33IMP
Well-Known Member
"not intended for street use" does not mean not legal for street use. Its got a dot, its legal. If it said "for racing use only" and DIDNT have a dot, then illegal.
Am I wrong?
Five year old article on the "15 inch tire problem"
- Thread starter MRGTX
- Start date
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Am I wrong?
gzig5
Well-Known Member
I’ve got a ways to go till I need them but I was considering trying a set of these vintage race radials. If they grip I don’t care if I replace them every couple years. Sizes are limited but there are other options.
Michelin TB 5 | R Medium Compound | 18/60-15
Michelin TB 5 | R Medium Compound | 18/60-15
Interesting find.
It doesn’t look like they make a narrow enough option for the front of our cars. Did I miss a size that would work?
Because of the geometry at play, 15x8 wheels aren’t going to work without a negative backspace and some fender mods…and boy would that look goofy. So I’m thinking something 9.5” wide (or a 235ish) would be about the widest we can do.
gzig5
Well-Known Member
I'm pretty sure if you look around, there are other brands or models that may fit. I know there are a lot of different vintage race cars still out there that would use a smaller size. Maybe one of the forums that support that group would be a good resource? Not going to be cheap though.
I certainly hope you are right but many of us have been looking around for years. If you know of something, that would be welcome information.
autoxcuda
Well-Known Member
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So you are looking for a specific size.
225/60/15 or 235/60/60 correct ?
They used to make V-rated stuff in those sizes, specifically 225/60/15 for 80’s and early 90’s Police and Highway Patrol car fleets. Diplomat, Mustang, Crown Vic, and Impala cop cars of that era all used that size.
that’s a lot of fleets, lots of miles, lots of tires.
Now those are hobby cars.
Stock late 80’s Mustang 5.0 and Full size Jag’s come to mind as using 225/60/15. The first tires I bought for my 68 Barracuda with 15x7 cop rims was a used set of Yokohama AVS off a 4-door Jaguar
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Topless69
Well-Known Member
Any size 215/60/15 to 275/60/15 or even 255/50/15 to 295/50/15 would work for me, and that’s about the same size 15’s we run anyway.
But I’m getting to where I resign myself to the idea that I’ll only find sticky tires if I move the rim size up to 16’s or bigger.
Personally? Yes. I am looking for 225-235/60/15 but any non-drag radial with 15” diameter and any kind of performance intentions is very interesting.
In reality, I would love to buy them if they come along. I’ll always hold onto a set of 15 inch wheels for my Dart but I’ve given up and ordered some 17” Torq Thrust wheels that are supposedly on the slow boat from China. Fronts are 17x8 +25, rears are 17x8 +8mm.
Obviously the 8” width isn’t going to allow for maxing out the tire size but they’re cheap, relatively light, replaceable if one gets bent, and I have an idea to make them fit the aesthetic of my car. I think they’ll work out well.
Once I get those in hand, I will probably be ordering Toyo Proxes R1R 245/45/17 front and 275/40/17 rear? Maybe 255s. I’m never going to be crazy about running 17 inch wheels but having a 200 treadwear tire is something that I’ve dreamed about for years.
Anyway, those 15” V rated tires you mentioned would be superb compared to what is out there now. So strange that they’re all gone. Does it mean we’re getting old when all of those cars dont seem all that old?
goldduster318
Overzealous Car Modifier
in a 17, an 8" wide rim you'd want to go max 255, and even that might be much. I used 245s on another vehicle with an 8" rim that came stock with 235s and it was fine.
Honestly for anything high effort, you go 18s because the tie rod fits inside the wheel.
Honestly for anything high effort, you go 18s because the tie rod fits inside the wheel.
You are certainly right that the biggest possible tires are available when you get to 18” diameter wheels. @72bluNblu and a handful of you guys have demonstrated that with impressive results. I’ve toyed with the idea of following this path, even strongly considering my own set of RPF1s inspired by Brian’s amazing Duster/Demon. It just never quite felt right to me for my vision.
I guess when it comes down to it, I’m willing to not be absolutely optimized in terms of contact patch. Of course I want a good wide tire but so long as it’s a legitimate performance tire with a sticky compound, I don’t believe the extra 15mm of rubber would make that much difference to the driving experience. In fact, the extra steering effort and tramlining with ~295s would exacerbate the unlovable characteristics of my 16:1 manual box and 5 degrees of caster combo.
So, to me the extra grip isn’t quite worth the extra weight, extra cost, extra mods, drivability penalties…and aesthetics that push the car even farther from my vision.
Also, my performance bottlenecks will almost certainly be steering and chassis related at this point. The car has upgraded torsion bars, control arms, springs, etc. it also torque boxes and subframe connectors but it’s not caged. That extra grip is just going to push against other built in limits that I have yet to address.
As for 17” fitment issues, from what I gather from 72Blu and others, 17x8” wheels typically don’t have tie rod interference issues if you are at 5.5” backspace or less. Of course the less backspace, the skinnier tires (since fender clearance becomes a problem). So if one was satisfied with 245s, there shouldn’t be much trouble fitting wheels to accommodate this. Corrections are welcome but I’m pretty sure about that.
