Moving sideways?

danix · 03-12-2024, 04:54 PM

So, my son has a 2008 135i. We did VRSF downpipes and intercooler, and he dropped a tune on, stage 2+ I think. Holy cow.

This thing pulls like a freight train, but I also noticed an instability - it feels like as the boost comes on, the car is shimmying sideways.
I suspect it's revealing some wear in the control arm bushings or similar.
Any thoughts?

ShocknAwe · 03-12-2024, 08:13 PM

Did power before chassis.

Car was designed with run flats in mind. Needs a lot of work to sort out even at stock power levels.

N55e82Simon · 03-12-2024, 08:28 PM

I would look at the rear subframe bushings and visual check with a pry bar around ball joints and really all suspension parts. It shouldn’t feel like what you describe even stock. It’s not great stock but very manageable. Could be poor alignment exaggerating it too.

Is everything stock on the suspension?

danix · 03-12-2024, 09:59 PM

Yes, suspension is stock. https://carsandbids.com/auctions/3vW...bmw-135i-coupe

danix · 03-13-2024, 11:06 AM

Rear control arm bushings were changed to M3 spec. Alignment may be slightly off as we just had the steering rack loose for the downpipe install, but it tracks straight.

N55e82Simon · 03-13-2024, 12:29 PM

I see the m3 subframe bushings which is a big help. Hmm. Seems to be a well cared for car too.

Happens with traction control on and off?

Some alignment places with give you an alignment check for cheap and you can see if something is just way off?

WeryPert1 · 03-15-2024, 03:45 PM

Agreed, replace the RSFB's with something better. Either the M3 parts or I went with the Whiteline 2-pc delrin parts. The consensus seems to be that BMW chose to use super soft RSFB's to compensate for the harshness of the crappy gen-1 runflat tires they put on the car. And now with more compliant tires the whole rear end just feels disconnected.

HP Autosport · 03-20-2024, 09:44 PM

Quote:

Originally Posted by danix

So, my son has a 2008 135i. We did VRSF downpipes and intercooler, and he dropped a tune on, stage 2+ I think. Holy cow.

This thing pulls like a freight train, but I also noticed an instability - it feels like as the boost comes on, the car is shimmying sideways.
I suspect it's revealing some wear in the control arm bushings or similar.
Any thoughts?

Bushing deflection. You will likely need solid subframe bushings and spherical end toe arms to keep that rear button down.

Feel free to PM us with any questions.

danix · 03-28-2024, 03:32 PM

Had the car aligned today and it was quite a bit off. Tracks straight, but when you hit the juice, it still feels like the back is moving. I'll look into some of the options suggested.

Eyeman · 03-28-2024, 06:03 PM

As long as not too bad, I kinda like the way our cars want to go wild when be up the boost. I have a higher hp car that is very well composed (AMG GTS) and it can be kinda boring at times. But yep, the stock 135 suspension sux.

Olgeezer1 · 03-29-2024, 02:21 PM

Quote:

Originally Posted by danix

Had the car aligned today and it was quite a bit off. Tracks straight, but when you hit the juice, it still feels like the back is moving. I'll look into some of the options suggested.

Rear subframe bushings. Fairly big job as subframe should be dropped. E90 M3 subframe bushings, Whiteline 2 pc. poly bushings ( that's the way I went ), or solid aluminum bushings will all be a major improvement. There are also bushing inserts, cheaper , easier install but are really only a halfway measure. My research before buying the car 10+ years ago showed the major E82 weaknesses were the soft subframe bushings and cheap shocks/struts. Dealing with those 2 issues along with premium tires will transform your ride.

HP Autosport · 04-01-2024, 01:27 PM

Quote:

Originally Posted by Olgeezer1

Rear subframe bushings. Fairly big job as subframe should be dropped. E90 M3 subframe bushings, Whiteline 2 pc. poly bushings ( that's the way I went ), or solid aluminum bushings will all be a major improvement. There are also bushing inserts, cheaper , easier install but are really only a halfway measure. My research before buying the car 10+ years ago showed the major E82 weaknesses were the soft subframe bushings and cheap shocks/struts. Dealing with those 2 issues along with premium tires will transform your ride.

We also like the Whiteline inserts that is the all the budget you have for parts and labor.

If you are dropping the subframe for the bushings, it is also a great time to replace the two flex brake hoses at this time.

Feel free to reach out to us for Whiteline, solid alum. subframe bushings and Stoptech SS brake lines.

