Alignment spreadsheet

[i3igpete]

keywords: camber toe front rear total in out negative positive bumpsteer stable unstable crash

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[TBK]

Nice initiative

That's my old setup. Increased front camber to -3.8

 

[i3igpete]

Yeah, at the end of the day, most folks are limited by the hardware they have installed on that particular day. But it's a starting point for someone coming to bmw alignments from something else that might be less sensitive

 

[Subydude]

Mine is right in the mix as well.

-3.7F/-2.5R camber
0 toe front/.2 degrees toe in each side for .4 degrees total toe rear
8.1 degrees caster (non-adjustable, but at least even on each side)

Initial install of the camber plates had the front at -3.4 degrees, but after 4 track events it seems to have settled at -3.7 and still not binding on the oem upper spring perch bearing. I also increased rear camber from -2 to -2.5 and it made it more stable.

 

[TBK]

So many people running 0 toe in the front. Preference I guess. I like the sharper turn in. And I don't feel any instability under braking

 

[razorlab]

life begins at -4 front with most strut based cars.

 

[TBK]

life begins at -4 front with most strut based cars.

At 3.8 I'm close. Not sure what to make of the fact that nankang recommend -2-3

 

[Subydude]

So many people running 0 toe in the front. Preference I guess. I like the sharper turn in. And I don't feel any instability under braking

I haven't done the ackermann angle calc to see what it says the car really wants, but my default preference on track is 0ish toe. Even in autox settings I rarely do more than .07 degrees toe out per side in front.

At 3.8 I'm close. Not sure what to make of the fact that nankang recommend -2-3

I once stumbled on the Bridgestone JP website that had their recommended camber settings for a lot of cars and it was much lower than I expected. I'm not surprised Nankang is similar. I think there's far too many variables between setups involved and it really comes down to what works for you and the car.

That said, I did have a good conversation with some Michelin engineers at one point about the GM spec PS4S tire construction. GM recommended -2 degrees front and rear, which wore the outside shoulder first. I tried running -3 degrees for better grip/wear and surprisingly it made the car harder to drive in stock form AND wore the inside shoulder more than I expected (with 0 toe). So there's always multiple sides to a given recommendation, and not always for the same reasons.

 

[TBK]

I haven't done the ackermann angle calc to see what it says the car really wants, but my default preference on track is 0ish toe. Even in autox settings I rarely do more than .07 degrees toe out per side in front.

What's worked for me is starting at either 0 or near 0 and then gradually adding a tiny bit more until any of the less desirable effects kick in. Mainly being a bit squirly under braking. But a little bit of toe adds both shaper turn in and feel. Give me that.

 

[Subydude]

What's worked for me is starting at either 0 or near 0 and then gradually adding a tiny bit more until any of the less desirable effects kick in. Mainly being a bit squirly under braking. But a little bit of toe adds both shaper turn in and feel. Give me that.

I'm glad that method works out for you

I tend to be a bit more ham fisted, or at least I once was when I started tracking so I generally prefer a car that has good feedback, but also is a bit softer in front. When I get in a car that's got a lot of front axle bite I usually end up getting more rotation than I expect and have to back it down. I haven't actually tried toe out on the Supra front axle since it's already happy to rotate when I want as it is.

 

[TBK]

I'm glad that method works out for you

I tend to be a bit more ham fisted, or at least I once was when I started tracking so I generally prefer a car that has good feedback, but also is a bit softer in front. When I get in a car that's got a lot of front axle bite I usually end up getting more rotation than I expect and have to back it down. I haven't actually tried toe out on the Supra front axle since it's already happy to rotate when I want as it is.

I find it fascinating how much much preference is baked into these things.

I'm all about front end feel. The S2000 has spolied me forever in that regard. Also need to offset going to a much wider tire in the front. 295.

 

[razorlab]

At 3.8 I'm close. Not sure what to make of the fact that nankang recommend -2-3

Really depends on a lot of factors, although I do know they like more negative camber than most because their sidewalls aren't the stiffest. I kept going faster with them the more negative camber I added on my car.

Then I tried the RE71RS and CRS were dead to me after that.

 

[razorlab]

I'm all about front end feel. The S2000 has spolied me forever in that regard. Also need to offset going to a much wider tire in the front. 295.

I would def nudge you to do slight stretch and use tires with stiff sidewalls. Minus the grip, the V730's in 275/35/18 on 18x10.5 have the best steering feel of all setups I have used so far on the supra. I contribute that to them running slightly narrow so slight stretch, and stiff sidewalls.

It's the Japanese Time Attack style setup.

 

[Nugs]

This is mine if you wanted to add.

 

[TBK]

I would def nudge you to do slight stretch and use tires with stiff sidewalls. Minus the grip, the V730's in 275/35/18 on 18x10.5 have the best steering feel of all setups I have used so far on the supra. I contribute that to them running slightly narrow so slight stretch, and stiff sidewalls.

It's the Japanese Time Attack style setup.

I do have a tiny bit more stretch than before. Went from 295/30 on an 18x10.5 to a 295/30 on a 18x11.

So are you essentially recommending running 275/35 on an 18x11 wheel? That's a lot of stretch, no? I'd also be worried about giving up, well, tire.

A 295/35 is heavy ass tire, and that would worry me as well. There's a 2lb difference per tire.

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