Question about alignment specs
Thread Starter
East bound and down...
Joined: Dec 2004
Posts: 987
Likes: 3
From: Jonesboro Arkansas
Question about alignment specs
Ok guys bare with me here, I am not very knowledgeable in the area of alignments. I am just now getting my car to the point where I would even consider the occasional autocross, up until now I have only been concerned about what the car would do in a straight line. 
I was comparing aligment specs between VBP and Guldstrand's recommendations. I have found they are very similar in most areas, aside from caster.
VBP recommends + 2.75 degrees across the board whether the car is a DD or a race car.
Guldstrand recommends anywhere from + 1.5 deg for a DD to +3 deg for a race car.
How noticeable are the effects of caster for everyday handling? My car will spend 98% of the time on the street, with maybe 1-2 small autocross events in the year.
Also, another stupid question, how do you adjust caster on a stock front end?
I was comparing aligment specs between VBP and Guldstrand's recommendations. I have found they are very similar in most areas, aside from caster.
VBP recommends + 2.75 degrees across the board whether the car is a DD or a race car.
Guldstrand recommends anywhere from + 1.5 deg for a DD to +3 deg for a race car.
How noticeable are the effects of caster for everyday handling? My car will spend 98% of the time on the street, with maybe 1-2 small autocross events in the year.
Also, another stupid question, how do you adjust caster on a stock front end?
Last edited by LS-Five; Sep 26, 2006 at 07:22 PM.
Thread Starter
East bound and down...
Joined: Dec 2004
Posts: 987
Likes: 3
From: Jonesboro Arkansas
As it stands right now, I plan on having the car aligned to these specs:
Front/ Rear
Toe 0" / 1/8"
Camber -.50 deg / -.50 deg
Caster +2.75 deg
Given the use of the car, does anyone see anything wrong with these specs?
Front/ Rear
Toe 0" / 1/8"
Camber -.50 deg / -.50 deg
Caster +2.75 deg
Given the use of the car, does anyone see anything wrong with these specs?
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by LS-Five
As it stands right now, I plan on having the car aligned to these specs:
Front/ Rear
Toe 0" / 1/8"
Camber -.50 deg / -.50 deg
Caster +2.75 deg
Given the use of the car, does anyone see anything wrong with these specs?
Front/ Rear
Toe 0" / 1/8"
Camber -.50 deg / -.50 deg
Caster +2.75 deg
Given the use of the car, does anyone see anything wrong with these specs?
Camber is adjusted by adding/removing EQUAL THICKNESS on the shims between the control arm shaft and the frame.
Thread Starter
East bound and down...
Joined: Dec 2004
Posts: 987
Likes: 3
From: Jonesboro Arkansas
Originally Posted by SanDiegoPaul
If the roads in your area are crowned for rain runoff, then use 1/4 neg on the right side camber, if you are ging to run 1/2 neg on the drivers side.
Camber is adjusted by adding/removing EQUAL THICKNESS on the shims between the control arm shaft and the frame.
Camber is adjusted by adding/removing EQUAL THICKNESS on the shims between the control arm shaft and the frame.
:o oops. I meant to say caster not camber.
Drifting
Joined: Jul 2002
Posts: 1,995
Likes: 110
From: Garland Texas
Caster is adjusted by adding or removing shim(s) from the front or rear upper a frame bolts. Caster gives hi speed stability. The more caster the more the front end fights to keep it straight. More caster also increases turning effort. 10 degrees caster would help keep the car straight at 150mph but would take both hands to turn the wheel at 10 mph.
Due to frame sag, worn or settled bushings, or bent parts you may not get to 2.75 castor. .5 neg camber on all 4 wheels is fine. Toe-in between 1/16- 1/8. You don't 0 toe. Car will be darty under braking. Also you need someone to sit in the car during the alignment or something to equal your weight. Specs can change more than half a degree.
Get a printout before and after they do the alignment so you can post the numbers for us.
Mike
Due to frame sag, worn or settled bushings, or bent parts you may not get to 2.75 castor. .5 neg camber on all 4 wheels is fine. Toe-in between 1/16- 1/8. You don't 0 toe. Car will be darty under braking. Also you need someone to sit in the car during the alignment or something to equal your weight. Specs can change more than half a degree.
Get a printout before and after they do the alignment so you can post the numbers for us.
Mike
Drifting
Joined: Jul 2002
Posts: 1,995
Likes: 110
From: Garland Texas
It really depends on what kind of driving you are doing. Let's say you are driving on the autobahn. Hi speeds and graceful curves. You would want to run as much caster as you can. But if you were driving a low speed autocross with a lot of tight corners you would want less caster since you don't need the hi speed stability and you would have reduced steering effort. Wheels and tires with more offset compared to stock require more caster to compensate for rolling resistance. There is no magic number for caster. All you can do is try different amounts and see what suites your driving. For a street driven vette 1 1/2- 2 degrees is a good starting point.
Mike
Mike
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Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by LS-Five
Ok, thanks for the info. Can you explain the variance between the recommended caster between what VBP recommends vs. what Guldstrand recommends?
Why are Gulstrand's settings different? Possibly because they are expecting you to be using thier modified suspension? Just a guess.
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
I like to put as much positive caster as possible in a car as long as it has power steering. You can run up to 8 degrees on the newer cars for good straight line running. On our vets with modifications you can get around 5 positive and it makes the car run true down the road.
Try for as much positive camber as possible but the most important thing, THE MOST IMPORTANT is to have the specs the same side to side. Don't just let the setting fall within specs, they MUST be the same side to side.
