Street to Track to Back - prep

[CobraR1339]

Forgive all the questions. I just bought he M coupe. I have lots of track days scca comp license, yada yada ..so not a noob, but a noob with this car.

I don't want to hate the car as a weekend get away car with the wife. She says I broke all the other cars, she is right. I have a Z06 I won't take anywhere but the track as it soo low, now rides like crap and brakes squeak like hell with PF01's. Otherwise the perfect track day weapon.

So here's where I am headed.

1. An Alignment at stock ride height that you have found to work well. That won't track the car all over the fwy grooves. I don't care about tire wear.

2. Will do two sets of wheels. Thinking Nittos for driving to an even on a whim and Hoosiers for when we bring the trailer for the other cars.
- Thinking I would just use extra sets of stock wheels.

Anyone run Nittios as driver tires? do you hate the noise or is it about the same as Conti's.

- Are there better options or size tips for these ?

3. Brake pads that work well enough at the track and I don't have to swap unless really wanting to turn up the volume. I don't want a super squeaky compromise pad. Or is OEM good enough?

Would carry a set of race pads in the trunk if needed. My circuit is Willow, BW, Cal Speedway, LS, Streets, Miller. Willow is normally easy on brakes in other cars, the others are more demanding.

- Suggestions that won't kill the rotors so pad I can't put the stock pads back on. May jump on the RB rotors if they get the back pad figured out. But for now assume stock rotors.

I run 7/10 on the first weekend then ...9/10 to 10/10 most of the time once I get the car figured out

4. Belt set ups - I listed this on another post, looks like I have to fab something.

[The HACK]

1. Corner balancing goes a long way on this chassis. Alignment that have done right by me:

-2.5 to -3 degrees up front. -2.5 still wears the outside faster. -3 would be ideal if the car does not get driven a lot on the street.
1/16th total toe-out front.
-2 degrees in the rear
1/16th total toe-in rear.

Of course, you'll need to play around a little bit depending on your tire to get optimum life and grip. But I'm sure I don't have to remind you.

2. Nittos are marginally more noisy, and you'll get that typical R-compound "hum" on street at speed higher than 50mph. But it is not that intrusive. If it weren't for the fact that they're hard to get, I'd drive on them every day on the street. Sizes are limited though, if you run on stock rims, because I'm a firm believer that running too wide a tire on too slim of a rim will be counter-productive, and 245mm and larger on 8", and 275mm and larger on 9" is a "stretch," no pun intended. If you are getting rims appropriately wide for the tire, knock yourself out.

3. Ugh. This is a tough one. I've not found a single set of pads that can do dual duty. Hawk HPS will survive WSIR and moderate AX duties but it will not do for any of the other tracks listed. Cool Carbon works well enough if you want to dance around and be very conservative on the brakes, but with R-comps you'll overwhelm them eventually. I've long given up on the quest to find a set of pads that's civilized enough for street use, and will stand up to real rigorous track work.

4. Technically, their current design for the rear works, except you need to keep a close eye on the pads. Meaning as they wear to about 45% you'll need to junk them because they'll come too close to the fasteners. Plus as they wear the pads will start to taper and cause problems. Too bad it's back-ordered, I can see when they'll have the hubs available again because the rotor rings are standard size(s). I'm using Cool Carbon S/T for the rear and RB ET500 for the front for the street, and Hawk DTC-60 for the track, with Motul RB600 and stock lines.

[CobraR1339]

You have given me a great starting point.

Lunch is on me, when we cross paths. I am almost set, just want to clarify a couple points. before I start spending money tonite.

If i read this right, the available Nitto sizes are a bit to wide for the stock rim. Any suggestion on track day wheel other have used that won't set me back too bad ? or other tire suggestion that works close to the Nitto's.

I get the toe out up front for the tighter tracks ... but for the freeway in other cars .. the toe out made them nervous and tracked grooves pretty bad. Do you notice that or is the M just more friendly that way?...sounds like you drive to the track ready to go.

Toe is the easiest adjustment in my exp. the diff is so small.. slight out to slight in.. that nothing else gets too upset. In your experience is true here as well?.

Can you adjust the stock suspension for corner weights?, Maybe I missed that, that would be very cool.

Or ....does someone sell an adjustable sleeve that can be used with stock springs and struts ?. I have something similar on another car that just made the stock stuff adjustable for this purpose.

You guys are a great help. Thanks Again.

[The HACK]

Ground control makes and sells adjustable sleeves, but for all intent and purposes, you can just get new rear springs and adjustable collars since all they need to do is adjust one or the other to get to ideal cross weight. No real need to adjust the front if you want to stay relatively stock. Or a good chassis shop (like Tri Point Engineering in Chatsworth) will likely have spring pads that they can install to get you pretty damn close.

