staggered wheels
03-28-08, 07:49 AM
#46
Lexus Test Driver
there has to be some tolerence, even if it's to account for wear. They just won't tell me what it is....cause lets face it .1" is almost negligable....I have to wonder if the tires them selfs are maufactured at that kind of tolerence...
This is a good point. What if you had the stock set-up with a worn tire that maybe under inflated? I'm sure the overall diam. wiould be different...
This is a good point. What if you had the stock set-up with a worn tire that maybe under inflated? I'm sure the overall diam. wiould be different...
03-28-08, 07:50 AM
#47
the rear tires (wider) would only have greater traction in a situation where the front tires are slipping. how often would this happen in an AWD 250? pretty much never, not enough power
just going down the road, all tires have equal traction or else they wouldn't be turning at the same speed; the wonders of an open differential.
i dont know for sure, but most likely the awd system works on an IS utilizing a viscous center differential.a viscous center diff works just like an open diff if traction between front and rear is equal; i.e. going down the road, driving normally. only in the event of either the front or rear axles spinning at different speeds would the viscous diff tighten up and lock the diff. in that event, since our OD on the tires is the same, again, there would be no issues, since rotational speed would be equalized momentarily by the vcd.
the additional traction of the wider rear tires is a non issue. technically, since the drivetrain is rwd biased, the stickier rear tires would grip better than stock, keeping the center diff from having to do more work than it would if it had stock wheels and tires; thereby reducing wear and tear.
the statement about offsets being differnt sounds like some political wool being pulled over someone's eyes. of course the offsets have to be different, the wheel widths are different, but the outer lips would be in line with each other front to rear if the setup is correct. again, he stated that the traction difference would cause a problem. there is no traction difference if there is no wheel spin! wheel spin would be minimized because of the wider rear tires anyway. the only time there would be a traction difference is going around a corner, but guess what? all cars have traction differences going around corners, that's why 99% of all cars have open differentials to allow this to happen without drivetrain stress. the IS has open rear and front diffs, so, NO wear. even the center diff, being viscous, won't activate going around a corner because it takes a certain amount of speed difference to lock it up , which isn't attained by simply going around a corner. even if it were, it wouldn't be any more than stock, because OD is still the same, so rotational speeds stay the same.
i really don't think it's about anyone being smarter than an engineer at lexus, but rather economics. IS250 people would rather be able to rotate their tires than have a cool looking staggered setup; bottom line. awd IS250' s are the practical cars for practical people.
even the understeer thought isn't really applicable because the guy wanting to stagger his 250 says he wanted it for looks, not performance. reaching hte limits of the suspension and tires isn't going to happen for a daily cruiser, besides, all stock cars understeer anyway.
just going down the road, all tires have equal traction or else they wouldn't be turning at the same speed; the wonders of an open differential.
i dont know for sure, but most likely the awd system works on an IS utilizing a viscous center differential.a viscous center diff works just like an open diff if traction between front and rear is equal; i.e. going down the road, driving normally. only in the event of either the front or rear axles spinning at different speeds would the viscous diff tighten up and lock the diff. in that event, since our OD on the tires is the same, again, there would be no issues, since rotational speed would be equalized momentarily by the vcd.
the additional traction of the wider rear tires is a non issue. technically, since the drivetrain is rwd biased, the stickier rear tires would grip better than stock, keeping the center diff from having to do more work than it would if it had stock wheels and tires; thereby reducing wear and tear.
the statement about offsets being differnt sounds like some political wool being pulled over someone's eyes. of course the offsets have to be different, the wheel widths are different, but the outer lips would be in line with each other front to rear if the setup is correct. again, he stated that the traction difference would cause a problem. there is no traction difference if there is no wheel spin! wheel spin would be minimized because of the wider rear tires anyway. the only time there would be a traction difference is going around a corner, but guess what? all cars have traction differences going around corners, that's why 99% of all cars have open differentials to allow this to happen without drivetrain stress. the IS has open rear and front diffs, so, NO wear. even the center diff, being viscous, won't activate going around a corner because it takes a certain amount of speed difference to lock it up , which isn't attained by simply going around a corner. even if it were, it wouldn't be any more than stock, because OD is still the same, so rotational speeds stay the same.
i really don't think it's about anyone being smarter than an engineer at lexus, but rather economics. IS250 people would rather be able to rotate their tires than have a cool looking staggered setup; bottom line. awd IS250' s are the practical cars for practical people.
even the understeer thought isn't really applicable because the guy wanting to stagger his 250 says he wanted it for looks, not performance. reaching hte limits of the suspension and tires isn't going to happen for a daily cruiser, besides, all stock cars understeer anyway.
