Slicks...Radial or Bias ???

[splicer]

Have a question for you racers with more experience than I have....
I've been running 28 X 10.5 X 15 MT ET Drags but have upgraded carburetor and am now overpowering the slicks both off the line and hitting second gear...even with good burnout and 85 degree air temp.

I'd like to upgrade to a 30 X 9 X15 Hoosier Radial drag or a 30 X 10.5 X 15 Hoosier radial drag.....

Any of you using Hoosier's drag radials ? My set-up is a 3700 lb automatic car running 11.70 at 116 mph....

Thanks
Splicer

 

[moparpoor]

A radial tire isn't going to help you.A radial slick usually helps with high speed stability.From the sounds of things you have shock and alignment adjusting to do.Need more details on your setup!

 

[splicer]

Not expecting that the radial versus bias is going to help that much...although a little more high speed stability wouldn't hurt...
I am hoping that going from a 28 inch tire to a 30 inch tire will help get more of the increased torque from the carb upgrade to the ground...
Car has 90/10 front shocks, 50/50 rears, launches hard and straight, but I'm
getting more wheel spin now and my 60 ft times have gone down from 1.62 to 1.72,,,back half of the 1/4 is .06 quicker now..

Splicer

 

[moparpoor]

The taller tire will give a little larger footprint wich in theory should help with the launch.As for you traction problem when hitting second gear could be shocks.You may need to tighten up the rebound.

 

[Endangered Species]

If you're having problems with traction the radials are the wrong direction. Radials are very temperamental on marginal tracks. (Speaking from experience). Now with that being said on a good track the radials are a good .10-.15 quicker than bias because of the low rolling resistance. The second problem with the radials is they are good for only 30 passes, after that they go away quick.

How many passes do you have on your tires? A carb change should have made that big of a difference in HP that it would affect your traction that much. There are guys running 8.50's and 1.20 60's with 10.5" tires. I would bet that your tires are going away or something is binding in your suspension.


What kind of suspension are you using, S/S springs, Cal Tracs, or Ladder Bars?

 

[Stumper]

Do you have room for 28x14.40/15s? You'll also loose some "gear" going up to a 30" tires

 

[HEMI-ITIS]

Kevins question is key,what suspention??:eusa_eh:

 

[splicer]

Current tires have 33 passes on them,,,,,, rears suspension is super stock springs....
Carb change was from an 870 vacuum carb to a 950 DP...made a huge difference...this is on a 505 stroker with 600 ft/lb torque at 3000...

I noticed the traction issue going from 1st to 2nd when I dropped my shift rpm from 5600 to 5200.........
Car is not tubbed(64 Polara) so I don't have room to go any wider..

 

[Moparmatt72]

I personally would go slicks, I had drag radials on my neon srt and swapped to slicks and dropped almost a full second in the quarter mile, I know its not big block, but hey its all I have for now. For my big block I'm going slicks, drs for the street.

 

[RacerAL]

how good was the track prep ??...was this a t-n-t night with 200 streetcars goin down the track ?..if so, i wouldnt make any decisions til you get on a well prep track...now, if it was a well prep track...i agree that theres a issue somewhere else, if the slicks you have now have only 33 passes on them they shouldnt be worn out. unless they are old, how long have you had the slicks ? if they have been sittin they will go away also. i use to get close to 75 passes out my 29x9's hoosiers..the side walls would go away before the wear indicator holes would, so after only 33 passes i wouldnt think your slicks are worn out..imo. i was at the divisional race this w/end at Norwalk(watching) and there were some of the fastest nhra stockers on this side of the country racing, and they were all flyin and most of them were usin hoosier 30x9 radial slicks(co6). alot of heavy body cars with plenty of hp. runnin well into the 10's some into the 9's..all on a 9 inch slick. i guess my point is that you dont have to have a big slick to hook and go fast..you need an efficent suspension that works. as far as how well the radial slicks work, well give me a few more weeks to get my junk runnin and i'll give ya my opinion. im switching to the co6 hoosiers...just waitin on a few parts and i'll have it running. i did talk to a couple of the racers over the w/end about the radials and they said the exact same thing that KD did..they are not very good on marginal tracks , but real fast when they hook. id be curious to see what you find..keep us informed on your progress.

Alan

[/IMG]

 

[splicer]

Alan:

Thanks for the input.....slicks are 8 months old, however they did sit in unheated trailer over the winter...don't know if that would affect them,...
Your point about track prep is valid...it may not be very good since my three trips there have been on TNT days....there is a nostalgia drag meet coming up in a couple of weeks and they will have to prep the track well for that..I'll see how it hooks then.

In the interim, I'm getting the impression that radial slicks are finicky and have a short life span...let me know what you find out about them...

