symmetric vs. asymmetric wheel setup on 10/2010 128i - BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)

clutch128 · 10-04-2012, 04:26 PM

I did another track day Monday. It is doing a number on the tires. I was thinking of getting a dedicated set of slicks or semi-slicks to just use for track use. If I did that I was thinking at the same time getting a wider set of front tires. Right now I'm running 18"x7.5" on the front and 18"x8.5" on the rear. I'm motivated to go bigger on the front in order to try to deal with understeer. I guess I could put in a bigger sway bar (front?) or play with the tire pressure. And of course a lot of it is technique and I'm working on that. Thoughts?

Kim Schwartz · 10-04-2012, 06:25 PM

I have a 128i with the sport package and have switched to 225/40 /18 in each corner and for me it is a very worhtwhile change as it does minimize the understeer and at least techniclly improves braking as there is more tire up front. I keep the staggered set with all season tires on them for when it snows which isn't very often in Albuquerque. And yes, I notice the improvement more on a track than on the street. There is a lot about this in the track section.

clutch128 · 10-05-2012, 01:12 PM

thanks. That's very useful. No rubbing on the front with that setup?

Kim Schwartz · 10-07-2012, 09:21 PM

.....no rubbing at all. I am using a 45mm offset on 7.5"x 18" wheels.

HeelToe · 11-25-2012, 06:55 PM

BTW. Bigger sway bar in the back for less understeer. Be aware though that the rear suspension assembly has to be lowered to change the rear sway bar so it can be pricey if you don't do it yourself. I'm running 235/40 in front with 245/35 in back. I also have Dinan fixed offset camber plates that offset the stock camber adjustment range by 0.7 degrees.

Greenkirby21 · 11-25-2012, 07:20 PM

no rubbing by me and I am using 17x8 all around rims with 225 front and 245 rear. Grip is definitely a plus, although it does still understeer vs going 225 all around

clutch128 · 11-25-2012, 09:08 PM

I ended up switching to 17x8's all around with slicks. No more understeer.

Now I have a *ton* of roll.
So, what next?
a.) rear subframe bushings/mounts?
b.) New roll bars? J&R, M3...?
c.) Coilovers...which?

HeelToe · 11-25-2012, 09:15 PM

Sway bars. Eibach or H&Rs.

dsdubs · 11-26-2012, 05:47 PM

What's the best way to mitigate under steer while maintaining a reasonable level of daily driving capability. A square setup with slicks seems extreme for most of us.

Camber plates? Rear sway? < 30mm staggered setup?

10-04-2012, 04:26 PM	#1
clutch128 New Member Drives: 2011 128i Join Date: Dec 2011 Location: Santa Barbara, CA Posts: 12 iTrader: (0)	symmetric vs. asymmetric wheel setup on 10/2010 128i I did another track day Monday. It is doing a number on the tires. I was thinking of getting a dedicated set of slicks or semi-slicks to just use for track use. If I did that I was thinking at the same time getting a wider set of front tires. Right now I'm running 18"x7.5" on the front and 18"x8.5" on the rear. I'm motivated to go bigger on the front in order to try to deal with understeer. I guess I could put in a bigger sway bar (front?) or play with the tire pressure. And of course a lot of it is technique and I'm working on that. Thoughts?
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11-25-2012, 07:20 PM	#6
Greenkirby21 Vrooom :) Drives: BMW 128i Join Date: Jun 2010 Location: Dream Land Posts: 1,737 iTrader: (1)	no rubbing by me and I am using 17x8 all around rims with 225 front and 245 rear. Grip is definitely a plus, although it does still understeer vs going 225 all around __________________ 2009 128i Coupe Crimson Red MODS: -Injen Intake-Magnaflow Exhaust-Carbon Fiber Spoiler - Carbon Fiber Grilles - OZ Ultraleggeras - CF Mirrors

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10-04-2012, 06:25 PM	#2
Kim Schwartz Private Drives: 128i Join Date: Aug 2010 Location: Albuquerque Posts: 82 iTrader: (0)	I have a 128i with the sport package and have switched to 225/40 /18 in each corner and for me it is a very worhtwhile change as it does minimize the understeer and at least techniclly improves braking as there is more tire up front. I keep the staggered set with all season tires on them for when it snows which isn't very often in Albuquerque. And yes, I notice the improvement more on a track than on the street. There is a lot about this in the track section.

10-05-2012, 01:12 PM	#3
clutch128 New Member Drives: 2011 128i Join Date: Dec 2011 Location: Santa Barbara, CA Posts: 12 iTrader: (0)	thanks. That's very useful. No rubbing on the front with that setup?

10-07-2012, 09:21 PM	#4
Kim Schwartz Private Drives: 128i Join Date: Aug 2010 Location: Albuquerque Posts: 82 iTrader: (0)	.....no rubbing at all. I am using a 45mm offset on 7.5"x 18" wheels.

11-25-2012, 06:55 PM	#5
HeelToe Captain Drives: Rapidly from A to B Join Date: Jun 2005 Location: Illinois Posts: 747 iTrader: (1) Garage List 2013 BMW 135is [0.00] 2006 330i [5.00] 2000 323Ci [0.00]	BTW. Bigger sway bar in the back for less understeer. Be aware though that the rear suspension assembly has to be lowered to change the rear sway bar so it can be pricey if you don't do it yourself. I'm running 235/40 in front with 245/35 in back. I also have Dinan fixed offset camber plates that offset the stock camber adjustment range by 0.7 degrees.

11-25-2012, 09:08 PM	#7
clutch128 New Member Drives: 2011 128i Join Date: Dec 2011 Location: Santa Barbara, CA Posts: 12 iTrader: (0)	I ended up switching to 17x8's all around with slicks. No more understeer. Now I have a ton of roll. So, what next? a.) rear subframe bushings/mounts? b.) New roll bars? J&R, M3...? c.) Coilovers...which?

11-25-2012, 09:15 PM	#8
HeelToe Captain Drives: Rapidly from A to B Join Date: Jun 2005 Location: Illinois Posts: 747 iTrader: (1) Garage List 2013 BMW 135is [0.00] 2006 330i [5.00] 2000 323Ci [0.00]	Sway bars. Eibach or H&Rs.

11-26-2012, 05:47 PM	#9
dsdubs New Member Drives: 2011 135i - DCT M Join Date: Nov 2012 Location: Texas Posts: 11 iTrader: (0)	What's the best way to mitigate under steer while maintaining a reasonable level of daily driving capability. A square setup with slicks seems extreme for most of us. Camber plates? Rear sway? < 30mm staggered setup?