got money, LSD or suspension upgrade?

[Iron Man]

Originally Posted by vampire81

i did mention the tire change to 225/255 front-rear to non RFT. but from what i understand, wider tires will have less steering response, while having a hard RFT sidewall will give me more! correct me if i'm wrong.

non RFT will yield a better grip and road imperfection soaking, but it won't improve steering response. correct me if i'm wrong!

I thought wider tires improve steering response. If I am not mistaken, the reduced steering response with non-RFT is from softer sidewalls.

[pixelblue]

Originally Posted by 3002 Tii

3) the turn-in, or lack thereof is due to limited negative camber. increase negative camber up front (and run wider tires or square setup) and your will feel sharper turn-in

also add a little toe out (1/16" total) for front alignment and this will increase your turn-in response

[John_01]

If you want to improve steering response I suggest to just add more negative front camber. The M3 front arms will add a bit of negative camber which is a welcome improvement for road use. I have some doubts about toe-out for road use - To me it gives a slightly weird on-center steering feel and it also won't be very good for tire wear. About zero to 1/16" toe-in is more like it.

Just forget about RFT tires, they aren't an option due to the road imperfection problem you mentioned. Once you add the M3 front arms and M3 subframe bushings you will have EXCELLENT steering feel with conventional tires, so there is absolutely no reason to ever think about RFT again!

[HP Autosport]

Originally Posted by vampire81

thank you everyone for the great enlightenment. M3 front control arms and rear subframe bushings are going in.
i wouldn't install a strut tower brace.
why would i put on M3 guide rods and upper links?

It somewhat eliminates wheel-hop under harsh acceleration. I noticed a HUGE difference after mine were installed. The strut tower brace also allows for easy access to camber plates if you ever decide to go that route. Also gives the front end a little bit more rigidity.

-Mike

[ilikebmxbikes]

Originally Posted by Iron Man

I thought wider tires improve steering response. If I am not mistaken, the reduced steering response with non-RFT is from softer sidewalls.

Wider rubber gives you more grip but with that it can often soften your steering feel a little and make your steering feel a bit heavier. The thin hard runflats feel very sharp and the wheel feels lighter, but again, that is not a reason to run them. They are terrible for anything other than running flat.

[vampire81]

Originally Posted by John_01

Just forget about RFT tires, they aren't an option due to the road imperfection problem you mentioned. Once you add the M3 front arms and M3 subframe bushings you will have EXCELLENT steering feel with conventional tires, so there is absolutely no reason to ever think about RFT again!

For the 4th time,, I will change the RFT

[pixelblue]

Originally Posted by John_01

I have some doubts about toe-out for road use - To me it gives a slightly weird on-center steering feel and it also won't be very good for tire wear. About zero to 1/16" toe-in is more like it.

drove 30000 miles with a slight toe out. changed tires once around 20k. there's a very slight on-center feel but as we all know everything is a compromise.

[TheBreeze]

Originally Posted by pixelblue

drove 30000 miles with a slight toe out. changed tires once around 20k. there's a very slight on-center feel but as we all know everything is a compromise.

I like 1/16 toe-out, 1/16 toe-in rear (I run -1.8*F/-2R camber). With the gobs of caster our cars have (mine is +7.6*), this setup works pretty well for the street. Not in the least bit squirrelly. Tire wear has been perfect for me after 11k miles with this setup.

[pixelblue]

Originally Posted by TheBreeze

I like 1/16 toe-out, 1/16 toe-in rear (I run -1.8*F/-2R camber). With the gobs of caster our cars have (mine is +7.6*), this setup works pretty well for the street. Not in the least bit squirrelly. Tire wear has been perfect for me after 11k miles with this setup.

[vampire81]

thank everyone for helping me decide what to do with my car.

can anyone confirm if these are the right part numbers for the M3 front control arms and rear sub frame bushings?

Wishbone, Left: 31102283577

Wishbone, Right: 31102283578

Tension strut with rubber mounting, Left: 31102283575

Tension strut with rubber mounting, Right: 31102283576

M3 Rear Subframe bushings: 33312283382-383 x 2

i have xenon headlight, do i need headlight regulating rod? part number?

[Stohlen]

Originally Posted by vampire81

thank everyone for helping me decide what to do with my car.

can anyone confirm if these are the right part numbers for the M3 front control arms and rear sub frame bushings?

Wishbone, Left: 31102283577

Wishbone, Right: 31102283578

Tension strut with rubber mounting, Left: 31102283575

Tension strut with rubber mounting, Right: 31102283576

M3 Rear Subframe bushings: 33312283382-383 x 2

i have xenon headlight, do i need headlight regulating rod? part number?

http://www.ecstuning.com/BMW-E82-135...ade/ES2586480/

http://www.ecstuning.com/BMW-E82-135...ade/ES2622633/

http://www.ecstuning.com/BMW-E82-135...frame/ES57295/

http://www.ecstuning.com/BMW-E82-135...frame/ES57296/

Done.

[vampire81]

purchased M3 control arms and rear sub frame bushings.
still got $1350 to spend haha ``

[John_01]

If you install M3 front arms and bushes, it makes sense to get springs and decent shocks/stuts installed at the same time. Personally I don't see the need go get super firm springs on a street driven car, but its all up to your preference.