So set the caster as positive as possible, I don't like alot of negative camber because the tires at rest look like the suspension is sagging so I set it close to zero with only a slight negative preference but again equal.
I set toe at toe in about 1/16.
Try for as much positive camber as possible but the most important thing, THE MOST IMPORTANT is to have the specs the same side to side. Don't just let the setting fall within specs, they MUST be the same side to side.
So set the caster as positive as possible, I don't like alot of negative camber because the tires at rest look like the suspension is sagging so I set it close to zero with only a slight negative preference but again equal.
I set toe at toe in about 1/16.
Melting Slicks
Joined: Jan 2004
Posts: 3,247
Likes: 210
From: Detroit MI
Originally Posted by norvalwilhelm
Try for as much positive camber as possible but the most important thing...
You guys have to keep your alignment parameter talk straight or you'll confuse the noobs!!!
Burning Brakes
Joined: Aug 2006
Posts: 1,217
Likes: 5
From: Stark County Ohio
Originally Posted by tracdogg2
It really depends on what kind of driving you are doing. Let's say you are driving on the autobahn. Hi speeds and graceful curves. You would want to run as much caster as you can. But if you were driving a low speed autocross with a lot of tight corners you would want less caster since you don't need the hi speed stability and you would have reduced steering effort. Wheels and tires with more offset compared to stock require more caster to compensate for rolling resistance. There is no magic number for caster. All you can do is try different amounts and see what suites your driving. For a street driven vette 1 1/2- 2 degrees is a good starting point.
Mike
Mike
For the street run as much caster as the car will allow, and if you have the stock A-arms that will not be a lot - unlike modern cars. If your car is a non-power steering car, steering effort will increase along with the caster angle.
Burning Brakes
Joined: Aug 2006
Posts: 1,217
Likes: 5
From: Stark County Ohio
Quote:
Originally Posted by SanDiegoPaul
If the roads in your area are crowned for rain runoff, then use 1/4 neg on the right side camber, if you are ging to run 1/2 neg on the drivers side.
Camber is adjusted by adding/removing EQUAL THICKNESS on the shims between the control arm shaft and the frame.
Quote:
Originally Posted by SanDiegoPaul
oops. I meant to say caster not camber.
/////////////////////////////////////////////////////////////////////////////////
You were correct the first time.
Originally Posted by SanDiegoPaul
If the roads in your area are crowned for rain runoff, then use 1/4 neg on the right side camber, if you are ging to run 1/2 neg on the drivers side.
Camber is adjusted by adding/removing EQUAL THICKNESS on the shims between the control arm shaft and the frame.
Quote:
Originally Posted by SanDiegoPaul
oops. I meant to say caster not camber.
/////////////////////////////////////////////////////////////////////////////////
You were correct the first time.
Thread Starter
East bound and down...
Joined: Dec 2004
Posts: 987
Likes: 3
From: Jonesboro Arkansas
Originally Posted by timemender
For the street run as much caster as the car will allow, and if you have the stock A-arms that will not be a lot - unlike modern cars. If your car is a non-power steering car, steering effort will increase along with the caster angle.Ok, sounds good. My car is P/S equipped so I will tell them to shoot for as much caster as they can get.
Anybody else have any contributions that they would like to make? The car goes into the alignment shop this afternoon.
Thread Starter
East bound and down...
Joined: Dec 2004
Posts: 987
Likes: 3
From: Jonesboro Arkansas
Well, bad news. I just thought that I was going to get my car aligned today. When they checked the front end we discovered that I have two bad lower ball joints. The worst part is that I rebuilt the entire front end only 700 miles ago. 
I hate fixing the same stuff twice.
Oh, well I guess I will just have to suck it up and go on.
I hate fixing the same stuff twice.
Oh, well I guess I will just have to suck it up and go on.
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Originally Posted by LS-Five
Well, bad news. I just thought that I was going to get my car aligned today. When they checked the front end we discovered that I have two bad lower ball joints. The worst part is that I rebuilt the entire front end only 700 miles ago.
I hate fixing the same stuff twice.
Oh, well I guess I will just have to suck it up and go on.
I hate fixing the same stuff twice.
Oh, well I guess I will just have to suck it up and go on.
Thread Starter
East bound and down...
Joined: Dec 2004
Posts: 987
Likes: 3
From: Jonesboro Arkansas
Ok, thanks for the tip. I can't believe that the ball joints would be shot so quickly. I know for a fact that they were lubed properly, because I did it all myself. It must have just been a bad batch.
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Did you use rubber or poly when you rebuilt em?
I set my alignment up to VB&P's autocross specs because I drive like 5 miles a day and it rains here like twice a year.
Toe out is great for autocross but don't dare take your hands off the wheel because it will TURN on you. 
I have my front toe out just a tad with the rear toe in a tad. Handles rather good for autocross that way.
I set my alignment up to VB&P's autocross specs because I drive like 5 miles a day and it rains here like twice a year.
Toe out is great for autocross but don't dare take your hands off the wheel because it will TURN on you. I have my front toe out just a tad with the rear toe in a tad. Handles rather good for autocross that way.
Thread Starter
East bound and down...
Joined: Dec 2004
Posts: 987
Likes: 3
From: Jonesboro Arkansas
I used poly bushings when I rebuilt the suspension. While I don't plan driving in the rain, the roads here in Arkansas can be pretty bad at times. Lots of wear ruts in the road from big rigs loaded too heavy.