Everyone seems to recomend running 8 inch wheels out back on S13's with 7's on the front. I'm very happy with my cars balance at the autocross with the same width front to rear. Why is everyone jumping on the staggered bandwagon?
Sorry if this has been asked i had no clue what to search for.
7's on the front 8's on the back
There is no practical daily driver reason for it. People forget that the expensive tires they buy, will wear at least twice as fast if they cannot rotate the tires from the front axle to the rear...
Changing wheel positions front to rear (tire rotation) cuts down significantly on excessive shoulder wear from the front axle.
Stagger means you cannot rotate tires, means more replacement tires, means more money down the drain. Considering most people cringe when they see current pricing for good tires, I see no benefit for a road car.
Besides, very sticky competition tires come in some common sizes now. You can get equal grip characteristics front/rear, have a very high level of grip, and actually SAVE money in the process... compared to frequently replacing fronts due to excessive shoulder wear.
Basically, it looks cool to have wide wheels and tires out back.
You can put wide meats on the rear in the hopes of better grip, but you may not be putting a better gripping tire on. You may just be putting a wider contact patch on the road. That doesn't mean more grip during acceleration, braking, and turning.
The truth is, better grip will be had with softer compound tires.
Changing wheel positions front to rear (tire rotation) cuts down significantly on excessive shoulder wear from the front axle.
Stagger means you cannot rotate tires, means more replacement tires, means more money down the drain. Considering most people cringe when they see current pricing for good tires, I see no benefit for a road car.
Besides, very sticky competition tires come in some common sizes now. You can get equal grip characteristics front/rear, have a very high level of grip, and actually SAVE money in the process... compared to frequently replacing fronts due to excessive shoulder wear.
Basically, it looks cool to have wide wheels and tires out back.
You can put wide meats on the rear in the hopes of better grip, but you may not be putting a better gripping tire on. You may just be putting a wider contact patch on the road. That doesn't mean more grip during acceleration, braking, and turning.
The truth is, better grip will be had with softer compound tires.
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whiterps13
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I'm glad this question was brought up... I was thinking of the exact purpose of staggered wheels...
So this brings up a question: Do people put staggered wheels because they can fit wider wheels in the rear? and wider wheels = larger contact patch.. which may bring out better grip?
Or is there another reason to run 8 in the rear and 7 up front vs running 8 all around(assuming everything fits fine)?
Thanks.
So this brings up a question: Do people put staggered wheels because they can fit wider wheels in the rear? and wider wheels = larger contact patch.. which may bring out better grip?
Or is there another reason to run 8 in the rear and 7 up front vs running 8 all around(assuming everything fits fine)?
Thanks.
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s13sr20chris
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Yah i know about the contact patch vs tire pressure thing posted a while back but i had forgotten about it. I guess it is purely cosmetic. I'm not getting a rim with a deep lip anyway so that won't matter.
Also i would run 8's all around but i have Tiens so there is no practical way to run wheels that wide out front unless you do something with the fenders.
Also i would run 8's all around but i have Tiens so there is no practical way to run wheels that wide out front unless you do something with the fenders.
Smith is dead on(as usual) and something to remeber, a wider tire means a wider contact patch, not a larger one(said also). I argue to death with M3 owners about width of the rear tires(some want to squeez 285-35-18's on the new E46 stock wheels..) since I ahve seen many, many autocrossing and road racing m3's swap to equal width wheels/tires front and rear for more omtimal handling balance.
If your car is not so heavy as to transfer too much weight in the rear during cornering there's no benifit from running such wide rear tires, unless you know...you want them just 'cuse.(Take a supra, its a 3600lb car, that weight transfer in the back, coupled with the large ammount of power makes a split setup more effective than a lightweight 240, mr2, or otherwise)
Anyways, I chose to run the same zie all around in a good sticky tire, and it hanldes very nicely and predictably, with minimal understeer to(clutch pop and/or throttle induced) oversteer characteristics.
-chet
If your car is not so heavy as to transfer too much weight in the rear during cornering there's no benifit from running such wide rear tires, unless you know...you want them just 'cuse.(Take a supra, its a 3600lb car, that weight transfer in the back, coupled with the large ammount of power makes a split setup more effective than a lightweight 240, mr2, or otherwise)
Anyways, I chose to run the same zie all around in a good sticky tire, and it hanldes very nicely and predictably, with minimal understeer to(clutch pop and/or throttle induced) oversteer characteristics.
-chet
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s13sr20chris
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ok, contact patch is a function of tire pressure and vehicle weight. there is a formula i just dont remember it. if weight stays the same and tire pressure stays the same then the AREA of the contact patch will stay the same. there are caveats for tire void ratio or vehicles with other that 4 wheels. if you put fatter tires on your car the contact patch will just get fatter and shorter. this is good as surface imperfections are less damaging to the contact patch and stuff. there is more info on this if you search around.
what part of this:"Why do people reccomend wider tires? Don't wider tires mean more grip?
