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Discussion Starter #1 (Edited)
I would like to buy some soon. I'm a total noob when it comes to slicks. I was thinking M&H 23.0'' x 7.5'' - 15'' or M&H 24.5'' x 8.5'' - 15'' I have 3.50 gears.

For arguments sake, my brother ran a 14.208 at 96.96 2.10 60ft Generally speaking, how much could he have shaved off his et by running slicks?
 

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He may have been able to crack a 13.9, assuming that was a FWD car.

I have m&h 23x7.5x15. Only went to the track once and couldnt get below 2.08 60' because of a weak clutch.

people have run 12s on the 23x7.5 but if you are running a turbo car i would go for 23.5 or 24.5 honestly. I just picked up the 23s because the majority of the cars that will use those slicks are low-power n/a and could use the gearing advantage.
 

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Old Matchbox runs 20.5x7x13 Hoosiers...they are midget front tires and also sold as sports car slicks...not really for drag racing. Before those I had itty bitty Goodyear Sports car specials that were 20x6x13!
 

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With slicks a 1.9 -ish short time should not be out of the question (and slightly lower with practice). That should take 3 to 4 tenths off of the 14.2. This is all assuming that there is a lot of wheelspin at the moment. I would stick with the short slick. I don't think there is enough power there for the taller one (or need).
 

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In general, the more power you have, the bigger slick you need, the easier it is to launch.

The less power you have, the smaller slick you need, the harder it is to launch.

IIRC the fastest stock 3.0 1/4 mile was run on 20" slicks. That's TINY. The smaller the diameter, the more gear reduction you get (and the less spinning weight), and the lower power you have, the more it helps. A non-turbo 3.0 is a low-power car, btw. Non-boosted 3.0 should be running 20-23" slicks imo.

On the other hand, the smaller it is, the easier it is to screw up the launch. I've accidentally lit up 23" slicks with my 3.0/5spd. If they were 26s i probably couldnt if it tried. If they were 20s id probably actually have to try to make them hook right.
 

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I had 26.5x8x15 MT slicks on my daytona and they were a bit too big. They would rub a little when making sharp turns. I've now gone a little smaller to 24.5x8x15 MT so hopefully those will help with my 60 foot times. I don't think I've even broken the 2 second barrier. I think 2.05 is my best, but hopefully with these smaller tires I can get there.
 

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Discussion Starter #8
In general, the more power you have, the bigger slick you need, the easier it is to launch.

The less power you have, the smaller slick you need, the harder it is to launch.

IIRC the fastest stock 3.0 1/4 mile was run on 20" slicks. That's TINY. The smaller the diameter, the more gear reduction you get (and the less spinning weight), and the lower power you have, the more it helps. A non-turbo 3.0 is a low-power car, btw. Non-boosted 3.0 should be running 20-23" slicks imo.

On the other hand, the smaller it is, the easier it is to screw up the launch. I've accidentally lit up 23" slicks with my 3.0/5spd. If they were 26s i probably couldnt if it tried. If they were 20s id probably actually have to try to make them hook right.
That makes sense. I don't think I want too much gear reduction in my low end because of the 3.50fd and the cams that i have. Pulls hard up top.
I'm going to try 22" if i can find them.

I see a lot of people run their slicks on regular steelies so, I guess that's what I'll do.

imo I'll be lucky if I can get a 1.7 60ft I don't have lsd but, have great suspension.
 

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7.5 inch slicks will go well into the 1.8's with practice and hp but you need to run tire pressure very low (10 to 12). The slicks will almost be squashed on the sidewalls. I use a 2 step for launch (5200 rpm) on a 2.2 and it works reasonably well (if all the planets are aligned). Consistency is tough (for me at least).

I have had the line starters halt the process and come over to tell me my slicks are flat, I assure them they are not, the lights drop and then off we go. A two psi difference in the slicks can be like night and day difference for launching. If you are bogging, raise the pressure to find a sweet spot that works with the combo. All trial and error, I would suggest starting at about 14 in the slicks and see how it works, if spinning, lower the pressure, if hooking very good, raise your launch rpm.
 

