What tire size to pick?

Spaniard · 10-14-2006, 08:05 AM

Ive got 15" x 6.5 rims for roadcoarse... Ive been running 225/50/15 sticky street tires but I am now ready to bump it up to Toyo RA-1

Im not sure if I want to go with 225/50/15 or 205/50/15.

Is it worth the slightly larger patch on the 225's, or is it better to have the tire width more lined up with the rim. I gotta say the 225/40/18 Kumho MXs on my 18x7.5 rims are AWESOME so Im actually thinking 205's to get them more sure-footed rather than a bit sloppier and wide.

Whatcha guys think?

Cheers-

gdmaxse · 10-14-2006, 12:27 PM

Id go with the 225 50 15, because you will lose a lot of top speed with the shorter 205 50s and they will not have as much grip in the corners. i have 225 50 15 kumho 711s on 15 by 6.5 and they respond pretty well as long as i pump them up to 45 psi in the front. any less than that and they feel too soft and do not transition well. for autocross the 205s might be better for gearing and response but roadcoarse you should be better with 225s. also they will handle the higher heat of the roadcoarse heat better. one other thing you should look at is the load rating of 205s, they tend to be around 88 for 205 50 and the stock load rating is 94 so they may not stand up to the weight of the car as well.

*98SEBlackMax* · 10-14-2006, 04:38 PM

Quote:

Originally Posted by Spaniard

Ive got 15" x 6.5 rims for roadcoarse... Ive been running 225/50/15 sticky street tires but I am now ready to bump it up to Toyo RA-1

Im not sure if I want to go with 225/50/15 or 205/50/15.

Is it worth the slightly larger patch on the 225's, or is it better to have the tire width more lined up with the rim. I gotta say the 225/40/18 Kumho MXs on my 18x7.5 rims are AWESOME so Im actually thinking 205's to get them more sure-footed rather than a bit sloppier and wide.

Whatcha guys think?

Cheers-

I have been running 225/50/15 Toyo T1-S on I30T BBS wheels (15 x 6.5) for two seasons now and for what I paid there pretty decent. The rims were out of a junkyard and the Toyos weren't to expensive considering the mileage I got out of them, also the total weight combo was a paltry 34 pounds when new. They grip quite well and your remarks about them convinced me to go with the Toyos.

However im sick of the sidewall rolling over on hard corners, even with the air pressure pumped up. I've actually scraped off a good deal of the sidewalls, not that it's becoming dangerously thin, but enough to know there's ALOT of sidewall roll.

Im due for new tires next season. If I was to keep the 15s I would go with the 205s with a R compound tire to make up for the lost grip of street 225s. Right now my car is setup with a stiff chassis, stiff suspension and some what soft tires. Next year the suspension is going to be dialed back and the chassis is going to be alot stiffer. Im thinking of trying a thinner/stiffer tire to make up for the softer suspension, if that makes sense.

Also have you considered Nitto NT-01? I was reading a review on a BMW forum and with the Nittos they were 2 seconds faster around Buttonwillow, however they did not mention their previous tires. Rumor has it these are Toyo R888 in disguise, only difference is the tread pattern. For 15s they are only available in 205/50/15 and 225/45/15.

Next season Im debating going with a Nitto NT-01 or Toyo RA-1 but with some 235/40/17 tires on Enkei RPF1 rims. But that's a $1800+ investment that are only going to be used on track days so keeping the 15s is tempting.

Edit: Using the tire calculator 205/50/15 is insanely small, 225/50/15 is an already tiny tire as it is. Now knowing that Im prob gonna hold out for some 235/40/17s...

Spaniard · 10-15-2006, 02:26 PM

Quote:

Originally Posted by gdmaxse

Id go with the 225 50 15, because you will lose a lot of top speed with the shorter 205 50s

Does this apply to roadcourse? Im not sure how it would; can you please elaborate?

Thanks for the posts guys-!

gdmaxse · 10-15-2006, 05:08 PM

on a fast roadcourse you could be geared to high and be redlining on the straightaways. i wouldnt use that tire on autocross either because it would require a shift into third gear. i am usually right at the top of second at the fastest parts of autocrosses around here. on top of that it has a smaller treadwidth. i would rather have a slightly sloppier tire with more overall grip that doesnt require more shifting.

gdmaxse · 10-15-2006, 05:36 PM

although, i had been considering both a 225/45/15 ra1 and a 23X10X15 slick, both of which have the same gearing as the 205/50/15.

so try that tire and tell us how it works for you

*BEJAY1* · 10-15-2006, 06:44 PM

I gotta jump in here. You guy's running 6.5" and similar narrow rims are really overdriving and flexing your sidewalls. A 6.5" rim for hard cornering really shouldn't even be supporting a 205 tire let alone a 225 one. The Maxima is a 3000lb boat which needs at least 225's in front if not 235 or 245's.

GRM states you want your rim width to tire section width to be 85% or higher.

Hoosier states you want a rim width approaching equal to tire tread width.

Even on a shoestring budget you can find some of those 300ZX rims around.

Spaniard · 10-15-2006, 07:27 PM

Glad to have you jump in BEJAY.

Going from 225/50/15 sticky street tires- which needed very high pressure until I got the k-sports coilovers.. I think 205/45/15 or 205/50/15 would be better for Kumho RA-1 than 225/50/15.
Going 225/50/15 with racing rubber probably would get me back into needing more tire pressure than I want as well as scrubbing the outsides of the tire again.

(A side note, ive gotten my maxima down to 2800 lbs, though its not a big difference, Im still kind of proud of it and so tend to mention it ;-)

*michaelnyden* · 10-16-2006, 10:30 AM

what have you taken out to hit 2800lbs...? have you kept a log or remember specifically what?

Spaniard · 10-16-2006, 08:12 PM

Quote:

Originally Posted by michaelnyden

what have you taken out to hit 2800lbs...? have you kept a log or remember specifically what?

Well, the caveat is that it is track weight...

starting from 3001 lbs

Credit: http://lighter.maxdes.net/

Aftermarket y-pipe (15lbs)*
UR or RVM UDP (3lbs)
Aftermarket Cat-back (5-10lbs)*
Remove Carpeting, cardboard, and everything else in trunk (6lbs)*
Remove plate behind back seat (6lbs)*
Remove Sound deadening under hood. (2lbs)*
Aftermarket Cat (2lbs)*
Aluminum Flywheel (15 lbs)*
Swap stock seat for ultra light racing seat (20lbs)
Coilovers (40 lbs)
Remove Jack (4lbs)*
Remove Metal piece that holds jack (2lbs)*
Remove Spare Tire (May be included in stage one, if not afraid of flat tires.) (28lbs)*
Remove Heat Shielding for exhaust system (8lbs)*
Remove Back seat (30lbs)*
Remove Passenger Seat (40lbs)*
Wheels and tires - 28 lbs
Remove all seat belts accept for driver (10lbs)*
lightweight battery - 35 lbs
cf hood 40 lbs

total = 338 (give or take a few)

Add:
FSTB - 5
RSTB - 5
Rear Sway bar - 15 lbs (?)
Blehmco stage 2 - 10 lbs(?)

*98SEBlackMax* · 10-20-2006, 07:32 PM

Just pulled a piece of wire out of the sidewall of my Toyo, right where the tire wears the most. The good news is the tread is near the wear bars and it was on the rear of the car. It felt funny driving home from the track tonight to, luckily I got home safely.

Well now Im going to have to get another set of track tires or buy two 225/50/15 Toyo T1-S if anyone has them left.