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Suspension ruminations and request for comments

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Old 03-08-2004, 09:55 PM
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Default Suspension ruminations and request for comments

I've been thinking about suspension lately. I did a search, and it looks like the hot setup is the Z bars. At least that is what the fast guys are reputed to run. Problem I see is, they function the same as the 2x4 box tube lift bars I put on customer cars back in the 60's. I think they were a rip off from Ford T-Bolts, but they were miserable on the street. Instant oversteer ... I eventually found a way to weld them on so that they wouldn't tear off from binding with the leaf springs, but I would not run something like that on the street myself. The Lakewood bars are the same thing. The old asymetric leaf springs on the Mopars worked good as lift bars when you clamped the front half, but that isn't an option for me.

I've seen what look like we used to call slapper bars that have a slip connection and rubber cushion, which might work. Replace the solid link on the Lakewood/Z bars with one that had freedom in one direction and a rubber bumper in the other. That would still be streetable, but it would take a lot of R&D to find a combination of rubber and compression that wouldn't cause wheel hop. It would have the advantage that you could control chassis loading by adjusting tighter on one side than the other.

You can't go four link and still run in a "stock" class, like at Thunder or SBSO. It would probably be a PITA to hang on a unibody anyway.

You can drop the rear mount for the LCAs, but that has limitations. Mine are at 7 degrees off horizontal, but that isn't enough to get much lift. It doesn't calculate to very much and my car still squats, so it can't be much in practice. If you angle them up enough to really get lift, you will increase the angle and lift as the body lifts, which will increase ... well you get the idea. IIRC, PSJ had traction trouble (wheel hop??) because of this and move the LCAs back up.

Stiff rear shocks can help minimize squat, and if you stagger the damping, you can help control chassis loading, but that only works if you let it squat so the shocks can work. As you get closer to neutral or even get the body to lift, this no longer works. Pretty much a bandaid, but better than lift bars for a street/strip car.

The torque arm is too long to get much lift out of, but if it was shorter, say 30", I could get enough lift to at least prevent squat. However, I don't know if that would be "stock enough" to run in the cam and head class at the F-Body meets. The load would be transferred to the body a bit off center, but probably not enough to matter. It might take a stiffer cross member to handle the increased load, and it would probably be too far back for the drive shaft loop. But if it were legal, that might not be a bad option.

Any comments, corrections, or whatever?
Old 03-09-2004, 09:08 AM
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Carl,

Give Madman a call. He sets up my hot rod and I cut 1.45 to 1.50 60 foot times. My Hot Rod is deadly consistance.

Coach
Old 03-09-2004, 09:22 AM
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Originally Posted by Coach 02 A3 Z/28
Carl,

Give Madman a call. He sets up my hot rod and I cut 1.45 to 1.50 60 foot times. My Hot Rod is deadly consistance.

Coach
Having owned a shop once, I am reluctant to call one up to fish for information
Old 03-09-2004, 10:12 AM
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Originally Posted by critter
Having owned a shop once, I am reluctant to call one up to fish for information
Hell, Bryan is cool. Tell him Coach told ya to call.

Coach
Old 03-09-2004, 11:20 AM
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Lakewood lift bars, well I consider them to be junk since some of the brackets broke when I tried them back in 1999. A few other friends had the same problem.

Tim with the 95 Formula down in Louisiana has the Pete Z bars.

Only downside is that they reccomend keeping the tq arm as a locator, but without a front bushing. So I think it would be a bit of a clanker.
Old 03-09-2004, 11:33 AM
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Critter you seem to be doing alot of research to determine what is correct on your car. I like that.

I sell the Z bars and they work killer. If they are installed correctly they will not tear off the housing BUT they are noisy. You still have to run the T/A but you mount the front in a 2X3 piece of box tubing and allow the front of the arm "float". This keeps the rear from binding.

On the aftermarket T/A setups my arm is 36" long and mounts to a added crossmember. I put extra holes allowing for instant center adjustments. This way you can control lift. The one drawback to a T/A setup is that the body tries to roll around the arm. (4links do this also). I use a antiroll barto stop this. Myself, Billingsley, and Wolfe all make killer antiroll bars.

On the shock issue I recommend a double adjustable to control the rear end. On any car when you launch the car the rearend tries to drop out of the car. The car only squats because the shock isnt doing its job. What you want is for the rearend to drop out and plant the tire. The compression side of the shock(bottom ****) controls this. You want this setting firm enough the hold the tire down on the track. The extension side of the shock(top ****) will keep the body from rising away from the tire and put load on the tire.
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Old 03-09-2004, 02:38 PM
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Originally Posted by Pro Stock John
Lakewood lift bars, well I consider them to be junk since some of the brackets broke when I tried them back in 1999. A few other friends had the same problem.
I'd believe that. I was more interested in the concept than the implementation.
Tim with the 95 Formula down in Louisiana has the Pete Z bars.