Very informative.
How about on snow or wet roads?
Last edited by Joeb427; 03-28-08 at 08:01 AM.
03-28-08, 10:54 AM
#51
Lexus Champion
there has to be some tolerence, even if it's to account for wear. They just won't tell me what it is....cause lets face it .1" is almost negligable....I have to wonder if the tires them selfs are maufactured at that kind of tolerence...
This is a good point. What if you had the stock set-up with a worn tire that maybe under inflated? I'm sure the overall diam. wiould be different...
This is a good point. What if you had the stock set-up with a worn tire that maybe under inflated? I'm sure the overall diam. wiould be different...
well, in limited traction situations, the center diff will be working more, but not any more than with stock wheels/tires because the actual rotational speeds will be the same.
the front and rear diffs are open, so you could have different speeds on each side of the car due to the nature of an open diff, but again, not any different than stock.
03-28-08, 02:58 PM
#52
the rear tires (wider) would only have greater traction in a situation where the front tires are slipping. how often would this happen in an AWD 250? pretty much never, not enough power
just going down the road, all tires have equal traction or else they wouldn't be turning at the same speed; the wonders of an open differential.
i dont know for sure, but most likely the awd system works on an IS utilizing a viscous center differential.a viscous center diff works just like an open diff if traction between front and rear is equal; i.e. going down the road, driving normally. only in the event of either the front or rear axles spinning at different speeds would the viscous diff tighten up and lock the diff. in that event, since our OD on the tires is the same, again, there would be no issues, since rotational speed would be equalized momentarily by the vcd.
the additional traction of the wider rear tires is a non issue. technically, since the drivetrain is rwd biased, the stickier rear tires would grip better than stock, keeping the center diff from having to do more work than it would if it had stock wheels and tires; thereby reducing wear and tear.
the statement about offsets being differnt sounds like some political wool being pulled over someone's eyes. of course the offsets have to be different, the wheel widths are different, but the outer lips would be in line with each other front to rear if the setup is correct. again, he stated that the traction difference would cause a problem. there is no traction difference if there is no wheel spin! wheel spin would be minimized because of the wider rear tires anyway. the only time there would be a traction difference is going around a corner, but guess what? all cars have traction differences going around corners, that's why 99% of all cars have open differentials to allow this to happen without drivetrain stress. the IS has open rear and front diffs, so, NO wear. even the center diff, being viscous, won't activate going around a corner because it takes a certain amount of speed difference to lock it up , which isn't attained by simply going around a corner. even if it were, it wouldn't be any more than stock, because OD is still the same, so rotational speeds stay the same.
i really don't think it's about anyone being smarter than an engineer at lexus, but rather economics. IS250 people would rather be able to rotate their tires than have a cool looking staggered setup; bottom line. awd IS250' s are the practical cars for practical people.
even the understeer thought isn't really applicable because the guy wanting to stagger his 250 says he wanted it for looks, not performance. reaching hte limits of the suspension and tires isn't going to happen for a daily cruiser, besides, all stock cars understeer anyway.
just going down the road, all tires have equal traction or else they wouldn't be turning at the same speed; the wonders of an open differential.
i dont know for sure, but most likely the awd system works on an IS utilizing a viscous center differential.a viscous center diff works just like an open diff if traction between front and rear is equal; i.e. going down the road, driving normally. only in the event of either the front or rear axles spinning at different speeds would the viscous diff tighten up and lock the diff. in that event, since our OD on the tires is the same, again, there would be no issues, since rotational speed would be equalized momentarily by the vcd.
the additional traction of the wider rear tires is a non issue. technically, since the drivetrain is rwd biased, the stickier rear tires would grip better than stock, keeping the center diff from having to do more work than it would if it had stock wheels and tires; thereby reducing wear and tear.
the statement about offsets being differnt sounds like some political wool being pulled over someone's eyes. of course the offsets have to be different, the wheel widths are different, but the outer lips would be in line with each other front to rear if the setup is correct. again, he stated that the traction difference would cause a problem. there is no traction difference if there is no wheel spin! wheel spin would be minimized because of the wider rear tires anyway. the only time there would be a traction difference is going around a corner, but guess what? all cars have traction differences going around corners, that's why 99% of all cars have open differentials to allow this to happen without drivetrain stress. the IS has open rear and front diffs, so, NO wear. even the center diff, being viscous, won't activate going around a corner because it takes a certain amount of speed difference to lock it up , which isn't attained by simply going around a corner. even if it were, it wouldn't be any more than stock, because OD is still the same, so rotational speeds stay the same.
i really don't think it's about anyone being smarter than an engineer at lexus, but rather economics. IS250 people would rather be able to rotate their tires than have a cool looking staggered setup; bottom line. awd IS250' s are the practical cars for practical people.
even the understeer thought isn't really applicable because the guy wanting to stagger his 250 says he wanted it for looks, not performance. reaching hte limits of the suspension and tires isn't going to happen for a daily cruiser, besides, all stock cars understeer anyway.
