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Ultimate AWD Sports Sedans

828 messages,  Last post on Oct 03, 2009 at 9:40 PM

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What is this discussion about? BMW 3 Series, Audi A4, Volvo S60 R, Subaru Legacy, Audi S4, Mazda MAZDASPEED MAZDA6, Sedan

#722 of 828 Re: Crunched tire numbers... [circlew] by shipo Mar 20, 2008 (4:14 am)
Replying to: circlew (Mar 20, 2008 4:00 am) I suppose I should temper my most recent comments by saying that I suppose it is possible for some new tire technology coupled with an ultra light set of racing rims to bend the rules by an inch or two, however, I've yet to see any evidence that that has actually happened.   My personal take on it is that anything beyond 17" is simply bling.   Best Regards, Shipo Replies to this message: bruceomega (Mar 20, 2008 4:28 am) bruceomega (Mar 21, 2008 11:48 am) shipo (Mar 21, 2008 4:49 pm) ateixeira (Mar 24, 2008 8:20 am)
#723 of 828 Re: Crunched tire numbers... [shipo] by bruceomega Mar 20, 2008 (4:28 am)
Replying to: shipo (Mar 20, 2008 4:14 am) Thanks to all for the responses.
#724 of 828 Re: Crunched tire numbers... [shipo] by ateixeira Mar 20, 2008 (12:35 pm)
Replying to: shipo (Mar 19, 2008 6:06 pm) Thanks for crunching those.   I know that Subaru specifies the circumference (2*pi*r = pi*diam) must be within 0.25".   So that 535xi is outside of Subaru's tolerances. The difference in circumference would be 0.13" * 3.14 = 0.41". Well over the 0.25" Subaru would allow.   The interesting thing is this probably means BMW's AWD system allows for more wheelslip before it would react, i.e. it seems to have looser tolerances for rotational differences from axle to axle. Replies to this message: kyfdx (Mar 20, 2008 1:57 pm) ateixeira (Mar 21, 2008 5:30 am)
#725 of 828 Re: Crunched tire numbers... [ateixeira] by kyfdx HOST Mar 20, 2008 (1:57 pm)
Replying to: ateixeira (Mar 20, 2008 12:35 pm) That would mean their tolerances have to be within 3/10ths of a percent? Do you think that's realistic in the real world?   I'd think you could find variances larger than that on new tires of the same model..   You sure the 0.25 inches isn't diameter? Replies to this message: ateixeira (Mar 21, 2008 5:30 am)
#726 of 828 Re: Crunched tire numbers... [kyfdx] by ateixeira Mar 21, 2008 (5:30 am)
Replying to: kyfdx (Mar 20, 2008 1:57 pm) Pretty sure it's circumference.   That's Subaru's specification, at least.   People complain when they blow out one tire (beyond repair), because if you have more than 10,000 miles on your other 3, you need a new set, or you have to shave the new tires to match the others, or find a used tire with similar wear.   Most people just buy 4 new tires.
#727 of 828 Re: Crunched tire numbers... [shipo] by bruceomega Mar 21, 2008 (11:48 am)
Replying to: shipo (Mar 20, 2008 4:14 am) Shipo,   If 17" is an ideal size, does that mean, in your opinion, that if I upgraded from the standard 17" wheels on my 535Xi to the optional 18" wheels and appropriately sized tires (probably non staggered per your comments) that it will not improve the handling of my car?   Thanks Bruce Replies to this message: shipo (Mar 21, 2008 4:49 pm) ateixeira (Mar 24, 2008 8:20 am)
#728 of 828 Re: Crunched tire numbers... [bruceomega] by shipo Mar 21, 2008 (4:49 pm)
Replying to: bruceomega (Mar 21, 2008 11:48 am) If I remember correctly, handling performance peaked with the 16" and 17" tire sizes and then slowly rolled off from there. Regarding adding the 18" optional tires on your car, I rather suspect that you'll probably not notice much of a difference either way, errr, unless you're going to be taking it to the track.   Best Regards, Shipo
#729 of 828 Re: Crunched tire numbers... [bruceomega] by ateixeira Mar 24, 2008 (8:20 am)
Replying to: bruceomega (Mar 21, 2008 11:48 am) It may sharpen the steering feel a bit, and have less sidewall deflection, but the ride will feel more harsh and you may have passed the point of diminishing returns by then.   A friend had a Z3 with big wheels and bent 3 rims. No kidding.   They're expensive to replace, and in some cases he even had to wait for a special order. Tires are also more expensive.   Finally, it adds to your unsprung weight, compared to a lighter 16" or 17" alloy of the same construction.
#730 of 828 Performance suspension for the 335Xi by bruceomega Apr 15, 2008 (11:42 am)
FWIW,   I just read where BMW is now offering an aftermarket performance suspension for the 335Xi: http://accessories.bmwusa.com/ItemView.aspx?modelId=280&perf=true&categoryId=136- &productCategoryId=&menuId=0&subItemId=3   With a tighter, sportier feeling and lower suspension setting of 15mm in comparison with series-production vehicles, the inclusion of a BMW Performance control arm with stiffer bushings gives your 3 Series an almost instinctual feel for the road. With adjusted spring rates and bushings, roll is drastically reduced, creating cat-like quickness, increased responsiveness, and stunning agility. Flexing with the motion of your vehicle around even the tightest curves, a BMW Performance control arm means athletic handling, faster turn-ins, and a totally immediate and much more intense reaction to the tarmac. It delivers a perfect compromise between racing car performance and driving comfort.   $695.00 Each price is the suggested retail price and is subject to change. Price excludes installation and taxes   Bruce Replies to this message: circlew (Apr 15, 2008 12:11 pm) lilengineerboy (Apr 15, 2008 5:16 pm) bruceomega (Apr 16, 2008 10:46 am)
#731 of 828 Re: Performance suspension for the 335Xi [bruceomega] by circlew Apr 15, 2008 (12:11 pm)
Replying to: bruceomega (Apr 15, 2008 11:42 am) I still doubt it will be equal to suspension settings of 335i sport.   Regards, OW

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