oppositelocksmith
oppositelocksmith New Reader
4/4/22 3:38 p.m.

Need suggestions/advice from the GRM hivemind finding the right tire for my vintage autocross car. 

I drive a 1973 TR6. Drive it very regularly- to work most Fridays, Car N Coffee, will drive it to the Mitty again at the end of the month (about a 1300 mile round trip for me) at the end of the month. 

I also autocross the car as often as family schedules allow (started doing this again last year after some time away from the cones). 

Tires are in need of replacement and the event I drove in yesterday reinforced that fact. 

I need to find a tire in either 205/65R15 or 215/65R15. Wheels they are going on are 15x7 Konig Rewinds. Worth noting that anything wider rubs, and anything smaller in dia and I'll start to get to a clearance issue underneath. I also know I'm not going to find a 200tw in this profile. 

I'm looking for something that will do well in the driving I do regularly, but will not be a total washout like the 11 year old Falkens I have on there now in an autocross. I know if you go for a compromise, you don't do either thing great, but that is Ok. Again, whatever I get is bound to be better than a worn, 11yr old pair of Ziex's. 

Vid below from this past weekend's autocross. 

https://youtu.be/MPQd3ji7ARs

 

Tom1200
Tom1200 UltraDork
4/4/22 4:26 p.m.

In reply to oppositelocksmith :

Can you go to a 60 series tire?

If not I would go with the lowest treadwear rating you can get in that size.

Dusterbd13-michael
Dusterbd13-michael MegaDork
4/4/22 4:44 p.m.

A 235/60/15 is the exact same overall height as your 215/65/15 tire. Its also available in a cooper cobra, which has a relatively stiff sidewall and may have a decent handling characteristic. Ig sure wont be anything super, but its another size option for you and would fit perfectly on that 15x7

Edit: crap. Just saw the wider rubs. Inside, where a small spacer will fix?

Keith Tanner
Keith Tanner MegaDork
4/4/22 4:53 p.m.

In reply to oppositelocksmith :

I had to laugh at this, 215/65-15 is the size I was just hunting down for my Vanagon. I was looking for essentially cargo van tires, though, so the results of my investigatons are unlikely to be useful to you.

oppositelocksmith
oppositelocksmith New Reader
4/4/22 5:30 p.m.

Tom/Michael, your suggestions give me some ideas about messing with the combinations of profile and width to see if there are other tire options out there that fit the bill. Definitely trying to find something in the lower treadwear area. 

As for the rubbing, on the front it hits the wheel arch edges if you go much wider, in the rear, it hits the inner fender well, so I'm burnt on both ends. However, in the rear, that was with some pretty crazy camber that I've corrected with new bushings and mounts. In the front, I installed upgraded axles to eliminate some flex that I was getting, and that may have changed the situation some (not sure of the geometry on that one). 

Keith, you found exactly what I found- numerous tires for family haulers, not much for something that goes faster. 

Dusterbd13-michael
Dusterbd13-michael MegaDork
4/4/22 6:12 p.m.

I ise a tacomaworld calculator i found via google. It takes your stock size and compares it to proposed size so you can see exactly what the differences are according to size.

Its been SUPER helpful in my shennannigans. 

Tom1200
Tom1200 UltraDork
4/4/22 7:20 p.m.

In reply to oppositelocksmith :

Hoosier Speeedsters come in a 205/60-15 but those are $250 per tire and probably not what you want for the road.

JoeTR6
JoeTR6 Dork
4/4/22 7:32 p.m.

You aren't going to like this, but you could move up to a 16" rim.  While the number of tire choices goes down, the larger rim let's you get away with lower profile (and stickier) tires.  On my TR6, I'm currently running a 205/55R16 200tw tire.  At some point we were running a 225 width r-comp on another TR6 with 16s, but it had fiberglass fenders with some of the lip removed and very aggressive camber.  Another problem with 15" rims is that they can rub on the upper control arm depending on offset and axle flex, but you have addressed that issue.

oppositelocksmith
oppositelocksmith New Reader
4/4/22 8:58 p.m.

Michael, I've been using a similar calculator. Super helpful in figuring out what the dims will be of each combination.

Tom, if I could find those in the right size and a 200tw, I'd just almost be tempted.

Joe, I know what you mean about the 15 vs 16. Other owners ask me about my wheels and I always suggest the 16" model. What you mention about the 225 confirms what I was concerned about. I love my wheels, but I'm usually discussing or cussing them. 

The tire with the lowest treadwear rating in a 205/65r15 is a Firestone Firehawk RS -480tw. Has pretty good ratings overall, and even on reviewer on one site that had it on a TR.

 

84FSP
84FSP UberDork
4/4/22 9:19 p.m.

This is my favorite online calculator tire and wheel dimension shenanigans.  https://www.willtheyfit.com/

The trick is to get under the car and measure clearances vs the current setup.

frenchyd
frenchyd MegaDork
4/5/22 8:16 a.m.