Only downside is that they reccomend keeping the tq arm as a locator, but without a front bushing. So I think it would be a bit of a clanker.
Yeah, I think it would be a clanker too. Have you ridden in or driven a car on the street with Z bars? You obviously drove one with Lakewoods What did you think? Would you do it again?
Old 03-09-2004, 03:00 PM
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Originally Posted by MADMAN
Critter you seem to be doing alot of research to determine what is correct on your car. I like that.
Thanks. Yeah, I have been away from the game a while. Last time I pulled the leafs and put in coils with a 4 bar, single pivot setup. Needed an anti-roll bar, but worked great. That won't fly in my Z28 though
I sell the Z bars and they work killer. If they are installed correctly they will not tear off the housing BUT they are noisy. You still have to run the T/A but you mount the front in a 2X3 piece of box tubing and allow the front of the arm "float". This keeps the rear from binding.
Yeah, I can believe the T/A floating in 2x3 would be noisy Do the bars themselves have play and are a source of noise? I saw the picture and it doesn't look like that is the case. If they are solid, I wouldn't want to run them on the street even if they weren't the noise source.
On the aftermarket T/A setups my arm is 36" long and mounts to a added crossmember. I put extra holes allowing for instant center adjustments. This way you can control lift.
That is more like it. Do your clients have trouble with tech at the F-Body meets with the short T/A? 36" is more like the right length for > 600 HP or so I think. 30" would be too short for your car, for instance.
The one drawback to a T/A setup is that the body tries to roll around the arm. (4links do this also). I use a antiroll barto stop this. Myself, Billingsley, and Wolfe all make killer antiroll bars.
Yeah, I was aware of that. I thought you can bias the 4 link to counteract the rotation, but not the T/A setup. I don't think I would want to run one of those anti-roll bars on the street It would be pretty much like the old lift bars I don't like. But with shock bias, or a lighter anti-roll bar with some bias cranked into it, or a shim under the right spring, or an air bar, or etc, I think the shorter T/A would work for a stree/strip car.
On the shock issue I recommend a double adjustable to control the rear end. On any car when you launch the car the rearend tries to drop out of the car. The car only squats because the shock isnt doing its job. What you want is for the rearend to drop out and plant the tire. The compression side of the shock(bottom ****) controls this. You want this setting firm enough the hold the tire down on the track. The extension side of the shock(top ****) will keep the body from rising away from the tire and put load on the tire.
I'm on the same page here. I don't like the idea of single adjustable (or non-adjustable). I really hate 90/10s on the street. Are you talking HAL? or AFCO? or ??? Jay is selling a Strange shock, but it is only single adjustable I think.
Old 03-09-2004, 03:01 PM
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Originally Posted by Coach 02 A3 Z/28
Hell, Bryan is cool. Tell him Coach told ya to call.

Coach
Thanks, but he is here
Old 03-09-2004, 03:43 PM
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I believe the torque arm might be the source of some noice on launch but it might not make noise during normal driving.

My Lakewood stuff was I think probably their attempt to make PeteZ bars. I would do them again if they worked and did not break.

BeaSSt also ran the PeteZ bars. Both cars that I mentioned hook great, BeaSSt went some low 1.3's I think very low.
Old 03-10-2004, 07:12 AM
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The shocks I recommend are either the AFCO doubles or the Strange doubles. The Hal or QA1 are a single adjustable.
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Old 03-10-2004, 09:22 AM
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I knew the Madman could answer all the questions.

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Old 03-10-2004, 09:54 AM
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My T/A is legal for all headsup classes. In the NHRA Stock Eliminator classes I have a different front mount to make it legal.
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Old 03-10-2004, 10:55 AM
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Originally Posted by Pro Stock John
I believe the torque arm might be the source of some noice on launch but it might not make noise during normal driving.

My Lakewood stuff was I think probably their attempt to make PeteZ bars. I would do them again if they worked and did not break.

BeaSSt also ran the PeteZ bars. Both cars that I mentioned hook great, BeaSSt went some low 1.3's I think very low.
The BeaSSt only went low 1.3's with the Z bars removed. The front of the torque arm was still in the factory mount when the car came to me after haveing the Z's installed. The rear of the car was bound up so badly you could'nt even actuate the rear suspension. I removed the Z bars and went about resetting the rear suspension. The car now has all Wolfe componentry under the rear and 60ft's plumeted from mid to high 1.3's to 1.30 - 1.31's on every pass.




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