Handling as good as an M3

[135]

Originally Posted by dbronnik

Why skip the rear bar?

Here is a response that I provided in another thread.

Originally Posted by 135

Unless you have a freak 135i, the advice should be that the front bar can be upgraded but the rear bar shouldn't (doesn't need to) be upgraded - this even applies if you have a torsion helical gear LSD installed, such as Quaife or Wavetrac. The exception is if you have a clutch plate LSD, such as Drexler or OS Giken, then a stiffer rear bar should be considered/used. At least, that is the advice from race teams and those that have considerable track time in their 135i. If considering an LSD then you also have to weigh up the pros and cons of the helical gear and clutch plate varieties as it relates to your use of your car.

Originally Posted by ilikebmxbikes

You will save money on labor if you need the bar- if you don't it is costing you more as you bought something you don't need.

The berk time attack car ran a stock rear bar.

+1 for Berk - they were one of the race teams that I was referring to in my other post.

[dbronnik]

Originally Posted by 135

Here is a response that I provided in another thread.

+1 for Berk - they were one of the race teams that I was referring to in my other post.

Thanks for that thread link.. But it made me even more torn on the rear bar - several people responded on that thread that they were happy with the rear bar.

A couple guys in my autoX club run an upgraded rear bar as well, both with an LSD, and they're also usually the fastest around the course. I wonder if the answer changes depending on the application (highly technical autoX course vs. track vs. street).

[Top Gon]

Anyone know how to reduce understeer on corner exit?

right now my car turns in well, but as I begin to accelerate out of a corner I feel the front end kinda lift up and start to track out leading to understeer. It gives me less confidence in it.

Is it the camber, rear not stiff enough, combo of things?

car setup: ST coils, e92 m3 front sway bar, 235/255 RE-11 tires, camber: -0.5 front, -1.5 rear (limited to stock range)

[dtla1]

You need more front camber for sure.

[BMW135pls]

Originally Posted by Basheezy

Anyone know how to reduce understeer on corner exit?

right now my car turns in well, but as I begin to accelerate out of a corner I feel the front end kinda lift up and start to track out leading to understeer. It gives me less confidence in it.

Is it the camber, rear not stiff enough, combo of things?

car setup: ST coils, e92 m3 front sway bar, 235/255 RE-11 tires, camber: -0.5 front, -1.5 rear (limited to stock range)

What tire pressures are you running?

[Top Gon]

Originally Posted by BMW135pls

What tire pressures are you running?

34 front, 36 rear

[Top Gon]

Originally Posted by dtla1

You need more front camber for sure.

I've got an upgrade in mind for all the control arms, rear toe links, and ST XTA coils with the integrated camber plates.

[BMW135pls]

Originally Posted by Basheezy

34 front, 36 rear

That's about where it should be, maybe try going down a hair in the front, or up a hair in the rear. I don't think it's the camber in this case, although if you are being competitve, you definitely want more than .5 degrees in the front. Camber is more about turn in, understeer on corner exit happens when the front tires lose traction. You are feeling lift up/squat of the chassis when this happens, so it's probably got more to do with weight transfer lowering the grip on your front tires. Are you running upgraded rear subframe bushings? If you are not, that would be your most likely cause.

[Top Gon]

Originally Posted by BMW135pls

That's about where it should be, maybe try going down a hair in the front, or up a hair in the rear. I don't think it's the camber in this case, although if you are being competitve, you definitely want more than .5 degrees in the front. Camber is more about turn in, understeer on corner exit happens when the front tires lose traction. You are feeling lift up/squat of the chassis when this happens, so it's probably got more to do with weight transfer lowering the grip on your front tires. Are you running upgraded rear subframe bushings? If you are not, that would be your most likely cause.

yeah this happens usually on the track. rarely on canyon cruises. no upgraded rear subframe no, I should think about upgrading that as well.

Not sure if the JB4 has something to do with the weight transfer thing. I would expect there to be some oversteer or rotation with the added power though, but there is none.

[slonik]

car setup: ST coils, e92 m3 front sway bar, 235/255 RE-11 tires, camber: -0.5 front, -1.5 rear (limited to stock range)

275/275 wheels will close all your problems

[BMW135pls]

Originally Posted by Basheezy

yeah this happens usually on the track. rarely on canyon cruises. no upgraded rear subframe no, I should think about upgrading that as well.

