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Veritas
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6,205 Posts
Discussion Starter · #1 · (Edited)
Hey, gang--

Went to the local 1/8th mile dragstrip last night, to test out the JWT S3 cams I recently installed in the '93 SE-R. Made one run at stock 8psi and a second run at 10psi, just to get timeslips.
Since my new Lenso VPD and 13x8x22 M&H slick combo was rubbing on the strut towers, instead I took a set of Miata wheels (with centers bored to fit our hubs) and tiny 14x6x20 MT slicks.

I was wary of these small slicks, thinking I wouldn't grip quite as well as my beefy-ass M&Hs. (Last year, I ran on 15x8x22 MTs, btw)

So, against a Mustang GT with i/h/e at 8psi, I get this (I'm 'Black' car):


Dig the .002 light! Looked at the 60-ft time, and was impressed with the 'little' slicks.

Second run (against another Mustang GT with a lumpy set of cams and other bolt-ons, running drag radials or MT ET Streets), I raised the boost to 10psi:


(I barely red-lighted, and didn't need it to beat the GT, btw)

That 1.81 60-ft time is the BEST EVER on my car (beating a 1.82 I cut last year)! What I cannot figure out is... how slicks that are 2" shorter and 2" narrower can cut better 60' times like that. I figured the grip just would not be there.

It just goes against logical thinking. Or am I missing something?

Added note: If boneheaded ME would haven set his rear AGXs at '8' instead of leaving them on '1', that 60-ft time *might* have dropped into the 1.7s.

I honestly feel the car has a 8.0 run in it at 13psi of boost. Maybe a 7.9999999999999999999 if everything's right.

Thoughts/comments welcomed and appreciated.
 

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Premium Member
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5,202 Posts
SERprise In WV said:
Hey, gang--

Went to the local 1/8th mile dragstrip last night, to test out the JWT S3 cams I recently installed in the '93 SE-R. Made one run at stock 8psi and a second run at 10psi, just to get timeslips.
Since my new Lenso VPD and 13x8x22 M&H slick combo was rubbing on the strut towers, instead I took a set of Miata wheels (with centers bored to fit our hubs) and tiny 14x6x20 MT slicks.

I was wary of these small slicks, thinking I wouldn't grip quite as well as my beefy-ass M&Hs. (Last year, I ran on 15x8x22 MTs, btw)


Second run (against another Mustang GT with a lumpy set of cams and other bolt-ons, running drag radials or MT ET Streets), I raised the boost to 10psi:

That 1.81 60-ft time is the BEST EVER on my car (beating a 1.82 I cut last year)! What I cannot figure out is... how slicks that are 2" shorter and 2" narrower can cut better 60' times like that. I figured the grip just would not be there.

It just goes against logical thinking. Or am I missing something?

Added note: If boneheaded ME would haven set his rear AGXs at '8' instead of leaving them on '1', that 60-ft time *might* have dropped into the 1.7s.

I honestly feel the car has a 8.0 run in it at 13psi of boost. Maybe a 7.9999999999999999999 if everything's right.

Thoughts/comments welcomed and appreciated.
What tire pressure are you normaly running for both sets of tires?

Mike
 

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rollin 4 deep with JoeD
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1,410 Posts
Are you able to build boost at the line Greg?

If not, then you're probably not going to need big 13" slicks. Where you spinning your 15" slicks on the launch? Like Mike said, what psi were you running in your slicks?

Also, track conditions vary. They may have been using more VHT. Sometimes I go to the drag strip and the track sucks, other times its well prepped and EVERYONE is hooking up much better.

I guarantee you those slicks won't handle much more boost though! YOu'll be spinning them as soon as the boost comes in hard!
 

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Veritas
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6,205 Posts
Discussion Starter · #5 ·
Mike--

I usually run 12-14psi of air in the slicks. I'm just baffled by a slick that is smaller in diameter AND in width pulling a solid-ass 1.81 60-ft time like that. Maybe you engineer-types know what's going on. :D

Frank--
I agree with you that it just could have been 'one of those good days' at the track. However, I've run on 15x8x22 MTs (last year) and made one aborted pass on my new 13x8x22 M&Hs this year, and man, these little 14x6x20s just rock.
I didn't dial in any timing retard to build boost on the line last night. I did that on my 'old' 15x8x22s last year, Frank, and it just spun them like crazy.

(Edit) I can understand the MPH being a little low due to the smaller diameter slick. The grip is what has me in a tizzy.
-GP-
 

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Wants Primera Race Motor
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2,390 Posts
Greg do you just pull up in the water box and burn out, until the slicks pull you out?
 

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Veritas
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Discussion Starter · #7 ·
Doug_O said:
Nice job there Greg. Man, 8.0/7.9* in the 1/8 (potentional), that's strong. Good luck.
It hit a 8.28 @ 86mph last year, during my 12.80 1/4 mile run, Doug. That was at 11psi and stock cams. So, I don't think an 8-flat is too far out of the question.

-GP-
 

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Veritas
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6,205 Posts
Discussion Starter · #8 ·
BlkB14 said:
Greg do you just pull up in the water box and burn out, until the slicks pull you out?
Not at this track. It has this funky waterbox that you have to BACK IN TO. You basically turn 90* onto the track, then back up into the water. I don't like that (getting the rears wet), plus....there's barely room to fit a B13 in there without hitting the wall that is behind you.

Too much hassle. I ran with just a dry hop last night.

-GP-
 

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Veritas
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6,205 Posts
Discussion Starter · #10 ·
I've lost about 6 pounds this month, Brian. The low carb thing works. :D

Actually...the rollbar is coming out of the '93 and going in the '92. That will remove about 50lbs or so, which couldn't hurt.

-GP-
 

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Registered
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4,498 Posts
I have always been told that the smaller tires help 60 fts do to gearing differences. The smaller tire changes the ratio and helps alot. I run 195-45-14 Street tires. They are 20" tall just like those slicks.
 

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great job greg! i know what you mean about the waterbox, my local track is like that. if you have rear wheel drive you're good, fwd you're backing up into a hill. anyway, i run 13x9x22 and best i could do was 2.00 60' and a friend with all motor integ. was cutting 1.9 60' on small slicks like you had. i can't figure it out either... then again he was dumping the clutch at 8500rpm! couldn't hear my 4500rpm launch over his car.
 

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Premium Member
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5,202 Posts
SERprise In WV said:
Mike--

I usually run 12-14psi of air in the slicks. I'm just baffled by a slick that is smaller in diameter AND in width pulling a solid-ass 1.81 60-ft time like that. Maybe you engineer-types know what's going on. :D

Frank--
I agree with you that it just could have been 'one of those good days' at the track. However, I've run on 15x8x22 MTs (last year) and made one aborted pass on my new 13x8x22 M&Hs this year, and man, these little 14x6x20s just rock.
I didn't dial in any timing retard to build boost on the line last night. I did that on my 'old' 15x8x22s last year, Frank, and it just spun them like crazy.

(Edit) I can understand the MPH being a little low due to the smaller diameter slick. The grip is what has me in a tizzy.
-GP-
Air pressure is sorta high, try 9-12 psi.

Mike
 

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Pat Pat Pat
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423 Posts
Smaller tire means more weight on the contact area. Therefor more traction, also smaller tire has less drag, so better top end. Its a compromise thing tho, obviously completely bagging them up if they are way too small wouldnt help..

My 2c.
 

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YES!! Thats some good news.

YOu got the BBS Miatas?
 
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