Silver or Bronze on red s13?

[nismofly]

I am curious why you want to go with something as drastic as 215's x 255's as opposed to 215's or 225's x 235's? Is it purely for looks or do you have 400hp and want to drag race?

extra width changes the shape of the contact patch, doesnt add more area

a 20mm stagger would be better, but a 235/40 front is pushing it, so he can either compromise the meatier rear tire and run a 245 or compromise the stagger and run a 30mm with the 255

[youngmanvr4]

Ok so simply tell me what tire size to do using the 17x8 +35 in front with or without spacer (give me the opitions what I can do with and without a spacer) and the 17x9 +35 in the rear. I would run a 245 in the rear if needed.

[nismofly]

instead of getting a spacer why not just get the 17x8 + 27 in the front, the lower offset is the same thing as getting a 1/4 inch spacer and its safer

if it was me getting a stagger id have 17x8 +27 front with 225/45/17, 17x9 +35 rear with 245/40/17

[youngmanvr4]

Ok I'll do just that then. If I cant find a place that sell the +27 I'll just get the +35 with a 8mm spacer up front with 225/45's.

[Looneybomber]

extra width changes the shape of the contact patch, doesnt add more area.

Explain this one to me because that doesn't make sense. If you have a tire, say 205/45 and that exact same tire but in 255/45 you will not only widen your contact patch, but also lengthen it slightly since your overall diameter of the tire is also increasing. Because your ratio never changed, your contact patch shape should not change, just increase proportionally in size, correct?

Now if you just went with a wider tire, but the same overall height 205/45/17= 24.26" tall The equivalent height in a 255 width would be a 255/36/17. Being that the tire is exactly the same diameter, it's contact patch length should be the same as the 205/45 but the width would increase by 50mm roughly.

One example shows the contact patch maintaining it's shape where-as the other shows it will change shape. However both examples of using a 255 over a 205 show that overall contact patch to the road will increase; we all knew that though back in grade school on our BMX bikes when going from a 1.75" to a 2.25" bike tire.

So back to my original question, is this purely for looks or do you have mad amounts of HP and need the extra square inches of contact?

[nismofly]

ive got a diagram somewhere that Greg (hitman) posted about the patch size

also its not as simple as "area = traction", you have to remember the air pressure of the tire, the weight of the car putting pressure on the tire, etc...

[Looneybomber]

ive got a diagram somewhere that Greg (hitman) posted about the patch size

also its not as simple as "area = traction", you have to remember the air pressure of the tire, the weight of the car putting pressure on the tire, etc...

I just remembered that right now, but you replied before I could edit mypost. It's flawed because you would have to change your air pressure or increase the weight of the car in order to get overall sq.in. of contact patch to have any worth while change.

So the only adventagious reason to get wider tires is for at the limit grip, once you've over come your friction coefficient with having a 205, the increased contact patch of the 255 (with having the load transfered to that tire) would net you higher friction coefficient correct?

So, why would you want 255's on the back instead of a more balanced (and less likely to understeer) setup of say 225f/245r?
Modified by Looneybomber at 12:37 AM 1/17/2006

[nismofly]

yeah

and honest to god i cant remember the whole area of the contact patch thing now, otherwise i woulda gone into more detail...its been a while, so now im searching my about 250gb of car stuff looking for stuff about it

[youngmanvr4]

I would rather have 245 than 255 really, but the wider tire is for two things, One looks, Two its say I'm driving and get a little to close (not saying I would be cause I'm a better driver then that) to the road median or something and I have streched tires, well then the wheel will get scraped more then tire, but when a wider tire the tire will take more of the hit then the wheel. Understand? But looks means more to me then scraping. Its not needed it just looks a little better IMO. But if I had to choose I would choose 245 over 255...which I am.

[Looneybomber]

ah, gotcha. That being said, I'm a big fan of running the exact same tires f/r so you can rotate them

[youngmanvr4]

Well I have a month before I buy the wheels so I can do somethinking and weight my options.

1. Front 17x8 +27 225/45/17 or if I cant get find a place that sells +27 get +35 with 8mm spacer with still same size tire, Rear 17x9 +35 245/40/17. No Rolling or pulling.

2. Front and Rear same 17x8 +35 with a 8mm spacer up front 225/45/17. No rolling or pulling.

Does this sound like the best of two plans that will work to you guys?

[mr_wizard]

I really need to learn the car tire and rim lingo here. Everything you guys are talking about is going in one ear and out the other. I really want to get those 5Zigen rims but I don't want to have to do a "fender roll". And I never realized what size tire matters so much. I'm wanting to do autox, so what size tires would I need for those rims? I'm assuming wider than normal?

[Looneybomber]

Autox in a miata 205/50/15's or 225/45/13's if you want slicks.In a 240 N/A I'd do 225/45's or 225/50's If you have F/I I'd going to a 235 in the back would help keep from getting quite as loose, but you better talk to some others on here that race.

Float_6969 been racing for a while now. He's a mod in the CA forum. You can find him there. I think he has 215's on his car f/r but I'd go for a bit more meat if it was me.

[DriftingJesus]

Bronze ftw

silver will look tacky

[mr_wizard]

Don't S13 SE's have wider fenders? Maybe if you have an SE you don't have to roll them?

[nismofly]

all the se designation on an s13 is is a few options on a hatch, it isnt a totally different car like with the s14

[w1ngzer0]

Silver with redBronze with white