In reply to oppositelocksmith :

I use Dunlop vintage racing tires.  Yes I know.  Horror of horrors they aren't DOT rated.  
They are sticky enough but don't fall off  and seems to last a very long time.  Yes I drive them mostly on the street,   they just look right and feel right.  

GameboyRMH
GameboyRMH MegaDork
4/5/22 8:35 a.m.
JoeTR6 said:

You aren't going to like this, but you could move up to a 16" rim.  While the number of tire choices goes down, the larger rim let's you get away with lower profile (and stickier) tires.  On my TR6, I'm currently running a 205/55R16 200tw tire.  At some point we were running a 225 width r-comp on another TR6 with 16s, but it had fiberglass fenders with some of the lip removed and very agressive camber.  Another problem with 15" rims is that they can rub on the upper control arm depending on offset and axle flex, but you have addressed that issue.

The 205/55R16s are smaller in diameter than the 205/65R15s though...the best I was able to come up with was 215/50R17s which has a bunch of "performance all-seasons" available in that size.

Really this car needs to be modified out of the tiny tire size corner it's painted into, nobody makes sticky performance tires with the kind of width-to-height ratio this car is currently running, to say nothing of the amount of sidewall. You need to be able to fit tires with a more modern width-to-height ratio somehow. If 215/45R17s could be fitted to this car there'd be a cornucopia of performance tires to choose from. Those are about 1.5" shorter in height than the 215/65R15s, could the suspension be raised a bit, with spring spacers maybe?

wspohn
wspohn SuperDork
4/5/22 12:21 p.m.

Would 215x60 work?  I run them on one of my cars on 6" rims with offset like the TR6.  Both Vredestein Sprint Classic and Pirelli P6000 are under 200 wear.  Neither are cheap...

JoeTR6
JoeTR6 Dork
4/5/22 12:46 p.m.

In reply to GameboyRMH :

You are correct that 205/55R16s are smaller than 205/65R15s, but they only lower the car 0.3" and the difference at 60 MPH is 1.5.  You are also right that 17" rims open up a larger choice in tires, but to my eye, they look weird on a TR6.  You can buy a set of Rota RB 16x7s from EBay or Amazon for $700 and they should be fine for autocross and street.  The weight is comparable to the Konig Rewinds, just under 17 lbs. IIRC.  But buying a set of 16" rims now may not be as future proof as something larger, so caveat emptor.

Have you considered rolling the fender lips?  This may allow you a slightly wider tire (225?) with some thin spacers and prevent rubbing on the inside at the rear.  I did this to my TR6 before paint, but it may be a concern with older paint.  Maybe someone local has a good tool and the skill (e.g., heating paint to soften it) to pull it off without cracking your paint.

oppositelocksmith
oppositelocksmith New Reader
4/5/22 2:01 p.m.

WSpohn, the 215/60's work mathematically. In addition to the Vred and the Pirelli, there is a BF Goodrich radial TA in that size with a 400tw. I actually had a set of those on the car at one time and autocrossed with them (in 205/65r65 when they made them).

Joe, I looked at the Rotas when I bought my Konigs. I found several sets of the 16x7's on eBay last night. Awful tempting.

I'd consider rolling the front fender edges and for the rears, when I had the hubs made, I had long ARP studs installed to allow different wheels and a spacer if necessary.

David S. Wallens
David S. Wallens Editorial Director
4/6/22 4:14 p.m.

I know it's a bigger investment, but what about two sets of wheels and tires? Could you then run something sticky and shorter for just autocross? 

oppositelocksmith
oppositelocksmith New Reader
4/7/22 1:47 p.m.
David S. Wallens said:

I know it's a bigger investment, but what about two sets of wheels and tires? Could you then run something sticky and shorter for just autocross? 

I like the idea and have one extra set of 15 x 5.5 steel wheels. I don't think a 50 series would fit on them unfortunately.
I'll keep watching the classifieds for a set of 16 x 7's or 15 x 7's.
 

 

VolvoHeretic
VolvoHeretic Reader
4/7/22 2:30 p.m.

Didn't you always want flares? smiley

JoeTR6
JoeTR6 Dork
4/7/22 6:11 p.m.

Two sets of wheels really is the best answer.  That way, you can run a good street tire on the 15s for touring and a wider/taller rim with sticky tires for autocross.  I hated autocrossing on street tires, but also didn't care for running R-comps or even 200tw tires in the rain or cold.  It might sound much more expensive, but both sets of tires will last longer not being asked to do what they are not good at.

FWIW, I'm also looking for a set of street tires to go on stock 15" rims.  So this has been a helpful discussion.

Stampie
Stampie MegaDork
4/7/22 6:28 p.m.
wspohn said:

Would 215x60 work?  I run them on one of my cars on 6" rims with offset like the TR6.  Both Vredestein Sprint Classic and Pirelli P6000 are under 200 wear.  Neither are cheap...

Hope you don't mind but I need a private moment.

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