Slicks - size and type?

[Shadow24]

Ok, with the season approaching, im looking to get some slicks this year. I'd like to get some advice for size and make/cost. id like to run the 15" steelies i got now as im too poor to get some 16"s or something.

Am i looking at a 24-24.5" slick and how wide can i go on the 15x6 steel rim?

im assuming a pair is around $300 or so (unless someone has some used ones in Ohio for cheaper... :eyebrows: )

[contraption22]

There really arent any 16" slicks in sizes we can use.

What vehicle is this going on? And are you on stock-type suspension?

[Shadow24]

oh, yeah, details lol

92 P-body 5 speed, 5 lug
24v V6 3.0
~200whp
coilover front suspension (rear is stock w/ KYBs all round)
poly A arm bushings
poly motor mounts
solid bobble strut
OBX LSD
4-puck clutch and HD PP

[turbovanman²]

23's,

http://www.mandhtires.com/store.php?crn=71&rn=330&action=show_detail

[Shadow24]

not something close to the ~24" 195/60/15 stock sized tires (or 215/60/15s i was running for summers)?

whats the reasoning behind a smaller tire in slicks?

[Keito]

23's,

http://www.mandhtires.com/store.php?crn=71&rn=330&action=show_detail

These are what I run on my GLH.
But I have an auto with .91 transfer gears, thats why I run a shorter tire.
1.8 60'

[Shadow24]

im just wondering why id want a smaller tire with a 3.77 FD A543 when i can smoke some Nitto 215/60/15s fairly easily off the line. wouldn't a 24ish tire keep me from spinning as much as a 23" tire?

[turbovanman²]

im just wondering why id want a smaller tire with a 3.77 FD A543 when i can smoke some Nitto 215/60/15s fairly easily off the line. wouldn't a 24ish tire keep me from spinning as much as a 23" tire?

You need wider rims and spacers, or diffferent rims to run 24's.

http://www.mandhtires.com/store.php?crn=71&rn=332&action=show_detail

You can't compare street tires to slicks. I did some racing on my street tires, couldn't leave on an boost, put my slicks on, I could then launch with 10 psi.

[Shadow24]

hmmm, i contacted M&H a while back and the rep mentioned a "tall rollout" tire that would fit the 15x6s and be close to a 24 inch tire (forgot i did that lol) now would it be advisable to find something i can stick a 24" slick on instead of the "tall rollout"?

EDIT: not to mention currently im clearing the traps at nearly 7000rpms in 3rd on the Nittos...:wow1:

[contraption22]

im just wondering why id want a smaller tire with a 3.77 FD A543 when i can smoke some Nitto 215/60/15s fairly easily off the line. wouldn't a 24ish tire keep me from spinning as much as a 23" tire?

Slicks and street tires are apples and oranges. Chances are you are not going to spin either a 23" or a 24.5" slick. But if you would like to stick closer to your current effective "gear" ratio, go with 24.5" slick. If you think a little more "gear" would help you out, go with the 23".

If you go with the 24.5 x 8.5 x 15, or 23 x 8.5 x 15 you might want to consider finding a 7" wide wheel. If you go with the 23 x 7 x 15, stick with the 15x6.

[Shadow24]

Chances are you are not going to spin either a 23" or a 24.5" slick. But if you would like to stick closer to your current effective "gear" ratio, go with 24.5" slick. If you think a little more "gear" would help you out, go with the 23".
the 15x6.

not sure quite how this works... are you saying stay towards 24" if i dont want to hit 4th at the line?

i was originally shifting earlier and hitting 4th, but it was killing my time, dragging each gear to 7000 or so and not hitting 4th brought me from consistent 15.1-15.0s to consistent 14.8s (with 2.2-2.3 60' on both) 3rd seems a bit tall ATM, but that was also on the really rich 189whp tune i had earlier...

[contraption22]

not sure quite how this works... are you saying stay towards 24" if i dont want to hit 4th at the line?


Yup, but if you would like to get more out of 4th gear, go with the shorter tire.

[Shadow24]

ok, that makes sense. takes some of the multiplication out of the gearing. Would it be worth it to run the 23s considering id probably have to hit 4th prior to the line? i guess im asking if the 23s would provide better acceleration and make up for the additional shift and reduction in MPH in each gear

[Shadow24]

Also, IIRC Ondonti is running 24.5x8s on 15x6 rims...(i could be wrong though)

[contraption22]

Also, IIRC Ondonti is running 24.5x8s on 15x6 rims...(i could be wrong though)


I'm only going by what the people that make the slicks recommend. So far, what they have recommended has worked for me 100% of the time.

[Shadow24]

i know what you mean, i just don't want to drop that kind of cash and have it be the wrong tire :( being poor sucks lol

[contraption22]

i know what you mean, i just don't want to drop that kind of cash and have it be the wrong tire :( being poor sucks lol

Oh I hear ya.

