Wider track or wider tires ? - Page 2

zbomb · Feb 26, 2009, 01:28 PM

I completely agree, why use a spacer when you could fit a 335 tire in the well.... If HKS thought a 335 tire would be faster than a 1" spacer I would think they would do it. But, as Nils said, maybe the mentality is that strong...I would like to see what they'd do with the fattest tire they could fit.

GTWORX.com · Feb 26, 2009, 01:36 PM

Didn't one of the SM auto-x EVO's run tires that weren't nearly as big as most people expected?

Can't remember exactly.

- Andrew

Bimmubishi · Feb 26, 2009, 01:43 PM

Porsche has been using spacers wider than that for years.

Narrow tires heat up faster than wide ones, all other factors being the same. (or should I say that smaller contact patch means more load, more heat) 3 laps isn't enough time to get enough heat into some compounds. Something to think about.

I think that if wider tires made the cyber evo faster that they would have them. There is no other evo track car in amateur racing that has had more money dumped on it for development.

My references

http://wtac.org/

http://www.youtube.com/watch?v=kqjKxDFEK98

GTWORX.com · Feb 26, 2009, 01:50 PM

^ True. Plus, less unsprung weight.

Was there ever a comparison of the AMS car and the Cyber EVO?

- Andrew

jjm4life · Feb 26, 2009, 01:54 PM

fireball is right. i use to run a 20mm spacer on my old setup and i miss the way it handled. 17x9.5 wheels with 255.40.17 advan neovas

V.8MR · Feb 26, 2009, 02:57 PM

Quote:

Originally Posted by Fireball

Uhh, think you're missin something there!

The car has been this way for 2 years

. Times are tight, so im holding out till they get better. Its an 05 with 16k on it

nils · Feb 26, 2009, 03:15 PM

Quote:

Originally Posted by V.8MR

Its an 05 with 16k on it

same mileage as my 04

zbomb · Feb 26, 2009, 03:21 PM

Bimmu, I'm with you in thinking that if a bigger tire was going to make either of the two car's I'm talking about faster they'd use them. I just don't think HKS would go to the effort to make such an outrageous car and then stick with 265 tires because it fit with the status quo in Japan.

For track guys...

If you had to choose and cost was not to be the deciding factor:

Suspension geometry/track or supa fat meats 295+ and could only have one for an evo, which would you take...

nils · Feb 26, 2009, 03:28 PM

Suspension geometry/track

GTLocke13 · Feb 26, 2009, 03:33 PM

I'd take the suspension geometry before taking the wider tire. I also can see the unsprung weight argument. From experience though, I'm faster on a 295/30 than on a 275/35 through an autocross course, with both tires on 8" rims. In autocross, more rubber on the ground is generally better. Less unsprung weight, and especially less rotational inertia in the wheel, can make a big difference on a track though.

V.8MR · Feb 26, 2009, 03:37 PM

BTW im running 265's at all four with 10.5" wide wheels in the front and 9.5" in the back. Its pretty tail happy!

BluByYouEvoVIII · Feb 26, 2009, 03:59 PM

great thread. It's definitely something to think about. I'll be interested to see more clear cut facts come up as I am in the process of going widebody right now.

zbomb · Feb 26, 2009, 04:41 PM

Quote:

Originally Posted by BluByYouEvoVIII

great thread. It's definitely something to think about. I'll be interested to see more clear cut facts come up as I am in the process of going widebody right now.

Well, That's kinda why I started looking at tire sizes to begin with. I have a widebody in process and a set of 9.5 +22 TE's. I was a little confused when I realized the Japanese guys were running 265's, although on 10+ inch wheels. I was originally and probably still will be running 285's but I thought this could start an interesting conversation. I also have 10mm spacers to mess with not sure how or if I'm going to use them. I think it would be kinda cool to run HRS control arms, some big spacers.

Nils, I had a feeling you'd say that

GTLocke13, a 295 on an 8" rim...Wowza !!!

eclip5e · Feb 26, 2009, 11:32 PM

Quote:

Originally Posted by Bimmubishi

Porsche has been using spacers wider than that for years.

Narrow tires heat up faster than wide ones, all other factors being the same. (or should I say that smaller contact patch means more load, more heat) 3 laps isn't enough time to get enough heat into some compounds. Something to think about.

I think that if wider tires made the cyber evo faster that they would have them. There is no other evo track car in amateur racing that has had more money dumped on it for development.

My references

http://wtac.org/

http://www.youtube.com/watch?v=kqjKxDFEK98

^^^ Thanks for the free plug.

Team Tarzan Tomei/Cusco/Voltex Impreza won Super Lap Battle on 275s.

When i talked to the suspension engineer at PRI Show in december, he said that they couldn't get enough heat into wider tires for those few laps, he also mentioned the weight issue.

Bimmubishi · Mar 1, 2009, 08:13 PM

There is an article in Race Car Engineering, I think one from this year that discusses the difference and tradeoff. We've covered it here pretty well. More weight with larger tires but better cornering. Better top speed with narrower tires but less corner speed so you will theoretically enter the straight with less speed... tradeoff. Combine that with the short amount of time to get heat into the tires when making a decision.

Another note is that factory teams have access to compounds that are "improperly" labeled.