Advice on camber setting for track

[TeeLew]

BUT then everyone gives a measurement but doesn't give the reference frame.
That is the stupid part.
Thanks for the links.

The difference you're noticing is between the guys that are actually doing the alignment and the ones who have it done at a tire shop.

If you're the one actually doing the alignment with string, then you really don't care what the actual toe angle is. All you care about is that you can accurately reproduce it.

And as I pointed out, the difference in toe measurement if running 18 or 19 inch wheels is about 3/5ths of F.A. You're not going to notice the difference in that 0.1-0.2 mm error and it's never going to be the thing that determines how fast you can get around the track.

PSA - run 18's. Ford tried to get cute with the original Dark Horse series car & look where they are now. Only run 19's if you have to because of brakes.

 

[TeeLew]

Point in case, "assume" an 18' wheel, which i wouldn't caus i don't use them.

The snip from your link gave me the full picture. Here is all the information required to know we are talking about the same measurement.
Assumptions, the mother of all F'ups.

Take it easy, Francis.

 

[TeeLew]

Or lasers mounted on each wheel

Which works just fine, but I'll take string any and every day of the week over a laser.

 

[JAJ]

So, back when dinosaurs roamed the earth, 2018 to be precise, I was a guest of a pro racing team at an event at Mid-Ohio race track. I had a pit pass - and I watched a couple of races from the hot pits. Great fun.

From the time I spent in the paddock, I can tell you with absolute certainty that pro teams - prototypes, Porsche Cup, miscellaneous sports car classes teams - use string to set the cars up. When there's prize money on the line, laser just isn't reliable or precise enough. With a string setup, there's nothing that can go wrong. If someone drops a laser tool, you can't be sure it's accurate any more. If somebody drops a ball of string, they just pick it up and carry on.

 

[Junkyard Dog]

So, back when dinosaurs roamed the earth, 2018 to be precise, I was a guest of a pro racing team at an event at Mid-Ohio race track. I had a pit pass - and I watched a couple of races from the hot pits. Great fun.

From the time I spent in the paddock, I can tell you with absolute certainty that pro teams - prototypes, Porsche Cup, miscellaneous sports car classes teams - use string to set the cars up. When there's prize money on the line, laser just isn't reliable or precise enough. With a string setup, there's nothing that can go wrong. If someone drops a laser tool, you can't be sure it's accurate any more. If somebody drops a ball of string, they just pick it up and carry on.

Sigh.

So I guess I need to learn how to do this. Back to YouTube.

 

[GTP]

What laser makes a super narrow line at 9 feet away?
And how visible would a super narrow red line be anyway?
And if there is one, how much does THAT cost?

 

[GTP]

Sigh.

So I guess I need to learn how to do this. Back to YouTube.

Just order the Caliper Garage kit. Works fine. You will never go to an alignment shop again, and you will be more accurate too.

 

[TeeLew]

In the time between then and now, you'll find some sportscar teams have converted to lasers (maybe 25%), but they've done so because many of the newer setup systems have lasers built in. When first being used, the lasers will be calibrated with strings. The actual measurement accuracy is no more accurate or precise with lasers vs. strings. The advantage of the lasers is that they're a little faster to use. If you've got to get 3 cars across the pad before the next session, that can be important.

 

[TeeLew]

What laser makes a super narrow line at 9 feet away?
And how visible would a super narrow red line be anyway?
And if there is one, how much does THAT cost?

• Bloody expensive ones.
• They're easy enough to read.
• More than I have to spend.

 

[TeeLew]

So I guess I need to learn how to do this. Back to YouTube.

It's good for the soul.

 

[GAR944]

Take it easy, Francis.

Not having a go at anyone, far from it. Hadn't done the maths in my head as to degree of accuracy between methods either.
I appreciate the information to understand the whole system first. Then understand the shortcuts/what is vs isn't needed.
I do know that i think my last alignment wasn't correct so i adjusted the camber shims to get one side back to -4 and now the steering feels dead again. Previously the turn in was sharp.
Looks like i'll be gaining some more setup tools. Thanks again everyone for the links and information.
@TeeLew i specifically asked you for a reason. A good reason. I like the way you explain suspension.
And was that a Stripes reference, Love that movie.

