Tire selection Options

[john914somers]

So I'm getting ready to buy tires for my 914/6-3.2 and I'm wanting input from you guys. My car is set up to be a race car ONLY and will never see the street again. Sooo this is what it is... I am looking to buy Toyo R-888's 235/40R-17 for the front and 275/40R-17 for the rear. Now I've been told that because my rims are 7.5x17 and 9.75x17 that I should not buy tires with a tread width that is wider than the rim width but both of these tires are wider than their respective rims. Any help/opinions are greatly appreciated. Thanks a ton!

[914forme]

Whats keeping you from running slicks?

Tire rack lists the specs for the tires the rears are for a 9.5" wheel. and the fronts work also for your tires per the manufacturer. So I see no issue. Actually I would not by from that dealer, find someone who knows something about what your doing.

[wndsrfr]

So I'm getting ready to buy tires for my 914/6-3.2 and I'm wanting input from you guys. My car is set up to be a race car ONLY and will never see the street again. Sooo this is what it is... I am looking to buy Toyo R-888's 235/40R-17 for the front and 275/40R-17 for the rear. Now I've been told that because my rims are 7.5x17 and 9.75x17 that I should not buy tires with a tread width that is wider than the rim width but both of these tires are wider than their respective rims. Any help/opinions are greatly appreciated. Thanks a ton!

Don't know about R888's but I'm loving my Toyo RA1's that I bought shaved down to 4/32nds so they only had just a bit of the circumferential grooves and none of the tread pattern, basically slicks. I'm at 2000 pounds with a 2.7/6 with about 185rwhp. I've got 225/45/15's on all 4 corners on 8 inch fuchs rims. I've tracked the car all year, over 50 heat cycles & they're still great.
That said, I'm not yet capable of putting as much work into the tires as some more aggressive drivers, but I am working them up from starting pressure of 31 to finish pressure of 37-38 in 25 minute sessions at VIR, Summit Point and Watkins Glen. Toyo's info says that 36-38 is the sweet spot for these tires. Shaving them was a good move as I'm enjoying max grip right out of the box and I can't see that I've sacrificed any life at all, maybe actually extended it...
I was also looking at the R888's but found comments that put me off of them and onto the RA1's.
As to the issue of rim width versus the tire width, get a second opinion....a great resource is Bob Woodman--a great guy who's a driver first, now a tire supplier. No vested interest but here's his website:
http://www.bobwoodmantires.com/

[brant]

You need Hoosiers for a track only car. Follow their recommende rim width chart and they will be faster than a wide tire on a narrow rim

[john914somers]

Yea I think Hoosiers will ultimately be the tire of choice but my car is all brand new and I was told three things that turned me away from Hoosiers at least for a little while. 1) in the time it will take me to obtain a reasonable suspension set-up I could destroy a nice set of Hoosiers potentially in one afternoon whereas the R888 might last a whole year 2) it would be good to learn the car with less grippy skins and 3) The Toyos would be better than the Hoosiers if it started to rain. I'm not certain if this is all true but at least at face value seems to stand to reason. Am I just wasting $1000 by going with the Toyos? How long might one expect a set of Hoosiers to last? Because I don't have the budget to be buying slicks every weekend. Thanks Guys!!!

[Woody]

I run 888s as my street rubber and for the occasional track days I do. The car seldom gets driven on the street except for going to AX events and maybe to work once every few weeks. I've also run the RA1s. Both of them are great tires. Just out of curiosity how much track or autocross time do you have under your belt? The reason I ask is because if your new to this, as well as being in a new car, R comps just add another level of difficulty all together.

[brant]

What is your wet wait.

We get a ton of life from Hoosiers. Our teener is fairly light and I attribute the above average tire life to our weight. For what ever reason we get about doublelife from Hoosiers as is the common belief. Most of a season. And when they loose their advantage they still don't cord. You can keep driving them with no harm and just know they are slower than they could be

What is your weight

[brant]

Also. Go to the Hoosier web site and look up their rim width chart. Should apply generally to other brands too

[ChrisFoley]

From the Hoosier Tires Specifications brochure:
Sports Car DOT Radial page
No 235 x 17 tire listed.

245/40ZR17, R6 compound
Tread width - 9.3"
Approx dia - 24.5"
Recommended rim 8.0 - 9.5"
Measured rim - 8.5"
Section width - 10.0"

275/40ZR17, R6 compound
Tread width - 10.3"
Approx dia. - 25.5"
Recommended rim - 9.0-11.0"
Measured rim - 9.5"
Section width - 11.0"

[john914somers]

Thanks Guys,

For all the great takes!

To answer your questions I don't have any experience in this car nor roadracing or autocrossing but I did race Karts for about 7 years and have owned porsches most of my life... and as for the weight of my car I'm going to guess 1850 + or - ??? It's been chopped up pretty good.

[brant]

my experience with rim widths and hoosiers...

we are really light cars
those rim width recommendations are an average including mustang/camero/heavy cars.

if you run a really wide tire on a really narrow rim with a light weight car, you won't get the operating temperature that a heavy car would

a tire probe is really the best way to look at your temps
but in using the hoosier recommendations, I'd stay towards the conservative side of the chart.

if they say an xxx wide tire needs a 9-11 inch rim.. you may want to go down in tire size a bit to make sure you are getting enough weight on the contact patch

our cars are pretty decent on tires.
the hoosier tech recommended that I go down from a 225 tire to a 205 tire on my set up due to the weight and extended life I was getting... the lower temps I was getting at the time.



brant