I really need a set of dedicated wheels for Auto-x and track days.

I'm thinking about getting a set Konig Heliums (11 lbs). What worries me is the wheels are only available in 15x6.5. I already have a set of 15x7 Kosei K1s (13 lbs.) with 205/50-15 Azenis and it's a great combo.

So, what are the disavantages of using the Azenis on a 15x6.5 wheel? Is the 2 lb. diffrence in the wheels noticeable as far as handling/acceleration goes?

 

I'm not sure if I'm understanding the concern. Are you afraid that the 6.5" wheel is too narrow? I ran 205/50/15s on the OEM 6" wheel with no problems at all.

If you're going to have a dedicated set of tires/wheels, why get the azenis?


*edit* As for the two lbs, yes. Two lbs per wheel is a significant difference, but it's not one that you're likely to notice in the feel of the car. Still, every little bit helps. The azenis are already a heavy tire.


[Modified by ITR#231, 9:21 PM 6/25/2002]

 

I ran the Azenis on a 6.5" wheel on the track last weekend. I know others have as well. This was my first event though, so I can't really offer any useful feedback. There were no obvious problems though.

I'm sure 7" would be preferable given the choice.

 

I compete in STS so I'm limited to 140+ treadwear tires, no R compounds for me. The reason I want to get another set of wheels is so I don't have to run the Azenis on the street. I have two options.

1) Mount the Azenis on the lighter Heliums for auto-x and use "normal" street tires on the K1s.

2) Leave the Azenis on the K1s and use the Heliums on the street.

Option 1 would be the way to go but I don't want to give up anything by using the Azenis on a narrower wheel.

 

I use them on a 6" wheel. No problems at all....

 

Same. Mine are on 6" wheels and have used them far above and beyond what they would see on an autocross course. I also daily drive them (and did so right through winter) with no problems. The fact that it never really snowed here this year helped, but my point is that they are great to use on the street. Cheap enough to wear them out often, too.

 

Oh, gotcha. Well if those are your two options, I would argue that (if there is a difference at all) the lighter wheel would serve you better than an extra .5" on the width. The azeni is a heavy tire, but it has a pretty stiff sidewall so the effect of the narrower rim will be less important.

Again, I think the two options are so similar you could basically flip a coin. Why not find a light weight wheel in a 15x7 since you don't already have the Heliums?

 

I know people who have run the 205/50x15" Azenis on OEM wheels (15x6") and they have no problems. I run 205/50x15" Kumho VictorRacers on OEM wheels (Civic Si) and they work great too. Just make sure you keep enough pressure in them as I heard there was creasing of the Azenis tires with not enough tire pressures.

 

I run 215/45/16 Azenis on a 6.5" 16, and don't have any problems. I'm able run 7-8 psi less than my previous tires (205/50/16).

 

A very tough call -- 2 lbs. is 2 lbs. (actually it's 2 lbs. x 4 wheels), and reducing unsprung weight is a very good thing. On a street legal-street driven-daily driver-kind-of-car, I'm not sure how noticeable this weight savings would be (vs. a striped down, gutted shell of a race car). Going a half inch wider in wheel width is also a good thing, theoretically causing less side wall flex/pinching so plausibly increasing the tire's contact patch. Again, I'm not sure how noticeable this would be. The best option, as already suggested, is to find a lighter 15x7 wheel, but your wallet might not appreciate doing that. How much do the Heliums cost? A light (~10 lb.) 15x7 wheel can cost $300 a pop, so that adds up in a hurry.

 

6.5" is the recommended rim width for a 205/50/15. I run the Azenis on 15x6.5 Rota's and they fit perfectly.

 

7" wide wheel is recommended for a 205 tire, but 1/2" up or down is fine too.

 

I don't know how applicable this is to you but I run a 205/50/15 Kumho V700 on a 6.5" wheel and I am happy with it. The tire has a nice flat surface so I wouldn't be concerned with the width.

In regard to the weight - with the torque monsters ( ) we drive any reduction in rotating unsprung mass is a benefit. That 8lbs. will make a difference. Will you notice the difference? Maybe, maybe not.

 

The Heliums cost $139 from Discount Tire, so far it's the lightest wheels I've found for that price. The K1 costs the same but they're 2 lbs. heavier. Rotas are cheaper but they are also heavier.

I'd love to get a set of 15x7 CP-08s but I don't like the prospect of eating Mac & Cheese for the next 6 months.

 

Not sure if it's relevant here, but I've been running a set of 205/50/15 Victoracers on a set of 15x6 Millenia wheels. The setup has worked great so far, and hopefully I'll be able to milk it for awhile...

 

Personally, I'd rather have the 7" wheel over the 6.5" even if it was a little heavier.

The 6.5" wheel will still pinch the sidewall of the ultra-wide Azenis. The more you can spread the tire out, there better off you will be. Why do you think the FWD SP guys run 8" and 9" wheels with only 225 tires?

I drove a 205 Azenis on a 6" wide tire and IMO it felt like crap compared to the 205 Azenis that I have mounted on my 7.5" wide wheels.

 

That's good info. Have you tried the different wheel widths while using R-compounds? Thanks!

 

R compounds have a much stiffer sidewall than any street tire so it won't be quite as pronounced, but again--wider is better.

 

I remember reading somwhere that a one pound reduction in unsprung weight = 5 pounds in sprung weight. Any validity to this?

If it's true, the 2 pounds per corner would equal to a 20 lb. reduction...

 

Check yer math, but you have the right idea. Weight is weight no matter how you look at it, but weight distribution is not trivial. Weight is best kept low and off of the wheel/tire.

 

oops...2 lb. per corner = 40 lbs. heh...

Guess I'll give the 6.5 a shot and see what happens...


[Modified by Snake, 4:13 PM 6/26/2002]

 

OT - digging the screen name , big ups to Tosh

you seen the movie ? if not hit me up i have it and its VERY hard to find , maybe I can make a copy for you

 

I must be blind then when I look at http://www.falkentire.com and it states that the 205/50/15 Azenis is built for a measured rim width of 6.5". That must be secret code for 7"


[Modified by Steve91, 3:32 PM 6/26/2002]

 

FYI:

I purchased two sets of 205/50/15 Azenis. One set I mounted on 7.5" wide wheels and the other set is still sitting unmounted. I stacked the mounted set on 7.5" wheels next to the stack that was unmounted. The height difference between the two stacks was *identical*. You think the 205 Azenis isn't a wide tire? Think again.

To further illustrate this, I put a set of mounted 205 Kumho 712's on 7" wide wheels next to a set of unmounted 205 712 Kumhos. The set that was mounted on 7" wide wheels was considerably taller.

Now, Falken also claims a 205 wide tire. Bullsh!t. The thing is at least a 215, and people have measured it to be a lot wider than even that. Take their width advice as merely a suggestion. You will want a wide wheel with these tires, trust me.

STS is a lot about speed maintainence anyways, so an extra few lbs per wheel isn't going to kill you. The STS national champ last year was on 7" wide Koseis on 195/50/15 tires.

 

No, it's not some secret code...

Measured rim width means that if the tires are mounted on a rim that is the stated width it would yield the specs that the manufacturer quoted.

Read this page http://www.tirerack.com/tires/tirete...especskey.html. Pay close attention to the "Measured rim width" and the "Section Width" sections of the page


[Modified by Snake, 3:30 AM 6/27/2002]