 

[Dave_W]

With a string setup, there's nothing that can go wrong. If someone drops a laser tool, you can't be sure it's accurate any more. If somebody drops a ball of string, they just pick it up and carry on.

I tried my hardest, but I can't let this slide. If all you're doing is substituting the physical string with a light beam from a laser, there is no possible way anyone can drop the laser in a way that will make the light beam not be straight. If the light beam is bending an amount that's measurable on a ruler over the distance of your car's wheelbase, hold onto something because you're about to be sucked into a black hole.

What laser makes a super narrow line at 9 feet away?
And how visible would a super narrow red line be anyway?
And if there is one, how much does THAT cost?

The cool thing about lasers is that the beam doesn't spread (much), so if it's got a narrow beam at 1 foot, it's got a narrow beam at 30 feet. Think laser pointer. The problem with using a laser is eye protection for the given power output. If you want to use it in daylight, you'll probably want green instead of red (human eye is more sensitive), but even then eye-safe power may not be visible in daylight.

String is cheap, widely available (kite string at the toy store, fishing line at the sports store, butcher's twine at the grocery store), and easy to see in full sun.

 

[TeeLew]

The cool thing about lasers is that the beam doesn't spread (much), so if it's got a narrow beam at 1 foot, it's got a narrow beam at 30 feet.

Not in my experience. If it's got a narrow beam at 30 feet, you've got a very bright razor blade at 1 foot. I haven't seen any that give a narrow beam at 30 feet. It's hard enough to get that at 15. I haven't found dropping the lasers to be a problem.

I prefer fluorescent monofilament line, about 8# test. It's bright enough to give a good contrast and thin enough to be able to minimize measurement error. I don't like anything with 'hairs' coming off it it, like a kite string. I keep 2 Zebco 33 mini's with my alignment kit. They hang off the end of the toe bar to keep tension on the line.

 

[JAJ]

I tried my hardest, but I can't let this slide. If all you're doing is substituting the physical string with a light beam from a laser, there is no possible way anyone can drop the laser in a way that will make the light beam not be straight. If the light beam is bending an amount that's measurable on a ruler over the distance of your car's wheelbase, hold onto something because you're about to be sucked into a black hole.


The cool thing about lasers is that the beam doesn't spread (much), so if it's got a narrow beam at 1 foot, it's got a narrow beam at 30 feet. Think laser pointer. The problem with using a laser is eye protection for the given power output. If you want to use it in daylight, you'll probably want green instead of red (human eye is more sensitive), but even then eye-safe power may not be visible in daylight.

String is cheap, widely available (kite string at the toy store, fishing line at the sports store, butcher's twine at the grocery store), and easy to see in full sun.

I agree on your point that a laser that's dropped is still a laser. Where the issue lies is with the apparatus that positions it relative to the vehicle and the apparatus that measures the light and converts it to an angle or two. With string, it's all done with simple mechanical devices. With a laser, there's more stuff involved and that "stuff" has to be within calibration limits for it to work. It's not that it can't work, it's just that, even if a laser is working perfectly, it's no more accurate than string, so what's the point in using it? Now, if you're running a shop and you need to do 10 alignments a day, then lasers are magic. Conversely, if the next time the race car goes out is tomorrow afternoon, the extra few minutes it takes to set up with string simply isn't a problem.

 

[S650GT]

ok folks ..sorry for the late reply. In my last event few weeks backs I took a photo after 1 session. This is how the front tire looks. There is some rolling over the tire...First session I went out with lower temperature (28psi cold) and probably the tire wasn't warm enough and the wear in the side was more "severe". The upper part of the sidewall wear is what I typically see after the track day. These tires have seen 4 track days so far. Car is also a daily. Depth currently is measured at about 7-8



Part of my upcoming upgrades will be the following and I would like your input:
Brake performance (4 pistons front): flush and replace with Castrol SRF and install R10/R8 G-locs for front/rear for track days then switch them back to stock for street. No rotors replacements.
Do I have to sand down rotors every time I switch pads or a bedding-in procedure is enough by itself for switching back and forth ?