N55e82Simon · 04-02-2024, 10:46 AM

Quote:

Originally Posted by HP Autosport

We also like the Whiteline inserts that is the all the budget you have for parts and labor.

If you are dropping the subframe for the bushings, it is also a great time to replace the two flex brake hoses at this time.

Feel free to reach out to us for Whiteline, solid alum. subframe bushings and Stoptech SS brake lines.

His cars and bids link shows it having m3 rear subframe bushing and arms. Kinda a weird situation. Unless the PO just lied about it. Idk

HP Autosport · 04-02-2024, 11:24 AM

Quote:

Originally Posted by N55e82Simon

His cars and bids link shows it having m3 rear subframe bushing and arms. Kinda a weird situation. Unless the PO just lied about it. Idk

If that is the case and alignment is good, have a look at the deflection in the toe arms. Toe changes under load will steer the rear of the car causing instability.

AshwinLB · 04-10-2024, 12:59 PM

I agree with the other posters, rear subframe bushings and toe arms made a big difference to straight line stability on my 135i.

I went with condor speed shop solid uhmw rsfb and I noticed no increase in NVH but it made a MASSIVE difference in how the chassis reacts in straight lines and around turns. I’d recommend getting the eBay tool to remove the stock bushings if you’re DIYing as it made it a lot easier than the struggles I’ve seen online. I’d also recommend removing the middle brake lines from the subframe so you can drop it a little bit lower. And might as well change the lines at the same time, I went with UUC stainless lines just cause they use factory style mounting faces so you don’t have to counter-hold while tightening the lines. Really doesn’t matter though

For toe arms, you can’t use e90 m3 toe arms as they’re too long so I went with Megan Racing Toe Arms which have spherical bearings on both ends and put on seals it rod end boots to keep them from eventually clunking (they already had seals but they were kinda wimpy). If you don’t wanna bother with that, the Manzo Toe Arms are the exact same design except with rubber bushings on each end which should be more durable but would have some compliance due to the nature of rubber (still better than stock). I also added a SPL eccentric lockout so all the toe adjustment is from the arm itself instead of the eccentric bolt.

I also did an mfactory LSD but it’s hard to justify/recommend it due to cost vs benefits (especially if it’s just a street car), but also made a huge difference to straight-line stability and handling around corners. The car just feels like it’s on rails. Still, the rsfb and toe arms have a much better cost to benefit ratio so I’d recommend just doing those initially.

03-12-2024, 04:54 PM	#1
danix Enlisted Member 14 Rep 31 Posts Drives: e39,e46 Join Date: Dec 2011 Location: Raleigh NC iTrader: (0)	Moving sideways? So, my son has a 2008 135i. We did VRSF downpipes and intercooler, and he dropped a tune on, stage 2+ I think. Holy cow. This thing pulls like a freight train, but I also noticed an instability - it feels like as the boost comes on, the car is shimmying sideways. I suspect it's revealing some wear in the control arm bushings or similar. Any thoughts?
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03-12-2024, 08:13 PM	#2
ShocknAwe 1Addict 3233 Rep 7,894 Posts Drives: E82 Mutt, M57 Truck Join Date: Jul 2012 Location: Charleston iTrader: (22)	Did power before chassis. Car was designed with run flats in mind. Needs a lot of work to sort out even at stock power levels. __________________ 2010 135i 6MT Jet Black N54/3 FE82 Mutt \| BUILD THREAD \| GARAGE SALE
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03-12-2024, 08:28 PM	#3
N55e82Simon Private First Class 151 Rep 116 Posts Drives: BMW 135i Join Date: May 2023 Location: SoCal iTrader: (0) Garage List 2011 bmw 135i [9.33]	I would look at the rear subframe bushings and visual check with a pry bar around ball joints and really all suspension parts. It shouldn’t feel like what you describe even stock. It’s not great stock but very manageable. Could be poor alignment exaggerating it too. Is everything stock on the suspension?
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03-12-2024, 09:59 PM	#4
danix Enlisted Member 14 Rep 31 Posts Drives: e39,e46 Join Date: Dec 2011 Location: Raleigh NC iTrader: (0)	Yes, suspension is stock. https://carsandbids.com/auctions/3vW...bmw-135i-coupe
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03-13-2024, 11:06 AM	#5
danix Enlisted Member 14 Rep 31 Posts Drives: e39,e46 Join Date: Dec 2011 Location: Raleigh NC iTrader: (0)	Rear control arm bushings were changed to M3 spec. Alignment may be slightly off as we just had the steering rack loose for the downpipe install, but it tracks straight.
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03-13-2024, 12:29 PM	#6
N55e82Simon Private First Class 151 Rep 116 Posts Drives: BMW 135i Join Date: May 2023 Location: SoCal iTrader: (0) Garage List 2011 bmw 135i [9.33]	I see the m3 subframe bushings which is a big help. Hmm. Seems to be a well cared for car too. Happens with traction control on and off? Some alignment places with give you an alignment check for cheap and you can see if something is just way off?
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03-15-2024, 03:45 PM	#7
WeryPert1 Private First Class 105 Rep 133 Posts Drives: 128i Join Date: Mar 2019 Location: SoCal iTrader: (0)	Agreed, replace the RSFB's with something better. Either the M3 parts or I went with the Whiteline 2-pc delrin parts. The consensus seems to be that BMW chose to use super soft RSFB's to compensate for the harshness of the crappy gen-1 runflat tires they put on the car. And now with more compliant tires the whole rear end just feels disconnected.
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03-28-2024, 03:32 PM	#9
danix Enlisted Member 14 Rep 31 Posts Drives: e39,e46 Join Date: Dec 2011 Location: Raleigh NC iTrader: (0)	Had the car aligned today and it was quite a bit off. Tracks straight, but when you hit the juice, it still feels like the back is moving. I'll look into some of the options suggested.
	Appreciate 0 Quote

