Track Alignment Setting

[JAJ]

You saved me a lot of writing.

However I will say that one of those laser alignment machines is only as accurate as the setup/operator/calibration.

I align my own car using a string alignment method. That's how the race teams do it.

Balls on.

Hey, @Tomster, that's a great shot of your alignment setup - your string arrangement is remarkably similar to mine. One question, though. How do you get the suspension settled back down to static ride height once it's up on the Race Ramp stands?

I have a set of those too, but when I lower the car onto them and the weight comes off the lift, the suspension doesn't relax all the way and the car sits a bit high. What's the trick? I'd love to be able to adjust the suspension, particularly the rear, on the stands but because of the the ride height difference, I don't.

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[Tomster]

Hey, @Tomster, that's a great shot of your alignment setup - your string arrangement is remarkably similar to mine. One question, though. How do you get the suspension settled back down to static ride height once it's up on the Race Ramp stands?

I have a set of those too, but when I lower the car onto them and the weight comes off the lift, the suspension doesn't relax all the way and the car sits a bit high. What's the trick? I'd love to be able to adjust the suspension, particularly the rear, on the stands but because of the the ride height difference, I don't.

My setup is obviously the poor man's setup. I plan to buy the gear you see on Dean Martins GT4 as pictured.

What I do is jack the car and put heavy duty contractor garbage bags below the wheel cribs so they move with ease during adjustment. That creates a near frictionless surface so that the wheels take the adjustment. Wheel turnstiles are a better option, but this gets the job done until I spring for the expensive gear.

Once the car is up in the air, install the steering wheel lock and then I bounce the front end and rear end extensively so that the car is settled. When it is up in the air like that, you have access to all the adjustments under the car.

Next, I string the car. The 1/2 EMT conduit is marked so that the front and rear strings are exactly the same distance apart. Next, I measure each center hub front and rear and square the strings and then begin to take measurements. There you know what needs to be adjusted. When you think you have it set, I bounce the car again. I recenter/verify the strings and remeasure. I tweak if necessary and then road test. If I have time, I'll string it out again to see how a road test moved anything. Usually, it is fine.

The advantage of the gear you see on the race car is that the points of reference are fixed to the car. You can bounce it all day long as well as Jack and lower it and the strings should maintain reference.

I use the following alignment calculator.

https://robrobinette.com/DIYAlignmentCalculator.htm

 

[Tomster]

Oh, and one other thing. Each track has its own alignment settings. A roval is different than a short more technical track. Always, the starting point (if you had no idea) would be to use the recommended track settings. Then through experimentation, you adjust. The best indicators are tire wear, handling, temps, and pressures.

I use a pyrometer to measure the inside of the tread vs the outside of the tread on the tire after I come in after several hot laps. If your tires are within 15 degrees from outer to inner, that is a good place to be.

Some think more camber is always better. Not always true. This last year at Daytona, I ran almost another degree of negative camber. Not only did the insides of my tires get chewed up, but I ran a second slower. More camber can also equate to less effective breaking as well as acceleration.

Its all experimentation based upon a learned result. Each varying condition will require a tweak. The pros usually are verifying all of this and re-stringing their car between sessions.

Anyway, my point was that alignment settings are not one size fits all.

 

[jmn444]

What's your usual setting Tomster?

 

[Tomster]

What's your usual setting Tomster?

For which track? It depends.

 

[Tomster]

For which track? It depends.

Up early. Have a long day tomorrow. I'll check in tomorrow.

 

[jmn444]

We are in diff parts of the country, so prob not much overlap maybe haha... I honestly just leave mine at -3.2 front and -2.2 rear. I'm kinda lazy about changing it up these days.

Mostly curious about where you felt braking was sacrificed. I've gone as high as -3.9 front and braking was my main reason for backing off.

home track is gingerman, i run grattan a good bit too... mid ohio, pitt race, ncm occasionally... adding indy road course this summer to the mix.

 

[pilotgore]

We are in diff parts of the country, so prob not much overlap maybe haha... I honestly just leave mine at -3.2 front and -2.2 rear. I'm kinda lazy about changing it up these days.

Mostly curious about where you felt braking was sacrificed. I've gone as high as -3.9 front and braking was my main reason for backing off.

home track is gingerman, i run grattan a good bit too... mid ohio, pitt race, ncm occasionally... adding indy road course this summer to the mix.

