Weight/Handling, 135i vs. 335i

R32 · 09-17-2007, 01:21 PM

i am not a physics person, but the following thought crossed my mind.

the 135i doesn't really weigh that much less than a 335i. but, i'd expect the handling to still be quite a bit better.

assuming that a car is a slender rod of uniform density (obviously not true), the moment of inertia should vary as the square of the length.

so, rotating intertia for the 135i (4360 cm long) vs. the 335i (4580 cm) should be 4360^2/4580^2 = .91, or about a 10% reduction, even if the cars weighed the same amount!

so, is it fair to assume that the 135i would turn with the same agility as a 335i with a 10% reduction of weight?

Crashspeeder · 09-17-2007, 01:27 PM

the 135 has wider rear wheels and tires than the 335 so it has more grip around the bend along with the ELSD, however the 335 is wider and that gives it a better stance and a slight advantage when cornering....however the 135 is lighter. I'd say the 135 will be marginally faster and may match the 335 in cornering ability and theoretically cheaper. i have no numbers to back up my speculations.

BMWeber · 09-17-2007, 01:58 PM

handling has to do with a lot more than just weight and the length of the car their is weight distribution not just front to back but the centrality of the weight, how high the center of gravity is, spring tuning, shock tuning sway bars, suspension geometry, suspension alignment, tire type and size. there are so many variables you cant just judge by one. we wont know anything until we start seeing independent tests. but I can almost guarantee the 135i is guna tool up on a 335i on the track.:biggrin:

1ster · 09-17-2007, 02:01 PM

Quote:

Originally Posted by Crashspeeder

the 135 has wider rear wheels and tires than the 335

Not if you get the 335i with the Sport Package.

jopali · 09-17-2007, 02:37 PM

Are the tires on the 128i going to be smaller in width than the 135? what about the wheel base (width wise)?

jopali · 09-17-2007, 02:38 PM

besides 70 horses and cool brakes what else will the 128 not have?

321 · 09-17-2007, 02:55 PM

Quote:

Originally Posted by jopali

besides 70 horses and cool brakes what else will the 128 not have?

a lot. If you have more questions start your own thread and ask them.:w00t:

I think the 135i will whip a 335i on the track

OniKoroshi · 09-17-2007, 03:16 PM

Any speculation about the 135's handling abilities right now a bit silly don't you think?

R32 · 09-17-2007, 03:22 PM

Quote:

Originally Posted by OniKoroshi

Any speculation about the 135's handling abilities right now a bit silly don't you think?

fun, tho.

what else is there to do? kinda dead lately with no new news.

plus, it seems like there is some dismay on the board that the 135i doesn't have a huge weight advantage over the 335i. i just wanted to point out that the compact dimensions might help the car more than one might expect given the similar weights.

grant · 09-17-2007, 03:41 PM

Quote:

Originally Posted by jopali

besides 70 horses and cool brakes what else will the 128 not have?

LOTS of torque (and the ability to cheaply increase power to 400hp/400ft-lbs)...

BMWeber · 09-17-2007, 03:50 PM

Quote:

Originally Posted by OniKoroshi

Any speculation about the 135's handling abilities right now a bit silly don't you think?

Nope

335i=:) · 09-17-2007, 03:50 PM

IT seems with the 6 piston's up front, slight weight advantage, and shorter wheelbase will make the oner beat the 3er on tighter, slower, tracks. But on longer, higher speed tracks, I doubt we will see much of a difference, as in the nurburgring.

Robert · 09-17-2007, 03:59 PM

Quote:

Originally Posted by Crashspeeder

the 135 has wider rear wheels and tires than the 335 so it has more grip around the bend along with the ELSD, however the 335 is wider and that gives it a better stance and a slight advantage when cornering....however the 135 is lighter. I'd say the 135 will be marginally faster and may match the 335 in cornering ability and theoretically cheaper. i have no numbers to back up my speculations.

uhmm no it doesn't 335i has wider rear tire than 135i. 335i with sportspackage of course but the sports package on 335i isn't really a SPORTS package.

sectos · 09-18-2007, 02:08 AM

why is this so important to some of you, that the 135i be quicker than a 335i?!

321 · 09-18-2007, 02:21 AM

Quote:

Originally Posted by sectos

why is this so important to some of you, that the 135i be quicker than a 335i?!

