another damn tire question

[Mars_302]

Alright, after checking out some fresh Kumho MXs saturday, I wanna try a set. Im more or less stuck on what tire size. Im going to be upgrading to 5 lug and 17" rims. Now my debate is, for a 17x8 would I be better off with a 225/45/17, 245/40/17, or 245/45/17? If I happen to pick up a set of 17x9 rims I will be doing 255/40/17 all around.


*edit*

Do you think it would be possible to get away with 255/40 on a 8" rim?

[MrSideways]

What kinda car and what class?

[Mars_302]

92 mustang, street mod.

[PseudoRealityX]

you can fit the 255s, or bigger... on the 8" wheel. The 9" wheel will be better, but either way, you can run the 255s.

[Leonard]

Mars, on a 17x8, go 245/45. on a 17x9, go 275/40.

you may want to consider the new Azenis.

[PseudoRealityX]

Id go 275 on both... but that's me.

[Leonard]

I wouldn't put a 275/40 on less than 9" wheels. Check any manufacturers specs for that size and they'll list allowable rim sizes as 9-11".

[PseudoRealityX]

Right, and Toyota says to never have more than 1 degree of negative camber on the front of my MR2.

Manufacturers are providing specs based on the general public, not us with special applications.

You can put a 225 on a 5" wheel, and you can put a 275 on an 8" wheel. Your tire guy will not like you and No, it's not ideal, but it fits, and the more tire you have, the more traction you have. And Mustangs need all the damn mechanical grip they can get, because their suspension isn't trying to help, it's trying to hurt you. ;)

[Mars_302]

I need grip, but I also need steering response. 275 on anything smaller than 9" will have too much bulge. Would the 245/40 have too little of a sidewall? I just also noticed they do make a 235/45 as well

[PseudoRealityX]

You could work around that....



But anyway, sidewall will help put down power a little bit. But I wouldn't sacrifice width for it.

[Mars_302]

the thing is also a 8" rim wont allow for true contact patch. Only way id be getting 275 to contact fukll would be with a 50 series sidewall. I have 245/45 on a set of 16x7 rims now. They bow a little and theres 1/2" of tread on each side that doesnt really touch the road like my 225/45s do.


believe me, all the drift guys would see me put 215s on 9" rims ;)

[PseudoRealityX]

blarg... Get whatever you want. You seem to have already decided what works and what doesn't anyway.


Drifters are idiots when it comes to car setup. Read the article in GRM about the "proffesional" drifter setup. They're morons.

[Mars_302]

some are, some arent. What was the jist of a D1 setup they made?

[PseudoRealityX]

drifters: "shocks don't matter because we spring it so stiff that there's not much suspension travel"

grm: "hmm, i don't know, F1 cars don't have much suspension travel, but they've got a team of engineers and a couple hundred thousand bucks in R&D that may contridict the drifters' theory."


Just look at the alignments those guys run.

[Leonard]

drifters: "shocks don't matter because we spring it so stiff that there's not much suspension travel"

grm: "hmm, i don't know, F1 cars don't have much suspension travel, but they've got a team of engineers and a couple hundred thousand bucks in R&D that may contridict the drifters' theory."



I'd probably be more likely to believe a couple hundred million dollars per team. Maybe a couple hundred thousand per season not counting track rental and wear/tear on the car for testing.


I'd say it's more likely that if they understood what was going on, they'd say that they want to underdampen the rear suspension because the ossilation of the suspension helps them to break the rear end loose more easily because the weight shifts on and off of the rear tires.


Of course, they'd never acknowledge that because it's all zen and mystical and above us. There's no science involved.

[Matt Vassallo]

Don't hate on the drifters and call them morons because they are setting the car up to not have traction. it's the exact opposite of what most other motorsports are doing.

I don't hate on you guys.

For the record, in my personal experiences with MX's (I'm sponsored by them, I get over 400 tires this year alone), I've found they run large. THe tires are physically wider than most other tire's i've come across.

I would do a 225-235 on an 8, no larger, and a 245 / 255 on a 9. this makes the sidewall very square, not bulging. The MX already does not have the stiffest sidewall on the market, anything you can do to keep it from bulging will improve response.

But hey, what do I know.

[Leonard]

Don't hate on the drifters and call them morons because they are setting the car up to not have traction. it's the exact opposite of what most other motorsports are doing.

I don't hate on you guys.


Matt,

Shocks DO matter regardless of how short your suspension travel is and regardless of whether your ultimate goal is grip or lack there of. Anyone who is willing to give a quote to a national magazine saying otherwise IS a moron.

As far as hating goes, I'll be the first to say that I can't fucking stand drifters who come to an autocross. The point of autocross is to leave as many cones standing as possible. As long as everyone has that intent, nobody working the course is going to have to pickup an unfair number of cones. (I understand that that's relative and sometimes we get a bad section of course or a troublesome newb, but it all averages out in the long run.) Enter the drifter. They don't care about how many cones they knock because cones don't matter for 'style'. Everyone else has to bust ass to clean up after them. That's not fair. In fact, the only person who doesn't get overworked is the one creating all the work.



For the record, in my personal experiences with MX's (I'm sponsored by them, I get over 400 tires this year alone), I've found they run large.



The fact that you're sponsored makes you an authority how??? Dale Jr. is sponsored by budweiser, but somehow I don't think he can tell me how to brew beer. I think I'd give you more credibility if you'd stayed at a Holiday Inn Express last night.


"LOOK AT ME!!! I'M A SPONSORED ATTENTION WHORE!!!! :monkdnce: :monkdnce: :monkdnce: "

[Mars_302]

woah her, lets settle down now

[OversteerS2K]

Cram the widest tires on that you can.
I have a 245/45 on a 7.5" rim (street & autocross). Yes, the sidewall buldges a bit. It still has a larger contact patch than a 225. They're only a few bucks more, each.
I'd take Leonard's advice on most Mustang related issues...

[Matt Vassallo]

That's fine that you want to yell, scream, call names, and tell me that I'm an attention whore. Honestly I think you're wrong. Don't shoehorn me in with the rest of the kids trying to drift. Dont' be mad at them for tryign to drift at an autocross, they could be out on the street endangering people women, children , etc. If they continue to cause problems, just ask them to leave. They usually will. Tell them it's not tolerated.

IF and when I drift at an event, it's usually because i'm coming hot into a corner. Rarely will I knock over cones, I've got enough control not to do that.

Where did I say I was an authority on Kumho tires? All I said was that in my experience, I have found they run wider for their size, than Bridgestones, Yokohama, Falken, Dunlop, Goodyear and Toyo. SOme others also, but those are just ones that I've found. The only tire's I've found that are almost the same size are the special S-02's.

If you run a physically the same tire size as a 245 would be on a Kumho MX, usually it will be a 225 or a 235. You can get out the tape measure and try it yourself sometime.

Lastly, Shifter Karts don't run shocks at all on their little karts, and they get around the tracks just fine. Granted you're looking at a 350lb setup vs a 2500 lb setup, but I'm sure in some strange setup of tire sidewall stiffness and the ability to change sidewall stiffness, you could probably build some sort of car setup that didn't require shocks. My car has fully adjustable coilover shocks, however, as I agree with you on the whole shocks are necessary thing. Yeah, if the engineers for the car companies paying millions of dollars for development say they need them, they are probably right.

I'm sorry you had to go to the personal bash to get your point across leonard, i'll remember to do that next time - -