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View Full Version : Mid Corner Steering Wheel Flutter/shake



Supercharged111
09-19-2015, 12:34 PM
Ever since I bumped my camber over 2 degrees, the front digs in really nicely. The other thing it does is the steering wheel will shake in a sweeper and also when the car understeers. Am I lifting a tire? Does this sound like a travel issue?

GlennCMC70
09-19-2015, 04:00 PM
What is caster @?

Suck fumes
09-19-2015, 04:58 PM
Front shocks wore out?

GlennCMC70
09-19-2015, 05:39 PM
Low tire pressures will also cause this.

Supercharged111
09-20-2015, 12:02 AM
Caster is unknown, I got wildly inconsistent readings the last time I tried, but they seemed to imply I was in the 4 degree range. I found this odd as the lower adjustment slots were maxed out. I've since hogged out the upper mounts as well so I could hit my camber targets, currently running 2.3 there with 1/8 toe out and the front is doing its job for once. I need to drop spring out back to balance the car better, but it's pretty fast as it sits. I target 35-36psi hot as this seems to get the tires to roll over optimally and the temperatures across the face are consistent too. To optimize, the car seems to want more camber to be 15 degrees hotter on the inside but at this point I feel I need to address the rear spring rate first and also this newfound steering wheel shake. As for shocks, I don't know how to assess them on a race car

GlennCMC70
09-20-2015, 09:21 AM
Did you slot the lower adjustment slots or are they the stock length?

Rubber bushings in the a arms?

Fbody383
09-20-2015, 06:49 PM
Front hubs gone?

I still run stock bushings. Only time i've had front end shimmy was bad hubs or loose control arm bolt.

Supercharged111
09-20-2015, 09:37 PM
Everything's slotted, stock hubs but a great brake pedal so I doubt they're to blame. It seems it does it when the tires break loose. Did it more with cycled out RA1s than not-yet-cycled out RRs. Lowers are the Global West heim kit (in good shape), uppers are new Moog rubbers.

Fbody383
09-21-2015, 11:15 AM
Everything's slotted, stock hubs but a great brake pedal so I doubt they're to blame. It seems it does it when the tires break loose. Did it more with cycled out RA1s than not-yet-cycled out RRs. Lowers are the Global West heim kit (in good shape), uppers are new Moog rubbers.


Ever since I bumped my camber over 2 degrees, the front digs in really nicely. The other thing it does is the steering wheel will shake in a sweeper and also when the car understeers. Am I lifting a tire? Does this sound like a travel issue? Steering rack/tire rod ends? Maybe it is the tires recovering...

Let me drive if off track... I mean for a few hot laps and see.

Supercharged111
09-22-2015, 10:33 AM
I see what you did there, but you know my car goes off road with this loose nut behind the wheel. So I did replace the steering rack with a functioning non-leaky junkyard unit prior to Hallett. There isn't any slop from what I can tell, is there some other mode of failure?

GlennCMC70
09-22-2015, 11:51 AM
I would spend the time and money and go to an alignment shop w/ a machine. Get it set and take it straight home and duplicate the numbers. At least see what your equipment reads and compare to the digital rack numbers. Get a good reference point. Caster is one of the more "subjective" measurements. Its also what could be hurting you. 4 degrees sounds low. I run 4.7 or so. Less static camber ='s more caster needed.

Supercharged111
09-22-2015, 12:14 PM
I was thinking the 5 range would have me close, but I don't see where that'd cause the wheel to shake? Unless I have way more than that somehow? Tire Temps are telling me to add more camber, but if my caster is actually 4 I'd prefer to get more camber gain from caster before bumping up more.

GlennCMC70
09-22-2015, 12:37 PM
Your on the right track. More camber hurts straightline stopping. So get that low to a point. Then work caster. Caster will be dictated some by how much slip angle you like in the rear.
My rule was if you turn the steering wheel more than 45 degrees, the rear is too tight. Let the back of the car turn the car some.
W/ 16's, my set-up was w/ 2.25 camber and 4.7 caster.
Swaybar size and spring rates will affect everything as well.

Supercharged111
09-22-2015, 05:09 PM
I'm definitely feeding in over 45 degrees ever since I dropped 300# of spring in the front and 50 out back. Despite that, the car is faster and more consistent. I'd been wanting to find that unicorn rack from some sport package Chevy supposedly offred, but can never locate a part number. I didn't realize there were other alternatives to reduce required steering input.

Pranav
09-23-2015, 10:51 PM
Are you running the f41 or fe2 rack? One is 2.75 turns lock to lock while the other (desirable) is 2.25. For the longest time most of the reman sources had separate part numbers for both. Unfortunately now they are all (including acdelco) sold under the same part number so your option is to check end to end turn count by hand in store before accepting or buy a known used junkyard rack and have turn one re do it right.

Supercharged111
09-24-2015, 09:12 AM
I think it's safe to assume the worst, old leaked was a reman and my current one is an original from a late V6 car. I'll be looking for those RPOs in the junkyard from now on. I've seen a mention of the LS1 racks being different than the LT1 racks, something with the angle of the input nub? Anything to watch out for there?

Pranav
09-24-2015, 10:32 AM
I think it's safe to assume the worst, old leaked was a reman and my current one is an original from a late V6 car. I'll be looking for those RPOs in the junkyard from now on. I've seen a mention of the LS1 racks being different than the LT1 racks, something with the angle of the input nub? Anything to watch out for there?

Yeah the angle on the LS1 racks are lower (45*) to clear that alternator. The 93-97 will have a steeper/taller (60*) Angle.

The best way to tell what you've got is just take wrench to the input shaft and turn it lock to lock. If the rack is in car just turn the steerign wheel

eBay has a good selection of racks where they take the picture of the car and tell you exactly what it is coming out of, no guess work. I believe all z28s/trans ams are going to have the correct 2.25 rack.

Supercharged111
09-24-2015, 02:09 PM
So the LT1 cars can run either I'm guessing? I'll see what I have when I get back.

Daniel Allford
09-25-2015, 10:58 AM
#82 LT Camaro has had shudder in the steering wheel on several occasions. In every case there was play in the steering. But there have been 3 different causes. 1. Loose steering rack, we now double nut the rack in place. 2. Broken steering rack mounts which require rack replacement 3. Broken K member. I have welded the K member 5-6 times, no my welds didn't break, the failure simply moves to another point on the K member as far away as 12" from the lower pick up point. It has be become routine maintenance for me to weld up the K member after most races this year. After TWS we had major cracking on the passenger side. After Hallet (no I didn't go off road or fly or hit anyone) we had cracks on the driver side along with a broken lower shock mount. This is why I voted against the stickier RR tires.

I would like to see tubular K members allowed as the stock units require constant repair & are hard to find.

Bottom line: ANY time I feel shudder in the wheel while cornering we look for cracks and fire up the welder.

Dan Allford
#82

Supercharged111
09-25-2015, 03:19 PM
Wow, I'd looked at the ears where the arms mount but gave zero consideration to the thing a foot away. I'll give that a peek in addition to the rack's mounting for sure!

Al Fernandez
10-01-2015, 07:42 PM
Maybe you should just drill a couple of holes in that k member and allow it to flex a bit Dan :)

Trublu
10-01-2015, 07:59 PM
Maybe you should just drill a couple of holes in that k member and allow it to flex a bit Dan :) or just drill a 1/16" hole to stop the crack propagating....

Supercharged111
10-01-2015, 11:03 PM
I gave mine a good once over and can't find any cracks.