tire size recommendation Lindsey Fuchs on the way!!

[jsmithcds]

I got me a set of Lindsey RSR finish 17x9 and 17x11’s on the way to me in a few days for my 79SC with flares(non-turbo). Looking for some advise on tire size. I love the look of the 315’s on the back but it sure seems like a lot of tire for the car.

I run the car about 5 track days a year at Road America and currently run RA-1’s (8’s and 9’s) and . I am ok with the wear i get currently while running them for both street and track. Hopefully start running autobahn next summer.

Original plan was to run 245/45/17 and 315/35/17 in either a Kuhmo ecsta xs or a nitto nt-01.

I am now leaning towards the toyo R1R in a 235/45/17 and 275/40/17. Tire is somewhere between the Ecsta xs and the Ra-1. I like the wet and dry traction aspects of the tire.
I also like the 7lbs per tire of weight reduction over the Ecsta xs.

What is the recommendation for tire size. The 275 or the 315 rears for my appliacation?

thanks for your input

Justin
I

[KTL]

Justin,

I run 245/40-17 on 17x8 or 17x8.5 fronts and 275/40-17 on 17x10 rears. Tires have been Hankook Z214 C51 (medium) DOT Rcomp or BFG R1-S DOT Rcomp

My car is a lot like yours. '79 SC with 930 flares. I would like my wheels to be 9 and 11 to stretch my tires out a bit, but I don't find my car wanting for more tire. Actually I get sort of unique tire wear in the sense that my fronts wear as fast as the rears. Normally rears have 1/2 the life of fronts. I have a wide front track with lengthened front control arms and the suspension is a bit too stiff with 500 lb front, 800 lb rear coilovers.

I think a 315/35-17 is a ton of rear tire for a light car like an SC with a moderate engine (no offense intended to your 3.2SS- I have had one too!). You may find it hard to get enough heat in the rear tire and end up with some oversteer.

I'd start with the 275 and see how the car behaves. In my opinion the 275 on an 11 in. rim is a better fit than is the 315. An 11 in. rim is the max recommended width for the 275 tire, whereas the 11 in. rim is typically the min. recommended width for the 315. You want to put the largest allowable rim width you can manage in a given tire size. Not the opposite (large tire width w/narrowest allowable rim).

Toyo R1R may be a nice compromise tire. The NT-01 has better ultimate performance but the Toyo would be a better overall choice for wet usage if you don't want to have two sets of tires. NT-01 (or RA-1) is a pretty solid wet tire. But the tread disappearance with wear will eventually hang you out to dry in the wet.

[Noah930]

I am running 245/275 tires on 17x9 and 17x11 wheels on my stock 930. I don't think it's undertired. I'm happy with the weight savings compared to runinng 315s in the rear. If I had a modded motor, with 100+ more HP, perhaps I would feel differently. But I like the balance I have right now.

[Flojo]

Originally Posted by jsmithcds

I also like the 7lbs per tire of weight reduction over the Ecsta xs.

speaking of weightreduction.
what do 17 weigh compared to OE 15* or 16* Fuchs?

[jsmithcds]

Originally Posted by Flojo

speaking of weightreduction.
what do 17 weigh compared to OE 15* or 16* Fuchs?

The 9" weight 19.25#, the 11" weigh 21.5# for the Lindsey wheels. I am not sure on the fuchs weight.

[jsmithcds]

KTL/Noah,

thanks for your responses. Pretty much the same conclusion I have come to by doing a little searching. Several of the other posts I have come across have included responses from both of you.

I currently run the RA-1 and like the tire alot at the track and it behaves well on the road. That being said when it rains...... I stay home. Hence the tough decision between the Kuhmo and the NT-01 in the 315 flavor.

The 245/275 gives a good deal more options like the R1R's which is a combo tire that may be worth a shot.

thanks for clearing up the size issue. KTL Wrote, "You want to put the largest allowable rim width you can manage in a given tire size. Not the opposite (large tire width w/narrowest allowable rim)."

This was my biggest concern as I was unsure. I would imagine one must just steer clear of the curb.....

Thanks for info guys. Much appreciated. I will let you know my impressions of the R1R when I get back to the track in Oct.

Justin

[wildcat077]

Can you safely fit an 11 inch rear wheel on a car with sc flares ?
I trial fitted some 275/40/17 R888's on my rear 9 inch Fikses but an 11 inch wheel on a non turbo flared car,isn't that very tight ?

Just curious ...

Cheers
Phil

[jsmithcds]

The car has turbo flares on it. I have had Kinesis 11's under it before with 315's on it.

It was tight but it worked.

[Mark Mcgarry]

The 315s just give the wide body the right stance....

[jsmithcds]

anyone have any pics of a 275 on an 11” rim or the 245 on a 9 inch? The Lindsey Rims shipped today. need to get the tires figured out. I am back to the r888’s or the nt-01’s. After some thought I am thinking to get a set of of tires for my 16x8 and 16x9’s for the rain day occasions. want to make sure they tires don’t look crazy stretched.

[JeremyD]

Here's 235/275 RA1's on 9's and 11's




[True Designs]

[jsmithcds]

that look does not scare me? Impressions on the difference between running the 275’s and the 315’s on the track? Btw the look of that car with the 9 and 11’s was one of 2 cars that persuaded me to spring for the widened wheels…..

[175K911]

I'll agree with Kevin- the 245/275 combo is plenty of tire for your weight and engine. I'll be running 295/35 Hoosier R6's on the rear and that's about all the tire the car needs. Local friend who's a pro racer and has a race shop runs the 315's on the rear of his wide body but he's also got a wicked fast 2.2L turbo engine that puts down lots of power on the track. Can't imagine getting any use out of a 315 for the street other than looks.

[JeremyD]

I had trouble getting heat in the tires with the 2.7 - even the 295/235's - with the 3.6, especially the Mike Bruns edition - I don't have that issue anymore, even with the 315/255 combo.

I could probably even go 275/315 next time. Of course Sebring is a fast track and it's over 80 degrees there (and around 90 on track) around 80 percent of the time I run there.

[Noah930]

I think the 275s (Nittos) look a wee bit stretched on an 11" rim. But I liked the sizing enough (from a performance perspective) that I stuck with it when it came time to replace 'em. I didn't want/need the heavier 315s.

[jsmithcds]

thanks for the pics guys. I ordered them up....

Justin