Koz
03-29-08, 07:40 AM
#53
Lexus Champion
ah,so it is a torsen. i wasn't sure which. either way though, unless there is a serious speed differential between front and rear, the diff won't do anything outside of it's built in bias.
03-30-08, 01:09 PM
#54
Driver School Candidate
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Thats what I plan to do on my AWD, just run same size rim with different lips. Do most manufactures have option to select different lip sizes? Or will I be limited on my choices?
03-30-08, 02:25 PM
#55
I only understood about 1/3 of what 19psi wrote, and due to my limited knowledge on car parts, I want to ask this:
If the back tire is wider than the front, then the back tire will inherently have more traction (contact surface) as compared to the front.
Now more traction is due to the fact that there is more friction generated from more surface, that would mean more power is needed to turn the back wheel as compare to the front wheels right? (to overcome the friction)
If this is the case, and lets say this applies every time you turn, stop, accelerate, would this not cause premature wear if the normal threshold wear of our drive train did not design for extra power in the back continuously like this? (as compared to the original skinner back wheels)
And since the exact threshold is unknown, and really no one can say this for sure, I dont feel safe with a stagger setup. However, this is only with my limited knowledge physics and no knowledge of differentials and what not, so BLESS ME WITH THE KNOWLEDGE haha (the way my back wheel is tucked in is aggravating)
If the back tire is wider than the front, then the back tire will inherently have more traction (contact surface) as compared to the front.
Now more traction is due to the fact that there is more friction generated from more surface, that would mean more power is needed to turn the back wheel as compare to the front wheels right? (to overcome the friction)
If this is the case, and lets say this applies every time you turn, stop, accelerate, would this not cause premature wear if the normal threshold wear of our drive train did not design for extra power in the back continuously like this? (as compared to the original skinner back wheels)
And since the exact threshold is unknown, and really no one can say this for sure, I dont feel safe with a stagger setup. However, this is only with my limited knowledge physics and no knowledge of differentials and what not, so BLESS ME WITH THE KNOWLEDGE haha (the way my back wheel is tucked in is aggravating)
Last edited by mikez; 03-30-08 at 02:29 PM.
03-31-08, 05:34 AM
#56
Lexus Champion
I only understood about 1/3 of what 19psi wrote, and due to my limited knowledge on car parts, I want to ask this:
If the back tire is wider than the front, then the back tire will inherently have more traction (contact surface) as compared to the front.
Now more traction is due to the fact that there is more friction generated from more surface, that would mean more power is needed to turn the back wheel as compare to the front wheels right? (to overcome the friction)
If this is the case, and lets say this applies every time you turn, stop, accelerate, would this not cause premature wear if the normal threshold wear of our drive train did not design for extra power in the back continuously like this? (as compared to the original skinner back wheels)
And since the exact threshold is unknown, and really no one can say this for sure, I dont feel safe with a stagger setup. However, this is only with my limited knowledge physics and no knowledge of differentials and what not, so BLESS ME WITH THE KNOWLEDGE haha (the way my back wheel is tucked in is aggravating)
If the back tire is wider than the front, then the back tire will inherently have more traction (contact surface) as compared to the front.
Now more traction is due to the fact that there is more friction generated from more surface, that would mean more power is needed to turn the back wheel as compare to the front wheels right? (to overcome the friction)
If this is the case, and lets say this applies every time you turn, stop, accelerate, would this not cause premature wear if the normal threshold wear of our drive train did not design for extra power in the back continuously like this? (as compared to the original skinner back wheels)
And since the exact threshold is unknown, and really no one can say this for sure, I dont feel safe with a stagger setup. However, this is only with my limited knowledge physics and no knowledge of differentials and what not, so BLESS ME WITH THE KNOWLEDGE haha (the way my back wheel is tucked in is aggravating)
1. porsche does it with their awd cars
2. try rolling a 265 tire and a 225 tire as fast as you can on a level street. there's not any difference. imagine 100x more hp and mechanical advantage from the transmission and rear end doing it on a car, it's even easier.
