so I have 255/60/15 street tires on outlaw II rims with 3.75" backspacing. I have a nice new 331 engine in so I want better tires for the track. I know with 4"+ backspacing I can fit 275/60/15 in there which would be 28" tall tires. Would it be better to go with 255/60/15 since it'll be 26" tire for the track? I'm thinking 255/60/15 mickey thompson ET streets which I can get for $180 from summitracing each.
The ET Streets are nice, but I would save them for track-night only. I have driven on them a couple times in town. They feel kinda weird. I keep a set of ET Streets on an old set of 15x8 AR aluminum rims. Rim and tire weighs next to nothing. Never run them at the track, but I bet they will be NICE.... I am pretty sure if you run M/T ETStreet 10.5X26 you will have no problem fitting them under your car if you don't use a really odd rim B/S size. Mine were pretty much identical to 245/60r14 BFG T/As in size and width. I had plenty of clearance.
should I get 4" or 4.5" backspacing on the rims? I think I'll only drive on those tires to go to the track and race and back home. I won't be driving with them around town.
The MT 255/60/15 Drag Radials are what I run. I run a 4" BS, and have no issues. Haven't really driven with them on the street any, so I can't help you there. Seem to hook ok though. I fought inconsistent 60 ft's the couple of times I took it out at the end of this year...and if I don't see drastic improvement at the first few T&T's next spring, I will be switching back to a regular slick. I kind of feel like my issues are new car bug related though...so, I'm not ready to ditch them just yet. At the tracks I run at...I HAVE to be able to repeat to be competitive. I've still got a lot of testing to do with pressures and cal-trac settings before I find what's optimal...COME ON SPRINGTIME lol...
The 26" tall tire vs. 28" tall tire is like a gear change. You should take that into consideration when choosing tire size for the track. Consider what gear your running, where your setup makes power, and how much HP your going to be making (RPM at the top end).As far as traction goes the 255 and 275 aren't that much different in tread width. My opinion is that if your car won't stick with the 255's your going to have inconsistent traction with the 275s as well and it's time to upgrade the suspension setup, so focus on the tire diameter more so then the width.
275 x 50 x 15's are a 26" tire. The 255 x 60 x 15's are actually a 27.10" tire. I have a set of 275 x 50 x 15's and I like them pretty well but I prefer my 275 x 60 15's.
M/T Streets are street legal, so you can drive from home to track and back, and not have to swap tires at the track. I don't have room in my car for 1) a set of slicks for the ride to the track, and 2) the room or weight of my street tires when on the track.
What we do over here is lock the street tires/wheels under the bleachers with a chain and lock its pretty ghetto but it works.
I think it would be more convenient for me to have tires that I can drive to and from the track with. But down the road I would like to get dedicated slicks.
I'm not quite sure yet where the power curve on this car is, the new transmission I think will have different gears, we might change the gears of the car down the road too. Right now it has a 3.25 gear in an 8". so it would be really a 1" difference in the tires, the 275/60/15 is 28" tall and the 255/60/15 is 27".
