REV vs. 1 %

1Bappel · 03-17-2014, 09:33 AM

We can all agree that staying within a 1% rolling diameter is key when upgrading your wheels to staggered. There is also a lot of discussion about Revs per Mile.

Some members believe that if you are in 1%, you are fine, period. But, I've seen others say that you need to be within 3-4 Revs per Mile.

Clearly there is a Green zone...within 1% and 3-4 RPMs.

What do you think is more important?

I just got into a setup which gave me a .7% on the wheel calculator, but has a 5 RPM difference. What results can members like me see?

SDemetris · 03-17-2014, 12:48 PM

Or just don't get staggered setup. Then you definitely won't have any problems. Anyways I would go with the % number. Like if you make a bunch of left turns even with a staggered setup, your left rear wheel will spin as many or maybe fewer times that front right.. so I don't think it means much

Rich_NYC · 03-22-2014, 02:38 PM

How do u check rpm difference? This might be why I have 235/35/19 and 375/30 and still having trouble

1Bappel · 03-24-2014, 03:52 PM

Check RPM difference through either Tire Rack or the manufacturer's website. Typically they have tire specs and data available. It’s something interesting to consider.

WhiteFury · 03-25-2014, 05:53 PM

I am having a vibration feeling when I let off the brake pedal I have a auto trans.

When I let off the brake pedal I start to coast forward and then after about 1-2 seconds it slightly slows down or a vibration feeling almost like a manual would stall out due to low rpms. 2nd gear is slightly worse.

Is this because I have 335/35/19 front (818 revs) and 265/30/19 rear (821 revs)?

I also used redline 75w90 in the front and rear diffs. Do they require friction modifiers?

stashtrey · 03-25-2014, 06:03 PM

I have 235/40/18 and 266/35/18. I was told by many this is best if staggered. Recent front and rear diff oil change, t case flush/change and tranny fluid/pan/sleeve and filter.

Wondering if long term staggered is just not a good idea.

critical05 · 03-25-2014, 07:08 PM

Since staggered 18" was offered as a option in XI's, why would it matter if BMW was willing to raise the top speed from 135 to 155mph? The faster you go, the greater the rpm difference.

So as long as you kept with the % difference as the OEM staggered setup is, the risk is low.

.....Unless the BMW engineers missed something, then your doomed!

03-17-2014, 09:33 AM	#1
1Bappel Private 9 Rep 54 Posts Drives: 2020 330i Xdrive & 2020 X5 Join Date: Oct 2013 Location: Cincinnati, OH iTrader: (3)	REV vs. 1 % - Which matters most in staggered upgrade? We can all agree that staying within a 1% rolling diameter is key when upgrading your wheels to staggered. There is also a lot of discussion about Revs per Mile. Some members believe that if you are in 1%, you are fine, period. But, I've seen others say that you need to be within 3-4 Revs per Mile. Clearly there is a Green zone...within 1% and 3-4 RPMs. What do you think is more important? I just got into a setup which gave me a .7% on the wheel calculator, but has a 5 RPM difference. What results can members like me see?
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03-17-2014, 12:48 PM	#2
SDemetris FSAE Dude 61 Rep 759 Posts Drives: E90 328xi Join Date: Jul 2012 Location: Pittsburgh, PA iTrader: (0)	Or just don't get staggered setup. Then you definitely won't have any problems. Anyways I would go with the % number. Like if you make a bunch of left turns even with a staggered setup, your left rear wheel will spin as many or maybe fewer times that front right.. so I don't think it means much
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03-22-2014, 02:38 PM	#3
Rich_NYC Private 9 Rep 81 Posts Drives: e90 328xi Join Date: Nov 2012 Location: Queens iTrader: (2)	How do u check rpm difference? This might be why I have 235/35/19 and 375/30 and still having trouble
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03-24-2014, 03:52 PM	#4
1Bappel Private 9 Rep 54 Posts Drives: 2020 330i Xdrive & 2020 X5 Join Date: Oct 2013 Location: Cincinnati, OH iTrader: (3)	Check RPM difference through either Tire Rack or the manufacturer's website. Typically they have tire specs and data available. It’s something interesting to consider.
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03-25-2014, 05:53 PM	#5
WhiteFury Boooost! 70 Rep 793 Posts Drives: 335i Join Date: Sep 2013 Location: NJ iTrader: (0) Garage List 2016 Dodge Charger ... [0.00] 2011 BMW 335i [4.80]	I am having a vibration feeling when I let off the brake pedal I have a auto trans. When I let off the brake pedal I start to coast forward and then after about 1-2 seconds it slightly slows down or a vibration feeling almost like a manual would stall out due to low rpms. 2nd gear is slightly worse. Is this because I have 335/35/19 front (818 revs) and 265/30/19 rear (821 revs)? I also used redline 75w90 in the front and rear diffs. Do they require friction modifiers? __________________ JB4 Stage 2 \| Injen CAI \| BMW PE \| AR Catless DP \| Alpina TCU Flash \| Eibach Pro Kit \| Custom TCKline Koni's \| 19" M359 Wheels \| DWS Tires
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03-25-2014, 06:03 PM	#6
stashtrey Lieutenant Colonel 294 Rep 1,834 Posts Drives: 08 E90 335xi TiAg Join Date: Dec 2012 Location: Sacramento, CA iTrader: (8) Garage List 2008 E90 335xi Sedan [0.00]	I have 235/40/18 and 266/35/18. I was told by many this is best if staggered. Recent front and rear diff oil change, t case flush/change and tranny fluid/pan/sleeve and filter. Wondering if long term staggered is just not a good idea.
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03-25-2014, 07:08 PM	#7
critical05 First Lieutenant 36 Rep 311 Posts Drives: E92 335xi 6 spd Join Date: May 2012 Location: IA iTrader: (0)	Since staggered 18" was offered as a option in XI's, why would it matter if BMW was willing to raise the top speed from 135 to 155mph? The faster you go, the greater the rpm difference. So as long as you kept with the % difference as the OEM staggered setup is, the risk is low. .....Unless the BMW engineers missed something, then your doomed! Last edited by critical05; 03-25-2014 at 07:15 PM..
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