I don't think it is a matter of importance. It's just reality.

sectos · 09-18-2007, 02:54 AM

Quote:

Originally Posted by zba857

I don't think it is a matter of importance. It's just reality.

it is, but it's not really big of a difference
they are 2 good cars, but they are not intended for the same owners

BMWeber · 09-18-2007, 06:58 AM

Quote:

Originally Posted by 335ito135i

IT seems with the 6 piston's up front, slight weight advantage, and shorter wheelbase will make the oner beat the 3er on tighter, slower, tracks. But on longer, higher speed tracks, I doubt we will see much of a difference, as in the nurburgring.

Those brakes are more important on high speed tracks than low speed ones. I'll bet the 135I would best the 335i on the nurburgring and mostly because of the better breaking performance.

BMWeber · 09-18-2007, 07:04 AM

Quote:

Originally Posted by sectos

why is this so important to some of you, that the 135i be quicker than a 335i?!

because performance is the main reason many people including myself are buying a 135i. BMW knows this too that is why it comes with huge fixed caliper brakes and an M sport package with staggered tires. There has never been a BMW marketed with so much performance in mind that is not an M car

inTgr8r · 09-18-2007, 07:16 AM

Quote:

Originally Posted by BMWeber

because performance is the main reason many people including myself are buying a 135i. BMW knows this too that is why it comes with huge fixed caliper brakes and an M sport package with staggered tires. There has never been a BMW marketed with so much performance in mind that is not an M car

Which begs the question... what have they done about oil cooling?

JMO, but if it's truly intended to be a performance machine,
the oil temps as per the 335i are way too high for much use on the track.

The S54 in my Z4M doesn't run much over 100 degC on the track.
The N54 on the street runs WAY hotter than that.

Advevo · 09-18-2007, 07:21 AM

The difference between M and normal bmw cars are not that much anymore.

A 135i can make it hard for an E92 m3 on the nurburgring. So tell me whats the point if youre going for performance to choose an E92 m3 which 2 times more expensive than an 135i. Ok if youre going for status the e92 m3 is youre car. But if youre going for pure driving fun and performance give me a 135i on track anyday i know for certain it give just as much pleasure maybe even more. And if you spend a little extra money on the 135i like a LSD 380 hp nice shocks you have the blast of youre life.

sectos · 09-18-2007, 07:23 AM

Quote:

Originally Posted by BMWeber

because performance is the main reason many people including myself are buying a 135i. BMW knows this too that is why it comes with huge fixed caliper brakes and an M sport package with staggered tires. There has never been a BMW marketed with so much performance in mind that is not an M car

I'm pretty sure in most cases (I don't know for you), it's also because it's a bit cheaper than the 335i

anyway, performance should be very similar and I think it's not very clever to choose a car because it's 0.1s faster on a short exercise like a quarter mile or a 0-60 ...
my point it's the 135i is a bit lighter, a bit smaller, has better breaks, less expensive....and for me more beautiful than the "banal" e92

0.1s or 1s faster it's just bonus

Advevo · 09-18-2007, 07:30 AM

Oh and if you think an M is track worthy i tell you some stories which i have seen on track.

M6 on track all oil under the car.
M6 on track Catalist on fire
M3 E46 Brakes on fire
M3 E46 CSL Vanos oil pipe broke oil under the car
Lots of M3 engines bearing problems blown engines on track oil temp above 120 degrees.
M5 E60 rear diff broke down on track

I race a lot with race cars and i drive also a lot street cars on track so i have seen enough.

Buying an expensive M doesn t mean it s more track worthy then non M cars.

I have driven the 130i cup it s almost a standard car with a roll cage. If you see how we use those cars you think this car will brake in 2 piece we are flying with 4 wheels of the ground over curbs drive in rev limiters etc. The car is just fantastic. An M model was much better in early days but nowadays a normal bmw is just as good.

