Vintage Tyre Q?

[gtgroupe3]

I’m hoping to have my ’67 911S (Alan Johnson inspired) on the road this spring. I plan on using unfinished early deep 6" Fuchs “.06” (have 6, 4 on, 1 spare and 1 backup). I’m looking for some input on vintage tyres, regarding to performance and usability (wet/dry/street/track).

Goodyear Blue Streak (5.50-15, G-12 or G-7)
Michelin (XWX or TB15)
Dunlop SP (550 L15 CR65)
Or any other avalible tyre (Avon?)

Thanks, Sumner

[boxster03]

I have just seen a nicely redone ST/R with period Dunlop 5.50 tyres. they sure did look nice.

[Chuck Miller]

Sumner,

Take a look at this:
https://www.rsracing.com/rscatalog/a.../rt-dotsrb.asp

I know allot of vintage race guys who are on these... kind of the old look, with new compound tech... they are bias though

Hope this helps,

Cheers,

[hgarazo]

The Bruce Jennings 1967 S car in Excellence this month runs the Goodyear Blue Streak. There are some nice pics if you want to see how they look.

I really like these Dunlops on "GaryZ" 's car - best vintage look, IMHO.

The other is "Matt911" with a 1969T. "The wheels are 6's on the front and 7's on the rear. Tires are 195/65 & 215/60 respectively. No rolled fender lips."

[JohnT]

Most of what's available is dear.

The Goodyear 5.50 G12 is pretty big. This is for 'A' sedans, GT350s and the like. 5.00 X 15 G12's would probably fit. The G7 is a very low profile, sticky tire. The OD is around 22", if I remember correctly. The guys that use the G7 talk about 1 race weekend for tire life.

An XWX from Coker would be a very traditional tire for a late 60s car. I had 205 X 15 XWXs mounted on my 275 GTB and got around 15,000 miles (including a few races) out of them. I expect a 165 X 15 or 175 X 15 XWX would look very period correct. I suppose a 185/70X15 XWX has more tread width and about the same diameter. These tires are not racing tires though.

Sometime you can get Yokohama AO48's at Tire Rack. In a 205/60-15 size these have a lot of grip. They're a big tire though and you may or may not have room for these with a "slab sided" car. I made room for them by removing the front shock absorber dust covers. Then they only rubbed on full lock. The fastest times my car has ever produced at Sears Point, Laguna Seca, and Thunderhill were on a set of AO32S Yokohamas.

Hoosier makes a bias ply, 5.50 X 15 Vintage TD that fits. The guys that race with Steve Earle at Monterey use this or the Goodyear G12. These are about $190 each.

Dunlop 'L' series tires were about $300 each the last I looked. This is a classis racing tire built for 4 wheel drifts and big forearms. I have a friend who runs 5.50 X 16 'L' series tires on his 250 Testa Rosa and likes them. 1) He's a traditionalist & 2) his tire budget could swamp my racing budget!

Hoosier also makes a Vintage Racing Radial, the "Speedster". I use the 205/60-15 size Speedster and like it. It looks like I can get about 10 race weekends out of a set (maybe I'm not going fast enough?) and unlike the Yokos, they are very well mannered. They give a lot of warning before breaking away. At about $150 each the Speedster is the cheapest tire in this discussion.

johnt

[CurtEgerer]

I'm thinking about giving these Avon CR6ZZ tarmac rally tires a try. I have no idea how these will wear on the street, but I love the vintage look. That, and it's one of the very few tires available in the correct size. These will go on 7" Torq-Thrust D's. So I'm going to try 215/60 all around (identical 25 inch dia. to the original 185/70 - using 70's on 7 inch rims just stretches the tire a bit too much). They're around $275 each, so not exactly cheap.

[JohnT]

But at $260.00 each (Roger Kraus Racing price) they're not cheap!

Many of the Vintage Formula and Sports Racer drivers I know use Avons. With the exception of the CanAm cars most of these cars are very light and cannot generate enough heat in a radial ply tire so they use bias plys. 911's and 912's weigh enough that the bias ply Avons won't last more than a weekend.

johnt

[CurtEgerer]

This particular Avon is made for vintage tarmac rally cars, like the 911 - it's got to have a fairly hard compound. Or maybe not?

[JohnT]

Not bias ply. The Yoko's I mentioned above were originally European Vintage Rallye Tires for the tarmac stages and they lasted me about 2 seasons. After that there was still tread, but the number of heat cycles had rendered it pretty hard.

Looks like there are at least two tread compounds. Pick the harder one. The softer is probably only suitable for autocross or a single tarmac stage (after all there are high budget teams in Vintage Rallyeing too).

johnt

[gtgroupe3]

I haven’t been able to find XWX 205/60 15’s only 70’s, which are a bit too tall. I’m a life long Michelin abuser, habit started with a ’67 TR4A IRS. Unfortunately, the only Michelins I have laying around (235/40 18, PS2) on BBS REs, which may have fitment issues and could be considered not period correct.

Then again I could cut the flares off a ’76 turbo and create a mutant ’67, Unique Whips meets Early S registry/RrrrrrGroup with a slant nose front clip. I digress, too many hours inside the beltway.

My next choice would be Avon’s; I was looking at the CR28 sports (wets), but too short (50’s). I just had the rear quarters “homemade” flares returned to slabs. So I really don’t think the 215 CR6ZZ’s will fit it the wells when it’s properly set up….or we could go with the period Dunlop’s.

I’m now in the Goldilocks Paradox (versus Pascal’s), too short, too tall, too wide……

I’ve been using the original Road and Track (APR ’68) article “An Amateur Champion’s Porsche and How it got that way” as a reference for the build and the tyres are clearly G-12 (25.5 dia) or G-12 A (24.9 dia) Blue Streaks, probably the G-12As on very nice and rare American Racing Torq-thrust Mg+ Wheels. Bruce Jennings ‘67S looks great on Blue Streaks.