Rusty knuckles
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So got my new tires and wheels in. Mounted the fronts and really am excited they don't rub. 275/50-15 front tires.
69 Charger on the autocross
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what brand/model tires?
Rusty knuckles
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Nitto nt555r2's. They're advertised as a drag radial but there's a lot of discussion on various forums that they actually handle quite well and they are very sticky. Keeping the muscle car look and feel is important to me. I could have gone with 17 or 18" wheels and made my life so much easier to find good cornering tires. But I want it to still be true to a classic muscle car. Ultimate performance is secondary to me. But I do enjoy tweaking and trialing on a budget. The wheels and tires are going to be the most expensive single change I make on the whole car.
So we'll see on Sunday what it's like and I'll share what I learn.
I run the Nitto 555R's for my rears. The 555R2's have a stiffer side wall and I want to get those next for my rears. You're the first person I've heard of running 555R2's on the front. Usually people run the normal 555 up front instead. Let us know how the drag radials behave up front for you.
Rusty knuckles
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I took it for a quick drive yesterday and all indications are that it won't rub. We'll see under race conditions if that changes. But I'm about 95% sure it won't at all. It certainly didn't just in my short drive and I was trying to get them to bounce into the fender by hitting bumps while turning hard.
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I have 275-40-18s on a 9 inch front wheel. Mine only rub at the frame rail behind the wheels.
Old picture...but the new tires I have are the same size.
Old picture...but the new tires I have are the same size.
Rusty knuckles
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Your tires about an inch taller than mine and I believe you have a 4-3/4" backspace right? Your setup helped convince me the 275s would fit before I ordered mine. But my fronts are 15x8 with 4.5" backspace. So it's certainly tight!
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The larger diameter of the 18" wheels does allow a bit more back spacing to help clear the fender.
Yes, I am at 4 3/4" back spacing.
How about some pictures of yours?
Here are 255-60s on a narrow 15 x 7 wheel:
Yes, I am at 4 3/4" back spacing.
How about some pictures of yours?
Here are 255-60s on a narrow 15 x 7 wheel:
SlinktRR
Well-Known Member
Squared 555R2's at 275/50 r15 may be the ticket let us know how your times improve. I'm thinking it will be significant. I'm not excited about a 26" tall tire but the handling would be worth it while still using 15" wheels.
Rusty knuckles
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So here's what they look like. At full lock static (obviously) I have about 3/4" clearance between the tire and anything it could touch like brake lines or frame.
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Rusty knuckles
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Finished up putting them on. Had to get longer wheel studs to get more lug nut engagement. I don't think she looks too bad though a taller and wider tire in the back would look better but this is a happy compromise for me.
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You will rub here once the tire flexes in the turns but nothing to worry about. It is just rubber against smooth steel. I rub right there on my car. Deeper back spacing and a wide tire with me.
Your car looks good. I'm happy to see others having fun with their cars.
Rusty knuckles
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You think so? It looks a little tighter in the pic than it is. I can pass my fingers between between the tire and frame. We shall see I suppose. I almost never turn full lock anyway and certainly not during the autocross so like you say I'm not concerned.
SlinktRR
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Rusty knuckles
Well-Known Member
Ok results time....
The course was longer than usual at about 60sec average. It was also very tight and technical. Several hairpins and even a 270 all of which are my car's weaknesses.
Only the faster of the 2 guys I'm comparing against showed up. That said he ran 57.293 fast lap and I ran 63.295 (with a passenger). So on a 20% longer course I still gained 2 seconds with just these tires. On a shorter course it would be an even closer gap. This puts me just under mid pack of the cars today.
As far as rubbing. I think I'm going to order 1/8" spacers. Course was hard left turn heavy. My tires never touched the frame but appear to have just barely touched the tie rod end. Also because I must not have gotten my wheel studs fully seated the wheel actually contacted the upper a-arm. Tightening it back up fixed that. So I think a very small spacer is all I need.
Tires performed great! They are still a 15" tire but wow do they stick. I ran them at 40psi. This was perfect in the back. Front needs about 45 I think. Fronts were rolling over more. After my first 4 runs rear psi had come up to 43. Fronts were at 45. My fastest lap was my last one with a passenger. I was pushing hard, almost felt overdriving it but the tires just took it. The whole day I drove in every corner deeper, braked hard, was on the throttle hard. Very happy with the performance. Balance is still good. Might be just a bit tight up front. But not heavily so.
My next upgrade is going to be a seat that holds my butt in place because it's kind hard to drive when you've skittered over into the buddy seat.
Also a note on brakes. The ole drum brakes have gone from sufficient to merely adequate now. I can't lock them up anymore. And the fronts were getting pretty warm. No brake fade but I need to get more bias to the rear and consider disks. But that's a long ways off.
The course was longer than usual at about 60sec average. It was also very tight and technical. Several hairpins and even a 270 all of which are my car's weaknesses.
Only the faster of the 2 guys I'm comparing against showed up. That said he ran 57.293 fast lap and I ran 63.295 (with a passenger). So on a 20% longer course I still gained 2 seconds with just these tires. On a shorter course it would be an even closer gap. This puts me just under mid pack of the cars today.
As far as rubbing. I think I'm going to order 1/8" spacers. Course was hard left turn heavy. My tires never touched the frame but appear to have just barely touched the tie rod end. Also because I must not have gotten my wheel studs fully seated the wheel actually contacted the upper a-arm. Tightening it back up fixed that. So I think a very small spacer is all I need.
Tires performed great! They are still a 15" tire but wow do they stick. I ran them at 40psi. This was perfect in the back. Front needs about 45 I think. Fronts were rolling over more. After my first 4 runs rear psi had come up to 43. Fronts were at 45. My fastest lap was my last one with a passenger. I was pushing hard, almost felt overdriving it but the tires just took it. The whole day I drove in every corner deeper, braked hard, was on the throttle hard. Very happy with the performance. Balance is still good. Might be just a bit tight up front. But not heavily so.
My next upgrade is going to be a seat that holds my butt in place because it's kind hard to drive when you've skittered over into the buddy seat.
Also a note on brakes. The ole drum brakes have gone from sufficient to merely adequate now. I can't lock them up anymore. And the fronts were getting pretty warm. No brake fade but I need to get more bias to the rear and consider disks. But that's a long ways off.
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nice.
Wow, that's some high tire pressures, especially for Nitto 555R's. I usually run 28 psi on the street, which was determined using thread chalk method. I may try to up my tire pressure for street use into the mid-30's and see how it does.
Rusty knuckles
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You can run them up to 50. On the street or for drag racing yeah I'd stay lower. But I'm battling extreme side load and psi helps that. At the expense of total grip yes but it is hard to explain just how hard these tires stuck. They are a little slow to respond when you change direction (duh, it's a 5.5" high sidewall) but after a few runs I gained more and more confidence, make the turn, do it hard, the tires will hang on.
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