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View Full Version : Diff tolorance for mild staggered setup



tyranosaurs-WRX
07-23-2012, 03:38 PM
anyone know? will the weight difference be an issue (each rear weighs approx 1-2 lbs more than the fronts)
if the circumfrence of the tires is the same then will it make a difference? ie 225/40 has the same circumfrence as a 245/30

CZ03WRX
07-23-2012, 03:46 PM
because racecar

dukenukem
07-23-2012, 03:59 PM
I wouldn't do it but then again I am boring and dislike most mods the cool kids do.

stinole
07-23-2012, 05:22 PM
There's a certain tolerance that you can run within, but why risk it?

dukenukem
07-23-2012, 06:09 PM
Is the weight difference for the tire or tire and wheel both?

VF34RX
07-24-2012, 10:15 AM
http://kcsubaru.com/showthread.php?6014-Staggered-setups&highlight=staggered

Basically its all about the circumference of the tires that will be the deciding factor in the life of your diff.

CZ03WRX
07-24-2012, 10:26 AM
http://kcsubaru.com/showthread.php?6014-Staggered-setups&highlight=staggered

Basically its all about the circumference of the tires that will be the deciding factor in the life of your diff.

so basically Sean could run a 17x8 +45 with a 225/40 on the front and a 17x9 +45 245/35 out back.... right? :lol:

VF34RX
07-24-2012, 10:51 AM
so basically Sean could run a 17x8 +45 with a 225/40 on the front and a 17x9 +45 245/35 out back.... right? :lol:

I dont want to do the math but it sounds about right.

CZ03WRX
07-24-2012, 10:55 AM
I dont want to do the math but it sounds about right.

good now I just need him to win the lottery.

tyranosaurs-WRX
07-24-2012, 12:26 PM
I am too on the fence about it. I hear too many people say no, and too many people say yes. In my research, I found that the only thing that can truely mess up the diff is the circumfrence difference but there is a 3/32nd diameter tolorance or .09375" tolorance wich is a little over 2 revolutions per mile that in and of itself is a possible fluxuation just in daily use expansion and contraction and wear. hell when the rear of our cars is lowered and the camber goes negative a lot that changes the circumfrence of the tire patch on the ground. but andy is right in asking why risk it.

VF34RX
07-24-2012, 12:39 PM
I am too on the fence about it. I hear too many people say no, and too many people say yes. In my research, I found that the only thing that can truely mess up the diff is the circumfrence difference but there is a 3/32nd diameter tolorance or .09375" tolorance wich is a little over 2 revolutions per mile that in and of itself is a possible fluxuation just in daily use expansion and contraction and wear. hell when the rear of our cars is lowered and the camber goes negative a lot that changes the circumfrence of the tire patch on the ground. but andy is right in asking why risk it.

There is risk in doing any modification to any vehicle. It just depends on how much risk you are willing to live with. A bigger turbo is far more risky than a staggered setup.

tyranosaurs-WRX
07-24-2012, 03:13 PM
There is risk in doing any modification to any vehicle. It just depends on how much risk you are willing to live with. A bigger turbo is far more risky than a staggered setup.

But you'll notice I'm running a full Cobb setup. Probably the safest mods possible. So this wold more than likely be the most dangerous mod I would have, at least until I got equal tires all around

VF34RX
07-24-2012, 03:19 PM
Mmmmm cobb. I miss that TBE.

CZ03WRX
07-24-2012, 03:24 PM
But you'll notice I'm running a full Cobb setup. Probably the safest mods possible. So this wold more than likely be the most dangerous mod I would have, at least until I got equal tires all around

YOLO. ahahahaha

Jagular1785
07-24-2012, 03:29 PM
Keep them equal, it's not worth the headache and cost of doing something wrong.

tyranosaurs-WRX
07-26-2012, 10:20 AM
well I guess I will just save my pennies and hope to find a decent deal on another set, based on everything said here combied with my research I COULD do it but it is entirely unknown the damage it could cause or how long before it caused damage. I hate logic, and stupid engineering tolorances and math.

dukenukem
07-26-2012, 10:32 AM
well I guess I will just save my pennies and hope to find a decent deal on another set, based on everything said here combied with my research I COULD do it but it is entirely unknown the damage it could cause or how long before it caused damage. I hate logic, and stupid engineering tolorances and math.