In a short version, no. Don't go e-mailing me about how wrong I am yet, either. Think about your tire as a balloon(more accurate than most people think) holding the weight of your car up. Now, if you place a balloon on the ground, it has a certain area that contacts the ground, this is the 'contact patch', now you can make the patch wider(wider baloon) but the total area remains the same, because the pressure on the balloon is the same.
Now, what does this mean to YOU? It means that since the same ammount of tread is in the contact patch area between either tire, 'grip' should be the same. Thusly, the only things affecting grip(since the area of potential contact is the same) are tread design and friction(tread compound).
Unfortunately it is not that simple. A wider tire does have some benifits over it narrower counterparts, with a wider contact patch comes a bit better lateral stability(to a point, lateral stress doesnt vary THAT much between narrow and wide tires), but sacrafices some ride comfort, and less noise cancellation(in theory).
Something else to consider:
Think of a gap in the road surface, typically these run perpendiculat to the tires contact patch. On a narrow tire, with a long contact patch, the gap in the road surface would take up more(percentage wise) of its contact patch than a wider tire. make sense?
..so wider tires do provide some benifit, to a point. Wider tires usually come in stickier compounds, too. Yet, the compound and tread design has more to do with tire grip than the size.
Now quit asking me how wide of a tire you can fit on something."
didnt you understand, since you 'read' the faq...
also, searching around would have revealed this page:url=http://www.chris-longhurst.com/carbible ... bible.html
which explains it with pictures.
In a short version, no. Don't go e-mailing me about how wrong I am yet, either. Think about your tire as a balloon(more accurate than most people think) holding the weight of your car up. Now, if you place a balloon on the ground, it has a certain area that contacts the ground, this is the 'contact patch', now you can make the patch wider(wider baloon) but the total area remains the same, because the pressure on the balloon is the same.
Now, what does this mean to YOU? It means that since the same ammount of tread is in the contact patch area between either tire, 'grip' should be the same. Thusly, the only things affecting grip(since the area of potential contact is the same) are tread design and friction(tread compound).
Unfortunately it is not that simple. A wider tire does have some benifits over it narrower counterparts, with a wider contact patch comes a bit better lateral stability(to a point, lateral stress doesnt vary THAT much between narrow and wide tires), but sacrafices some ride comfort, and less noise cancellation(in theory).
Something else to consider:
Think of a gap in the road surface, typically these run perpendiculat to the tires contact patch. On a narrow tire, with a long contact patch, the gap in the road surface would take up more(percentage wise) of its contact patch than a wider tire. make sense?
..so wider tires do provide some benifit, to a point. Wider tires usually come in stickier compounds, too. Yet, the compound and tread design has more to do with tire grip than the size.
Now quit asking me how wide of a tire you can fit on something."
didnt you understand, since you 'read' the faq...
also, searching around would have revealed this page:url=http://www.chris-longhurst.com/carbible ... bible.html
which explains it with pictures.
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s13sr20chris
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s13sr20chris
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well not neccesarily grip, but contact area. sooooooo many factors involved. the point is not to think something like this..."i can get versatile all weather tires in 355/35/17 and have more grip than those doofusses running r-compound 205's. then i can drive in the snow with the same tires and they will last longer too."
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s13sr20chris
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im looking at some 7.5s for front and rear. they are really cheap at tirerack.http://www.tirerack.com/servle...cial=+43 offset
cheap too. $99only prob is that i cant find a nice r compound tire to fit it except the goodyear f1gsd3.
oops i thread jacked.
dont stagger your wheels/tires
cheap too. $99only prob is that i cant find a nice r compound tire to fit it except the goodyear f1gsd3.
oops i thread jacked.
dont stagger your wheels/tires
That would be working against yourself. You're looking for more grip? Buy better tires, period. Better tires means expensive tires that wear out quickly and offer gobs of dry weather grip. You'll have to replace expensive competition tires more frequently, so the quest for ultimate grip gets even MORE expensive...but this wasn't ever and isn't a cheap hobby.. but I digress.
You don't need fat tires to grip, you need sticky tires to grip.
Grip is dictated by friction first, all other variables second.
So it's either looks(big wheels and wide tires), or function(smaller wheels and expensive competition tires).
OR big wheels AND expensive competition tires, but then your wallet will be the yardstick by which your car's grip will be measured. Refer back to the expensive hobby part of rant...
You don't need fat tires to grip, you need sticky tires to grip.
Grip is dictated by friction first, all other variables second.
So it's either looks(big wheels and wide tires), or function(smaller wheels and expensive competition tires).
