Proof that Coilovers Reduce Lap Times??????

[ApexEight]

Originally Posted by cjd

Less than no camber, more than camber for even tire temps. Others that have done this can probably give a better idea. I went straight to STX prep, had no desire to fight limited setup options.

As much as I would like to prep for STX, it just seems a little too far out of the budget for me. Main concern for me is getting as much seat time as possible (still a noob, relatively), so I think D Street will be best.

[strat61caster]

Originally Posted by ApexEight

For stock springs and shocks with just crash bolts up front (so like -1.5 camber) and a 22mm Strano front sway bar and some 200TW tires (225/45 on stock 17x7s) do you think I would still see bad outer shoulder wear on my front tires on track? What about the rears? I would imagine the rears would be ok since they aren't digging to hard. Concerned about the fronts though. This setup is what I plan for on my D Street autocross setup, but I would like to take it on a couple track days a year.

Yes you'll get as much if not more outer shoulder wear than you would when autocrossing due to longer steady state cornering time. But imo it's still worth heading out to the track and getting the seat time and you'll still have a blast.

I did 4x track days with limited camber and one with camber plates, yes better wear and balance (imo) with camber plates but it wasn't like the car was unfun or unsafe to drive home with limited camber, the biggest issue was getting good brake pads and fluid into the car. Yes, rear tire wear was more even (they gain camber under compression) so rotating tires will help extend their life a bit.

I'd avoid tracking RE71R's and BFG Rival S' though if that's going to be your autocross tire, I went with a street DD tire that would last awhile on track if I went back with my autox tires living an autox specific life, MPSS for the record, lots of alternatives like Continental Extremecontact, Firehawk Indy, more aggressive trackable tires like RE11 RS4 and ZIISS that are DD-able, and whatever handful of options I'm forgetting.

You can certainly track the competitive autox tires but I would imagine they won't last a full autox season +2-4 track days. Less so if you're driving on them daily.

[churchx]

BTW, with just crashbolts front but in both holes it's possible to go -2.2 front. Have yet to try, how much powerflex PFF69-801G front lca bushings may add. And expecting whiteline KCA434 with extra 0.5 caster to help a bit with dynamic camber.

[strat61caster]

Originally Posted by churchx

BTW, with just crashbolts front but in both holes it's possible to go -2.2 front. Have yet to try, how much powerflex PFF69-801G front lca bushings may add. And expecting whiteline KCA434 with extra 0.5 caster to help a bit with dynamic camber.

Not legal for the class he wants to run, factory camber bolts only, not worth changing alignment in between events multiple times a year imo

[Icecreamtruk]

Originally Posted by ApexEight

For stock springs and shocks with just crash bolts up front (so like -1.5 camber) and a 22mm Strano front sway bar and some 200TW tires (225/45 on stock 17x7s) do you think I would still see bad outer shoulder wear on my front tires on track? What about the rears? I would imagine the rears would be ok since they aren't digging to hard. Concerned about the fronts though. This setup is what I plan for on my D Street autocross setup, but I would like to take it on a couple track days a year.

On stock suspension and those kind of tires, you are still lacking a lot of camber for even wear. With a slightly more sticky tire on similar size, I still had more wear on the outside shoulder (to the point of cording the shoulder with a good amount of thread left on the inside) at -3.0 camber at the frond.

Like many are saying, I think you are wearing the tire faster by not having enough camber than by having more and wearing it on the way there. I would do something like -3.2 and -2.5 for a street friendly setup. Mind you, you arent only leaving tire wear on the table, you are leaving a metric ton of time.

Edit: Autox rules I see, well, do what you can to get more camber, but you will never have enough under them useless rules (my opinion, dont jump me here, I think autox rules are really, really bad, not for autox itself, but because it becomes really hard or expensive to build acar that can do both, autox or track, and spending so much money for a couple of minutes of driving per day seems very unreasonable to me, but thats a debate for another time).

[churchx]

Are lowering springs legal in that class? If yes, another way to get some negative camber even if i don't like way to gain it

[Icecreamtruk]

Originally Posted by churchx

Are lowering springs legal in that class? If yes, another way to get some negative camber even if i don't like way to gain it

Lowering only gives you camber in the rear. The front does not gain negative camber from shoter springs, so that is still not ideal.

[strat61caster]

Originally Posted by Icecreamtruk

Lowering only gives you camber in the rear. The front does not gain negative camber from shoter springs, so that is still not ideal.

Incrementally it should be a tenth of a degree or so more camber up front, the big benefit would be increased roll stiffness reduces the need for more camber, not by much but by a bit.

Regardless the lowering springs would bump him out of a competitive class, maybe no big deal and running CS is more attractive than DS, but doubtful. Edit: BRZ has no lowering spring option so nevermind for the moment on that.

idk, it's a casual track day, you're not going to ruin your car running <-1.5 degrees of camber on track 3-4x per year. You chew up a set of tires, buy a new set and re-evaluate.

This is a great car to just go fucking try it, learn a bunch of stuff, and then decide what you want to do. I got my last set of tires for <$600 mounted and balanced for MPSS, when you sign up for a track day you're basically setting a few hundred bucks on fire for fun and tires are part of that.

[jamal]

Originally Posted by Purist

Educate me. Is this because the springs compress so much that the geometry goes back to zero/positive camber?

The front suspension on these cars hardly sees any camber change throughout the whole travel, from full droop to on the bumpstops. The most negative camber occurs when the inner pivot and ball joint are level (so the ball joint is the farthest out it will get) which happens between stock height and full bump, but after that it goes back to where it was. But anyway, lets say we gain a degree under bump travel for the fun of it.

Take your brz to the track with a set of RS3s or something and stock suspension, and in corners you're going to get probably 5-6 degrees of body roll. But the suspension only gains a degree, so in a corner that would put your tire at 4-5 degrees positive assuming you started at zero. You'd need that much static camber to compensate and put the tire flat on the ground. Plus there's tire and bushing flex which make things worse.

So, long story short, you need a good amount of camber and to up the spring rates to keep from cooking the outsides of a decent tire on track, especially up front.

[ApexEight]

Thanks for all the input guys.

Wait so I can run my BRZ in CS if I get the TRD mods? What does that encompass? TRD springs (can I run the Eibach Pro Kit springs? I've heard they're the same) and what else?

[strat61caster]

Originally Posted by ApexEight

Thanks for all the input guys.

Wait so I can run my BRZ in CS if I get the TRD mods? What does that encompass? TRD springs (can I run the Eibach Pro Kit springs? I've heard they're the same) and what else?

No you can't, I didn't realize you had a BRZ and as such edited my post.

[Surok]

i dropped 1 second a lap. on a 70 second lap.

from just the suspension.