Thanks
John

 

[Tex013]

Splicer,
i think i would be looking at somebetter rear shocks for a start,i use rancho 9 way's with caltracs.
as to tyres,i use a 275/60R15 hoosier radial slick on my 3771lb 68 satellite and run 1.52-54 60' to go 11.09-14at just over 119mph.this is a stock stroke 440.this is a foot brake car.
these hoosier's are more consistant than a mt et street radial.the rag slick should be even more consistant.
i fitted the hoosier's in may 2011 and done 70-80 passes and still good
good luck,

Tex

 

[Budnicks]

Just Spit-Balling here; get some better Adj. Shocks, maybe more pinion angle & an adj. snubber with the S/S springs, a different rubber compound in the slick, maybe free up the front end to transfer more weight or even maybe restrict it if that's what's making you blow off the tires, how about move the battery to the pass. side trunk rear, how about sub-frame connectors, stiffen the car up some more, lighten the front end more, a taller tire &/or gear may help with less torque multiplication at the rear axle, maybe more or less air in the slicks, go up or down a 1/2lb, see what happens, maybe leave at a higher or lower RPM see if your shocking the tire too much or not enough, not keeping the car planted, maybe too much wheel speed... Just some food for thought....

 

[Budnicks]

What is your complete combo ??, be more specific, it could help someone make a better assertation of your situation... Engine, Camshaft, Carb set up, ignition, gears, trans, converter stall, suspension, cars overall weight, cars weight front to rear, have you ever 4 wheel scaled the car ??, what exact tire & compound, rim width & diameter ??, any fiberglass panels, any other lightening ??, any cage or other stiffening ??, any modifications to the suspension other than S/S springs & are they rated for the proper weight car ??... Just spit-balling here...

 

[mark42202]

In the interim, I'm getting the impression that radial slicks are finicky and have a short life span...let me know what you find out about them...

Thanks
John

It's not been my experience that they are finicky, nor have a short lifespan. I ran nothing but Hoosier 30x9 radial slicks on my 3424lb Fury for years. I would get around 80-90 passes on them, and they hooked no matter what night I went to the track, and no matter what track I went to. BTW, my combo was a stock stroke 440, 4.30 gear, foot brake leaving at 2900rpm, shifting at 5600rpm, super stock springs, Rancho 9 way rear shocks. Consistent 1.43 60', 6.74@102mph 1/8 mile times (which equates to somewhere in the mid 10's 1/4 mile).

http://www.youtube.com/watch?v=eH-5MvIBIJk&feature=g-upl

 

[splicer]

Additional info:
-05 stroker with Eddy heads, 10.5 CR, Torker intake, 950 HP DP, Comp cam with 280 duration(seat to seat) and .490 lift
-Timing at 10 initial, 35 total, all in at 2600 rpm...
- 2600 stall TCI converter
- TCI Super Street Fighter 727
-Strange custom driveshaft
-8 3/4 diff with Auburn posi and 3.73 gears, strange axles.
-Battery is in right rear trunk
- 4 wheel power disc brakes
- 6 point roll bar
- car weighs 3545 lbs with full fuel tank and no driver. 46% rear
- footbrake and preload to 1600 rpm , shift at 5200...
-rear slicks MT 28.1 X 10 X 15

I'm going to try 29.3 inch slicks drop gearing a bit..

Splicer

 

[splicer]

Mark:

Thought you might find this interesting...the track I race at mostly is just outside Sparta, Ontario. Thanks for the input...

Splicer

 

[73duster340]

A radial tire isn't going to help you.A radial slick usually helps with high speed stability.From the sounds of things you have shock and alignment adjusting to do.Need more details on your setup!

YEAH,I AGREE. a maginal track won't work with a radial slick. Just my obervetion.

 

[Endangered Species]

What kind of air pressure are you running?

Next time you're out and having problems check with some of the other racers and see if they're having problems hooking. Like someone said on here it could very well be the track.

I'm not saying go out and spend a bunch of money but here are but you may need to go to a set of adjustable rear shocks. They will control the suspension when launching.

You also want to see how tight your front end is. You want between 4" - 5" of wheel separation. Measure from the fender to the front bearing cap with the car on the ground and the driver in the seat. Then jack the car up and re measure. There should be 4-5 inches difference in the number.

Also have someone record your runs and watch what the rear of the car is doing. See if they can shoot it from the side rear of the car.

Just a few thoughts.

 

[383man]

Just for reference I use the Hoosier 30 x 9 x 15 radial slick on my street car. Its my 3700 lb 63 Sport Fury with a 493 pump gas stroker I built. All I have for suspension is 3400 lb SS springs with longer C-body rear shocks. Thats it for the rear and the front suspension is all stock with 90/10 comp front shocks. I have found on tracks not prepped the hook is average but on prepped tracks as long as I line up in the grove the hook is great for what it is which is a street car driven all the time and driven to the track. Has a best 60 ft of 1.50 with a 10.76 et. They work fine for me and handle good since I have a radial street tire up front. Ron