how does rear wheel camber effect rear steer
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by C3Racing
OMG you mean the upper control arm ? yes tighten that nut .. The last guys who did the aling might have not tightend it .. those dont come loose on there own..
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
would you believe that using a 10" box end wrench i got 3/4 of a turn on all 4 front upper control arm studs (both sides) i'm so pissed at this shop right now i could scream
Drifting
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From: Shore NJ
Originally Posted by bobs77vet
I haven't hit any curbs or anything other then regular pot holes, the strut rods are firmly in place and the trailing arms seem to have all the shims in place and the cotter pins are still in place. i will put the car up on jacks tomorrow and really go over the suspension componets. i bled all the brakes yesterday and went over each wheel pretty good as i took them off and reinstalled them. i didn't notice any problems i even grabbed each strut rod and tie rod end and really pulled on them to see if they were loose, i also checked for the front wheel bearings and did the 3-9 and 6-12 wobble check onthe rear wheels and it was nice and tight,
Jay what do you set the rear camber at in "negative inches" i'm at
(-3/16) to (-1/4) now on both rear wheels?
Jay what do you set the rear camber at in "negative inches" i'm at
(-3/16) to (-1/4) now on both rear wheels?
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by 73jst4fun
Bob, I never really measured the rear camber for +- numbers, I just make sure the tire/wheel is as plumb as I can get it and check it with a digital level or block level...
no negative camber then. well that shoots my theory that negative camber stopped rear steer....
those loose upper control arms do explain why on a particuarly bumpy section of road the car seemed kind of loose.....the damn wheels were not only going up and down they were going in and out.....i will have to see if that fixed the rear steer issue
Last edited by bobs77vet; Mar 8, 2006 at 08:47 AM.
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From: Waterloo ontario Canada
Originally Posted by C3Racing
I would take it to a shop that does alighnment's and see what all 4 wheels look like( SAE , total toe, ect)
It is time consuming but a labor of love. I feel my accuracy is better then the shop. While they have expensive equipment they don't take the time to get everything right.
Sure they get it within specs but one side can be on the high side of specs and the other wheel on the low side but again they are within specs.
That is not good enough. Both sides need to be the same.
My car steers alot better with the home alignment then with any of the 3 attemps by the "professionls".
A friend of mine worked the alignment rack for a about a year. He is an apprentice mechianic. I asked him about bump steer and he gave me a blank look.
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Norval do you remember me asking about "torque steer" a while back.....there is this section of road which is particuarly washboarded/rutted.....and it comes out of a traffic circle so you need to accelerate in it....the steering was particuarly driffty in this section....i was thinking it had to do with the rear end squatting down and the front end rising...bump steer...i'm now thinking it had more to do with the upper control arms being loose and the car would react differnently as the suspension moved up and down and also in and out...in essence the washboard effect really was making the upper contol arm move....i bet if i could get a leverage on those contol arm stud bolts i could get another 1/8 turn on them.....what do you suppose that 3/4 - 7/8 of a turn on the bolt holding it down translates into in terms of steering sloppiness?
Last edited by bobs77vet; Mar 8, 2006 at 10:49 AM.
Melting Slicks
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From: Montreal Qc.
Originally Posted by bobs77vet
..there is this section of road which is particuarly washboarded/rutted.....and it comes out of a traffic circle so you need to accelerate in it....the steering was particuarly driffty in this section....
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From: Waterloo ontario Canada
Originally Posted by Star79
I'd think this is more due to wide front tires following the ruts in the road surface. There's one busy elevated roadway here in Montreal that's so bad I'm scared to drive on it in my Vette, it jerks the wheel in my hand and tosses the car across the lanes. If it's raining there will be 2 inches of water in the "ruts" and none across the crown of the lane.
I ran soft springs and 90\10 shocks so the front end was comming up.
I then switched to 50/50 shocks and worked the bump steer out of it, same springs.
The car sticks like glue out of the hole, absolutely no torque steer. As for ruts and the seldom exibitted any funny steering but in one spot I new it always did show a little drift.
