traction problems

[flips72]

i am running a 275/60/15 m/t drag radial and cant consistently get it to hook, just wondering what kind of tire pressures and how long of a burnout your doing. my set up is a 65 fleetside stock suspension except for a 4 inch lowering spring, 4.10 gears, turbo 350 leaving off the foot brake at several different rpms, tci 3500 stall, basically everything is stock except fuel tank is in the rear, healthy 406 sbc and a 150 shot. any help would be appreciated. my 60 foot ranges from 1.510 to who knows.

[Super73]

Flip,

The lowering spring is not helping the situation as it is too short/stiff. Get the truck weighed both front and rear axle weights and I can try and point you in the right direction for a better front spring.

What size wheel is on the rear?
What do you have for shocks?
Any idea on your pinion angle?
I am assuming no rear anti-roll bar.

[PGSigns]

Also learn to read the starting line and look at the track out to about 60 foot. Watch the way the track prep is done and how it is maintained during the day. Over time you will learn to read the conditions and make changes to the launch and the timing of the nitrous based on the track. This will also help you when you test to tell if the changes you make help or not. Also pay attention to where you line up on the starting line and what the track looks like in that grove. Some time being off a foot can make the difference between good or bad hook.
Jimmy

[hotrod 80]

Radials are kind of a different monster . Moving over out of the "groove" is a start . The "groove" i have found is not always the best place to even with a slick . My track is very narrow and moving to one side or the other typically yeilds ma a good launch . Next round all i here are mutters of the track is junk . A radial likes to be pressured to the point of spinning and that pressure steadily applied . If the extension is set to fast on the rears and youapply and unload the tire i have found they dont work . I have only had about 30% success with radials .

[Keith Seymore]

1.51 doesn't sound too bad to me (depending on ET).

I spent all weekend running on the 10.50 index and my 60's were in the 1.51 to 1.54 range (naturally aspirated) in my big 'ole Chevelle.

K

[Super73]

I will be trying to better my 1.43 at the end of the month. I don't see any reason I can't get in to the mid/low 1.3's.

[flips72]

Originally Posted by Super73

Flip,

The lowering spring is not helping the situation as it is too short/stiff. Get the truck weighed both front and rear axle weights and I can try and point you in the right direction for a better front spring.

What size wheel is on the rear?
What do you have for shocks?
Any idea on your pinion angle?
I am assuming no rear anti-roll bar.

8,inch,monroe gas, not sure on the pinion angle but im sure its off because of the lowering but i cant find shims to corrrect it and no anti roll bar, there are some videos on you tube under flips72 with some of the best leaves it made the 6.98 pass is the 1.5 60 footer

Originally Posted by PGSigns

Also learn to read the starting line and look at the trac k out to about 60 foot. Watch the way the track prep is done and how it is maintained during the day. Over time you will learn to read the conditions and make changes to the launch and the timing of the nitrous based on the track. This will also help you when you test to tell if the changes you make help or not. Also pay attention to where you line up on the starting line and what the track looks like in that grove. Some time being off a foot can make the difference between good or bad hook.
Jimmy

our local track is kinda hard to get a grasp on, it all depends on who is actaully doing the prep that day,and we only go and play so its always test and tune night so there's not alot of prep to start with.the juice is on a wide open throttle switch i have just now gotton the nerve up to hit it dead out of the hole, i have been flipping the activtion switch about 40 foot out. i did buy a eldebrock controller but haven't had any sucess getting it to work right so far.

Originally Posted by hotrod 80

Radials are kind of a different monster . Moving over out of the "groove" is a start . The "groove" i have found is not always the best place to even with a slick . My track is very narrow and moving to one side or the other typically yeilds ma a good launch . Next round all i here are mutters of the track is junk . A radial likes to be pressured to the point of spinning and that pressure steadily applied . If the extension is set to fast on the rears and youapply and unload the tire i have found they dont work . I have only had about 30% success with radials .

now that blows my mind, i would have never thought getting out of the groove would help, i will try it though and see how it works.

Originally Posted by Keith Seymore

1.51 doesn't sound too bad to me (depending on ET).

I spent all weekend running on the 10.50 index and my 60's were in the 1.51 to 1.54 range (naturally aspirated) in my big 'ole Chevelle.

K

1.5 is my personal best if it were consistant i would be very happy, sounds like you have the chevelle dialed in

Originally Posted by Super73

I will be trying to better my 1.43 at the end of the month. I don't see any reason I can't get in to the mid/low 1.3's.

cant even imagine a 1.3 thats just unreal to me, what does your truck weigh? i have never had a chance to weigh mine yet everyone at the track always ask and i just say somewhere around 4000 lb i guess, its full steel body with oak bed and full interior, i haven't done anything to shave weight.
just want to say thanks to all that have replied to this thread its greatly appreciated.

[Keith Seymore]

Originally Posted by flips72

1.5 is my personal best if it were consistant i would be very happy, sounds like you have the chevelle dialed in

After 36 years you kind of get the hang of it...

[PGSigns]

You get the hang of it. My last car would 60 in 1.03 and run 4.60's in the 1/8 mile in good air. A long way from the 13 second quarter mile passes in the late 70's. Now back to low and slow.
Jimmy