Hey all,

I'm starting to attack a problem that I've had for a pretty long while. The car is pulling to the left. The faster I go, the more I have to adjust. Here are the relevant specs on the car:

- Strange Dana S60
- Spohn rod/poly LCAs
- Stock PHR
- Spohn tranny mounted adjustable torque arm (set at 0* preload)
- American Racing TT2s (17x9.5" fronts and 17x10.5" rears)
- Nitto 315 555Rs in the rear (~5k miles)
- BFG 275 G-force Sports in the front (~20k miles, swapped left to right due to sholder wear at ~15k miles)
- Brembo blanks, Hawk HPS pads, stock calipers, stock master, stock lines (except line lock) all with ~35k miles... pads and rotors are on their last leg

So, the first thing I did was take the car to get the front end aligned. It was not far out, but they did bring it in to some extent. This seemed to make little to no difference in the issue.

I started thinking at that point that the rear end must not be square to the front. So, I put the car in the air today. I pulled the front on ramps and jacked the back up on and set it up on jackstands. I used a plumb bob on the bolts that connect the LCAs to the rear end and marked the spot on a piece of tape on the floor. I then went to the front of the car and used the holes in the bottom of the A-arms to do the same thing. To keep it consistant, I ran the string up through one hole and back down out of another.

When I measured the front-to-back distance on each side, it was exactly the same. It might've been 1/64" off at most. I then thought about the fact that the rear end might not be centered because of my stock LCA and the fact that the rear suspension was completely unloaded. So, I measured from corner to corner and found the difference to be 1/16". That's pretty damn accurate for a 112.5" measurement (roughly).

So, where do I go from here? I supposed it could be a brake issue, but as far gone as my rotors and pads are, if one of them had been dragging all this time, I'm sure it would be metal to metal by now. I hear no scraping sounds from the brakes at all yet. It could also be an issue with tires being different diameters in the rear, but the Nittos have seen the same miles. Plus, if one would be smaller, it would no doubt be the passenger side, which would promote the car pulling to the right, not the left.

Can anyone suggest some more troubleshooting steps for me? Do I need to have the rear end aligned professionally, or something?

 

Tony... glad to see you verify that the car is "square". I know I had Mike check that axle to ensure that it was installed correctly when you and I first met.. glad to see it has not moved.

It might be that the car wants some preload in the suspension as taking measurements in a static state is different than in a loaded state. If you'd like to get me some detailed info on the nature of the condition I would be happy to run it by my Chassis Tuner Jason from Tx Racewerks. He and I have been working closely on Tuning several cars this year.

I also want you to get in touch with Madman... Brian knows his ****. Make no mistake his opinion would be valuable.

Call me next week and we'll see if you can't come out to the track when we are running next weekend. We have a couple of big tire cars to Tune on. I want to see what it does in a controlled environment.

g

 

Hey Gilbert,

Thanks for the reply, man. I'll try jacking the car up a bit more and putting the rear on ramps, too, instead of jackstands. That way I can measure it all again with the rear suspension loaded.

I'll be eager to hear what Jason says about it. I'll give you a buzz this week to talk about it.

When/where are you going to the track? We're going to be at Ennis on Saturday for TMCCC. We're gunning for first in our class.

 

While I'm following Gilbert's advice here, does anyone have any other insights?

 

Just for posterity, I thought I would post what the actual problem was... tires. I talked to Gilbert (Ratchthed) on the phone, and we discussed the troubleshooting I'd done, and he suggested swapping my front tires (left to right) to see if the problem changed any. Sure enough, the car started pulling the other way just a tad.

I went and bought a new set of tires. What do you know?! The car drives straight as an arrow now! Thanks a bunch, Gilbert. You saved me again.