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ASE Master Tech - 35 yrs
 
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Question why stagger frt/r wheel & tire sizes?

this old thread made me wonder what the benefit is of staggered sizes front/rear,

What size tires for 16 x 8 Fuchs on a SC?

i.e. why 7&8 vs all 7s or all 8's? or 6&7 vs all 7s?, etc

- is it mostly a factor of 40/60 rear engine 911s, (or the SWBs 35/65 where tail-happy was a serious concern)

- is it even relevant to more balanced cars

like 914's (46/54) (or 914-6 at 49/51 according to Hemmings ???) ?
- or maybe 50/50 Miatas?

this for grist: - Stop and weight! A 50/50 weight distribution is not optimal | Automotive Thinker - Discussing the finer points of automobiles
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Old 12-02-2017, 10:07 PM
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To maximize the transfer of power to the road, you want bigger tires over the drive axle. You want bigger tires still over the drive axle that the engine sits on.

Honda civic drag cars have the big tires up front.
Old 12-03-2017, 04:21 AM
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Perhaps more traction when "lifting" off throttle in corners?
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Old 12-03-2017, 04:44 AM
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To help control off throttle oversteer. If you drive an early 911 and lift off the throttle in the middle of a corner, you’ll understand the meaning of ‘loose’ that NASCAR drivers use. A quick way to back into the guardrail! The wider rear tires tame this behavior significantly.
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Old 12-03-2017, 05:25 AM
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Question

Quote:
Originally Posted by Jack Stands View Post
To help control off throttle oversteer. If you drive an early 911 and lift off the throttle in the middle of a corner, you’ll understand the meaning of ‘loose’ that NASCAR drivers use. A quick way to back into the guardrail! The wider rear tires tame this behavior significantly.
yes - i owned a swb 911 - know all about that and had the experience

but i constantly read about people staggering wheels on cars that are a good bit more balanced (see above) - why?

? maybe it's just for the cafe racer "look"?

as for honda dragsters - that's a quite different straight-line objective

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Old 12-03-2017, 10:05 AM
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Toyota MR2 came stock with staggered tires.
I replaced with same size tires all around
and it handled much better (more neutral vs. understeer)

I wouldn't try that on a 911.
Big ass rear tires keep the pointy end in the right direction.

Manufacturers build in too much understeer.
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Old 12-03-2017, 10:33 AM
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so i asked google "do wider rear wheels cause understeer"

this pelican thread from 2006 is on top
What is effect of difference in wheel track width on handling?

and that gets to the universal question - "What are you going to use the (fill in the blank) for?"

- same thing the BestBuy salesperson asks about every tech gadget we look at

I should have asked: "on a street car? - what's the benefit"
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Last edited by larrym; 12-03-2017 at 11:01 AM..
Old 12-03-2017, 10:53 AM
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Quote:
Originally Posted by larrym View Post
so i asked google "do wider rear wheels cause understeer"

this pelican thread from 2006 is on top
What is effect of difference in wheel track width on handling?

and that gets to the universal question - "What are you going to use the (fill in the blank) for?"

- same thing the BestBuy salesperson asks about every tech gadget we look at

I should have asked: "on a street car? - what's the benefit"
track width is not the same thing as wheel width

the answer to you original ? is that a tire has a friction circle
the more work it does in acceleration the less it can do in cornering, the more in braking the less in cornering and vice versa

Typical friction circle diagram



when the rear wheels are also drive wheels to get more total grip you use wider wheels/tires in back. Even front engine cars like Camaro and Mustang do that. As do more balanced cars like mid engine Cayman and Ferrari.

The 911 and all it's derivatives have an additional impetus in itheir weight distribution.
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Old 12-03-2017, 11:07 AM
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My MB E350 has staggered wheels too.
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Old 12-03-2017, 11:40 AM
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