03-28-2024, 06:03 PM	#10
Eyeman Colonel 121 Rep 2,037 Posts Drives: 2008 135 blk, blk, step Join Date: Jan 2009 Location: Atlanta, GA iTrader: (0) Garage List 1994 Porsche 968 Cab [0.00] 2017 AMG GTS [0.00] 1994 Porsche 968 Coupe [0.00] 1977 Mercedes 450SE ... [0.00] 2008 135 [8.00]	As long as not too bad, I kinda like the way our cars want to go wild when be up the boost. I have a higher hp car that is very well composed (AMG GTS) and it can be kinda boring at times. But yep, the stock 135 suspension sux. __________________ Injen, RR OCC, MadDad Whisper, donut spare, 19x8.5et43fr 19x9.5et45r Volk LE37's, rear fenders rolled/pulled, PSS4S 225/35fr 255/30r, KW V1's, AR coated catless dps, Cross strutbar, CF grills and license plate holder, iCarbon diffuser, ETS black anodized FMIC, M3 control arms, Quaife, ER chargepipe, ForgeDV's, Topspeed Custom Tune, V3sims, Braille, Andrey_GTA rear hub mod, Ebay Mstyle front bumper and performance style side skirts.
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04-10-2024, 12:59 PM	#15
AshwinLB Private 47 Rep 95 Posts Drives: 2008 BMW 135i 6MT Join Date: Jan 2018 Location: Toronto iTrader: (0)	I agree with the other posters, rear subframe bushings and toe arms made a big difference to straight line stability on my 135i. I went with condor speed shop solid uhmw rsfb and I noticed no increase in NVH but it made a MASSIVE difference in how the chassis reacts in straight lines and around turns. I’d recommend getting the eBay tool to remove the stock bushings if you’re DIYing as it made it a lot easier than the struggles I’ve seen online. I’d also recommend removing the middle brake lines from the subframe so you can drop it a little bit lower. And might as well change the lines at the same time, I went with UUC stainless lines just cause they use factory style mounting faces so you don’t have to counter-hold while tightening the lines. Really doesn’t matter though For toe arms, you can’t use e90 m3 toe arms as they’re too long so I went with Megan Racing Toe Arms which have spherical bearings on both ends and put on seals it rod end boots to keep them from eventually clunking (they already had seals but they were kinda wimpy). If you don’t wanna bother with that, the Manzo Toe Arms are the exact same design except with rubber bushings on each end which should be more durable but would have some compliance due to the nature of rubber (still better than stock). I also added a SPL eccentric lockout so all the toe adjustment is from the arm itself instead of the eccentric bolt. I also did an mfactory LSD but it’s hard to justify/recommend it due to cost vs benefits (especially if it’s just a street car), but also made a huge difference to straight-line stability and handling around corners. The car just feels like it’s on rails. Still, the rsfb and toe arms have a much better cost to benefit ratio so I’d recommend just doing those initially.
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