C4 auto-x alignment questions
08-23-2006, 12:02 AM
#1
Drifting
Thread Starter
C4 auto-x alignment questions
Thinking about doing my first auto-x in many years. Thing is, I've got new tires with fresh alignment to street specs. Two questions:
1. If I removed front a-arm shims for negative camber just for the event, then replaced the exact shims afterward, would it have any effect on long term tire wear? Seems pretty simple. Maybe I'm missing something.
2. Existing shims appear to be about the thickness of a nickel. How many of these would equal approx. 1-2 degrees of camber?
1. If I removed front a-arm shims for negative camber just for the event, then replaced the exact shims afterward, would it have any effect on long term tire wear? Seems pretty simple. Maybe I'm missing something.
2. Existing shims appear to be about the thickness of a nickel. How many of these would equal approx. 1-2 degrees of camber?
08-23-2006, 08:39 AM
#2
Burning Brakes
If all you do is drive to the event and back without shims it will not have a great effect on tire wear (toe has more effect than camber).
I would recommend bringing the tools with you and removing the shims at the event site. That way there is no effect on the street.
Keep in mind that pulling all the shims on both sides may result in some uneven camber. But the conventional thinking on C4s is to pull all the shims on the front since the C4s are camber limited.
I would recommend bringing the tools with you and removing the shims at the event site. That way there is no effect on the street.
Keep in mind that pulling all the shims on both sides may result in some uneven camber. But the conventional thinking on C4s is to pull all the shims on the front since the C4s are camber limited.
Last edited by astock165; 08-23-2006 at 08:43 AM.
08-23-2006, 11:01 AM
#3
Melting Slicks
You need to yank all the shims, and then expect only to get about -.8 degrees in the left front and -1.2 on the right... There isn't much adjustment in there, so you get what you get and you don't pitch a fit....
There is generally a bit of a toe change associated with pulling all the shims and not resetting the toe. Not sure but I seem to recall that it resulted in a bit of toe out, just don't recall how much it was.
I generally just drove my C4's with my autocross alignment, with about an eighth of an inch of toe out and took the hit in tire wear. Yea, it chewed up the inside edge, but by the time the inside was gone the middle was 80% gone, so it really didn't kill the tire life that bad. Also, I rotated from front to back, and that kept them from cupping too much..Since you can only get, on average about a degree or so of negative camber in stock with all the shims out, it isn't worth the effort to yank them every time you run... I just left them out and set the toe and was done with it... If you are only running a few events a season, then I guess that I would do it, but if you are running every couple of weeks it isn't worth the trouble. I would check your toe, and see what you get with all the shims out, and expect to reset that if it is too much for running day to day.
I think it's easier to reset toe at each event than to yingyang with the shims. If you set you street settings to no shims and 1/8 inch of toe in, and then crank in about a turn of toe out at race time you will have the best of both worlds, the wear won't be that bad, and you will have a good race day setup.
There is generally a bit of a toe change associated with pulling all the shims and not resetting the toe. Not sure but I seem to recall that it resulted in a bit of toe out, just don't recall how much it was.
I generally just drove my C4's with my autocross alignment, with about an eighth of an inch of toe out and took the hit in tire wear. Yea, it chewed up the inside edge, but by the time the inside was gone the middle was 80% gone, so it really didn't kill the tire life that bad. Also, I rotated from front to back, and that kept them from cupping too much..Since you can only get, on average about a degree or so of negative camber in stock with all the shims out, it isn't worth the effort to yank them every time you run... I just left them out and set the toe and was done with it... If you are only running a few events a season, then I guess that I would do it, but if you are running every couple of weeks it isn't worth the trouble. I would check your toe, and see what you get with all the shims out, and expect to reset that if it is too much for running day to day.
I think it's easier to reset toe at each event than to yingyang with the shims. If you set you street settings to no shims and 1/8 inch of toe in, and then crank in about a turn of toe out at race time you will have the best of both worlds, the wear won't be that bad, and you will have a good race day setup.
08-23-2006, 01:39 PM
#4
Drifting
Thread Starter
If pulling all the shims results in a little toe out, that's good for auto-x, right? I'd think you'd want it to feel "twitchier" or quicker to turn as opposed to a highway setting where you'd want it to hold it's own line on interstate ruts, for example.
08-23-2006, 02:27 PM
#5
Team Owner
I'm running the "Advanced Street" alignment settings from this Vette Brakes page: http://www.vbandp.com/instructions/h...ruct/align.htm
The "Autocross Baseline" specs may not be very good for daily street use, but the Advanced Street settings work fine in my 87. I have not seen any adverse tire wear with that setup and I run -.5 degree neg camber and 0 toe in the front and the specs listed for Caster and the rear camber/toe settings.
The total thickness of shims on the passenger side are over twice what is on the driver's side and the driver's side has about 1/8" total shim thickness. I'm to too sure that removing all of the shims would help me too much given the disparity of the shim pack thickness.
I have the R-D Racing Camber Brace installed but I don't think that impacts the shim pack thickness for the alignment.
The "Autocross Baseline" specs may not be very good for daily street use, but the Advanced Street settings work fine in my 87. I have not seen any adverse tire wear with that setup and I run -.5 degree neg camber and 0 toe in the front and the specs listed for Caster and the rear camber/toe settings.
The total thickness of shims on the passenger side are over twice what is on the driver's side and the driver's side has about 1/8" total shim thickness. I'm to too sure that removing all of the shims would help me too much given the disparity of the shim pack thickness.
I have the R-D Racing Camber Brace installed but I don't think that impacts the shim pack thickness for the alignment.
08-23-2006, 04:06 PM
#6
Melting Slicks
Originally Posted by Scooter 94
If pulling all the shims results in a little toe out, that's good for auto-x, right? I'd think you'd want it to feel "twitchier" or quicker to turn as opposed to a highway setting where you'd want it to hold it's own line on interstate ruts, for example.
08-23-2006, 11:27 PM
#7
Burning Brakes
just go to a shop get maxed out camber you can get more by monkeying with the big chamfered washers i think i switched mine fromt to back have them set the toe out in front 1/8 inch in on back 1/8 inch
i have 1.5 degrees neg camber in front makes it a bit squirly on the street but awsome on the track
i have 1.5 degrees neg camber in front makes it a bit squirly on the street but awsome on the track
