happy and angry
Member
Says the guy who thinks the ECU busts out a ruler to figure out tire circumference, just gotta reset the thing.
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Tire fitment
- Thread starter iBoost
- Start date
Not so much a specification nazi, really. I just want people to have all the information they need to make informed choices. I'm pretty anal about tires, though. Most important part of the car.
I wish I could find an article about potential problems with smaller circumference tires and the impact it might have on ABS/TC, etc. Anyone know of a good place to look? So far google has failed me.
It's a hard topic to find good info on... I was looking because I decided to replace two tires, I ordered slighlty different from stock thinking, oh it'll be fine.. then I realized, wait, I'll have different diameter tires on the car at the same time, got a lil paranoid and started searching. Manage to find some specs for other cars on how far off the front and rear diameters could be different before the abs system went crazy... Well i was well within spec of other cars but still unsure about our car. Luckily before the tires arrived I ran across a sweet deal on tires and wheels I couldn't pass up. So I never did try the mismatched thing to know if there would be a problem. Never did find anything solid on smaller diameter tires that are matched all the way around. For the most part what I found said it'd be fine, which it is in my case, no problems. If you run across that info you're talkin about post it for sure, I have alot of interest in this topic. Reguardless, the abs and tcs is going to be much less sensative to smaller diameter tires all the way around than if you start mismatching. Main issue I see would be that you're going a different speed than the computer thinks, and I'd say the abs behaves differently at different speeds, but it's gonna take more than a little difference to cause any major issues.
Last edited:
happy and angry
Member
That size is within ~1% of stock tire circumference, and won't cause any problems. 7% is a bit more. Stock tire size and stock tire/wheel combo circumference are different.im running 225/45/18's on my car and it has not affect the TC/DSC or my ABS from what i can tell, i know its not the same size as you said but its the same principle.
im running 225/45/18's on my car and it has not affect the TC/DSC or my ABS from what i can tell, i know its not the same size as you said but its the same principle.
This is a good size, nothing wrong with it, it is very close to stock.
The issue is- numnuts wants to run a 215 35 18 tire on his wheel, this will fit but is 2 profile sizes smaller, ride quality will be diminished along with all the points made by the Canadian and 1 other fella. This is not good. Just because they are free does not make it a good deal. Granted they may not actually cause any issues but they are not appropriate for our application.
This is a good size, nothing wrong with it, it is very close to stock.
The issue is- numnuts wants to run a 215 35 18 tire on his wheel, this will fit but is 2 profile sizes smaller, ride quality will be diminished along with all the points made by the Canadian and 1 other fella. This is not good. Just because they are free does not make it a good deal. Granted they may not actually cause any issues but they are not appropriate for our application.
WTF man? "numnuts" was the one asking for advice on if it'd be alright. I'm the one that feels it's not going to be a problem. Call me numnuts, not the op. Sheesh.
But yea, if you're not gonna do it iBoost, I'll pay shipping on em and slap em on mine without a second thought. If there are problems I'll let yall know. lol
And, uh, just how exactly is it going to perform this magical feat?
i'd like an explanation on this one as well. how is the ECU supposed to
1) recognize that there are different sized wheels/tires on the car
2) determine the size of the new wheel/tire combo
3) adjust the speedo, odo, etc to accomodate for the difference in size
happy and angry
Member
I got a name, Texas.made by the Canadian
WTF man? "numnuts" was the one asking for advice on if it'd be alright. I'm the one that feels it's not going to be a problem. Call me numnuts, not the op. Sheesh.
But yea, if you're not gonna do it iBoost, I'll pay shipping on em and slap em on mine without a second thought. If there are problems I'll let yall know. lol
I was referring to iBoost, not you buddy, no big issue.
I got a name, Texas.
lol, but i am not a texan.
I was referring to iBoost, not you buddy, no big issue.
Hehe, that's my point. nevermind.
whitey4311
Member
- :
- MS3 GT Black Mica w/nav
Ghost Rider
Banned
The thing about the ECU being capable of adjusting to differences in tire diameter was just a thought. I mean now days with the advancements in technology I wouldn’t be too surprised. However, I agree with your post (H&A) in this thread and would disregard what I said about the ECU. I was indeed talking out of my ass on this one, lol!
Okay. Let me be more clear. It's actually a 9% reduction in total diameter, and as a result a 7% reduction in total diameter.
Actually, a 9% reduction in diameter results in a 9% reduction in circumference. Since diameter and circumference are directly proportional, any increase or decrease would be by percentage identical.
dude, you really must not have a life if you're just following around ghostrider and making troll comments whenever he posts.
if youre really that concerned with the issue, like mentioned before, talk to a moderator and let them handle it. im getting sick of reading your stupid troll posts every time i look at a thread. they're far more obnoxious than anything he's ever said.
john blutarski
Member
- :
- 2004 Subaru WRX STI
I'll pay shipping on em and slap em on mine without a second thought. If there are problems I'll let yall know. lol
Let us know when your shocks are blown and rims bent. This car shouldn't be running a 215/35 on these heavy stock rims. Our suspension is not designed for something that far off the stock size. On an MS3 they will feel like s*** unless you drive on smooth roads all the time.
happy and angry
Member
You're right. I was just pulling numbers from here:Actually, a 9% reduction in diameter results in a 9% reduction in circumference. Since diameter and circumference are directly proportional, any increase or decrease would be by percentage identical.
http://www.miata.net/garage/tirecalc.html
and I did some math wrong, YOU PEDANTIC JERK.(doh)
Let us know when your shocks are blown and rims bent. This car shouldn't be running a 215/35 on these heavy stock rims. Our suspension is not designed for something that far off the stock size. On an MS3 they will feel like s*** unless you drive on smooth roads all the time.
I doubt he's gonna send me these for shipping only, but I fail to see how it has anything to do with the suspension other than there's less tire to absorb some of the shock. The suspension's not gonna be sitting any different. It'd be the equivalent of running more psi on the stock tire's as far as the suspension is concerned. And It's not like i'm going out hitting every pothole I see, sure it's gonna be easier to bend a rim by hitting something but come on. You act like I'd screw everything up if I were to put that size on.
john blutarski
Member
- :
- 2004 Subaru WRX STI
I doubt he's gonna send me these for shipping only, but I fail to see how it has anything to do with the suspension other than there's less tire to absorb some of the shock. The suspension's not gonna be sitting any different. It'd be the equivalent of running more psi on the stock tire's as far as the suspension is concerned. And It's not like i'm going out hitting every pothole I see, sure it's gonna be easier to bend a rim by hitting something but come on. You act like I'd screw everything up if I were to put that size on.
The tires are part of the suspension. Running something with that much smaller of a sidewall increases what the the shock has to absorb over every bump.
The tires are part of the suspension. Running something with that much smaller of a sidewall increases what the the shock has to absorb over every bump.
Fair enough. Definitely something to take into consideration.
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