Not sure if the JB4 has something to do with the weight transfer thing. I would expect there to be some oversteer or rotation with the added power though, but there is none.

The stock suspension and alignment is tuned for understeer. From the rears having 3x more camber than the fronts, to the absurdly soft rear bushings, to wider rear contact patch, the entire car is tuned from factory so that understeer is the most likely traction failure.

RSFBs are absolutely essential, night and day difference from stock. Put either M3 bushings in it (expensive for some, but feel great), Whiteline, or some form of poly bushing kit, and your problem will be solved. Launches better, corners better, overall feels more confident in its ability to handle the power it has.

[Top Gon]

Originally Posted by slonik

275/275 wheels will close all your problems

lol yeah maybe with 1M front conversion

[Top Gon]

Originally Posted by BMW135pls

The stock suspension and alignment is tuned for understeer. From the rears having 3x more camber than the fronts, to the absurdly soft rear bushings, to soft rear dampers and wider rear contact patch, the entire car is tuned from factory so that understeer is the most likely traction failure.

RSFBs are absolutely essential, night and day difference from stock. Put either M3 bushings in it (expensive for some, but feel great), Whiteline, or some form of poly bushing kit, and your problem will be solved. Launches better, corners better, overall feels more confident in its ability to handle the power it has.

good to know. What do you think about subframe inserts as an alternative to bushings?

the car stock feels more like a front wheel drive.

[BMW135pls]

Originally Posted by Basheezy

good to know. What do you think about subframe inserts as an alternative to bushings?

the car stock feels more like a front wheel drive.

Can't say I have much input on them. However, just from browsing the forum for a few months, I've seen a handful of owners pull the inserts out and install an actual bushing kit. If you eventually feel the need to install real bushings anyway, I would just skip the middleman and go with the real thing from the start.

[Top Gon]

Originally Posted by BMW135pls

Can't say I have much input on them. However, just from browsing the forum for a few months, I've seen a handful of owners pull the inserts out and install an actual bushing kit. If you eventually feel the need to install real bushings anyway, I would just skip the middleman and go with the real thing from the start.

yeah might as well do it right.

Thanks for the input

[850tgul]

Originally Posted by Basheezy

yeah might as well do it right.

Thanks for the input

+1
This was me. Tried the inserts but in the end removed them and went with the full kit from Whiteline. About $100 more than the inserts and the install is the same except you need to remove the stock bushings with the full kit. Many go with the oem M3 bushings but they require pressing the bushings in. Whiteline kit is much much easier wiht their two piece design and just as effective from what I can gather.

[chris82]

My advice is to put more money into your coilovers. That is such an important part of how your car feels. Try something high end like a JRZ, MCS, KW Competition, etc., and skip out on some of the other parts. It will literally transform the car. A single click of compression on a high end damper can make your car feel more planted and responsive than any control arm upgrade will. It's astonishing really. That's my advice if you want the car to feel equal or better than an M3.

However there are 2 problems though that are just part of the 1 series

a. tires. we can barely fit a 245-255 up front, M3s have that stock!
b. wheelbase. nothing we can to do about that, a longer car is just more stable.

Good luck to you op!

[chris82]

Originally Posted by ilikebmxbikes

This - I had all the m3 suspension except steering rack and the e92 still felt better.

OP - I would also likely skip the rear sway bar.

What felt better about it? Was it just more stable? I need to drive an M3
What coilovers were you running at the time btw?

[lowbudgethero]

I've always thought the car was pretty stable at high speed in a straight line, there's too much rear end movement than I would like over uneven bumps though. Maybe I'm just used to crap cars and have no M3 to reference.

[ilikebmxbikes]

Originally Posted by chris82

What felt better about it? Was it just more stable? I need to drive an M3
What coilovers were you running at the time btw?

I have had different coilovers set ups. Coilovers alone worn make a 135i feel like a 1m or m3.

I attribute a lot to the rear subframe bushings and steering racks.

[BMW135pls]

Originally Posted by ilikebmxbikes

I have had different coilovers set ups. Coilovers alone worn make a 135i feel like a 1m or m3.

I attribute a lot to the rear subframe bushings and steering racks.

Are you still running the M3 subframe bushings, or have you gone to solid bushings?

[ilikebmxbikes]

Originally Posted by BMW135pls

Are you still running the M3 subframe bushings, or have you gone to solid bushings?

My 1series now has solid subframe bushings and handles equally to an m3 with the same mods- it essentially is a lighter m3 at this point.