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Discussion Starter #1
Hey folks. I'm planning to finally track my car. I've never tried it and my interest is peaked. What size drag radials or slicks should I run with my combo?

347
3.35 first gear but considering 2.95 Astro
3.73 gears
Engine makes peak hp at 5800
Car hits the fuel cutoff at 115mph in 4th
Car is a '95 GT coupe. Not sure of weight.
I'm 200lbs
Car has fiberglass hood and aluminum heads.
 

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Slicks or QTPs. You should be able to trap 115 mph, assuming decent heads. If your street tires are typical 25.5" tall, you'd be best served with a 26x8.5 outlaw type slick. I like the Hoosiers and have gone 1.41 60' on them and consistently run low 1.4s. You can get a Hoosier Quick Time pro in 27 by 10.5 which is a 9 inch tread if you want a little bit more room for mile per hour. I ran those too, and got into the mid 1.4s on them as well.

Drag radials won't last as long, will be terribly inconsistent, will be hard on your drive line, and won't recover if you lose traction.
 

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Discussion Starter #3
Slicks or QTPs. You should be able to trap 115 mph, assuming decent heads. If your street tires are typical 25.5" tall, you'd be best served with a 26x8.5 outlaw type slick. I like the Hoosiers and have gone 1.41 60' on them and consistently run low 1.4s. You can get a Hoosier Quick Time pro in 27 by 10.5 which is a 9 inch tread if you want a little bit more room for mile per hour. I ran those too, and got into the mid 1.4s on them as well.

Drag radials won't last as long, will be terribly inconsistent, will be hard on your drive line, and won't recover if you lose traction.
Heads are the AFR 185 Renegades.
I currently run 25.5" Nitto 555R's.
My rear wheels are 10.5". Being a newbie; I'm not sure if I want more trap speed using a taller tire. My SLR isn't good with the 3.35 first gear. I definitely need the 2.95 first.
I think when we spoke before; you figured a higher trap speed than my current 115mph limit in 4th.
I don't put any miles on the car so I may just toss on some Hoosiers and run them all of the time on a 17" wheel. The cops don't seem to care here whether tires are DOT or not.
I'm thinking of dropping the road race style suspension and running Strange coilovers up front and shocks in the rear. Mustangs just look so natural dressed in drag.
 

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Are you looking for a tire strictly for the track, or still wanting a dot radial? Not considering legality of a slick on the street, but obviously it’s dangerous and care should be taken. In a perfect world, where money isn’t an issue, I’d have a street set and a race set, but I’m more track oriented, so I went with the qtp’s. I’d think their 26 11.5 r15 flavor would serve pretty good.
 

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I would not go 2.95 yet. SLR with 3.73 and 3.35 is as low as I would ever go for drag racing. Get some good slicks and try it first and then you can compare if you make a change
 

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Discussion Starter #6
Are you looking for a tire strictly for the track, or still wanting a dot radial? Not considering legality of a slick on the street, but obviously it’s dangerous and care should be taken. In a perfect world, where money isn’t an issue, I’d have a street set and a race set, but I’m more track oriented, so I went with the qtp’s. I’d think their 26 11.5 r15 flavor would serve pretty good.
Here in Phoenix; it rarely rains and I've never drove my car in the rain. I would consider running a DOT race tire full time unless they are too dangerous for the highway. I know the sidewalls are flexy.
Is there an ideal tire width for different hp levels? You mentioned 11.5's which would fit my 10.5" wheels. Will they offer too much bite and add unnecessary rolling mass?
 

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I’ve driven the mickey thompson et Street radials on the highways, and they come in two different tread patterns, the regular radials and the ss. I have yet to drive the qtp’s as I just got them mounted this past weekend. They are more or less a slick with two grooves in them. A friend of mine runs those nittos, and they make a really nice tire, I feel like the compound is too hard and they err towards the street side versus more of a track tire.

Either way, you either have a slick that’s good for the track and horrible for the street, or the other way around.
 

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I'd run it 3 or 4 times. Full power passes to get a a representative mph at the track. IMO you should run the tallest tire that both fits and that you have the power to turn.

If you run 115 in the 1/4, for example, with a 26" tire you will be through the traps at about 5500-5600.

You will need 4.10's to use all your rpm's with 26" tires.
 

