M/T Drag Radials,which ones?

[Renato Velati]

I read in a few threads that some guys are running out of mph with a 26" tall tire. I'm looking at buying M/T drag radials 255/60/15 or 275/50/15. Which ones should I go with. I know I won't have a fitment issue with the 255 on stock t type rims.Car is mostly stock with a Jim Testa 93 octane chip,k&n 9" air filter,adjustable fuel pressure reg,rjc powerplate,walbro 340 pump w/hot wire,adjustable wastegate,stock injectors,stock turbo,stock intercooler,stock d5 converter. I'm going to run it with a race chip at a later date, once I get the best out of the 93 chip.

 

[usetaboost]

I need tires too and have been considering m/ts. Bald firestones suck!

 

[UNDER-PRESSURE]

255-60-15 M/T Drag radial's fit on my stock T aluminum wheels great, are 27" tall & hook my high 11 sec. car real good.

 

[pacecarta]

no way you should be running out of rpm on a stock turbo with 26" tires


with that said with the power youll make on stock turbo ive always gone slower (Et not MPH) on the taller tire
if choice of 255/60 27" or 275/60 28" i would go with the 27"
i run the 255/60 cooper on the street and also like the look better than 28s

 

[Renato Velati]

My choice is between the 26" and 27" tall m/t's. I think the 28" is to tall for my setup.

 

[Renato Velati]

What was your 60' time with the 27" tire?

 

[pacecarta]

havent tried the MT 27" but i plan to
with the 27" coopers on stock turbo i ran 1.8 60' at 109.88 witha 12.41 timeslip

my 87 runs 26" tall MT radials at the track , actually measure 25.75" 255/55-16 MT radials
has been 1.57 stock turbo, usually leaves low 1.6s launching at about 3psi
never needed 4th gear with the 26" tire

the 86 has run many 1.50 60s on same 26" tire leaving 7-8psi (3750rpm) off trans brake . with the 26" tire I use 4th gear shifted at 5500rpm due to higher speed running 10.5s at 127 .
with a 28" MT radial tire i can run in 3rd gear to the end of 1/4 , had the 1.42 60 on a well worn set , required 10psi launch boost to get that 60
tried a new set of 28 MT DRS wed night and best 60 was 1.49 with a 10.6 run at only 125+

 

[PaCemkr86]

these work great on the daily driver for 11.40's

 

[RUQWKNF]

Currently on the fence myself....

I'm currently in this same predicament myself with Sarah. I want to run a 27" tall tire, which both of my radials give me now. A 28" rear tire installed height will kick the rear end up, and I've always tried to have the car sit level. No nose in the dirt look for me. I have always run bias ply tires and always launched with high boost on production motor combos in the past. The stage motor was another animal all together. I've run 28x12.5" MT ET Streets, (basically a 28x10.5 slick with grooves, a DOT # and larger size number) on 15x10 rims on my old Limited. I would typically run 11psi cold and launch at 12-15psi off the foot brake/e-brake. Best 60ft was a 1.52. And I've run 28x10.5 ET slicks on the Grey car. I know the benefits of running a radial, but will I be able to launch just as hard to get the 60fts down enough to reach 11.30-11.20's? That is the big kicker for me. As of now, I'm on the fence between these two tires.

1. MT ET Street Radial 255/60/15 on factory T wheels, should be 27" x 8.8 wide.
2. MT ET Street bias ply 27x10.5 on factory T wheels, which should also be 27" tall and 9" wide.

I know the bias ply ET Streets will hook a 15psi launch, but I seriously doubt the radials will hold that violence with no suspension mods other than air bags and removed front sway bar. With the little bit of power mods that I've got too work with, and I don't plan on going with heads or intake, I know I've got to launch very hard to get the short times down and get the ET where I want it. Especially with the limited power that I have to work with from the TE-60R turbo. I also know the ET bias plys will hook slightly better on the street if I run them down to 15-18psi. I guess I'm just old school and like bias ply tires for their hooking characteristics at the track under high boost launches.
Couple of questions for two of you guys.

UNDER-PRESSURE
What's your best 60ft with the 255s? What tire pressure do you run? And what boost do you launch with? Got any pictures of those 255s mounted up?

PaCemkr86

What's the specs? Tire pressure you've run, boost level you launch with and best 60ft time?

Do tell and thanks to all.

Patrick

 

[V6POWER]

I run the 255/60-15 MT Street radials and I can get 1.5x 60' with 7-8# launch (best=1.506). Tire pressure is 22#.

 

[RUQWKNF]

Now that shows me a lot of promise for sure. Nice short time Look Quick.
From the looks of it, if the tune is right and the car can really move out (IE: not lazy) with only a 7-8psi launch, they hook good. Now that's very interesting. Totally goes against my old school train of thought, but then again, I never had the luxury of complete tunability with chips in the past like we have today. Especially with the capabilities of the Gen II.
Thanks for sharing Look Quick.

Patrick

 

[Renato Velati]

pacemkr86, What size tire?

 

[V6POWER]

Thanks Patrick. I was really amazed at how well these tires hook with not too low air pressure or high boost launch.

 

[PaCemkr86]

pacemkr86, What size tire?

275-50-15