OR big wheels AND expensive competition tires, but then your wallet will be the yardstick by which your car's grip will be measured. Refer back to the expensive hobby part of rant...
s13sr20chris wrote:im looking at some 7.5s for front and rear. they are really cheap at tirerack.http://www.tirerack.com/servle...cial=+43 offset
cheap too. $99only prob is that i cant find a nice r compound tire to fit it except the goodyear f1gsd3.
oops i thread jacked.
dont stagger your wheels/tires
Cant run coilovers with that offset. i had to find some +35
ive just read that link, and its an excellent read, but i still question it. i understand that in a straight line driving normal your tire has the same contact patch no matter what tires are on, but the problem is under load. this post is a question on grip by contact patch. obviously sticky tires give you more grip all on its own. when your whipping around a corner and a very large sum of your weight transfers over to the side, then your contact patch sizes change. essentially they are under more load. same thing with a rapid burst of accelleration or braking. your weight shifts to the rear when launching (especially in a high hp application), and front when braking, again changing the size of your contact patches in your favor (on rwd cars). wouldnt a wider (not grossly wide) tire accommodate for the contact patch better? essentially to 2 wheels in all those instances its like your car is 3500 lbs (just a random guessed weight). id imagine a more neutral, circular contact patch would be better than an oval one for a road car, that will accelerate, brake, and corner. wouldnt it?
let me pose a question to you:
if a contact patch varies directly with force and the cars weight is the same, and only the shape varies, how's is transfer weight different from any other?
Its still the same principle, weight on a baloon/surface area.
quick example: a really wide tires contact patch in a turn will shift toward the outside edge, sure, but since the patch itself is wide and not long, more of it will stay that way, it will be longer than a thinner tire.
A thin tire, on the other hand, will get more load on the side, and its contact patch will remain the same size as the other(wider tire) but because of the weight transfer it will get longer, just as the wider tire did, and the overall contact areas will remain the same, although both will(unless the tire rolls off its contact patch, but thats got to do with suspension) gain grater contact patch.
this brings up a small point about wider versus narrower tires:
a wider tire will have more lateral stability because the contact patch will stay wider, distributing the focrce a bit better across the patch, in theory, whereas a thinner(longer contact pach) will distributre it more length wise, causing it to possible feel "less stable".
does that make sense? likewise, in snow or messy conditions longer tires are desirable because you want a longer contacth patch to "dig" out, and in summer/dry conditions widers ones are favored because of better lateral stability.
hopefully that will help you out a bit.-chet
if a contact patch varies directly with force and the cars weight is the same, and only the shape varies, how's is transfer weight different from any other?
Its still the same principle, weight on a baloon/surface area.
quick example: a really wide tires contact patch in a turn will shift toward the outside edge, sure, but since the patch itself is wide and not long, more of it will stay that way, it will be longer than a thinner tire.
A thin tire, on the other hand, will get more load on the side, and its contact patch will remain the same size as the other(wider tire) but because of the weight transfer it will get longer, just as the wider tire did, and the overall contact areas will remain the same, although both will(unless the tire rolls off its contact patch, but thats got to do with suspension) gain grater contact patch.
this brings up a small point about wider versus narrower tires:
a wider tire will have more lateral stability because the contact patch will stay wider, distributing the focrce a bit better across the patch, in theory, whereas a thinner(longer contact pach) will distributre it more length wise, causing it to possible feel "less stable".
does that make sense? likewise, in snow or messy conditions longer tires are desirable because you want a longer contacth patch to "dig" out, and in summer/dry conditions widers ones are favored because of better lateral stability.
hopefully that will help you out a bit.-chet
exar: your in the same thinking process as i am on this, only you conveyed it better. i think that the wider tire would also carry attributes better for cornering in a sense that with the wider contact patch, your essential getting benefits of almost like having a shorter sidewall. to think this way, when you are taking a corner, lets setup a situation with tire a, and tire b. tire a is a thinner tire with a long contact patch normally, tire b is a wider tire with a wider contact patch normally. if you were to try taking a very sharp hard corner the tires would do something like this:
rim |.................| |.................| |.................| |________ | /...tire........./ /................./ /_|_|_|_|__/
as you can see the rim wants to go out from ther sideways force, but the tires grip and actually roll a little, relying a bit on the sidewalls for grip. tire a; being the longer patch, would have a more severe case of "rollout" (dont flame me i dont know the technical term for this)because the tire wants to go sideways, more opposite to the direction of the contact patch. the car adapts by relying on the sidewalls for the wider patch needed, but the sidewalls dont function very well for the job being they arent designed to be in contact with the road. tire b has that wider patch enhancing stability while cornering and being less reliant on the sidewalls. same reason people like thin sidewall tires, because a shorter sidewall can roll less, and provides more response because its usually stiffer. essentially by having the wider tire, i would think response would be better from having less sidewall reliance. im talking street tires here too, slicks are a whole different ballgame. dont mind me if i rambled a bit, but you get my point...