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Here in Phoenix; it rarely rains and I've never drove my car in the rain. I would consider running a DOT race tire full time unless they are too dangerous for the highway. I know the sidewalls are flexy.
Is there an ideal tire width for different hp levels? You mentioned 11.5's which would fit my 10.5" wheels. Will they offer too much bite and add unnecessary rolling mass?
I run a 26x8.5 Hoosier on a 10" wheel. It can pretty much take as much power as you can put to it....once you are moving. The first 60' is critical. I can manage 1.29 60' and run 5.30's @ over 133 mph in the 1/8 on that tire. But you have to have your chassis set up right and be able to manage power on the hit to make them work. So in my opinion, you better be making huge power to justify a bigger tire. Unless of course you don't want to set up the chassis properly, then run some 32x16 steamrollers that will hook on anything short of ice. Just be prepared to take the penalty in lost performance due to all of the mass you are dragging down the track. :wink2:
 

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Discussion Starter #10
I'd run it 3 or 4 times. Full power passes to get a a representative mph at the track. IMO you should run the tallest tire that both fits and that you have the power to turn.

If you run 115 in the 1/4, for example, with a 26" tire you will be through the traps at about 5500-5600.
Considering that the engine makes peak power just a tad over 5800; is the 5500-5600 trap speed a good thing?
 

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Discussion Starter #11
Here in Phoenix; it rarely rains and I've never drove my car in the rain. I would consider running a DOT race tire full time unless they are too dangerous for the highway. I know the sidewalls are flexy.
Is there an ideal tire width for different hp levels? You mentioned 11.5's which would fit my 10.5" wheels. Will they offer too much bite and add unnecessary rolling mass?
I run a 26x8.5 Hoosier on a 10" wheel. It can pretty much take as much power as you can put to it....once you are moving. The first 60' is critical. I can manage 1.29 60' and run 5.30's @ over 133 mph in the 1/8 on that tire. But you have to have your chassis set up right and be able to manage power on the hit to make them work. So in my opinion, you better be making huge power to justify a bigger tire. Unless of course you don't want to set up the chassis properly, then run some 32x16 steamrollers that will hook on anything short of ice. Just be prepared to take the penalty in lost performance due to all of the mass you are dragging down the track. /forums/images/Corral_net_2015/smilies/tango_face_wink.png
It's just your typical 347 with no power adders. 389rwhp on a 105° day. From what I've been reading; soft slicks don't like the AZ road heat. The tires would fling rocks like crazy and my lower quarter panels wouldn't look so nice. I mostly drive the car in the evening but the roads retain heat for hours after the sun goes down. That's why you'll find rattle snakes stretched across the road at night.
 

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Discussion Starter #13
Well, you ruined Arizona for me, I used to think of it as a rust free Mecca of vintage vehicles. Now all I think about are rattlesnakes on the road.
Haha!!! Gila Monsters too!
I love AZ. I've been here 30 years and only seen a hand full of rattle snakes. The only reason I saw those is because I was into dirt biking and Jeeping. The rust free cars here are amazing as long as the younger crowd doesn't butcher them.
 

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Considering that the engine makes peak power just a tad over 5800; is the 5500-5600 trap speed a good thing?
Neither good nor bad, IMO. You are just giving up a little potential at the very top of the track. On a less than all out race car, I doubt it would matter. Unless you are the kind guy that wants every hp and RPM to be used.
 

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Discussion Starter #15
Neither good nor bad, IMO. You are just giving up a little potential at the very top of the track. On a less than all out race car, I doubt it would matter. Unless you are the kind guy that wants every hp and RPM to be used.
Cool. Good to know. What calculator do you use to figure RPM at end of 1/4 mile?
 

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Discussion Starter #17

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Well that's kinda why I said I'd run it a few times. Once you know what mph you are turning, you can use the following

3.73 * mph / 26" x 336 = rpm

My last Mustang that I ran at the track trapped at 100 mph but the indicated mph in the car was 110 as it was still accelerating through the finish line.
 

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Discussion Starter #19
tjm73 said:
My last Mustang that I ran at the track trapped at 100 mph but the indicated mph in the car was 110 as it was still accelerating through the finish line.
I don't understand the speed discrepancy. I'm old.
 

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1/4 mile terminal speed is measured over a distance of (I think) 66 feet at the end of the track. If you are still accelerating through this "trap" you get a trap speed that is different from you speedometer at the finish line.

Personally I don't see why they can't make the finish line speed true with today's technology.
 
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