I then tied the rearend down with a massive rear sway bar and suddenly absolutely all ALL squirrelness in the steering is gone.
I do run 265 tires on the front and they do not follow any grooves.
I feel removing the bump took away most of the adverse steering and the rear sway bar finished it off.
All our corvette's benifit from dropping the outer tie rod, all of them.
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From: Brazos TX
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3/4 to 7/8 of a turn is about .033" to .040" or so. That could completely nullify a 1/16" toe-in setting but even the toe wouldn't be accurate becase that is the last thing you set during an alignment. If the nuts weren't tight when the toe was set then it could be anywhere. I think you are definitely feeling the upper a-arms moving around causing steering input via toe and camber change.
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by norvalwilhelm
.....I then tied the rearend down with a massive rear sway bar and suddenly absolutely all ALL squirrelness in the steering is gone......
I feel removing the bump took away most of the adverse steering and the rear sway bar finished it off.
All our corvette's benifit from dropping the outer tie rod, all of them.
I feel removing the bump took away most of the adverse steering and the rear sway bar finished it off.
All our corvette's benifit from dropping the outer tie rod, all of them.
i do have the steeroid setup so I think i do have the longer tie rod,although i don't think its dropped ....my front tires are 245/60..... Norval do you think all vettes benefit from a rear sway bar?
Originally Posted by burners
3/4 to 7/8 of a turn is about .033" to .040" or so. That could completely nullify a 1/16" toe-in setting but even the toe wouldn't be accurate becase that is the last thing you set during an alignment. If the nuts weren't tight when the toe was set then it could be anywhere. I think you are definitely feeling the upper a-arms moving around causing steering input via toe and camber change.
i appreciate everybodies help i really need to get this sorted out before i take it to another alignmnet shop. what do you guys use to tighten these stud bolts ? my deep sockets hit stuff, the short ones are too short....
Last edited by bobs77vet; Mar 8, 2006 at 12:02 PM.
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From: Brazos TX
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Yep, a zero toe or toe-out makes for a very responsive (twitchy) steering. If the upper a-arms are changing camber and toe I would expect very unpredictable handling. Between that and the loose strut rod your alignment was pretty goofy. I tighten the nuts on the a-arm studs with an open end wrench. The nuts are prevailing torque type so they won't back out on their own. They just need to be tight to hold the cross shaft against the frame.
You can do a basic alignment pretty easily yourself, especially to get it in the ball park. Use your level like you did with the rear to set camber. Set toe by sighting down the side of the car from about 15 ft in front of it. Get both wheels parallel or slightly toed in. Or use a tape measure to compare the front and back of the front tire to get a total toe reading. Or setup a string parallel to the side of the car and measure the front and back of the wheel.
The steeroids does lower the outer tie rod and shims can be added to lower it more, as needed.
You can do a basic alignment pretty easily yourself, especially to get it in the ball park. Use your level like you did with the rear to set camber. Set toe by sighting down the side of the car from about 15 ft in front of it. Get both wheels parallel or slightly toed in. Or use a tape measure to compare the front and back of the front tire to get a total toe reading. Or setup a string parallel to the side of the car and measure the front and back of the wheel.
The steeroids does lower the outer tie rod and shims can be added to lower it more, as needed.
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From: Waterloo ontario Canada
i do have the steeroid setup so I think i do have the longer tie rod,although i don't think its dropped ....my front tires are 245/60..... Norval do you think all vettes benefit from a rear sway bar?
I don't know how bad the steroid is for bump steer??
As for the rear sway bar I resisted until I started having problems braking in turns at high speed. I got my azz handed to me by a special selen mustang in the handling department.
I then went to the bar and it seemed to have solved all my problems with braking while turning.
I do run coilovers on the back as well so that might have something to do with how the bar helps.
I don't know how bad the steroid is for bump steer??
As for the rear sway bar I resisted until I started having problems braking in turns at high speed. I got my azz handed to me by a special selen mustang in the handling department.
