Quote:
Originally Posted by Ginger_Extract
This car has always been edgy to drive, since day one when it was bone stock. I've been through 3 different notable suspension setups and the car has always been a bitch to drive, so I've just gotten used to it. The car wants to understeer a lot unless I drive it intentionally loose. I'd rather have oversteer than understeer, so I just deal with it.
Right now here is the setup:
Wheels:
- 17x9" w/ 255/40 F
- 18x9.5" w/ 265/35 R
- Nexen SUR4 tires
Suspension:
- TC Kline Singles w/ Vorshlag plates
- 336 lb/in front springs/ 700lb/in rear springs
- AKG 75D subframe bushings
- E90M3 OEM 27mm front bar (May go back to OEM 135i 26.5mm bar)
- 335xi OEM 15mm rear bar
Alignment:
Front: -3* camber, 0 toe
Rear: -2* camber, 1/8" toe-in
Car needs more camber front and rear, the Nexens need closer to -4 all around for optimum performance. I delaminated the outside edge of a rear tire when the camber was set to -1.6*. After that, I had a chat with Nexen and brought the car to them for some track talk. They advised -4 all around, though, my butt dyno is saying -4 up front and -3 out back would be good.
Need to figure out how to get more camber up front. Thinking SPC/SPL control arms. Out back, I need lower offset wheels and more fender work before I can add any more camber. I'm rubbing against the chassis under compression with the 265 Nexens on an 18x9.5 +57 wheel.
Everyone should check their fuel filler tube in the rear wheel well. I nearly burned all the way through mine with the fat tires out back. Additionally, my chassis has burn marks from tire contact under compression, hence the need for a lower offset wheel.
With the stock rear suspension arms, it looks like I can get around -2.5-8* of camber and still have enough toe adjustment to get it in spec. At least, as per my friend's DIY alignment tools and some eyeballing measurements on my part. Once I address tire clearance, I'll bump the camber figures up higher. With the rear camber adjusted from -1.6* to -2.0* rear tire wear is much better, but still not ideal.
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Why are you running staggered diameter wheels? You should just run my setup for stock fender, max effort. 18x9 +42 APEX ARC-8, 255/35/18 Nexen Sur4G's all around. 3mm spacer up front.
I'm maxed around -3* front as well, you'll need to either notch your strut tower or run an offset lower control arm bushing, or, an adjustable lower control arm.
You have NOWHERE near enough rear camber, and that's a big reason your car is so tail happy. I'm running -3 out back and it feels great.
Do you have an LSD? Not to critique your driving, but your turn in super aggressively and it almost looks like you're initiating oversteer on purpose. Of course you'd rather have oversteer than understeer, but it just looks like you're far on the oversteer spectrum and actually need to dial in some understeer to correct.