Dragstrip tech updated, Need help with 60' times

[422STROKER]

Well got the driveshaft loop in and some smaller M/T's to keep what gear I have effective(235/60/15's) and a 3.23 gear.  Managed to run a 12.84 @ 109.17 but my 60' were still bad i think at 2.01 on the 12.84 run.  So how do i get this thing to move off the line?  I spun for 20-25' off the line before it hooked up.  Before it would spin until I let off with the street tires.

What do i need to do within reason of keeping it streetable?

Tom

[CHUCKS71]

I had great luck with the Hooser Quicktime tires on my Grand National I could leave the line at 14 P.S.I. of boost and they would hold.
I bet with some traction you will be in the low 12's.

[422STROKER]

Well I just got these dradials so tires are out.

Tom

I did burnouts each time about 5-7 seconds at 4K, do I need more RPM's to heat them up better?  There isn't much rubber on my lower quarters.

[vinb]

I agree with Chuck, get some traction and you should be in the 12.15-12.25 range with that kind of mph.....
Me personally, Mono Cal-trac's and a adjustable rear shock , adjustable Koni's up front , but you could use more gear......

[422STROKER]

I may go to a more strip friendly set up later when my 70 is driveable.  For now this needs to do double duty.  I will end up doing heads and cam later, then do the gears and converter and a bigger tire to match the gear.

I want to optimize this combo before I change too much on the car.

Tom

[71chally416]

Are you running the right tire pressure?  There really is no magic number that works for all cars. Sometimes MORE pressure is the answer, not less. Do a short burnout and see what the footprint looks like. It should be an even black mark across the width of the tire. Two lines on each side and it's underinflated, a mark not as wide as the tire and it's overinflated. When you get it right then experiment a few lbs each way to see if it helps. And check the pressure right before you run each time when you figure out where it hooks best. It can go up 3-4 lbs just sitting in the sun.

Also experiment with how you leave. Off idle, then stall the vert a little and try that. But ONE THING AT A TIME! Or you'll never know what hurts and what helps. A 235 is a pretty small tire. Sounds like you have plenty of power, so maybe you shoulda got something bigger? Moving the battery into the trunk over the right rear wheel helps a bunch. It not only adds weight over the rear tires, it removes weight from the front end.  Disabling the front swaybar will help transfer weight at the track too.... 

[Oldschool]

Get a 3800 or so converter and a set of 3:91 -4:10 gears and she will get moving in a hurry.  Still be streetable, but with a much harder launch...        

[422STROKER]

I went with the 235 since I could keep all the gear(3.23) I do have and also use a set of rims I had as well.  Need to work with it now.  Remember that article you posted a link to about the slick built small block?  They used a 235 /60/15 to achieve 1.6 60' times in a challenger so I was thinking it didn't hurt them.

I was running the 18lbs that M/T recommended.  Where do I check the footprint?  In my driveway?  I did notice that the tires had more pressure in them as I checked them too.  There is a line(50 cars) for a while not sure how I would check them right before but could check them while waiting for the row to go.

I get limited time to do this eitherway, been getting 4 runs in at street night having some fun.  Figured the more info I was armed with would help.  The one time I went to 2500 stall I redlite and it was down hill from there.LOL  

I stalled it to 2K with the good run, went to 2500 on the next and got antsy.  Got one more run after that and spun hard launching from 1500 and matting it.  Almost caught the guy in his Shelby Mustang GT500 13.096 @ 107 to my 13.16 @ 108

Thanks for the suggestions
 
Tom

No more converter as of now.  I do a fair amount of highway driving in this car.  I drive it to the track too!


By tdavist at 2008-06-08

[71chally416]

"Off came the tall 275/60Rl5s and on went the shorter 235/60 Drag Radials. We needed to spend a few more seconds in the burnout box with the shorter and one inch narrower shoes to achieve the same traction"

Maybe a better burnout?? Try to time checking the tires to just before they call you up.  It only takes a minute or two. A couple of lbs of air can make a big difference. A full gas tank is another way to put some weight over the rear tires. Just write down what you do on each run to keep track of what works best. Writing it right on on the back of the timeslip right after the run is a good plan. Then you can log it at the end of the night and be able to look back and see how each thing affected your performance. 

[Chryco Psycho]

experiment with the burnout , often more burnout just makes the tires more greasy & less likely to hook up

[ntstlgl1970]

It just takes time, and experimentation. Get a good tire gauge and check it like 416 said. What works for one car/person may not work for you. Might even try leaving @ or just above idle not loading the converter hard and see if it makes any difference. The MPH shows you are making the power....

[422STROKER]

Thanks Guys, I will try a few things the next time out.  I try and write the stuff down but with the adrenaline flowing that isn't so easy.LOL

Tom

[Chryco Psycho]

try installing a short square top U bolt over the front spring section , this will greatly stiffen the front section aiding traction

[nivvy]

mancini racin sell spring clamps...... 

[71chally416]

I think the problem is a tire that works on a mild low compression 360
(The article I referenced) might not be adequate on a stroker motor with more cam and everything else. Apples>Oranges