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Discussion Starter #10
Sounds like I'll be running down the track a lot before I get the slicks just right. I wonder if my launches will be screwy, no sort of lsd installed. Our difs are tough but, will blow some day. I got mine out of the jy Are you more prone to break axles without an lsd? shadow24v would break the axle on his but, can't remember if he had an obx installed at that point.

My summer street tires are 225/50/15 They measure almost 24" tall. my trap speeds would be interesting to compare to 22" slicks
 

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No, a limited slip doesnt make all that much difference with slicks because there's pretty much no situation where one slick will spin very much more than the other.. you're on a flat surface with roughly equal traction on both sides and generally dont have the power to spin the slicks much anyway. And if you do you can air them down. You can also run different tire pressures per side if you really are spinning one more than the other.

So not having an LSD will not stop you from running good 60's with slicks.

Breaking axles comes down to how you work the clutch and whether the axles themselves suck to begin with. If you are racing with a manual than you'll want to let the clutch out fairly slow until the point where it starts to engage and move the car, which takes the slack out of the drivetrain (mounts), and then let it the rest of the way out much faster. If you just dump the clutch you will either spin the slicks or snap an axle, most likely, and having a LSD doesn't change that either.
 

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No, a limited slip doesnt make all that much difference with slicks because there's pretty much no situation where one slick will spin very much more than the other.. you're on a flat surface with roughly equal traction on both sides and generally dont have the power to spin the slicks much anyway. And if you do you can air them down. You can also run different tire pressures per side if you really are spinning one more than the other.

So not having an LSD will not stop you from running good 60's with slicks.

Breaking axles comes down to how you work the clutch and whether the axles themselves suck to begin with. If you are racing with a manual than you'll want to let the clutch out fairly slow until the point where it starts to engage and move the car, which takes the slack out of the drivetrain (mounts), and then let it the rest of the way out much faster. If you just dump the clutch you will either spin the slicks or snap an axle, most likely, and having a LSD doesn't change that either.
Not sure about snapping axles. I think a lot of people have run their cars pretty hard with slicks and have not had axle issues (unless you're using N/A axles or worn out/crappy old axles). I've always dumped the clutch at the track at 4-4.5K and I've never had any axle issues (Probably done 50 passes like this). Now if you're making 400hp then that's probably a different story. Some people also say sidestepping the clutch is a way to launch which is even harder on axles than dumping it. Not sure if feathering the clutch out would not glaze it and cause clutch slipping....
 

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Work on reducing weight transfer, that helps a ton.
A guy I work with has a newerCobalt TC and goes 12.90's on the
factory radials
He has chains from the A arms to the frame so the front end doesn't lift on launch
 

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Not sure about snapping axles. I think a lot of people have run their cars pretty hard with slicks and have not had axle issues (unless you're using N/A axles or worn out/crappy old axles). I've always dumped the clutch at the track at 4-4.5K and I've never had any axle issues (Probably done 50 passes like this). Now if you're making 400hp then that's probably a different story. Some people also say sidestepping the clutch is a way to launch which is even harder on axles than dumping it. Not sure if feathering the clutch out would not glaze it and cause clutch slipping....
Well, i was launching off the rev limiter at 5800 rpm in my dynasty, which is a heavier motor (more momentum into the driveline at launch).

I dont think there is a difference between turbo and n/a axles other than turbo cars were more likely to have the weak-link equal length setup.

As for clutch glazing, depends on the clutch disc. Ceramic is definitely prone to glazing and does NOT like to be slipped much. And once it glazes it usually wont come back. An 'organic' disc like what is stock in these cars, and almost everything, is pretty forgiving with overheating and wont really glaze. If you get it too hot (by slipping it) it will pretty much come back when it cools off unless you ground too much off of it and now the pressure plate cant clamp it hard enough.

So stock clutch= forgiving, ceramic clutch= easy to glaze.

I had to take out a ceramic puck clutch and hit it with a sandpaper roloc disk to get it to hold more than 6-7psi after i glazed it. Ive never successfully ruined an organic disk. :p
 
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