Do this .. run the 17x9 on left and 17x8 wheels on the right side. I bet that would work.

WRXNFX
08-04-2012, 12:30 PM
Sean, why not just rock all 4 wheels the same and put 1" spacers under the rears?

fishawrx
08-04-2012, 06:20 PM
Sean, why not just rock all 4 wheels the same and put 1" spacers under the rears?

That would require longer studs, running spacers over about 1/4 inch required longer studs on my stock wheels if I actually wanted more than a few turns on the lugs. Easy enough mod to replace studs.

CZ03WRX
08-04-2012, 06:23 PM
Sean, why not just rock all 4 wheels the same and put 1" spacers under the rears?

the whole point was he wanted my staggered RPF1s lol

WRXNFX
08-05-2012, 01:21 AM
That would require longer studs, running spacers over about 1/4 inch required longer studs on my stock wheels if I actually wanted more than a few turns on the lugs. Easy enough mod to replace studs.

Son, are you teaching your papa about spacers??

1" bolt on spacers work. I am rocking 4 year round.. :) 3 years now?

Jagular1785
08-05-2012, 01:47 AM
Would it not be cheaper for extended studs than screwing up the center diff?

92tsiawdguy
08-05-2012, 04:20 AM
As long as the roll out is the same or close to the same then you will be fine. Do you think all four tires wear evenly on an awd car? Because they dont. So basically if the roll out is the same(same diameter) then you will be fine. Width doesnt matter.

CZ03WRX
08-05-2012, 07:41 AM
meh, the wheels are aold already anyways. I'm headed to STL to drop them off in an hour

VF34RX
08-06-2012, 10:05 AM
Would it not be cheaper for extended studs than screwing up the center diff?

How are you screwing up any diff? extended studs arent needed for 1" spacers. They have their own studs.
As stated at the beginning, if the diameter is close/same it will not affect the center diff.

Jagular1785
08-06-2012, 01:58 PM
How are you screwing up any diff? extended studs arent needed for 1" spacers. They have their own studs.
As stated at the beginning, if the diameter is close/same it will not affect the center diff.

I'm told that even having unevenly worn tires will wear out a center diff quickly (though the STI is not a viscous center diff).


Trying to make a staggered setup will be next to impossible to get the exact circumference on different width tires because the sidewall height is a ratio to the tread width. So having wider tires will put sidewall ratios on a different scale. A 225/60/17 is not going to be the same circumference as a 235/60/17. And trying to play with the aspect ratios is not a good idea because they are usually in 5% increments from the manufacturers, meaning you won't be able to match the scaling of the narrower tires exactly.

For example, the original suggestion on the first post:

225/40/18- Total circumference = 78.81", Revolutions per mile = 803.94
245/30/18- Total circumference = 74.73", Revolutions per mile = 847.85

Difference of 5.18%, 43.91 Revolutions per mile difference

For 17s, if you are running those:

225/40/17- Total circumference = 75.67" Revolutions per mile = 837.32
245/30/17- Total circumference = 71.59" Revolutions per mile = 885.06

Difference of 5.39%, 47.74 Revolutions per mile difference

Using the tire size calculator here v

http://www.csgnetwork.com/tireinfo4calc.html

At the very least, run a ton of combinations through a the calculator and try to get that percentage way down.

VF34RX
08-06-2012, 02:16 PM
Here is the example that i contacted hankook about. This is well within range of a setup that will work.

For whoever is wondering i contacted Hankook direct and got this answer about their Ventus V12 evo tires.

265/35R18 – 25.3” od, 79.44” circ.

235/40R18 – 25.4” od, 79.75” circ.