I "live" with the little bit of wander that toe-out produces. It's no bad, really, especially if you don't tend to drive excessively fast on the freeway. It does tramline worse than stock alignment, but it keeps you sharp and focused on the road ahead when driving. And it really isn't THAT bad on this chassis for some reason. I can drive it daily if I must (I drive my Subaru daily but that car has NO FEEL when it comes to steering)

Toe adjustment is easy on the MacPherson Strut, but since I don't really know what I'm doing when I adjust it, I leave it up to the professionals. I did mess with it once just to see if I can get the car to track a little straighter on tires that's got a bit of track bias in them, and sort of got it right, but went back to the chassis shop's alignment specs just because, well, they're the professionals (and the track bias went away on the track tires when they got flipped on the rims).

Please note, you'll need either camber plates or camber shim bolts for the front to get more than -2 degrees of negative camber.

[jmillet]

With TC Kline camber plates I run -2.0 degrees camber with slight (0.1 degrees) toe-in front for the street and -3.5 degrees camber with slight toe-out for the track. I have -2.0 degrees rear camber with slight toe-in (not easily adjustable)
I run Toyo R888 tires (245/40-18 front and 255/35-180 rear) mounted on E46 M3 wheels.
I run Performance Friction PF-01 pads for track driving and OE Textar pads for the street.

[CobraR1339]

Sounds like you guys have worked hard to dial them in. I think you guys for all the advise. Now I need to get busy.

I look forward to a track day to see what the car can do.

I really like the way the car feels. It communicates more than the Z06. But down on power and up in weight as a comparison.

I know it's not as powerful, but I am hoping it can carry speed like the 95-98 M3's did. Those were really really good cars IMO. Lighter than us too. Amazing how porky we have got in the last 10 years. Crud, I resemble the remark too ;-).

[sipman]

I used bolts/washers I sourced from Fastenal to get to -2.5 camber in the front. It's much cheaper than the plates.
I used Porterfields brakes last year... I was having a hard time with them.

But this year I switched to Raybestos up front and PFCs for the rear. I loved them! I hear PFCs last forever, but they are wearing faster than the Raybestos up front. If that gives you any idea to how long the Raybestos will last. I switched to them on Porterfield's recommendation and the Raybestos are slightly cheaper than the PFCs.

Just another opinion.

[The HACK]

Brake pad wear on different compounds is very hard to "gauge" when installed on different axles of the same car. You can't tell if one side is wearing better or faster because the other end is doing a better job or a poor job.

When I was forced to use Cool Carbon on the rear and Cobalt XR3 up front, the Cool Carbon looks like they've never been used. The Cobalts had so much more initial bite once warned up, it was literally doing 90% of all the braking work.

[CobraR1339]

Well a few things done. None exactly as planned though.

Compromise #1: The tire shortage from Nitto/Toyo pushed me toward the Hankook Z214 Slicks Compound 51. America's Tire had availability where no one else did till early June at the time I placed the order.

245/40/18 front and 275/35/18 rear. Drove it around and did some lock to lock circles, not rubbing so far. The rears fit the rim nice, the fronts could use a 8.5 rim as expected, but still roll out ok when checking the contact areas.

Compromise #2 : Just got back from doing the alignment. We used a fairly new Hunter unit. It did not request weight in the seats or rear. We pulled up some other applications for BMW and they did require it. We keep playing with it until we were satisfied that Hunter did ask for weights on some cars and not others. Not sure if it is right, will call Hunter next week to see if the program is jacked or it was compensated for. I read in a couple places that it wanted weight, but since the weight it wanted was the same lbs L and R, the software may compensate.

Rear: There was no way to get more than 1.8 deg in the driver rear. The eccentric was maxed and that's all she wrote. Anyone have a fix for that ????. Everything looks great under there, no damage.

The Pass Rear would go to 2.3 deg neg. ?

Set is up at 1.8 /1.8 with 1/16th toe in per side.
(The original toe was wacky with one side toed in 3/16 and the other out 1/16.)

Fronts:

Pulled the pins up top and started to see what we could get w/o the turner kit. was able to get 1.3 on one side and 1.4 on the other. ( Originally .8 and 1.1) .

Stuck in 1 washer thinking it would get me 2.0 - 2.1. Turns out the single washer was only worth .5 deg on this car ( Had read somewhere that one thought they were worth .70). Ended up at 1.7 on both sides with 1/32 toe in per side.

I mic'd all the washers and and found 4 that were a match and used them. They happen to be the thickest ones .0098. They ranged from .0092 - .0098.

