Performance !

CEG02 · 07-20-2009, 06:05 PM

So i just got new 19'' VMR V710s for my 328 e92. They look great but much to my dismay, they very noticeably decreased performance. Of all things, i was not expecting this, perhaps i was naive. Has anyone else had this problem with their car and more specifically a 328??? and what can i do to counteract the loss of performance???

AND

What are the best performance mods for the 328 in terms of HP and Torque gains??????

Please Help!

Sorry guys that this is confusing. And BTW, i was just on my way to CT for a few days and got a flat tire... so now im back at my house in NJ after hours of AAA.

So anyways... I'm not sure what the difference is in weight from the stock wheels, but there is a noticeable difference in acceleration. Especially at higher gears, the acceleration is a lot worse. When im crusing around at 50 mph in 6th gear, i can put my foot down and the car will barely move. Thats a big difference from before. Even low gear acceleration is very noticeably slower.

NightStalker · 07-20-2009, 06:16 PM

for performance you can add an aftermarket exhaust option & or an intake!
maybe you have different tires on it may feel a bit odd after using run flats?

SV Concepts III · 07-20-2009, 07:09 PM

Exhaust, intake and software would be a good start. You can then move on to headers and pulleys for additional gains.

NiVeDh · 07-20-2009, 07:22 PM

How did they decrease performance?

NightStalker · 07-20-2009, 08:22 PM

i think it was naturally aspirated and on ours we gain more because of twin turbos? no?

snipersix · 07-20-2009, 08:24 PM

maybe he means the car tends to have a harder time picking up since, the rims are heavier?

Curt2000 · 07-20-2009, 08:28 PM

I thought that the VMR's were still lighter per corner than the stockers? Less rotational mass would equal an increase in performance...

snipersix · 07-20-2009, 08:34 PM

Quote:

Originally Posted by Curt2000

I thought that the VMR's were still lighter per corner than the stockers? Less rotational mass would equal an increase in performance...

then maybe im mistaken..

Kleinacus · 07-20-2009, 08:52 PM

Yeah, this thread confuses me from the start. I don't understand how larger, lighter VMR wheels could decrease 'performance'. As long as the wheels are the same or lighter weight, I was under the impression this would reduce unsprung weight and help acceleration and braking.

Lowcruzr · 07-20-2009, 09:00 PM

Quote:

Originally Posted by jklein5525

Yeah, this thread confuses me from the start. I don't understand how larger, lighter VMR wheels could decrease 'performance'. As long as the wheels are the same or lighter weight, I was under the impression this would reduce unsprung weight and help acceleration and braking.

They may weigh less than stock, but the mass is concentrated farther out from the center. (Do you really want to see the math involved in this???)

We switched from stock, 15" Saturn rims on our SCCA ITA Coupe to 15" RAYS wheels. It was not only a HUGE difference in feel and performance, you could actually hear the motor rev way faster on the in-car video when comparing like-for-like footage. Unreal!! We were hitting 5th gear on tracks that we could barely top out fourth!! Imagine what 20's would do to your ride!

Curt2000 · 07-20-2009, 09:13 PM

Quote:

Originally Posted by Lowcruzr

They may weigh less than stock, but the mass is concentrated farther out from the center. (Do you really want to see the math involved in this???)

We switched from stock, 15" Saturn rims on our SCCA ITA Coupe to 15" RAYS wheels. It was not only a HUGE difference in feel and performance, you could actually hear the motor rev way faster on the in-car video when comparing like-for-like footage. Unreal!! We were hitting 5th gear on tracks that we could barely top out fourth!! Imagine what 20's would do to your ride!

Yeah, lets hear the rotational mass mathematics

Tee-Dub · 07-20-2009, 09:36 PM

I doubt the average driver is going to notice the difference. I put Rays forged wheels on my S2000 in the same 17" stock size and noticed an improvement, but were talking a wheel that is drastically lighter than the stock S2K wheels, plus on a car that has far less torque than a 328i.

Pyrat 2 · 07-20-2009, 10:13 PM

Quote:

Originally Posted by Curt2000

Yeah, lets hear the rotational mass mathematics

The moment of inertia is:

I = integral (R^2 dm)

where m is mass and r is the perpendicular distance to the axis of rotation.

Been a long time since I studied this but basically think of it as a flywheel. The more mass at the edge of the flywheel the harder it is to speed up, slow down, and change direction.

NightStalker · 07-20-2009, 11:03 PM

Quote:

Originally Posted by HeelToe

The moment of inertia is:

I = integral (R^2 dm)

where m is mass and r is the perpendicular distance to the axis of rotation.

