Any 128 STXers around?

[Kgolf31]

For those who autocross their E82 128, especially in STX, I want to hear your set-ups and what you run


(sorry 135 guys, you're not wanted unless you have generic information )

Specific information:
LSD - What is the best option here?
Suspension/Alignment - What coilovers have you gone with and how do you like them? Spring rates appreciated. I've been looking up TCK, Motons seem too rich for my blood and I don't think ASTs make them for the E82. KW V3s are also an option
Wheels/Tires - Really interested if you can squeeze 255s up front
Exhaust - The N52 doesn't have secondary cats...but I do. So I can go headers without needing to replace the primary (i think). Anyways, options on headers and the most free-flowing set-up appreciated.
Tuning - Self Explanatory here
Seats - What seats were considered with mounts.


I can go on, but these are the main things I'm thinking about when it comes to STX.


I'm not immediately looking to mod the car...yet, but come a year or two I'm building this car to take to nationals.

[Hops128i]

I was planning to do the new street class next year, but when I found out there will be no camber allowance, I'm now going to STX. I'm just tired of the under steer and wearing through the outside edges of the front tires.

I don't have much info to contribute here, I'm just staying at the local level, and the only things i have planned are Vorshalg camber plates, and a 245/40/17 square on BFG rivals.

[Kgolf31]

Originally Posted by Hops128i

I was planning to do the new street class next year, but when I found out there will be no camber allowance, I'm now going to STX. I'm just tired of the under steer and wearing through the outside edges of the front tires.

I don't have much info to contribute here, I'm just staying at the local level, and the only things i have planned are Vorshalg camber plates, and a 245/40/17 square on BFG rivals.

Yea, if I could use crash bolts I'd run my Z4M in RTR like I do now (well it would be BS then but you get what I mean).

On a high HP, camber limited car it is virtually impossible to turn, so I'm just going to have fun, co-drive cars nationally and start to save-up on a build

Let me know how the 245s Rivals end up working up front and if you had to roll the fender. You can roll the fender, you just can't flare it out. I'm assuming APEX wheels would be one of the better bets, IMO

[Hops128i]

will let you know on the rivals, really hope I don't have to roll. I've found a couple forum members with a 245/40/17 et40 square ( on OEM suspension), one tracks the car on xs Ecstas, and there's a z1 square. The rivals run about as wide as the z2 (according to tirerack)

[Kgolf31]

Bump.

STX build is a go for me, I'll be starting with suspension, sway bar, and wheels.

Any information is greatly appreciated

[pj.rodriguez]

I remember reading on the apex wheels commercial sale thread that you can fit 255's upfront with some camber and a small roll.

[Kgolf31]

Originally Posted by pj.rodriguez

I remember reading on the apex wheels commercial sale thread that you can fit 255's upfront with some camber and a small roll.

Thanks

255s would be awesome. Ideally 265s would be the best bet (since that is allowed max for STX) but I know that isn't happening.

Going to see if I can try and budget a LSD for this year...Just need to know what one to get and prices...sent a PM to HP Autowerks, as that is all I see offering LSDs for 128s

Is the same diff from a E9x compatible with the E82s?

Looks like I answered my own question:

Part 33107591015 (Rmfd final drive) was found on the following vehicles:
E82: Details on E82
E82 128i Coupe

E88: Details on E88
E88 128i Convertible

E90: Details on E90
E90 325i Sedan
E90 328i Sedan

E90N: Details on E90N
E90N 328i Sedan

E91: Details on E91
E91 328i Touring

E91N: Details on E91N
E91N 328i Touring

E92: Details on E92
E92 328i Coupe

E92N: Details on E92N
E92N 328i Coupe

Details for all

[The Dowager Countess]

I'm in the process of getting a custom built 2 clutch LSD built right now. I'm lowering the final drive to 3.64 as well. I went through turner but they outsource it to an amazing shop. These things last forever now and I like the on/off feel of s2 clutch versus the quaffes I've had on other atx cars

[The Dowager Countess]

I've had in the past. Shit was not cheap- but I'm a terrible haggler and didn't question price because I was prepared to pay that. The diff was 1899 plus a refundable $750 core deposit-$300 labor for the labor and & $30 for oil. I'll let you know- but I really think lower gears coupled with a competition grade LSD will be the biggest change I ever do to the car.

[Kgolf31]

Originally Posted by The Dowager Countess

I've had in the past. Shit was not cheap- but I'm a terrible haggler and didn't question price because I was prepared to pay that. The diff was 1899 plus a refundable $750 core deposit-$300 labor for the labor and & $30 for oil. I'll let you know- but I really think lower gears coupled with a competition grade LSD will be the biggest change I ever do to the car.

That price for a clutch LSD isn't bad.

When you look at it, Wavetrac is going similar value with the Quaife around $3k for a fully built unit

[Bimmer-Bob]

Just noticed this thread. Been competing in STX with the local SCCA chapter sort of lackadaisically the last few months, as this past year was my novice season. I've also been running with the BMWCCA chapter locally. In a few months I'll be relocating to North Carolina and will try to get involved with SCCA out there.