So, if I were to do it again I would stick in both washers, pull the pin and refine the adjustment up top.

Will post some pics of the tires later. Not enough of a drive yet to say if it feels better or not. But based on the wacky OEM alignment, it should.

[Finnegan]

I could be wrong, but I don't think many here are getting more than -1.8 rear. Those that are are lowered using springs or coils.

On the front, here's a tip from The Hack: "Align the suspension with 2 washers (that's nearly 1 full degree of negative camber added) for the street. If you have the alignment pin pulled, at furthest out point you'll probably get about -1.5 to -1.7 degree of negative camber with about 1/16" toe-in. Suitable for street use while not too aggressive on the tires. At auto-cross or track events, push the strut all the way in to get to -2.5 to -2.7 (they don't have to be even). With the negative camber pushed up, you'll get zero to slight toe-out which will aid in steering response. Mark the top of your strut tower with a permanent market to indicate where the street alignment is at."

So, you're running those tires on the OEM wheels? Do you think the 245s up front, ont he 8" rims, give that much more contact patch than 235s would? I'm asking as I'm in the market soon for tires and wheels + tires aren't in the budget this year, and I'm toying with running 245s up front (but not if the benefit over 235s is very marginal or has downsides).

[CobraR1339]

Originally Posted by Finnegan

I could be wrong, but I don't think many here are getting more than -1.8 rear. Those that are are lowered using springs or coils.

On the front, here's a tip from The Hack: "Align the suspension with 2 washers (that's nearly 1 full degree of negative camber added) for the street. If you have the alignment pin pulled, at furthest out point you'll probably get about -1.5 to -1.7 degree of negative camber with about 1/16" toe-in. Suitable for street use while not too aggressive on the tires. At auto-cross or track events, push the strut all the way in to get to -2.5 to -2.7 (they don't have to be even). With the negative camber pushed up, you'll get zero to slight toe-out which will aid in steering response. Mark the top of your strut tower with a permanent market to indicate where the street alignment is at."

So, you're running those tires on the OEM wheels? Do you think the 245s up front, ont he 8" rims, give that much more contact patch than 235s would? I'm asking as I'm in the market soon for tires and wheels + tires aren't in the budget this year, and I'm toying with running 245s up front (but not if the benefit over 235s is very marginal or has downsides).

Here is a very un-scientific report.

I will try to post some pics on the rim. All I did was mount them and drive about a mile really slow around the housing track to see how much tire would scuff lightly and make a pattern. Keep in mind I have 37 psi in them cold right now to simulate warm tires.

The contact pattern is decent at 8.75 inches wide vs. 7 inches on the pilots. There is about 1/4 on either side that did not scuff.

They picked up many small pebbles on my short journey leaving a nice witness mark. I did do two complete slow lock to lock circles in both direction with no rubbing. WIll report back on that after a track day. An 8.5 rim would be ideal, but I do think this will result in at least a 20% larger and stickier patch.

The tire heights are nearly identical mounted.

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Yeah, I should have stuck in the two washers and used the adjustment up top. Was trying to be conservative thinking it would be insurance against rubbing the strut with the wider tire. Hack's advise above is sound.

But for now I am locked in at max adjustment with one washer. Will try to get it back on the rack again later and put in the other washer, mark all settings accordingly, and have room to play.

When you aligned the car did you have to add balast?. I sent an email to Hunter with no response yet.

[Finnegan]

Thanks for the update on the tires. I think I'll go with the 245/275s since it give a bit more contact patch.

Yes, I had ballast added per BMW's recommendations. See this post for BMW TIS recommendations.

[CobraR1339]

Ah, Not sure why Hunter did not specify it. Wonder if that is why the camber would not get to where some had it.

I would think the weight would lower the car a bit, lowering tends to create some negative camber. I may have more than I thought with it weighted down. But hat would also mean my toe would move out as well. Humm

More curious than ever now. 150lbs per seat and 31lbs in the trunk area.

[Finnegan]

Originally Posted by CobraR1339

Ah, Not sure why Hunter did not specify it. Wonder if that is why the camber would not get to where some had it.

I would think the weight would lower the car a bit, lowering tends to create some negative camber. I may have more than I thought with it weighted down. But hat would also mean my toe would move out as well. Humm

More curious than ever now. 150lbs per seat and 31lbs in the trunk area.

Indeed. All I can tell you is that's the BMW TIS recommended procedure. BMW procedures may vary from general Hunter specs? I have no idea.

[CobraR1339]

Some pics of the Hankook Z214 C51 on the stock rims as promised. Stock springs.
245/40/18 275/35/18