll answer all your questions. I have a chevy 360 engine, no a/c. I have not cut the front springs, but as we are talking about the front springs the drivers side is touching the side of the top perch of the frame. I had tryed to bang some of the perch to clear the spring from not riding on the frame. Maybe this is one of the problems and If so what would cause that to happen?. The front springs are a 2" drop. I don't know if you have springs with a 2" drop do you need the spindels to have 2" drop as well?. This is the problem when I try to race I floor the pedal the nose comes up and the rear squats. The nose is not coming of the ground but comes up. If I keep the gas pedal floored I'm ok, it's when I let off the pedal when I feel like the nose wants to go. I would say it goes left to right and I kinda think I feel the passengers side rear give a little push our like a kick something like that. I'm trying to feed you all the info so you can try to help me the right way. Could it be the drivers side lower control arm? How can you tell if a control arm is bend our tweaked?. I thank all of you for your help in me finding this messed up problem. I just don't want to start changing everything and it's not the problem.
 

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2nd gen's are tough to get the front springs located properly in the upper perch. It's deep inside the frame and super hard to see. The only way I was able to check for proper spring engagement was to remove the shock and look up thru the hole in the lower A arm.
If the coil was hitting on it's side, you might not have it in there right. This would also make the car not sit level up front.

Look at your lower ball joints for movement, they are known to come loose where they are pressed into the lower A arm, but I doubt this is your problem, it would show up hitting bumps at freeway speeds.

Check your upper A arm bolts to the frame, and make sure the alignment shims haven't fallen out. This would make a clunk when you hit the brakes.

It's very hard to tell without driving or seeing your car, but I think the low rear leaf spring rate is allowing the rear to squat too much under power, then when you lift off the gas, the rear pops up and you get a sudden unweight of the rear and dive up front, which is probably bottoming out the front. There is no extra room for bump travel up front so the rear spring rate and action is very important.

You might try your local SCCA Region, and see who autocrosses or tunes muscle car suspension in your area. Someone with a good seat of the pants feel would be very helpful in diagnosing the problem.
David
 

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Discussion Starter #17
Ok I have good news, Well I hope this was the problem still working on it, but I just finished taking off the front shocks and springs. First thing I found was that the place that put them in put Spring Isolators on the top if I'm not mistaken my car does not need them. Second thing they put the ****ing springs in backwards. The rounded flat part they put on the top and the spiral long part of the spring they put on the lower a arm. I hope this was my problem as far as the car swaying off the gas pedal and the spring hitting the top spring perch of the frame.
 
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