[turbovanman²]

Also, IIRC Ondonti is running 24.5x8s on 15x6 rims...(i could be wrong though)

You can do alot of things that work but your not getting the full benefit. If you run a stock wheel, you can't run 24's without a spacer otherwise the tire will hit the strut. 22's clear using stock TM wheels, 23's I heard do, 24's, not so much.

Are you planning anymore mods, if not, I would stick with the shorter tire and use 4th, your probably losing some time by winding out the engine. If you can get on a dyno, you can see where your power drops off and get the tire that suits that powerband. It could be 7000 rpm in 3rd is the best setup, so then tire for that, :thumb:


i know what you mean, i just don't want to drop that kind of cash and have it be the wrong tire :( being poor sucks lol

I am having the same dilema, either go 24.5 or 26, :(

[Ondonti]

Also, IIRC Ondonti is running 24.5x8s on 15x6 rims...(i could be wrong though)

Yeah, 24.5x8 on a 15x6 pt steelie fits with no spacer.

My personal 24.5's on some VW RIM need spacers and positive camber to fit :(

You have coilovers too but the rubbing problem is side clearance, not perch clearance. you could run 26's and I cant :P

[Shadow24]

ahh i see. so it IS possible :)

btw, heres the 189whp dyno graph, i know winding out 3rd isn't where the power is but results dont lie, .2-.3 off of a consistent time says alot. Although my 60' sucks. supposed output for this motor is 205(c)hp@5500 and 205(c)tq@4500, i havent had it re-dynoed or tuned really, but it is more around 13:1 instead of 10:1-7:1 at WOT so i should have more power
http://i76.photobucket.com/albums/j16/shadowplane676/s7300098.jpg

as for more mods, the M90 supercharger i have is in the works :evil:

I way look at the 24.5x8s if they fit a stock suspension ok and i have coilovers with more room (also leaves room for more power without re-specing the slick size)

[turbovanman²]

Well go with the 24's then as you won't need to upgrade later.

Ideally you want to hit 4th so the rpm is around 4300 rpm, just at the beginning of the torque.

[Shadow24]

ill see what shifting at 5500 does (about a 1000rpm drop between gears) but im not sure its going to net me an equal or better time... in the mean time ill start saving for slicks :)

[contraption22]

Well go with the 24's then as you won't need to upgrade later.

Ideally you want to hit 4th so the rpm is around 4300 rpm, just at the beginning of the torque.

I agree with this on both points.

[Ondonti]

150hp or less at 7000 rpms in 2nd gear = lots more power to the ground then 150hp @ 4000 rpms in 3rd gear.
Doesnt matter what the Torque says on the dyno chart.
You dont look at torque when choosing shift points.

Advice that ignores the torque multiplication of gears is bad

Be prepared to run some mid 15's if you follow the bad advice. There is a reason you already hit 14's and its not from making mistakes on your shift points.

[Sloride]

150hp or less at 7000 rpms in 2nd gear = lots more power to the ground then 150hp @ 4000 rpms in 3rd gear.


I would wind out 1st and 2nd if you have the traction.... lots of guys shorten first gear because all the engine work is going to spining tires rather then accelerating.... It looks like your 14.8 run was done because of the 1/2 second it takes to shift from 3rd to 4th....

Around the 200 hp mark, for me i found that staying in 3rd netted a better time but shifting to 4th got me a better mph. Im thinking this is because

A) My vehicle needs the ol' "driver mod"

B) I didn't have the power to make up the time i spent shifting

I think that if you stick with the 3rd gear rollouts and slicks you should pull a 14.1 or 2 somewhere around 95mph
if your ok with a 14.5 then shift to 4th and run a 95+ in a mad attempt to trap 100 :evil:

[Ondonti]

Yes a lot of cars out there dont matter about winding out 1st if there is no traction.

With slicks there would be enough traction for his car though :)

The slicks are going to hurt your traps speeds though. Its not just the diameter, its the sidewalls and high friction.
My 14.8@92 was on 225/60r15 tires which are about 25.6" diameter. About how tall 24.5" slicks would grow around 100mph on a 6" wide rim. Maybe they wouldn't grow that much.

Short diameter is how my Duster went 107mph on 5psi bost and 4400 foot elevation on a low compression motor. 205/50r15 drag radials (23.0" diameter and they suck) were tapping the redline just after the traps.
I put 24.5" slicks on and lost 5 mph lol. Way harder to drive on slicks. I am still not used to them.

I have old crappy 24.5" slicks that I am saving and i will use them on my Spirit in the future. I am okay with losing a little MPH.

I think you should try to maximize your setup for the future m90. Don't want to buy tires twice. you are going to have to shift to 4th unless you start reving really really high (which is possible).