*edit* nico didnt seem to like me using spaces in my high tech diagram so i put in crappy looking periods.
rim |.................| |.................| |.................| |________ | /...tire........./ /................./ /_|_|_|_|__/
as you can see the rim wants to go out from ther sideways force, but the tires grip and actually roll a little, relying a bit on the sidewalls for grip. tire a; being the longer patch, would have a more severe case of "rollout" (dont flame me i dont know the technical term for this)because the tire wants to go sideways, more opposite to the direction of the contact patch. the car adapts by relying on the sidewalls for the wider patch needed, but the sidewalls dont function very well for the job being they arent designed to be in contact with the road. tire b has that wider patch enhancing stability while cornering and being less reliant on the sidewalls. same reason people like thin sidewall tires, because a shorter sidewall can roll less, and provides more response because its usually stiffer. essentially by having the wider tire, i would think response would be better from having less sidewall reliance. im talking street tires here too, slicks are a whole different ballgame. dont mind me if i rambled a bit, but you get my point...
*edit* nico didnt seem to like me using spaces in my high tech diagram so i put in crappy looking periods.
Maybe this is a good place to post what I've been thinking about lately. When cornering, wider tires seem to grip better than more narrow tires. It seems as if a more wide tire can withstand a greater cornering LOAD. Is load the correct way to think about this? Why do wider tires have greter load index ratings? I first thought about this when I found a post by Q45tech on FA:
[IThe contact patch area is always the same at the same inflation pressure. The shape does change: wider. The real advantage in the surface area of the tire increases helping to lower the intenal temperature rise, at the same time the load index is usually higher so more reserve and less slip angle at the same load......thus an increase in handling power [robustness] roughly equal to 30% of the load increase [amount] rating in pounds [Newtons what ever].
Example: Same tire, same make, same sidewall aspect ratio, just bigger ---- a 95V[225/60/15 [1521#] vs 98V[235/60/15] [1640#] = 7.8% stronger x 0.3= 2.3% improvementThe contact patch area is always the same at the same inflation pressure. The shape does change: wider. And after a couple of track events this year, I really can say that even 20mm difference in tire width is noticable at the same tire pressure, with the same conditions. Wider tires seem to gip better when cornering. Comparing widths for the same sticky tire, same aspect ratio, same speed rating, same wheel diameter, the wider tires have greater load ratings. Does this influence anything? Are wider tires more resistant to camber change?
Also, how will sidewalls affect grip? Stiffer sidewalls? Shorter sidewalls? Stretched, square, or bulging sidewalls? I know generally what will happen with different sidewalls, but how would this change the tires reaction in relation to its contact patch? In essence, if contact patch remained the same, then width wouldn't matter so much, but it does change when the car is accelerating (in any direction). Cool thread. I'm still confused though.
[IThe contact patch area is always the same at the same inflation pressure. The shape does change: wider. The real advantage in the surface area of the tire increases helping to lower the intenal temperature rise, at the same time the load index is usually higher so more reserve and less slip angle at the same load......thus an increase in handling power [robustness] roughly equal to 30% of the load increase [amount] rating in pounds [Newtons what ever].
Example: Same tire, same make, same sidewall aspect ratio, just bigger ---- a 95V[225/60/15 [1521#] vs 98V[235/60/15] [1640#] = 7.8% stronger x 0.3= 2.3% improvementThe contact patch area is always the same at the same inflation pressure. The shape does change: wider. And after a couple of track events this year, I really can say that even 20mm difference in tire width is noticable at the same tire pressure, with the same conditions. Wider tires seem to gip better when cornering. Comparing widths for the same sticky tire, same aspect ratio, same speed rating, same wheel diameter, the wider tires have greater load ratings. Does this influence anything? Are wider tires more resistant to camber change?
Also, how will sidewalls affect grip? Stiffer sidewalls? Shorter sidewalls? Stretched, square, or bulging sidewalls? I know generally what will happen with different sidewalls, but how would this change the tires reaction in relation to its contact patch? In essence, if contact patch remained the same, then width wouldn't matter so much, but it does change when the car is accelerating (in any direction). Cool thread. I'm still confused though.
" a wider tire with a wider contact patch will wear less allowing you to run a softer compound, without changing your tires as much. it is in a sense more rubber on the road, not at once but in the long run."
your friend is a moron. contact patch size DOES NOT vary with width, christ. search around! HELL! Read the previous posts! Its explained not even more than a few posts up with links!Also, if the roce exterted on the tread is the same, how will it "wear less" did your friend like, fail physics or something?
geeze...-chet
your friend is a moron. contact patch size DOES NOT vary with width, christ. search around! HELL! Read the previous posts! Its explained not even more than a few posts up with links!Also, if the roce exterted on the tread is the same, how will it "wear less" did your friend like, fail physics or something?
geeze...-chet