[midlife]

i have been modding my 335 and also my 1995 alpina (bmw) track car.
although i am almost finished with both cars........i am running out of $$$

my 2008 335 cabrio has extensive engine mods, but suspension is STOCK and at stock height (only change is the rear M3 sway bar already in). i am looking for aggressive street handling and occasional (both quarter mile and circuit racing) track use.

i will do the suspension in 2 steps, BUT which is best to do FIRST?
in other words, which of the below will make the biggest difference at this time?

1/ street / racing tires - i have great deal on dunlop DZZ1s......they would go on my 18 inch JLine rims
OR
2/ billstein pss10

thanks

[BMW F22]

I'd do suspension first as you will use that more often than racing tires. Let us know if we can help.

[nicknaz]

i'd get the tires first.

[BMdblU]

suspension.

[stressdoc]

Remind us what your stock tires are; if still on runflats, ouch.

An E93 would greatly benefit from more chassis stiffening. The Hotchkis chassis brace and a front strut brace are good moves.

If you already have the M3 rear sway then the F/R balance is, uh, radical. Definitely get the PSS10s on to even things out and control wheel movement better. But with that much rear sway you still have got to get a LSD or you will be a cripple.

Oh, and stick to the Alpina for racing; the E93 is not meant for the track.

[midlife]

Originally Posted by stressdoc

Remind us what your stock tires are; if still on runflats, ouch.

An E93 would greatly benefit from more chassis stiffening. The Hotchkis chassis brace and a front strut brace are good moves.

If you already have the M3 rear sway then the F/R balance is, uh, radical. Definitely get the PSS10s on to even things out and control wheel movement better. But with that much rear sway you still have got to get a LSD or you will be a cripple.

Oh, and stick to the Alpina for racing; the E93 is not meant for the track.

1/ Tires
my e93 is currently on yokohamo advan sport, was told that dunlop street / racing DZ1 would give me ALOT more grip. thought i would bite the bullet and switch out to the dunlops, and try to sell the yokos - even though my yokos are practically new.

will the dunlops be that much better to make the switch worth it ?

2/ re: M rear sway
unfortunately, due to occasional bad road conditions here and dealer recommendation: my car came with STOCK (non sport) suspension...my first week of driving, i did not like the floaty feel so i had installed a M3 rear sway....car immediately seemed much better on highways.

since stock front sway and M sway are the same, why would installing the rear M sway kill make me way unbalanced??
...this is basically the M3 sway setup correct?

3/ re racing
i agree the alpina is much better for circuit racing.
i want to setup the 335 for best handling (without sacrificing too much car comfort) because i want to canyon run with my friends who have porsches and heavily modified european M3s.

lastly, due to very high altitude here, my modded 335 is relatively VERY fast. thought the dunlops would help with my occasional 1/4 mile challenge races.

under the above circumstances, what do you think doc ?
First the shocks, the braces you mentioned, or the dunlops?
what would you do second??

thanks alot, cause i am lost suspension-wise.

[stressdoc]

No, the front sway bar on the non-sports version is much too soft. And, although the M3 front sway is the same thickness as the one on the sport 335, this does not mean that they are equivalent, as there are other design factors at play. In brief, if you have a M3 rear sway (20mm) and a non-sport front sway, your car is way out of the normal range of front/rear balance. Even with the sport front sway it would be still much stiffer at the rear.

I would stick with the Yokos for now. The key is to mod your car so that you can best learn how to drive fast. You want 'feel' and control, not absolute maximum grip that lets go on a fine line. The thick rear sway is especially nasty in that it creates snap oversteer and lifts the inside rear tire during cornering, resulting in loss of traction -- very frustrating in tight canyon runs, you can't put your power to the ground, Yokos burn up in smoke. You need to restore balance. Get a front sway that will match the M3 rear. I would put the coilovers on to get the spring and damper rates more in synch with the stiffer sways. That will really help with the 'float.' After all that suspension tightening, you will eventually want to reduce the amount of flex in the chassis -- the tighter suspension will cause more unwanted stresses. The E93 is especially difficult, as it lacks a roof structure. I am not sure what additional reinforcements the E93 comes with (there are a hundred pounds or so of more internal bracing compared to the E92), but it can't be enough. And when you have restored your savings account to a healthy balance, look into a LSD.

[midlife]

thanks doc,

sounds like very good and thorough advice.

what are the Hotchkis chassis brace and a front strut brace you have referred to? is the chassis brace similar to the e36 "X" brace ?
kindly post - if you have - an internet link where i can view theses braces.

note that:
i will definitely recheck my M rear sway...i ordered it from my dealer, but during install do not remember it being 20mm....my memory says it was like 18mm.
btw, an LSD is definitely in my future...but in the pretty distant future for now

thanks

[leftcoastman]

The PSS9 or any other coilover will likely result in a harsher ride while driving slowly. That might really really suck on slower city streets that are in bad shape.

Personally, I wouldn't do anything. The Advans are good enough for street use and the Direzzas won't help you THAT much. The downsides of a harsh suspension might not be enough to justify the minority of the time you spend canyon'ing.

If you go down the track ready path, be ready for a car that sucks on bumpy streets and will scrape on surface irregularities. If you're ok with that, then go for it!!