I then went to the bar and it seemed to have solved all my problems with braking while turning.
I do run coilovers on the back as well so that might have something to do with how the bar helps.
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From: Waterloo ontario Canada
I feel to need a special toe gage to set toe. I don't believe you can do it with a simple tape measure. You need to be near the center height of the tire to set it and there is no way a tape measure can be used on the back at that height.
I use a homemade toe gage that measure toe in the center of the tire height.
I use a homemade toe gage that measure toe in the center of the tire height.
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From: Brazos TX
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I'm just recommending that method for a ball park setting, not an accurate one. It will at least get him to the alignment shop without being totally squirrelly and difficult to control.
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
well i got to tighten the drivers side front nut another 1/8 turn....the rest were tight....i had to use a crows foot wrench and a ratchet to get the best angle and leverage.....and i took it for my test drive, it was like a different car....remember that washboard road....i couldn't tell where it was....it was that noticable of a difference...under full acceleration it ran staright even over a wash board road, and it was quiet...
again here were all the symptons...i added some since they are now obvious:
1. noisy while going over bumps almost like something was loose(duh)
2. i called it torque steer...when the car shifted from one gear to another it pulled to the right
3. really darty on a wash board road
4. and some times it felt like rear was controlling the car...
5. kind of scary around a clover leaf almost like a over steer condition
6. the drivers side rear wheel was leaning noticably funny in towards the car
and heres the cure ....I took out about a 1/2" of negative camber out of the drivers side rear wheel since the jamb nuts were loose. I Tightened the nuts on the two upper control arms that hold the cross shaft to the frame one of them a full turn and the other three about 3/4 - 7/8 of a turn....funny how two loose control arms make a car steer funny!!!
again here were all the symptons...i added some since they are now obvious:
1. noisy while going over bumps almost like something was loose(duh)
2. i called it torque steer...when the car shifted from one gear to another it pulled to the right
3. really darty on a wash board road
4. and some times it felt like rear was controlling the car...
5. kind of scary around a clover leaf almost like a over steer condition
6. the drivers side rear wheel was leaning noticably funny in towards the car
and heres the cure ....I took out about a 1/2" of negative camber out of the drivers side rear wheel since the jamb nuts were loose. I Tightened the nuts on the two upper control arms that hold the cross shaft to the frame one of them a full turn and the other three about 3/4 - 7/8 of a turn....funny how two loose control arms make a car steer funny!!!
Last edited by bobs77vet; Mar 8, 2006 at 07:17 PM.
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From: Waterloo ontario Canada
Originally Posted by Yellow73SB
I have an alignmetn shop down the street from our shop that has been doing corvettes for 20 years. 
The novice mechanic doing the alignment really most of the time don't really know what is going on. The really good experienced guys aren't working on the alignment machine. That is reserved for the young apprentices.
I have friends who are mechanics, both put in their time on the alignment rack and both look at me with a dumb look when you talk about bump steer.
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by norvalwilhelm
20 years or a 100 years it doesn't matter....... The guy doing the alignment is the major factor. :
i am seriously thinking of getting the tools to do this at home....i just dont have any luck when ******** work on my car....the three shops that i trust just don't do alignments
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Norval i would be interested in the tools you used....as i was cutting some moulding tonight in the garage a small piece got sent airborne over the 37 ford and i realized that when i put the IFS in that i will have to learn to do my own alignments or else i could go broke taking it to a shop to tweak it....so i might as well practice on the vette. i bet the tools and techniques all apply
anybody use this??? alignment plate
http://www.harborfreight.com/cpi/cta...emnumber=45742
or this toe in measureing tool??
http://www.harborfreight.com/cpi/cta...emnumber=30167
anybody use this??? alignment plate
http://www.harborfreight.com/cpi/cta...emnumber=45742
or this toe in measureing tool??
http://www.harborfreight.com/cpi/cta...emnumber=30167
Last edited by bobs77vet; Mar 8, 2006 at 09:01 PM.