With 17x8’s and 5.5-5.7” backspace you should be able to pull off 255’s up front if you want. They’d be tight everywhere but as long as you’re willing to do a little rolling or trimming if needed they’d work. It’d be a ride height and individual car thing. And I don’t think that the difference between 255’s and 275’s would be super noticeable for anything much less than all out competition.
Unfortunately even the selection in 17” isn’t what it used to be. Heck even selection in 18” isn’t as good as it was when I bought my RPF1’s. I mean, there’s still options but especially for 295’s the choices are getting pretty small.
On the chassis I don’t think that cage is necessary. Again, maybe for all out competition it would make a difference but on the street it’s not gonna make a handling difference. I’m running 275’s and 295’s with a 200 tread wear compound, 1.12’s and Hellwig sway bars. I’ve got subframe connectors, torque boxes, j-bars and a tubular radiator support brace and the chassis feels rock solid. Now, with my Challenger, 275’s all around, no chassis reinforcement and some rust I sure as heck could. That girl would start feeling spooky when you pushed her on the street, I could tell the stuff between the suspension points was moving around. But the challenger had structural rust so that’s a different story.
Unfortunately even the selection in 17” isn’t what it used to be. Heck even selection in 18” isn’t as good as it was when I bought my RPF1’s. I mean, there’s still options but especially for 295’s the choices are getting pretty small.
On the chassis I don’t think that cage is necessary. Again, maybe for all out competition it would make a difference but on the street it’s not gonna make a handling difference. I’m running 275’s and 295’s with a 200 tread wear compound, 1.12’s and Hellwig sway bars. I’ve got subframe connectors, torque boxes, j-bars and a tubular radiator support brace and the chassis feels rock solid. Now, with my Challenger, 275’s all around, no chassis reinforcement and some rust I sure as heck could. That girl would start feeling spooky when you pushed her on the street, I could tell the stuff between the suspension points was moving around. But the challenger had structural rust so that’s a different story.
goldduster318
Overzealous Car Modifier
I think the most choice tire size you get is 245/45-17 and 275/35-18 that fit these cars.
67charger383
Well-Known Member
You can pick up a set of Pro Trac 60 tires.
The '70s classic Coker recently started making again.
The '70s classic Coker recently started making again.
goldduster318
Overzealous Car Modifier
Those are Bias ply. It says right on their website:
"Pro Trac tires are perfect for your Pro Street, street machine or hot rod, thanks to a super wide profile that offers the race ready look without the safety concerns of driving on the street with actual racing slicks. Protrac tires are DOT approved, bias ply tires and they're perfect for a car that is mini-tubbed. The tread pattern has been thoroughly tested to ensure safety in dry and wet conditions. Street machines are making a big comeback, so put your ride back on the road with a new set of BIG Pro-Trac tires. Check out the front runners, too!"
They're made for a look. What's the treadwear? Temperature rating? Speed Rating? Sounds like they're for show poodles.
33IMP
Well-Known Member
Yep, show poodle tires.
I had a pair of the original pro trac "performance" tires. Turned a 11 second car on slicks into a high 13 second car. Terrible tires then, I suspect no better today.
Want big traction tires for your tubbed car? M/T et street bias, or Hoosier quick time Pro. If you must have tread, Hoosier quick time.
Not doubting this for straight line grip but these aren’t, as far as I know, suitable as front tires and are not built for lateral loads.
33IMP
Well-Known Member
Most tubbed cars aren't built for lateral loads. Mine has 165x15s on the front, and 18.5/ 31x15 ET streets in the back.
The only turning it does is onto the turnoff road. And into the in-n-out drive thru. ( Edit: legendary local hamburger joint, double-doubles, four x four, and ten x ten, yep, ten patties)
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Right, but the whole thread is about the lack of 15" tires for HANDLING performance. As in, lateral loads on the front tires. Not a drag race only tire thread.
And there are a ton of pro-touring mopars that are at least mini-tubbed.
33IMP
Well-Known Member
Agreed. But it was asked if the protracs were "show poodle" tires or not. I just offered my opinion, and personal experience.
33IMP
Well-Known Member
Found a few A/AA 200 and 100 tread rating 15" tires, on summits site. Trouble is, they are all SHORT, you know, for handling?
Yeah, most of them are for miata's, which is why you see the 225 width a lot with a 23-24" height. The 275/50/15's that are available won't fit up front either, unless you're doing your fenders dirt car style. And most are track only, they're not street tires by any stretch of the imagination.
Hence, the reason for this entire thread. DOT legal, actual street runnable 15" handling performance tires aren't made in a useful size for these cars. Which is why I run 18's.
As for the "short" thing, F1 cars still use 13" rims (changing to 18" this season allegedly). You can make a taller sidewall work for a handling car, it's simply about tire design. The only reason a 245/55/15, or a 235/55/15 or 235/60/15 doesn't exist in a 200 AA/A is demand and cost. The reason those shorter tires are available has nothing to do with a shorter tire handling better, it has to do with the demand created by all the damn miata's that are used on the track. And you're not gonna get a 25.5" tall tire on a track going miata.
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