09-17-2007, 01:21 PM	#1
R32 Second Lieutenant 7 Rep 222 Posts Drives: Join Date: Jul 2007 iTrader: (0)	Weight/Handling, 135i vs. 335i i am not a physics person, but the following thought crossed my mind. the 135i doesn't really weigh that much less than a 335i. but, i'd expect the handling to still be quite a bit better. assuming that a car is a slender rod of uniform density (obviously not true), the moment of inertia should vary as the square of the length. so, rotating intertia for the 135i (4360 cm long) vs. the 335i (4580 cm) should be 4360^2/4580^2 = .91, or about a 10% reduction, even if the cars weighed the same amount! so, is it fair to assume that the 135i would turn with the same agility as a 335i with a 10% reduction of weight?
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09-17-2007, 01:27 PM	#2
Crashspeeder Enlisted Member 0 Rep 36 Posts Drives: E46 TiAg M3 Join Date: Aug 2007 Location: Bergen County, NJ iTrader: (0)	the 135 has wider rear wheels and tires than the 335 so it has more grip around the bend along with the ELSD, however the 335 is wider and that gives it a better stance and a slight advantage when cornering....however the 135 is lighter. I'd say the 135 will be marginally faster and may match the 335 in cornering ability and theoretically cheaper. i have no numbers to back up my speculations.
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09-17-2007, 01:58 PM	#3
BMWeber Major 36 Rep 1,329 Posts Drives: 08 135i Join Date: Sep 2007 Location: Amesbury, MA iTrader: (5)	handling has to do with a lot more than just weight and the length of the car their is weight distribution not just front to back but the centrality of the weight, how high the center of gravity is, spring tuning, shock tuning sway bars, suspension geometry, suspension alignment, tire type and size. there are so many variables you cant just judge by one. we wont know anything until we start seeing independent tests. but I can almost guarantee the 135i is guna tool up on a 335i on the track.:biggrin:
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09-17-2007, 02:37 PM	#5
jopali Private 0 Rep 56 Posts Drives: Join Date: Aug 2007 iTrader: (0)	Are the tires on the 128i going to be smaller in width than the 135? what about the wheel base (width wise)?
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09-17-2007, 02:38 PM	#6
jopali Private 0 Rep 56 Posts Drives: Join Date: Aug 2007 iTrader: (0)	besides 70 horses and cool brakes what else will the 128 not have?
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09-17-2007, 03:16 PM	#8
OniKoroshi Private First Class 2 Rep 112 Posts Drives: 08 535i Join Date: Jul 2007 Location: San Diego iTrader: (0)	Any speculation about the 135's handling abilities right now a bit silly don't you think?
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09-17-2007, 03:50 PM	#12
335i=:) Second Lieutenant 27 Rep 290 Posts Drives: 335i sedan-blk/blk-Poplar Join Date: Oct 2006 Location: utah iTrader: (0)	IT seems with the 6 piston's up front, slight weight advantage, and shorter wheelbase will make the oner beat the 3er on tighter, slower, tracks. But on longer, higher speed tracks, I doubt we will see much of a difference, as in the nurburgring.
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09-18-2007, 02:08 AM	#14
sectos Private 2 Rep 82 Posts Drives: 325 Join Date: Jul 2008 Location: lyon iTrader: (0)	why is this so important to some of you, that the 135i be quicker than a 335i?!
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09-18-2007, 07:21 AM	#20
Advevo Banned 581 Rep 1,170 Posts Drives: M2 Competition, E30 M3 DTM Join Date: Apr 2006 Location: Country where the taxes are too high!! iTrader: (0)	The difference between M and normal bmw cars are not that much anymore. A 135i can make it hard for an E92 m3 on the nurburgring. So tell me whats the point if youre going for performance to choose an E92 m3 which 2 times more expensive than an 135i. Ok if youre going for status the e92 m3 is youre car. But if youre going for pure driving fun and performance give me a 135i on track anyday i know for certain it give just as much pleasure maybe even more. And if you spend a little extra money on the 135i like a LSD 380 hp nice shocks you have the blast of youre life.
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09-18-2007, 07:30 AM	#22
Advevo Banned 581 Rep 1,170 Posts Drives: M2 Competition, E30 M3 DTM Join Date: Apr 2006 Location: Country where the taxes are too high!! iTrader: (0)	Oh and if you think an M is track worthy i tell you some stories which i have seen on track. M6 on track all oil under the car. M6 on track Catalist on fire M3 E46 Brakes on fire M3 E46 CSL Vanos oil pipe broke oil under the car Lots of M3 engines bearing problems blown engines on track oil temp above 120 degrees. M5 E60 rear diff broke down on track I race a lot with race cars and i drive also a lot street cars on track so i have seen enough. Buying an expensive M doesn t mean it s more track worthy then non M cars. I have driven the 130i cup it s almost a standard car with a roll cage. If you see how we use those cars you think this car will brake in 2 piece we are flying with 4 wheels of the ground over curbs drive in rev limiters etc. The car is just fantastic. An M model was much better in early days but nowadays a normal bmw is just as good.
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