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Bigben
Bigben HalfDork
3/14/24 9:08 p.m.

I couldn't tell what was rubbing even at full compression so I had to put the wide wheel on. It seems to be rubbing the sway bar at full lock.

Now the question is what to do about it? 

sevenracer
sevenracer HalfDork
3/14/24 11:33 p.m.

Love this build.

My rx7 has a bolt and jam nut on the steering knuckle that lets you adjust the max steering angle. Assuming nothing like that on your car?

jfryjfry
jfryjfry UltraDork
3/15/24 12:47 a.m.

Wheel spacers?

different offset wheels?

Bigben
Bigben HalfDork
3/16/24 1:02 a.m.
sevenracer said:

Love this build.

My rx7 has a bolt and jam nut on the steering knuckle that lets you adjust the max steering angle. Assuming nothing like that on your car?

There is a tang on the steering knuckle that stops against a loop of metal on the side of the control arm. The metal loop on the control arm has become concave over time so I filled it in with weld to limit steering angle. I suppose I could try building the stop up more. 

Bigben
Bigben HalfDork
3/16/24 1:10 a.m.
jfryjfry said:

Wheel spacers?

different offset wheels?

I'm already running 1.25" wheel spacers on the front due to the offset of modern 4x100 wheels. If I go any thicker the tire will stick out beyond the fender, which I'd like to avoid. 

I really didn't want to run anything wider than an 8" wheel but choices are limited on a Challenge budget.  Previously the best I was able to find in 15's were 6.5" wide which were not wide enough. Then I found these 9" wide ones last year with an offset that would be close, but I'm finding them just a bit too close to suspension parts. 

Bigben
Bigben HalfDork
3/16/24 1:27 a.m.

So looking more at the suspension and the rub marks on the wheel I'm second guessing what is rubbing. Yes the wheel lip can make contact with the body of the sway bar, but it only does so at full lock and at full compression on the inside tire. So, yeah, I'm not sure how that's gonna happen without hitting a pothole mid corner.

As I look closer I think it is more likely rubbing on the sway bar hardware or the tip of the composite front leaf spring.

Bigben
Bigben HalfDork
3/26/24 1:18 a.m.

Progress has been much slower than I'd like. I just finished up the left side front suspension:  areas that may be rubbing on the wheel were trimmed and smoothed, control arms painted and new poly bushings installed, and brake caliper painted. I also added a metal flange (flat washer) between the rear lower control arm bushing and the outer sleeve to remedy the problem of the thrust load on the control arm shearing the flange off the bushing and allowing the control arm to move rearward. (Damaged bushing on right, new one on left)

Bigben
Bigben HalfDork
3/26/24 1:22 a.m.

Here is the passenger side before:

And the driver side after:

Bigben
Bigben HalfDork
3/29/24 9:27 a.m.

I decided to remove the replacement KYB shocks and give the old original Koni single adjustable another try..

Bigben
Bigben HalfDork
3/29/24 9:34 a.m.

I also remedied one spot of wheel rub on the back with the strategic application of zip ties.

Bigben
Bigben HalfDork
3/30/24 7:33 p.m.

Side 2 done and all 4 shocks installed.

Bigben
Bigben HalfDork
3/30/24 10:07 p.m.

Time to see if I've fixed the wheel rub spots. 

Bigben
Bigben HalfDork
3/30/24 11:17 p.m.

I love this wheel and tire combo!

Bigben
Bigben HalfDork
3/31/24 12:21 a.m.

Went for a drive and something is still rubbing on the wheel, but the good one news is I now know what it is.

As the leaf spring compresses it flattens out and pushes the end link out and it contacts the wheel. 

Bigben
Bigben HalfDork
4/15/24 11:08 p.m.

So, last weekend at the Challenge the spring bolts still rubbed the wheels and what made it worse was the welds on my cut down Firebird front sway bar broke half way through the second run.

Since I no longer had a front bar I also disconnected the rear bar to help the Pro Driver get the power down on corner exit, and the additional body roll resulted in even more wheel rub.

Bigben
Bigben HalfDork
4/15/24 11:12 p.m.

The pro driver did a great job with no sway bars trying to get the best time while trying not to shred my front wheels too much with the spring end link bolts. He posted an autocross time good enough for 17th overall (including both over and under budget cars.) Compared against only $2000 cars it was good enough for 9th best time. It was also 9th overall of cars on street class tires, and 4th against $2000 cars on street class tires.

 

Bigben
Bigben HalfDork
4/16/24 12:11 a.m.

We came back with a bit of hardware.

And special thanks to my pit crew and detailer!

My son is already planning to build a car for next year and build one with his friends.

DeadSkunk  (Warren)
DeadSkunk (Warren) MegaDork
4/16/24 9:01 a.m.
Bigben said:

So, last weekend at the Challenge the spring bolts still rubbed the wheels and what made it worse was the welds on my cut down Firebird front sway bar broke half way through the second run.

Since I no longer had a front bar I also disconnected the rear bar to help the Pro Driver get the power down on corner exit, and the additional body roll resulted in even more wheel rub.

I'll offer up a couple of suggestions. Don't try welding a sway bar on the main bar, just weld new attachment tabs on the ends, less stress on the weld that way. Find a simple shape to do it to. I spent some time Googling an Opel bar and I have no dimensions to compare to, but a bar like a Dodge Caliber might work. It all depends on finding an approximate width and I suspect your bar is quite narrow. I'll see if I can find a picture of the bar I modified for my Challenge Miata a few years ago. It was a Ford Ranger unit with new end pieces welded on. It didn't break.

Bigben
Bigben HalfDork
4/16/24 2:01 p.m.

In reply to DeadSkunk (Warren) :

I shortened the bar from both ends and welded the ends back on to the shorter center section. In addition to welding the tube I also put a short piece of rod inside the tube and drilled holes through the tube to spot weld the rod to the tube in addition to butt welding the tube. 

In my mind it should have worked but it looks like the weld did not have enough penetration.

I may still look at something different because the ends of the bar did limit the amount of steering angle before tire rub occurred.

Bigben
Bigben HalfDork
4/16/24 2:22 p.m.
Bigben said:

I took off the solid 7/8" VW sway bar I had on the front and picked up a significantly larger diameter 4th Gen Firebird sway bar. I shortened it to fit, swapped the ends and welded them back on.

Here are the pics of the weld connection that failed.

DeadSkunk  (Warren)
DeadSkunk (Warren) MegaDork
4/16/24 2:51 p.m.

In reply to Bigben :

Hmmm....I would have thought that would work. Post the stock Opel bar dimensions. I enjoy a puzzle and might stumble on something that can be welded at the ends and fit. That's a simple bar, so something else might work. How thick is the Firebird bar?

Edit: Do your wide wheels hit anything with the stock bar in place?

 

Bigben
Bigben HalfDork
4/16/24 7:11 p.m.

In reply to DeadSkunk (Warren) :

I'll have to get some pictures of the underside and dimensions. The bars they sell for Opels don't work because the SR20 oil pan is different from the Opel one, and yes the steering angle is limited by the wide wheels. Also the brake caliper can hit the end of the sway bar at certain points in the suspension travel when at full lock. 

preach
preach GRM+ Memberand UltraDork
4/16/24 8:02 p.m.

In reply to Bigben :

Fantastic!

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