[ilikebmxbikes]

Originally Posted by vampire81

purchased M3 control arms and rear sub frame bushings.
still got $1350 to spend haha ``

Good move -

Front sway bar w/ end links or springs / shocks next

[bselim3]

I have been following this thread for a while because I believe I'm going to do the same upgrades, I have 2 questions though:
-In the links that Stohlen provided the items are for the n54, I'm guessing it's the same for the n55 but I just wanted to make sure.
-Also there's a link for the front control arm and a link for the rear control arm, are you doing both and if so what are the differences between the two. Besides the location obviously haha..

Thanks for the help and good luck with your build!

[Stohlen]

Originally Posted by bselim3

I have been following this thread for a while because I believe I'm going to do the same upgrades, I have 2 questions though:
-In the links that Stohlen provided the items are for the n54, I'm guessing it's the same for the n55 but I just wanted to make sure.
-Also there's a link for the front control arm and a link for the rear control arm, are you doing both and if so what are the differences between the two. Besides the location obviously haha..

Thanks for the help and good luck with your build!

Yes engine is irrelevant.

The front control arms add .75 degrees of camber, the rears do not add anything. Otherwise the fronts are essentially the same as stock, just with more robust/stiff bushings. The rears are much stronger that stock rears as the stockers are made from thin plate steel essentially. Again with stiffer/more robust bushings.

[vampire81]

Originally Posted by bselim3

I have been following this thread for a while because I believe I'm going to do the same upgrades, I have 2 questions though:
-In the links that Stohlen provided the items are for the n54, I'm guessing it's the same for the n55 but I just wanted to make sure.
-Also there's a link for the front control arm and a link for the rear control arm, are you doing both and if so what are the differences between the two. Besides the location obviously haha..

Thanks for the help and good luck with your build!

+1 on Stohlen.
what i purchased:
front control arm kit x 1
rear control arm kit x 1
rear sub frame bushings x 2 from each link

gonna give feed back once installed.

tire change after this
`

[BMhead]

Not sure if this helps, but I got rid of the RFTs for Continental Conti Sport 5 and replaced the suspension with Eibech springs and Bilstein dampers all round, fitted by a UK tuner called Birds. They have produced the settings based on the orginal e30 M3 and looked at Lotus and Jaguar to get the optimum sport/comfort balance.

This has transformed the handling of the car, especially over uneven road surfaces. I have found it good on the track.

At the limit its fun without being too scary as you can progressively feel the decline in grip. If I wanted to go faster I would add a quaife LSD which Birds also provide and stiffer roll bars to reduce understeer.

But I like it the way it is for now. Plenty of entertaining performance and comfortable for everyday.

Hope these comments help

[vampire81]

had the parts installed yesterday, the M3 rear sub frame "forward" bushings had to be installed from the top, that's the only thing different than the 135i spec.

car should have come from the factory like this

turn in has improved a lot, A LOT, that cannot be noticed on low speeds.

there is a high speed ramp on my commute, i used to take it at 60 mph due to 3 wide expansion things that make the rear jump. this morning took the ramp doing 75 mph and the jump reduced by ~50% ``

i did a 75% throttle acc in 2nd gear and amazingly the rear was planted and didn't slide not a single inch. is this from the bushings?

in the highway car feels solid, no more floaty.

what needs to be improved now is damping/shocks and front stiffness. what do you think?

thanks for the advice everyone

[timhatimay]

Better than stock shocks and springs will make a great improvement in daily driving enjoyment, and should help with the performance of the car. It will make the car even more solid! If you have a daily driver and just want a modest improvement, why go with coilovers? For the money you have left you could get matched springs and shocks. Everyone always suggests coilovers, but most people don't frequently change their ride height. You could get an adjustable shock with BMW Performance or similar springs for a more reasonable price, less hassle, and great improvement. Hope you enjoy the M3 parts, and you HAVE to get ride of the RFT! Seriously get rid of the RFT! Don't even think about keeping the RFT!

Tim

[mechavore884]

Originally Posted by timhatimay

Better than stock shocks and springs will make a great improvement in daily driving enjoyment, and should help with the performance of the car. It will make the car even more solid! If you have a daily driver and just want a modest improvement, why go with coilovers? For the money you have left you could get matched springs and shocks. Everyone always suggests coilovers, but most people don't frequently change their ride height. You could get an adjustable shock with BMW Performance or similar springs for a more reasonable price, less hassle, and great improvement. Hope you enjoy the M3 parts, and you HAVE to get ride of the RFT! Seriously get rid of the RFT! Don't even think about keeping the RFT!

Tim

+1 on the coilover and RUN FLAT COMMENTS!!! Ive seen far too many people on here get KW variant expensives lol just to drop the car a little over an inch and nothing more. And no knock against coils by any means but many people don't fully utilize them

[froop]

Originally Posted by mechavore884

+1 on the coilover and RUN FLAT COMMENTS!!! Ive seen far too many people on here get KW variant expensives lol just to drop the car a little over an inch and nothing more. And no knock against coils by any means but many people don't fully utilize them

Slamming a car doesn't always improve handling. In some or most cases, lowering a car too much will actually hinder performance and may actually result in possible damage to suspension components and accelerated wear on tyres.

All of the mounting points and suspension arms, angles etc were designed to work at stock or near stock heights (probably within 1" due to normal compression of springs when loading a car). Slam a car and everything is pulled out of alignment. Too much toe, too much camber, not enough suspension travel, angled axle shafts etc etc.