Anyway, here's my build so far:

Suspension: Ohlins R&T coilovers with Swift springs in custom rates (roughly #400F/#700R). Also Ground Control "street" camber plates, Whiteline rear subframe bushings, & E92 M3 front sway bar. Alignment-wise, I'm running 2.5° or more of negative camber with very slight toe-in in front (two different shops, one quite reputable, talked me out of zeroing toe).
My impressions are that the setup overall is very good, but over time it's become noisier than I care for on the street. From a performance perspective, I have no real complaints, however. Might be nice to get a little more negative camber up front.
The rear subframe bushing inserts are fantastic at settling the rear end, very noticeable even during lazy highway cruising.
Contribution of the sway bar is unknown to me at this point. It was one of the first mods I did after buying the car, and certainly reduced body roll. No idea how it's impacting my performance on the autocross course, though, vs the OEM bar or another size aftermarket bar.
The car is going to the shop tomorrow to address some of the suspension creaks and rattles. Right now we're thinking the camber plates might be the source, and my shop was thinking about maybe trying the Vorshlags as they're supposed to articulate better with coilover springs. I'll update this thread with any changes.

Wheels/Tires: Running APEX ARC-8's (17x8.5 ET40) all around. Wearing Dunlop ZII in 245/40/17. Wonderful combo. Definitely notice the lighter wheels. The tires grip well, and for autocross they work much better than my old Michelin PSS, but I'm really not qualified or experienced enough to compare them to the current crop of competition tires out there. I know your feelings on the PSS, and that you know (and probably have some experience with) the 3 or 4 good AX tires out there, so I'll just leave it at that. I will say, however, that I don't think I could squeeze 255's up front. In fact, my 245's will rub my lower spring perches if I have them set too low.

Exhaust: BMW Performance unit. Sounds sublime. I get compliments all the time from guys shagging cones during my runs. Performance enhancement? Likely nil. But worth every penny.

Tune: Recently did the AA tune along with the DISA intake manifold. Have only run one event since, and been through ony a tank and a half of gas, so perhaps the ECU is still adapting. Nice little bump in power, but not mind-blowing by any means. Throttle doesn't feel jerky to me. I wouldn't start here, but if you're looking for every ounce of advantage, certainly a tune makes sense at some point.

Seats: Still stock, and probably will never change this. I think we have really phenomenal sport seats from the factory. I'm usually able to keep my self pretty planted with a foot firmly planted on the dead pedal. I'll probably eventually invest in a Schroth Quick Fit harness for events because it's so easily reversible and, why not? But it's more of a nice-to-have than need-to-have, I think.

LSD: This is the big question right now. I want one. Was pretty sold on going with a clutch-type from Jim Blanton (Performance Gearing) since I could get a complete final drive with shorter gearing, but lately I'm reading that it might introduce too much understeer, especially for AX. Plus there's the increased maintenance requirement. Now I'm leaning towards a Quiafe (better reputation) or Wavetrac (better feature set). But I really want to go with a more aggressive final drive, too. Not sure if this is an option with the gear-type diffs, but I think Diffsonline builds them that way, maybe? Any opinions here?

[Kgolf31]

Just a FYI - A DISA Manifold (if you're a N52) is illegal in STX, as well as changing the final drive ratio.


Do you think with more camber you can run 255s? With 245s, how is your rear tire clearance?

As well, any reason why you didn't go with 0 toe?

I'm still very new to LSD education, but is there any OEM LSD that we can use and sway into our case? Give that the ring gears and case are identical, it would be a straight swap.

[Bimmer-Bob]

Originally Posted by Kgolf31

Just a FYI - A DISA Manifold (if you're a N52) is illegal in STX, as well as changing the final drive ratio.

Yeah, I know. I'm probably never going to take this car to Nationals, though, lol. Might just run in ASP or even X class.

Originally Posted by Kgolf31

Do you think with more camber you can run 255s? With 245s, how is your rear tire clearance?

Not sure. The biggest problem with a wider tire would be clearing the strut - I don't think camber (one way or the other) would affect this.

Originally Posted by Kgolf31

As well, any reason why you didn't go with 0 toe?

Only because one of the local alignment gurus recommended against it. His reasoning was that on hard braking the front tires would transition towards toe out, and thus the car would be more stable if it started out with slight toe in (basically, under hard braking the car should be around zero toe, whereas if I had zero toe to start with, it would be toeing out).

[fe1rx]

Originally Posted by Bimmer-Bob

My impressions are that the setup overall is very good, but over time it's become noisier than I care for on the street.

I run ZII's and Ground Control street plates also (but with OE struts and springs). I have noted that ZII's are very loud tires when new and they just get louder with age. Also as soon as I installed the the camber plates I started noticing a lot of wheel bearing noise (although the bearings felt good, they had about 75,000 km on them at the time). I suspect some part of that was the increased noise transmission through the GC camber plate. Even though it has a urethane element it is much stiffer and transmits more sound than an OE top mount. New front wheel bearings fixed that issue though.

Although the Street plates can apparently be used with coilovers, I am not surprised that the lack of articulation in the urethane bushing (vs a spherical bearing in a normal camber plate) would cause some interesting spring noises when steering with a race spring. Race springs are obviously less happy about being bent than regular front springs and quite a bit of bending is required as the front wheel steers as the steering axis is not coincident with the axis of the strut/spring.

None of this is probably news to you Bimmer-Bob, but may be useful to others.

[mikal7]

Any update on this?? Just seeing what us 128 guys are upto

[Kgolf31]

Originally Posted by mikal7

Any update on this?? Just seeing what us 128 guys are upto

Might want to start reading up:

http://www.1addicts.com/forums/showthread.php?t=946030

[Hops128i]

I've just moved from DS to STX this year, I haven't been competitve at all, although my only mods have been with camber plates and a 245 ZII square, and I'm more of a causal autocrosser, and have only 15+ events under my belt in DS.

How important a suspension upgrade is to being competitve in STX?