Boaty feel at highway speed... what are you xi's running your tire PSI 18s?

Boostin335 · 05-08-2011, 07:03 AM

Hey guys,

Just picked up new Miro 111s staggered setup with 225/40/18 and 255/35/18 Pirelli Pzero Nero All-seasons!

Right now its like 35f/36r

Car feels a little boaty at highway speeds...no pulling to 1 side or shimmy at 120... just a little wind blown at highway speeds. Alignment is spot on.

Car is mainly used for 65-70% highway / 30-35% around town.

What are you guys running on recommended 18" setup, NON RUNFLATS for Daily Driving.

FWIW: I live in New Jersey and these are used year round

MeeTsenPu · 05-08-2011, 08:44 AM

I believe im running 36/42 on my Summer Non-RFT setup. Feels great to me.

MassBimmer · 05-08-2011, 12:10 PM

Sounds like the typical stock xi suspension to me!

nicocho · 05-08-2011, 01:03 PM

I had the exact boaty feeling since I got a new set of conti DWS non RFT. I also have 18 inch similar tire setup on my 330xi.

Because of this Im in the process of getting KW v1 coils. Will let u know of the result

tomtom11 · 05-08-2011, 01:04 PM

i believe its because of your XI suspension, its not a sports suspension

fdriller9 · 05-08-2011, 01:23 PM

It's the xi suspension. I run the pressures listed on my door jamb.

1QuikWS6 · 05-09-2011, 12:33 AM

Well, I recently switched from 17's with RFT's to 18's with Conti DW's on a staggered setup.

The ride is definitely different, but I wouldn't describe it as 'boaty' the new setup is much less harsh over bumps and road seams even thought the new non-rft's are a lower profile tire.

You might notice a tiny bit more movement on high speed turns due to the more flexible sidewalls on the non rft's - but if you add in about 3-4 psi to tires over the reccommended pressures listed on your door sticker it will handle better.

ix suspension is not stellar track setup to begin with + the high stance doesn't help either, but fine for me as a daily driver.

I'm definitely not unhappy with the non-rft setup over original in any way...

BAMxi · 05-09-2011, 09:10 AM

Quote:

Originally Posted by MassBimmer

Sounds like the typical stock xi suspension to me!

Agreed. Drop it!!

MeeTsenPu · 05-09-2011, 09:12 AM

Quote:

Originally Posted by MassBimmer

Sounds like the typical stock xi suspension to me!

I didnt fully read the op, I dont have stock suspension hence great feel!

05-08-2011, 07:03 AM	#1
Boostin335 Lieutenant Colonel 562 Rep 1,723 Posts Drives: G82 M4CX, C8, MKIV Supra Join Date: Sep 2007 Location: North/Central NJ iTrader: (2)	Boaty feel at highway speed... what are you xi's running your tire PSI 18s? Hey guys, Just picked up new Miro 111s staggered setup with 225/40/18 and 255/35/18 Pirelli Pzero Nero All-seasons! Right now its like 35f/36r Car feels a little boaty at highway speeds...no pulling to 1 side or shimmy at 120... just a little wind blown at highway speeds. Alignment is spot on. Car is mainly used for 65-70% highway / 30-35% around town. What are you guys running on recommended 18" setup, NON RUNFLATS for Daily Driving. FWIW: I live in New Jersey and these are used year round
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05-08-2011, 08:44 AM	#2
MeeTsenPu Second Lieutenant 10 Rep 270 Posts Drives: 09 335i X-Drive Join Date: Sep 2009 Location: PA iTrader: (3)	I believe im running 36/42 on my Summer Non-RFT setup. Feels great to me.
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05-08-2011, 12:10 PM	#3
MassBimmer Major General 306 Rep 7,433 Posts Drives: 2023 i4 M50 Join Date: May 2009 Location: MA iTrader: (6) Garage List 2009 BMW [9.24]	Sounds like the typical stock xi suspension to me!
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05-08-2011, 01:03 PM	#4
nicocho Private 2 Rep 75 Posts Drives: 330xi Join Date: Mar 2011 Location: Toronto iTrader: (1)	I had the exact boaty feeling since I got a new set of conti DWS non RFT. I also have 18 inch similar tire setup on my 330xi. Because of this Im in the process of getting KW v1 coils. Will let u know of the result
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05-08-2011, 01:04 PM	#5
tomtom11 Captain 84 Rep 703 Posts Drives: 335i Join Date: Jan 2011 Location: Earth iTrader: (1)	i believe its because of your XI suspension, its not a sports suspension
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05-08-2011, 01:23 PM	#6
fdriller9 Banned 253 Rep 7,089 Posts Drives: '06 AW 330xi Join Date: Mar 2009 Location: North Jersey/Philly/NYC iTrader: (4) Garage List 2006 330xi [6.44]	It's the xi suspension. I run the pressures listed on my door jamb.
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05-09-2011, 12:33 AM	#7
1QuikWS6 No 55mph 1622 Rep 8,476 Posts Drives: F32 435ix MSport Join Date: Jul 2009 Location: Blitzburgh, PA iTrader: (113) Garage List 2022 BMW M440ix Vert [0.00] 2015 BMW 435ix MSport [0.00] 2000 Pontiac Trans Am [0.00]	Well, I recently switched from 17's with RFT's to 18's with Conti DW's on a staggered setup. The ride is definitely different, but I wouldn't describe it as 'boaty' the new setup is much less harsh over bumps and road seams even thought the new non-rft's are a lower profile tire. You might notice a tiny bit more movement on high speed turns due to the more flexible sidewalls on the non rft's - but if you add in about 3-4 psi to tires over the reccommended pressures listed on your door sticker it will handle better. ix suspension is not stellar track setup to begin with + the high stance doesn't help either, but fine for me as a daily driver. I'm definitely not unhappy with the non-rft setup over original in any way... __________________ F32 435ix//MGM//M Sport-Prem-Tech-Driver Assist-Lighting-Cold Weather-Dyn Handling Pkgs//M4 Black Lthr Int w/M4 Alum Blade Trim//HK w/Bavsound Stg3//763M//M4 Euro LCI Tails//M4 Mirrors w/CF Covers//AWCarbon CF F/R Spoilers-Side Splitters-Diffuser 6WB/ID6 HU+HUD/IND M4 Alcantara Armrest//PURE S2 Turbo//AA FMIC+DP//ER CP+TIC//3.5bar TMAP/TS DV//AWE Tuning Exh w/Blk Tips//Turner MS CF Intake//BM3 Cary Jordan Tune//MPerf Diff//PrecRW Ignition Kit
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