Differential fluid change to Amsoil 75W-80 or 75w-110 or 75W-140. Do I need to add friction modifier? Any noticeable changes when driving in the street? Can has no differential cooler

Driver's seat: FX 1 Pro. Anyone has experience with this one? Does it hold well? Every time I finish my HPDE I feel like I squatted 400 lbs with the stock seat

Transmission: Will add a transmission cooler from FP



Thank you

 

[TeeLew]

What corner was that and how the hell did you do that? 28 is not a low starting pressure.

 

[bnight]

ok folks ..sorry for the late reply. In my last event few weeks backs I took a photo after 1 session. This is how the front tire looks. There is some rolling over the tire...First session I went out with lower temperature (28psi cold) and probably the tire wasn't warm enough and the wear in the side was more "severe". The upper part of the sidewall wear is what I typically see after the track day. These tires have seen 4 track days so far. Car is also a daily. Depth currently is measured at about 7-8

View attachment 111073

Part of my upcoming upgrades will be the following and I would like your input:
Brake performance (4 pistons front): flush and replace with Castrol SRF and install R10/R8 G-locs for front/rear for track days then switch them back to stock for street. No rotors replacements.
Do I have to sand down rotors every time I switch pads or a bedding-in procedure is enough by itself for switching back and forth ?

Differential fluid change to Amsoil 75W-80 or 75w-110 or 75W-140. Do I need to add friction modifier? Any noticeable changes when driving in the street? Can has no differential cooler

Driver's seat: FX 1 Pro. Anyone has experience with this one? Does it hold well? Every time I finish my HPDE I feel like I squatted 400 lbs with the stock seat

Transmission: Will add a transmission cooler from FP



Thank you

R10/R8 are fine on the street though a bit on the noise side I drove with mine all the time but actually switched to DSUno/OEM Rears and I'm happier my car has never stopped like this. And it's also very good on the street. SRF is great for the fluid but if you can switch to6 pistons brembo's.

 

[GTP]

... There is some rolling over the tire...First session I went out with lower temperature (28psi cold) and ...

for track days then switch them back to stock for street. No rotors replacements.
Do I have to sand down rotors every time I switch pads or a bedding-in procedure is enough by itself for switching back and forth ?

Differential fluid change to Amsoil 75W-80 or 75w-110 or 75W-140. Do I need to add friction modifier? Any noticeable changes when driving in the street? Can has no differential cooler
...

Is that a summer tire? Perhaps a track tire would have stiffer sidewall.

I swap brake pads between street/track but I use the same rotors. I do not sand them. I never had a good result trying to sand off pad material. It doesn't budge for me.

I run Valvoline 75w140 diff fluid from Walmart, includes friction modifier in my Torsen diff. My exhaust is double heat wrapped around the diff area. I run DIY cooler. I used to turn on a battery powered Lowes shop fan, then back up to it (stopped by wheel chocks) until it was 2" off the diff. That worked fine. Once you exceed 260F diff temp, you should consider adding an active diff cooler. My steady state diff temp is now 230F regardless of session length. I certainly cannot tell what viscosity fluid is in the diff while driving. But I run 140wt simply for the elevated temp on track.

 

[Junkyard Dog]

I swap brake pads between street/track but I use the same rotors. I do not sand them. I never had a good result trying to sand off pad material. It doesn't budge for me.

Are your track and street pads from the same manufacturer?

 

[GTP]

No. I don't subscribe to that POV.
However, when I upgraded to GT350 brakes, I put track pads on with the new rotors and ran that on the street for a couple weeks. That way track pad material was the base material. I still doubt that it even matters.