03-31-08, 08:24 AM
#57
I gave this a bit more of a thought last night and here is what I came up with;
Porsche are rear engine designed and the weight ratio if not close to 50/50 are pretty much butt heavy, therefore their back wheel already have more traction due to force (another way to gain traction with same contact surface is to add more force pushing down), however with a bigger contact surface on the back wheel, the force/weight is spread out and thus the friction per unit area depending on the type of tire, are slightly more if not the same as a non stagger setup.
That same cannot be said of our IS which are front heavy.
Now, the thing being that, I would ASSUME running with a stagger setup would PROBABLY cause as much frictional/force difference as if you are running with or without a spare tire, or a trunk full of groceries, or driving with a full car as oppose to yourself.
I'm doing engineering in school right now and unless you know what to assume and what magnitude the equation/stress/strain changes by, the result of assuming something wrong can be catastrophic.
I don't want that to happen to our cars you know?
But I really want that stagger setup... trying to find good deals on nice looking rims thats not stagger is pita
Porsche are rear engine designed and the weight ratio if not close to 50/50 are pretty much butt heavy, therefore their back wheel already have more traction due to force (another way to gain traction with same contact surface is to add more force pushing down), however with a bigger contact surface on the back wheel, the force/weight is spread out and thus the friction per unit area depending on the type of tire, are slightly more if not the same as a non stagger setup.
That same cannot be said of our IS which are front heavy.
Now, the thing being that, I would ASSUME running with a stagger setup would PROBABLY cause as much frictional/force difference as if you are running with or without a spare tire, or a trunk full of groceries, or driving with a full car as oppose to yourself.
I'm doing engineering in school right now and unless you know what to assume and what magnitude the equation/stress/strain changes by, the result of assuming something wrong can be catastrophic.
I don't want that to happen to our cars you know?
But I really want that stagger setup... trying to find good deals on nice looking rims thats not stagger is pita
03-31-08, 08:21 PM
#58
Someone call or ask a Tech at Lexus if this can be done! I will see if i can reach them tomorrow. I was in there a few days ago but they where so into my car when i was there and trying to talk me into the ISF and some track event they are trying to get with the ISF. I will post an answer later tomorrow.
04-01-08, 06:42 AM
#59
Lexus Champion
I gave this a bit more of a thought last night and here is what I came up with;
Porsche are rear engine designed and the weight ratio if not close to 50/50 are pretty much butt heavy, therefore their back wheel already have more traction due to force (another way to gain traction with same contact surface is to add more force pushing down), however with a bigger contact surface on the back wheel, the force/weight is spread out and thus the friction per unit area depending on the type of tire, are slightly more if not the same as a non stagger setup.
That same cannot be said of our IS which are front heavy.
Now, the thing being that, I would ASSUME running with a stagger setup would PROBABLY cause as much frictional/force difference as if you are running with or without a spare tire, or a trunk full of groceries, or driving with a full car as oppose to yourself.
I'm doing engineering in school right now and unless you know what to assume and what magnitude the equation/stress/strain changes by, the result of assuming something wrong can be catastrophic.
I don't want that to happen to our cars you know? But I really want that stagger setup... trying to find good deals on nice looking rims thats not stagger is pita
Porsche are rear engine designed and the weight ratio if not close to 50/50 are pretty much butt heavy, therefore their back wheel already have more traction due to force (another way to gain traction with same contact surface is to add more force pushing down), however with a bigger contact surface on the back wheel, the force/weight is spread out and thus the friction per unit area depending on the type of tire, are slightly more if not the same as a non stagger setup.
That same cannot be said of our IS which are front heavy.
Now, the thing being that, I would ASSUME running with a stagger setup would PROBABLY cause as much frictional/force difference as if you are running with or without a spare tire, or a trunk full of groceries, or driving with a full car as oppose to yourself.
I'm doing engineering in school right now and unless you know what to assume and what magnitude the equation/stress/strain changes by, the result of assuming something wrong can be catastrophic.
I don't want that to happen to our cars you know?
But I really want that stagger setup... trying to find good deals on nice looking rims thats not stagger is pita
04-01-08, 06:45 AM
#60
Lexus Champion
Someone call or ask a Tech at Lexus if this can be done! I will see if i can reach them tomorrow. I was in there a few days ago but they where so into my car when i was there and trying to talk me into the ISF and some track event they are trying to get with the ISF. I will post an answer later tomorrow.
me; i am an aftermarket nut, so i dont' care. based on my experience, knowledge and training, i really don't see any problem with doing it. i'd do it on my personal car if i had an awd IS. hell i've been considering it for my WRX, nobody has staggered wheels on one, i'd like to be the first.