Something weird happened at Barber last weekend, Input, ideas welcome. Options

[FASTFATBOY]

Lets back up to this March, the car snapped around on me at Barber in turn 5. I hear a squeak in the front, put it on stands to look and find nothing, go out for the next session and the steering wheel is crooked. I go right back in, back on stands and find nothing. Go drive the paddock and the wheel is straight.

Get home and find the LF shock top is broken off the Koni and the shaft had hung up in the shock mount and caused the wheel to be crooked.


This past weekend, I had a mismatched set of tires on the car trying to kill them off. I set the shocks per Lee Grimes@Koni on the front 8 on rebound and 4 on compression which is opposite of what I usually run.

Took the car out and it was all over the damn place, no grip.

Come back in, decide to put a better set of tires on the car and set the shocks back like I had been running them, 9 on compression and 5 on rebound. Car was back but the steering wheel was crooked.

So I check the shocks on the front, not broken. Check my newly slotted front lowers and they are fine(adjusters were tack welded) , toe adjusters have not moved.

Scratch me head a little bit and think what else would make the steering wheel crooked and look at the rear tires in the wheel well, the damn rear end is crooked in the car ....WTF?? By almost an inch back on the drivers side.

So I pull out the tool box and adjust that side back up, all adjusters were tight on the lower control arms. I have UMI Roto-Joints on the rear with relocation brackets.

Was fine the rest of the weekend, steering wheel was back perfectly straight. When I got home I checked the car over very good and found nothing.

Any ideas what caused this?

This post has been edited by FASTFATBOY: Nov 10 2013, 01:39 PM

[StanIROCZ]

Broken PHB mount on the chassis? This usually only happens with lowered PHB brackets, but theres a first for everything.

[Blainefab]

In the front, torque the 2 rack mount bolts and the 6 Kmember bolts to spec.

In the rear, check the welds on the LCA relo brackets. If they are only bolted on, weld them. Pull the 4 LCA bolts, look for a busted one.

[FASTFATBOY]

In the front, torque the 2 rack mount bolts and the 6 Kmember bolts to spec.

In the rear, check the welds on the LCA relo brackets. If they are only bolted on, weld them. Pull the 4 LCA bolts, look for a busted one.

Relocation brackets are welded, will pull the bolts and look at them.


This has me worried I must say, I had no more issues with the car that weekend.

[slowTA]

I would check the rag joint and the splined shaft where it clamps on to the rack.

[FASTFATBOY]

I think I found it, we did not weld the LCA relocation brackets, they are from UMI and use the shock mount to secure it so we didn't think it needed to be welded. Appears it bent the arm that wraps around to the shock mount. I guess wheel hop caused this, I have no idea.

(IMG:http://i1122.photobucket.com/albums/l528/FASTFATBOY1/20131112_135029_zpsb926120d.jpg)

Ok so how do I fix it? I run stock lowers in the off season so it has to be back "square". Can I repair the bracket?

My thoughts are to put the stock lowers back on and bend the bracket back until both sides are square then weld it. Am I thinking right?


EDIT

I had better pull both roto joints, equal them in length, put them back on and bend the bracket until both sides are even then weld. The roto joints have no rubber in them and would be accurate.

This post has been edited by FASTFATBOY: Nov 12 2013, 08:10 PM

[trackbird]

You want the LCA's "level" or slightly nose down for handling applications. Having relocation brackets on the back leads to "roll oversteer" and makes the car harder to drive. If you're on Strano springs I'd suggest getting rid of those or fabricating a hole/bracket so you can mount the LCA's level.

[FASTFATBOY]

You want the LCA's "level" or slightly nose down for handling applications. Having relocation brackets on the back leads to "roll oversteer" and makes the car harder to drive. If you're on Strano springs I'd suggest getting rid of those or fabricating a hole/bracket so you can mount the LCA's level.

Bars are almost perfectly level when sitting on the ground. Without them them they were nose down pretty bad if memory serves.

[Blainefab]

Yes, wheel hop will destroy stuff. The LCA brackets have to be welded, those tabs to the shocks don't do anything but get in the way, cut them off. You'll need to get the axle back to a zero thrust angle - set the LCA's to 19.25" long, clean up the axle and brackets down to bare shiny metal, and weld them on, inside and outside. If there is gap in the back, fill it with some 3/16"

Cut that pbrake tab off so you can get a good weld, then weld it back on when you're done.

(IMG:http://blainefab.com/projects/2013_11_12/IMG_5931.JPG)

(IMG:http://blainefab.com/projects/2013_11_12/IMG_5933.JPG)

This post has been edited by Blainefab: Nov 13 2013, 03:01 AM

[Blainefab]

If that is an eyebolt that I see in the LCA hole, and if you use it to tie the car down to the trailer - I recommend replacing it with a load rated eye nut. You'd need to go to a 5/8" dia to approach the load rating of your tie down straps. Pulling sideways like that derates the load rating by about 50%.

If you have room to clear the LCA end, just drill a hole in the back of the LCA bracket to clip your tiedown onto. Or better yet, use the factory tie down spots on the chassis.

[FASTFATBOY]

If that is an eyebolt that I see in the LCA hole, and if you use it to tie the car down to the trailer - I recommend replacing it with a load rated eye nut. You'd need to go to a 5/8" dia to approach the load rating of your tie down straps. Pulling sideways like that derates the load rating by about 50%.

If you have room to clear the LCA end, just drill a hole in the back of the LCA bracket to clip your tiedown onto. Or better yet, use the factory tie down spots on the chassis.

It is an eye bolt for tie down yes.

It is load rated, 5000 lbs if memory serves. Using the "T" bolt factory tie downs suck to access, I have eyebolts welded into the front of the K member for tie down also.

[FASTFATBOY]

Got it squared up today, was a PITA.

The torque arm bolts were loose, you could rotate the rear end 3/8 of an inch with a long screw driver.

I left the bolts loose, got the control arms adjusted correctly, straightened the bracket and put it all back together then tightened the torque arm bolts. Rear is now perfectly square in the car.

I also made some 3/16 plate fillers for the back of the plates.

Buddy will weld it up on Monday.

Thanks guys. This site is the shit.

PS I got my 35mm front bar, 21mm rear bar is on the way and my white Z28 rear end snubbers got here. Hope all this helps the old barge turn better.

This post has been edited by FASTFATBOY: Nov 14 2013, 11:46 PM