That is plenty close (2.5mm dia and 7.8mm circ) to be within spec and not screw with the center diff.

Im just saying it can be done.

CZ03WRX
08-06-2012, 02:26 PM
I'm told that even having unevenly worn tires will wear out a center diff quickly (though the STI is not a viscous center diff).


Trying to make a staggered setup will be next to impossible to get the exact circumference on different width tires because the sidewall height is a ratio to the tread width. So having wider tires will put sidewall ratios on a different scale. A 225/60/17 is not going to be the same circumference as a 235/60/17. And trying to play with the aspect ratios is not a good idea because they are usually in 5% increments from the manufacturers, meaning you won't be able to match the scaling of the narrower tires exactly.

For example, the original suggestion on the first post:

225/40/18- Total circumference = 78.81", Revolutions per mile = 803.94
245/30/18- Total circumference = 74.73", Revolutions per mile = 847.85

Difference of 5.18%, 43.91 Revolutions per mile difference

For 17s, if you are running those:

225/40/17- Total circumference = 75.67" Revolutions per mile = 837.32
245/30/17- Total circumference = 71.59" Revolutions per mile = 885.06

Difference of 5.39%, 47.74 Revolutions per mile difference

Using the tire size calculator here v

http://www.csgnetwork.com/tireinfo4calc.html

At the very least, run a ton of combinations through a the calculator and try to get that percentage way down.

idk where you puled those tires sizes from, because the tires that were actually in question were within spec.

Jagular1785
08-06-2012, 02:34 PM
anyone know? will the weight difference be an issue (each rear weighs approx 1-2 lbs more than the fronts)
if the circumfrence of the tires is the same then will it make a difference? ie 225/40 has the same circumfrence as a 245/30

That's where I got them from, I just plugged those in with 18 and 17 inch wheels because I couldn't remember what sean had. I'm not trying to be a dick here, I'm trying to help.

tyranosaurs-WRX
08-06-2012, 02:49 PM
That's where I got them from, I just plugged those in with 18 and 17 inch wheels because I couldn't remember what sean had. I'm not trying to be a dick here, I'm trying to help.

I was only throwing numbers out there to give a format example, not necessarily the actual numbers. and its no longer relevant as caleb said because he already sold the wheels and with my little battery escapade a week ago I was set back slightly

Jagular1785
08-06-2012, 03:18 PM
Gotcha, definitely misunderstood what you meant.

CZ03WRX
08-06-2012, 03:22 PM
That's where I got them from, I just plugged those in with 18 and 17 inch wheels because I couldn't remember what sean had. I'm not trying to be a dick here, I'm trying to help.
I understand, was just trying to clarify :)

I was only throwing numbers out there to give a format example, not necessarily the actual numbers. and its no longer relevant as caleb said because he already sold the wheels and with my little battery escapade a week ago I was set back slightly

werdz. tires are now gone also

VF34RX
08-06-2012, 04:26 PM
So are the wheels and tires still for sale?

CZ03WRX
08-06-2012, 04:26 PM
no everything is sold. lol

VF34RX
08-07-2012, 08:31 AM
no everything is sold. lol

Will they fit my truck? would you want to trade for some honda 15's?

-kcsr/craigslist

CZ03WRX
08-07-2012, 09:47 AM
Will they fit my truck? would you want to trade for some honda 15's?

-kcsr/craigslist

yes.

VF34RX
08-07-2012, 01:18 PM
yes.

ok i'll get with you when i get the honda 15's. I should be picking them up this weekend if i sell some stuff to get the money for those.

CZ03WRX
08-07-2012, 01:45 PM
ok i'll get with you when i get the honda 15's. I should be picking them up this weekend if i sell some stuff to get the money for those.

sounds good, they're JDM right?

namcu
08-08-2012, 08:25 PM
Winning

VF34RX
08-09-2012, 08:52 AM
Winning

What do you know about wheels and fitment. gtfo



j/k wub u

namcu
08-11-2012, 02:46 AM
I drive a Honda, I don't know anything

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