[neilvosko]

What are the best suspension upgrades for street and limited track (NO LSD).

was thinking eibach pro-system plus , all in one solution.

any one running the kit??

[CALWATERBOY]

Originally Posted by neilvosko

What are the best suspension upgrades for street and limited track (NO LSD).

was thinking eibach pro-system plus , all in one solution.

any one running the kit??

No LSD is no way to run. But to answer to your question: Ground Control's Street/School package - ~$2100

Take to heart their recommendation to add M3 sways. You're smart to run the whole M3 parts package - ~$2400

Toe adj'rs for rear ~$250

Bite the bullet. Get a LSD - $2000+ depending on the mfg. Really.
.

[CJ421]

+1 LSD and a good set of tires ... gotta put power to the ground first.

[The HACK]

What's so wrong with the factory sport suspension? I've found BMW's sport suspension is about the best compromise between street and track. It's already more can capable enough for 99% of the actual track attendees I see on a weekly basis, and for that 1% that can out-drive the BMW factory sport suspension, they'll already know what to do to maximize its potential on the track, that the gains there does not outweigh the detriment to its street manner.

Heck I drove on my factory stock suspension for 3.5 years on the track until I upgraded to GC Coil overs, and that was mainly for the ability to fine-tune the dampers, the added camber, and the ability to corner balance.

[neilvosko]

hack, how do you compare the sport to coilovers

[cvc 22349a]

Originally Posted by The HACK

What's so wrong with the factory sport suspension? I've found BMW's sport suspension is about the best compromise between street and track. It's already more can capable enough for 99% of the actual track attendees I see on a weekly basis, and for that 1% that can out-drive the BMW factory sport suspension, they'll already know what to do to maximize its potential on the track, that the gains there does not outweigh the detriment to its street manner.

Heck I drove on my factory stock suspension for 3.5 years on the track until I upgraded to GC Coil overs, and that was mainly for the ability to fine-tune the dampers, the added camber, and the ability to corner balance.

I've seen you pose this question a couple times now so I'm going to answer it. The E9X suspension was engineered for rft's. Take away the rft's and add torque (which is easy to do w/a turbo motor) and you've got one mushy and unpredictable handling car (no, I have not taken my car to the track). So, to get handling close to my previous E46, I've had to change out most control arms and bushings to M3 parts and add stiffer dampers. Your car's suspension was engineered around traditional tires. Have you driven an E9X with the added grip of +1 size go flat tires?

[e90pilot]

I never really liked the ZSP in my. I preferred the non-sport in terms of balance. Sure it was soft but it had low limits do the fun factor is good. The sport suspension adds a ton of grip but also more safety. I've hear they've changed the settings since though.

[mike-y]

for someone's car that is only going to see "limited" track time, I'd probably just say upgrade the dampers, and save your money for other things.

Unless you want coilovers for other reasons, but don't design your upgrades around the track if you are only going to spend limited amounts of time there.

[The HACK]

Originally Posted by cvc 22349a

I've seen you pose this question a couple times now so I'm going to answer it. The E9X suspension was engineered for rft's. Take away the rft's and add torque (which is easy to do w/a turbo motor) and you've got one mushy and unpredictable handling car (no, I have not taken my car to the track). So, to get handling close to my previous E46, I've had to change out most control arms and bushings to M3 parts and add stiffer dampers. Your car's suspension was engineered around traditional tires. Have you driven an E9X with the added grip of +1 size go flat tires?

I've driven my wife's E92 with the run-flats on. And it is still far more capable than 90% of the populace can handle on any given track day.

And as far as the E9X suspension being specifically engineered for RFTs? There's no magic to the geometry of the E9X suspension. All it has is softer springs and dampers than cars from a generation ago. To be honest? A sport suspension equipped E9X is still about the best compromise for a car that's driven on a daily basis and taken to the track occasionally.

My old Z4 was "built" with shocks and springs tuned for RFTs too, and I've taken that car to the track with and without RFTs, and really? The main difference was the RFTs responded better and quicker to turn-in, but the traditional soft-sidewall tires braked better. Don't ask me why since I myself don't really know, but it was done back to back with the RE050A RFT and RE050A non-RFT.

The whole "we engineered the suspension specifically for RFTs" was just a marketing spiel from BMW to get you guys to buy into the RFT implementation. Frankly, running an E9X with sport suspension and compliant, non-run-flats is like running an E46 with sport suspension springs and non-run-flats with standard, non-sport dampers (and yes I have driven that combination back to back). It's not THAT much different...Especially not for track purpose.

[cvc 22349a]

Originally Posted by CALWATERBOY

No LSD is no way to run. But to answer to your question: Ground Control's Street/School package - ~$2100

Take to heart their recommendation to add M3 sways. You're smart to run the whole M3 parts package - ~$2400

Toe adj'rs for rear ~$250

Bite the bullet. Get a LSD - $2000+ depending on the mfg. Really.
.

Wow. That GC kit looks like a good value Do you have that kit on your car?

[CALWATERBOY]

Originally Posted by The HACK

What's so wrong with the factory sport suspension? I've found BMW's sport suspension is about the best compromise between street and track. It's already more can capable enough for 99% of the actual track attendees I see on a weekly basis, and for that 1% that can out-drive the BMW factory sport suspension, they'll already know what to do to maximize its potential on the track, that the gains there does not outweigh the detriment to its street manner.

Heck I drove on my factory stock suspension for 3.5 years on the track until I upgraded to GC Coil overs, and that was mainly for the ability to fine-tune the dampers, the added camber, and the ability to corner balance.

Rear subframe bushings. Pointlessly vague, subtracts feel and ability. Replacement w/M3 bushings a big plus.

Inherently bouncy. Handles bumps & dips poorly, aftermarket matched shocks & springs make big gains.

Pothole explosions. Good Lord, what possessed BMW to put such miserable performance in production? Big black eye for Munich.

Understeer. I hate sloth; 'sport' suspension has some.

Precision. BMW's 'sport' suspension arms are made to deflect. M3 arms are not. Hey....that's planned inferiority. Also check the front tower brace. Weird.

E-differential. A miserable, accelerated rear tire wear device w/so-so result. Wavetrac and Quaife have hopelessly outclassed this kludge with performance and feel.

Sway bars. M3 bars good juju. 'Sport' bars pencil thin. Effect commensurate.


Those are the obvious lows - fixing 'em results in huge improvement.


I like the car yet detest what BMW delivered as a 'sport' suspension as well as RFT's, which I replaced w/PS2's. At the end of this tunnel is a gratifying sports car - Cayman w/PASM is better, but I require the larger living space of my 3 and love the retractable hard top. Like its looks inside & out and BMW creature comforts, which is more than I can say for Porsche!
.

[CALWATERBOY]

Originally Posted by cvc 22349a

Wow. That GC kit looks like a good value Do you have that kit on your car?

Should have by now, but experiencing continuing delays from Ground Control. Now saying Koni's will be in on the 23rd.

Have other items. It's all good! LSD a heavenly improvement.