John, the new set-up weighs 47 lbs. per corner. 3 lbs. less than my OEM fronts, and 5 lbs. less than the rears.

Yes, 265's would work, but I thought a tad narrower would help stiffen the sidewall. 245's would be even better , but I didn't want to lose "Rim Protection" from ........curbs!

ALong, I thought about going with 40 series tires, but I chose to stay close to OEM diameters.........for now.


I will see how it works Wednesday at Blackhawk Farms!

 

Well, I'm going to try and make it up for the event on 5/15. I can't confirm just yet, as I may have the car in the body shop then (I had an argument with a concrete pole in my parking garage this morning). Do you have registration info available?

 

I just had a set of Toyo RA-1s installed by Radial Tires today: 245-40/18 all the way around. I decided that since I've always had an understeer problem on track, I'd go with no stagger and see what it's like. Also, I like the idea of being able to rotate all the tires, since, as John mentioned, I've been wearing the fronts faster than the rears. (Unlike John, I'm running the stock suspension.) Finally, if I had gone for the 275-40/18s in the back, the speedo/odo would have been 4.1% off. As it is, it'll be 3.6% slow.

This week is my first Friday at the Track as an instructor candidate, so I'll have a report for you all on the weekend about that and the tire performance. I think I only get two sessions in the day, so not a tremendous amount of testing time.

Just to remind anyone who's interested (and because I feel like griping about this again), the RA-1s replace the Bridgestone S-03s that I put on back in October and that I wore out in 4,500 miles and 10 track days! [sarcasm] That was $1,000 well spent! [/sarcasm] I hope the Toyos last longer. Or at least perform a lot better.

Since someone mentioned it earlier, can anyone tell me what the symptoms of boiling the power steering fluid are? (I know all about boiling brake fluid, thanks.) Racers on another thread are talking about coolers for the power steering, the oil, and the LSD. Is boiling the steering fluid a big problem in non-racing track events?

John: Deer, foxes, various other critters, and now a concrete pole? Ouch! Sorry to hear about that.

 

Let us know how those RA1s work out. Did you get them shaved and heat cycled? Good luck with your student... hehe...

Since the stock rear size is 245/45: 245*.45 = 110.25 and 275*.40 = 110. Should be the same, no speedo difference.

Pure talent on my part...

 

John: I got 245/40-18s all the way around, not 275/40-18 on the back. Not shaved or heat cycled.

And according to this site, 275/35-18 is an exact match for the 245/45-18s on the rear, and the others differ as I outlined above.

 

You sure you calculated it correctly? Says 245/45 and 275/40 is a 0.1% difference. And yes, I know you got 245/40s all around... Enjoy your track day...

 

I think he calculated wrong, this is also from that same website, bottom calculator:
Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
245/45-18 4.3in 13.3in 26.7in 83.8in 756 0.0%
275/35-18 3.8in 12.8in 25.6in 80.4in 788 -4.1%
275/40-18 4.3in 13.3in 26.7in 83.8in 756 -0.1%

 

Hehe... 10 track days is a lot!

I'm getting about 4-5 days out of each $1000 set of Hoosiers. But man, those lap times are great!

 

I actually put 275's on the 9" rim and they seem to fit really well. There is no bulging. They look just like the stock 245's on a 8" rim.

 

Oops. I got it backwards. The size the RA-1s come in is 275/35-18 (which is 4.1% off), and as you pointed out, the precise match is 275/40-18.

 

Just treat the smaller rolling circumference as a bonus to your final drive ratio...

How was SP?