Been a long time since I studied this but basically think of it as a flywheel. The more mass at the edge of the flywheel the harder it is to speed up, slow down, and change direction.

ahh yes physics your correct, and hmm centriptal acceleration or force mayb

CEG02 · 07-20-2009, 11:26 PM

Sorry guys that this is confusing. And BTW, i was just on my way to CT for a few days and got a flat tire... so now im back at my house in NJ after hours of AAA.

So anyways... I'm not sure what the difference is in weight from the stock wheels, but there is a noticeable difference in acceleration. Especially at higher gears, the acceleration is a lot worse. When im crusing around at 50 mph in 6th gear, i can put my foot down and the car will barely move. Thats a big difference from before. Even low gear acceleration is very noticeably slower.

TSM330i · 07-21-2009, 06:50 AM

Read this:
http://www.e90post.com/forums/showthread.php?t=281392
Light weight wheels are a performance part. Heavier wheels or the same weight with a larger diameter will definitely affect all dynamics of driving.

I don't know what size you had from stock, but it looks like the V710 combo for the front rim/tire is 50lbs. You may be around the same weight, but with a larger diameter, which would decrease performance.
http://www.e90post.com/forums/showthread.php?t=148405

nhhiep · 07-21-2009, 01:42 PM

the feeling that you get is normal. I switched the 16" stock to 18" 162s and it feels slower

Lowcruzr · 07-21-2009, 01:50 PM

Quote:

Originally Posted by HeelToe

The moment of inertia is:

I = integral (R^2 dm)

where m is mass and r is the perpendicular distance to the axis of rotation.

Been a long time since I studied this but basically think of it as a flywheel. The more mass at the edge of the flywheel the harder it is to speed up, slow down, and change direction.

He beat me to it; well done!! This is why your lighter, but larger, wheels can still have an impact on performance.

mike-y · 07-21-2009, 02:37 PM

you didn't mention what size tire you put on those 19s either. the overall tire diameter can also make a difference

chaz58 · 07-21-2009, 03:42 PM

I dropped 20lbs/wheel and can't say I felt a difference in acceleration (although the axle hops around a lot less). But, I certainly can feel a difference when I change the gear ratios from changing tire size. You didn't do that, did you?