I did, lol.

[TSM330i]

Originally Posted by leftcoastman

The PSS9 or any other coilover will likely result in a harsher ride while driving slowly. That might really really suck on slower city streets that are in bad shape.

Personally, I wouldn't do anything. The Advans are good enough for street use and the Direzzas won't help you THAT much. The downsides of a harsh suspension might not be enough to justify the minority of the time you spend canyon'ing.

If you go down the track ready path, be ready for a car that sucks on bumpy streets and will scrape on surface irregularities. If you're ok with that, then go for it!!

I did, lol.

My coil-overs ride about the same as the ZSP suspension. The car feels so much better planted (control is so much better over bumps) and doesn't ride harsh at all (the beauty of 15 way adjustable shocks). I installed the M-tech front end and have yet to scrape anything. My car is pretty low too.
Getting rid of the runflats will dramatically change the ride for the better and adding the coil-overs balances it out for sure.
On the track - forget about it. Anything with stock suspension didn't stand a chance, even cars with much more hp.

[leftcoastman]

Wow. Ok, a few things:

1) The OP lives in an area where your average paved road is similar to what you would consider "off-road" here in the states.

2) Track use is 80% + driver. As an instructor, I've ridden in an E30 318i that ate a C6 Corvette Z06 in the corners. Why? Driver skill.

3) I presume you meant that you have single or double adjustable shocks...with 15 settings? The Motorsport Motons are only 4 way adjustable...and those are like $10,000.

[TSM330i]

Originally Posted by leftcoastman

Wow. Ok, a few things:

1) The OP lives in an area where your average paved road is similar to what you would consider "off-road" here in the states.

2) Track use is 80% + driver. As an instructor, I've ridden in an E30 318i that ate a C6 Corvette Z06 in the corners. Why? Driver skill.

3) I presume you meant that you have single or double adjustable shocks...with 15 settings? The Motorsport Motons are only 4 way adjustable...and those are like $10,000.

1) I had no idea where he lived since his sig doesn't say so my bad

2) Yes, you're correct that at least 80% is the driver for sure. I was actually thinking that myself when I was typing it.

3) 15 different settings that are double adjustable. Motons are SWEET - but for the track only.

Where are you an instructor? I would assume on the opposite coast from where I am from your sig.

[S4to335]

Well...seeing as you have a cabriolet...I dont know why you need either. You cant safely take the cabriolet on the drag strip..or the circuit course without proper roll over protection. For aesthetics...I would get the PSS9s.

[midlife]

Originally Posted by S4to335

Well...seeing as you have a cabriolet...I dont know why you need either. You cant safely take the cabriolet on the drag strip..or the circuit course without proper roll over protection. For aesthetics...I would get the PSS9s.

...not looking for aestetics really...in fact dropping my suspension about 1¨ (pss10 minimum drop) is no fun for me occasional bottom outs?). just want the car to handle better for caynon running.

is the sacrifice in comfort (and possibly bottoming out) worth it ?
on a scale of say 10 with 10 being great, i would take 4 minus points to get 4 plus points in handling. any idea of the tradeoff here relative to benefits?

btw, re 80% is the driver:
i just started racing my 1995 alpina - had only 4 races ... but making alot of progress, but need more practice.

thanks

[nicknaz]

OP, everyone has a different opinion on what is 'streetable' you aren't going to get good answers this way. go to a meet, ride in E93 with the suspension you are thinking about buying, see how close it comes to scraping on driveways similar to the ones you encounter and go from there.

Keep in mind that 'scrape' and 'bottom out' could potentially mean you hit your oil pan if you hit a big pothole 'just right'. remote chance but it SUCKS when if it happens to you (i've seen it happen) IMHO, all the canyon fun in the world isn't worth getting stuck in the middle of nowhere because your modded daily driver couldn't clear a road imperfection. your car, your call

[stressdoc]

Maybe consider the BMW performance suspension kit. Less expensive and would not lower car much.

[midlife]

Originally Posted by Nick Nazareno

OP, everyone has a different opinion on what is 'streetable' you aren't going to get good answers this way. go to a meet, ride in E93 with the suspension you are thinking about buying, see how close it comes to scraping on driveways similar to the ones you encounter and go from there.

Keep in mind that 'scrape' and 'bottom out' could potentially mean you hit your oil pan if you hit a big pothole 'just right'. remote chance but it SUCKS when if it happens to you (i've seen it happen) IMHO, all the canyon fun in the world isn't worth getting stuck in the middle of nowhere because your modded daily driver couldn't clear a road imperfection. your car, your call

alot of good responses from all...thanks

doc: your idea to balance out the rear M3 sway with the front M3 sway seems like a sound idea.
hopefully with both m3 sways in, my stock shocks and springs will be o.k. for now.
maybe instead of spending $$$ on coilovers, i can use that money for a LSD instead.
leftcoastman: thanks for the tire tip....i will upgrade to DZ1s later.
do u think after both m3 sways are in that the lsd will be better (with my STOCK springs and shocks), or should i sacrificing comfort with coilovers for my canyon runs??

nick: in my country there are approx four 335s, and there is only one e93 besides mine....no real chance of trying out your suggestion.

btw, note that these other 335 guys do not even know what a piggybck is