Ohh really, what group is running indy this year?!?! PCCA? I thought I heard Penske was backing off from HPDE stuff, but was hoping that was just a rumor. I might have to sign up for that one.

 

[jmn444]

Ohh really, what group is running indy this year?!?! PCCA? I thought I heard Penske was backing off from HPDE stuff, but was hoping that was just a rumor. I might have to sign up for that one.

It's a SAAC event so lots of shelbys/fords!

http://saac47.com/

*edit - not as many sessions as I'd like, but not a lot of opportunities to run there from what I've seen over the years... 5 sessions on thursday and 2 more on friday....

 

[Tomster]

We are in diff parts of the country, so prob not much overlap maybe haha... I honestly just leave mine at -3.2 front and -2.2 rear. I'm kinda lazy about changing it up these days.

Mostly curious about where you felt braking was sacrificed. I've gone as high as -3.9 front and braking was my main reason for backing off.

home track is gingerman, i run grattan a good bit too... mid ohio, pitt race, ncm occasionally... adding indy road course this summer to the mix.

I haven't forgot about you. Its been a long day and I'm on the road. Ill PM you what I use when I get home and check my notes.

 

[jmn444]

I haven't forgot about you. Its been a long day and I'm on the road. Ill PM you what I use when I get home and check my notes.

thanks, no rush!

 

[azshelby350]

Today at the track my car was experiencing understeer like I’ve never felt before, especially in one corner. It was a long 180 right hand decreasing radius turn with a late late apex, and my car kept wanting to push. My settings haven’t changed at all from the last couple tracks (-2.5F/-2R, neutral toe, SC2’s at 28 cold, 30-33 hot) so it must’ve been the crappy asphalt surface.

I want to start experimenting with toe more. Some tracks (again I think it’s the surface) almost make my car feel “slow”at responding to steering inputs where I think a tiny amount of toe out could help quicken it up.

 

[Egparson202]

Today at the track my car was experiencing understeer like I’ve never felt before, especially in one corner. It was a long 180 right hand decreasing radius turn with a late late apex, and my car kept wanting to push. My settings haven’t changed at all from the last couple tracks (-2.5F/-2R, neutral toe, SC2’s at 28 cold, 30-33 hot) so it must’ve been the crappy asphalt surface.

I want to start experimenting with toe more. Some tracks (again I think it’s the surface) almost make my car feel “slow”at responding to steering inputs where I think a tiny amount of toe out could help quicken it up.

It might be worth checking the toe. It could have changed. If it turns in well but starts under steering mid corner, I’d say you may have picked up some toe-in. Or maybe the tires are starting to heat cycle out.

 

[JAJ]

Today at the track my car was experiencing understeer like I’ve never felt before, especially in one corner. It was a long 180 right hand decreasing radius turn with a late late apex, and my car kept wanting to push. My settings haven’t changed at all from the last couple tracks (-2.5F/-2R, neutral toe, SC2’s at 28 cold, 30-33 hot) so it must’ve been the crappy asphalt surface.

I want to start experimenting with toe more. Some tracks (again I think it’s the surface) almost make my car feel “slow”at responding to steering inputs where I think a tiny amount of toe out could help quicken it up.

Sounds like heat cycling has run its course. Front grip tends to go away first.

 

[ShatterPoints]

Today at the track my car was experiencing understeer like I’ve never felt before, especially in one corner. It was a long 180 right hand decreasing radius turn with a late late apex, and my car kept wanting to push. My settings haven’t changed at all from the last couple tracks (-2.5F/-2R, neutral toe, SC2’s at 28 cold, 30-33 hot) so it must’ve been the crappy asphalt surface.

I want to start experimenting with toe more. Some tracks (again I think it’s the surface) almost make my car feel “slow”at responding to steering inputs where I think a tiny amount of toe out could help quicken it up.

Toe settings really are imo about min/maxing and almost driver preference. Basically you're fine to mess with toe until the car is not stable for you under braking or acceleration. When you cannot brake in a straight line then you have too much toe out in the front. What that amount is changes based on the car and what tires you're running. You're going to want a compromise of the best toe setting for turn in and tire life, and so that is somewhere between recommended toe settings and where the car has issues with straight line stability under braking and acceleration.

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