07-20-2009, 06:05 PM	#1
CEG02 Private 7 Rep 75 Posts Drives: F32 435i xDrive Join Date: Apr 2009 Location: Manhattan iTrader: (0)	Performance ! So i just got new 19'' VMR V710s for my 328 e92. They look great but much to my dismay, they very noticeably decreased performance. Of all things, i was not expecting this, perhaps i was naive. Has anyone else had this problem with their car and more specifically a 328??? and what can i do to counteract the loss of performance??? AND What are the best performance mods for the 328 in terms of HP and Torque gains?????? Please Help! Sorry guys that this is confusing. And BTW, i was just on my way to CT for a few days and got a flat tire... so now im back at my house in NJ after hours of AAA. So anyways... I'm not sure what the difference is in weight from the stock wheels, but there is a noticeable difference in acceleration. Especially at higher gears, the acceleration is a lot worse. When im crusing around at 50 mph in 6th gear, i can put my foot down and the car will barely move. Thats a big difference from before. Even low gear acceleration is very noticeably slower. Last edited by CEG02; 07-20-2009 at 11:26 PM..
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07-20-2009, 06:16 PM	#2
NightStalker ✰ 267 Rep 2,741 Posts Drives: Audi Join Date: Nov 2008 Location: New York City iTrader: (12)	for performance you can add an aftermarket exhaust option & or an intake! maybe you have different tires on it may feel a bit odd after using run flats?
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07-20-2009, 07:09 PM	#3
SV Concepts III Lieutenant General 375 Rep 17,017 Posts Drives: BMW Duh Join Date: Apr 2005 Location: Santa Clara iTrader: (13)	Exhaust, intake and software would be a good start. You can then move on to headers and pulleys for additional gains.
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07-20-2009, 07:22 PM	#4
NiVeDh Major General 422 Rep 8,003 Posts Drives: '08 E90 335i, '99 E36 M3 Join Date: Apr 2009 Location: Houston, TX & Atlanta, GA iTrader: (132) Garage List 2008 BMW 335i Sedan [8.66]	How did they decrease performance?
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07-20-2009, 08:22 PM	#5
NightStalker ✰ 267 Rep 2,741 Posts Drives: Audi Join Date: Nov 2008 Location: New York City iTrader: (12)	i think it was naturally aspirated and on ours we gain more because of twin turbos? no?
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07-20-2009, 08:24 PM	#6
snipersix Brigadier General 228 Rep 3,807 Posts Drives: Retired 2017 F87 M2 Join Date: Jan 2008 Location: Burnaby iTrader: (3) Garage List 2017 BMW M2 [0.00]	maybe he means the car tends to have a harder time picking up since, the rims are heavier? __________________ 2017 M2 Coupe:\|Black Sapphire Metallic\|DCT\|Nav/Idrive\|M Performance CF Spoiler\|M Performance CF DCT Interior\| M Performance Gloss Black Kidney Grills\| M Performance Steel Pedals \| Eventuri CF CAI \| 19" Brixton Rims \| KW V3 Clubsport \| Retired: \|2008 328i Sedan\|Montego Blue\|
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07-20-2009, 08:28 PM	#7
Curt2000 Brigadier General 1013 Rep 3,157 Posts Drives: '93 Supra Turbo Join Date: Jun 2007 Location: Washington D.C. iTrader: (25)	I thought that the VMR's were still lighter per corner than the stockers? Less rotational mass would equal an increase in performance... __________________ Former Car: '16 SUNBURST GOLD F80 ///M3--6MT/Carbon Cloth (ED Thread) Former Car:'13 SANTORINI BLUE E92///M3--6MT/Speed Cloth/ZCP(ED Thread) INSTAGRAM:@C2KMotorsports
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07-20-2009, 08:52 PM	#9
Kleinacus Captain 671 Rep 873 Posts Drives: M2C 6MT Build Week 33 Join Date: Jan 2009 Location: Philly Suburbs iTrader: (1)	Yeah, this thread confuses me from the start. I don't understand how larger, lighter VMR wheels could decrease 'performance'. As long as the wheels are the same or lighter weight, I was under the impression this would reduce unsprung weight and help acceleration and braking. __________________ 2019 m2c 6MT C33/29U/MDOE/4MC/ZEC/Z4G/Z09/AA mid/Remus Axle-back Race/Carbahn Stage 1 2014 B8.5 s4 6MT Monsoon Gray Metallic/Black Optics/RS Grille/GIAC Stage 1/AWE Touring Exhaust & S-Flo Intake/H&R Sway Bars/Bilstein PSS10
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07-20-2009, 09:36 PM	#12
Tee-Dub Captain 35 Rep 753 Posts Drives: 2008 135i Join Date: May 2009 Location: Vancouver, WA iTrader: (9)	I doubt the average driver is going to notice the difference. I put Rays forged wheels on my S2000 in the same 17" stock size and noticed an improvement, but were talking a wheel that is drastically lighter than the stock S2K wheels, plus on a car that has far less torque than a 328i.
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07-20-2009, 11:26 PM	#15
CEG02 Private 7 Rep 75 Posts Drives: F32 435i xDrive Join Date: Apr 2009 Location: Manhattan iTrader: (0)	Sorry guys that this is confusing. And BTW, i was just on my way to CT for a few days and got a flat tire... so now im back at my house in NJ after hours of AAA. So anyways... I'm not sure what the difference is in weight from the stock wheels, but there is a noticeable difference in acceleration. Especially at higher gears, the acceleration is a lot worse. When im crusing around at 50 mph in 6th gear, i can put my foot down and the car will barely move. Thats a big difference from before. Even low gear acceleration is very noticeably slower.
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07-21-2009, 06:50 AM	#16
TSM330i 2006 330i, TSM, Black, manual, sport 878 Rep 3,699 Posts Drives: '17 C2, GTI, Z4 3.0si Racecar Join Date: Nov 2005 Location: Chester Springs, PA iTrader: (2)	Read this: http://www.e90post.com/forums/showthread.php?t=281392 Light weight wheels are a performance part. Heavier wheels or the same weight with a larger diameter will definitely affect all dynamics of driving. I don't know what size you had from stock, but it looks like the V710 combo for the front rim/tire is 50lbs. You may be around the same weight, but with a larger diameter, which would decrease performance. http://www.e90post.com/forums/showthread.php?t=148405 __________________ 2017 Porsche C2 - manual of course 2015 GTI S 2008 BMW Z4 3.0si Coupe - because racecar
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07-21-2009, 01:42 PM	#17
nhhiep Captain 88 Rep 863 Posts Drives: bmw Join Date: Jan 2006 Location: Denver, CO iTrader: (0)	the feeling that you get is normal. I switched the 16" stock to 18" 162s and it feels slower
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07-21-2009, 02:37 PM	#19
mike-y just another bmw douche bag 195 Rep 3,640 Posts Drives: 1.9L of fury Join Date: Nov 2008 Location: Los Angeles, CA iTrader: (4)	you didn't mention what size tire you put on those 19s either. the overall tire diameter can also make a difference
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07-21-2009, 03:42 PM	#20
chaz58 Captain 15 Rep 701 Posts Drives: 328iT Join Date: Oct 2007 Location: Detroit Burbs iTrader: (0)	I dropped 20lbs/wheel and can't say I felt a difference in acceleration (although the axle hops around a lot less). But, I certainly can feel a difference when I change the gear ratios from changing tire size. You didn't do that, did you? __________________ _________________________________________________
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