First Time Drag Racing!

[bOb shingler]

clinteg, i'm just trying to help here and don't want to seem critical and if you don't want any just tell me so. anyway, how many times did you loose traction at the hit and have to back pedal? several that i saw in the video. basic physics stuff, for every action there has to be an equal and opposite reaction. this applies to the rear of a drag car a bunch. when the body goes down it is not pushing the rear axle down, it is pulling it up, the opposite reaction, loosing a lot of traction. when the body goes up, the opposite reaction is the pushing down of the rear axle to make the tires stick or hook. now with no body rise the hook is dependent on how sticky you get the tires which doesn't heat up the same every time and you loose traction some of the time. if you have one of the non-adjustable tri 4 links you're sol on changing any thing with the link bars but maybe stiffening up the rear shocks might help some.
your passengers will get freak out for sure when given a ride when they feel and hear the power your hotrod is making.

 

[CudaDust]

Clint,
Looked good to me. You went straight as an arrow. Some of the traction issues may have been how cold it was also that north wind was cold. So after some of burn outs the guys sat for awhile staging not sure if it was long enough to cool the tires off. Might wait and see how it hooks when the temps are a little warmer. "I'm no drag racer". So maybe talking out of my you know what. Do they make some adjustable rear drag shocks that you could adjust for different conditions? Like temp. It was cold the night before so I would think the track was pretty cold and setting there after burn outs your tires could have cooled down some.
Just thinking

 

[clinteg]

clinteg, i'm just trying to help here and don't want to seem critical and if you don't want any just tell me so. anyway, how many times did you loose traction at the hit and have to back pedal? several that i saw in the video. basic physics stuff, for every action there has to be an equal and opposite reaction. this applies to the rear of a drag car a bunch. when the body goes down it is not pushing the rear axle down, it is pulling it up, the opposite reaction, loosing a lot of traction. when the body goes up, the opposite reaction is the pushing down of the rear axle to make the tires stick or hook. now with no body rise the hook is dependent on how sticky you get the tires which doesn't heat up the same every time and you loose traction some of the time. if you have one of the non-adjustable tri 4 links you're sol on changing any thing with the link bars but maybe stiffening up the rear shocks might help some.
your passengers will get freak out for sure when given a ride when they feel and hear the power your hotrod is making.

No problem. I'm open to critiquing since I'm just starting into this game and have plenty to learn about suspension and launching. I would say half the runs I lost traction. Those were the runs when I tried to hit it hard off the line, whether it was when I was stalling the motor high or when I tried to nail it from 1500 rpm. It hooked pretty good when I eased into it, but that prohibited my 60' from being better.

"when the body goes down it is not pushing the rear axle down, it is pulling it up, the opposite reaction, loosing a lot of traction. when the body goes up, the opposite reaction is the pushing down of the rear axle to make the tires stick or hook." I'm sorta getting what you're saying about this BUT with the 4 link, I don't see any way the body will go "up" like it would with leaf springs. I can adjust the bars in and out, but not so much up and down except the lower bars I can. From what I've been reading, my car shouldn't have much more if any more than a 110# spring and I have 130# at the moment. It barely moves up and down with 130# and I can't imagine going stiffer on those.

A guy at work who has raced a bunch there said I was letting out too early and hurting my mph and et. I was letting out essentially at the score board but he claimed that the triggers are 30-40 ft past those. Woops!

Clint,
Looked good to me. You went straight as an arrow. Some of the traction issues may have been how cold it was also that north wind was cold. So after some of burn outs the guys sat for awhile staging not sure if it was long enough to cool the tires off. Might wait and see how it hooks when the temps are a little warmer. "I'm no drag racer". So maybe talking out of my you know what. Do they make some adjustable rear drag shocks that you could adjust for different conditions? Like temp. It was cold the night before so I would think the track was pretty cold and setting there after burn outs your tires could have cooled down some.
Just thinking

Yes it was chilly! I know I wasn't heating the tires very good at first, but by the end of the evening, I was getting them heated up better. It was getting into the 40's I think and probably with the North wind, it was cooling the tires quickly. The shocks are single adjustable and have 3 different settings depending on what you're trying to do with the car. I need to take the springs off them and make sure they are working right and go from there.

 

[bOb shingler]

I started of with a 150lbs and when is went to 110's the hotrod was much more tunable.
try the lower bar at a higher hole in the front or a lower hole in the rear.

 

[7e5hangten360]

congratulations for going 10`s the first time out! concerning traction, before you try any suspension changes, just try better burnouts. could you lower the rear tire pressure? i understand this is not a race-only car and that is why i wouldnt touch the suspension yet. one more thing: take it easy on the return road, keep it for going down the track!

 

[clinteg]

congratulations for going 10`s the first time out! concerning traction, before you try any suspension changes, just try better burnouts. could you lower the rear tire pressure? i understand this is not a race-only car and that is why i wouldnt touch the suspension yet. one more thing: take it easy on the return road, keep it for going down the track!

I tried tire pressure down to 19. From what I've been told, it can get sketchy with that tire below that pressure and that it could make traction issues worse. I'lllhave to play with it in the spring. One problem at the beginning was short burnouts. But by the end of the day when my burnouts were longer, it was getting too cold to make much difference at that point I believe. I've seen a Satellite on YouTube that runs the same tires that pulls big wheelies and runs 9s so I know with the right setup the tires can hold. But I'll still probably pick up a set of Hoosier slicks to run anyhow. Just need to find a set of cheap wheels that will fit.

 

[crackedback]

A change in the IC of the rear suspension will cure the squatting. Search the net for tuning 4 links. There is an Anti-Squat line that runs from the contact patch of rear tires to horizontal center of gravity line at the front axle point on your car. The lift point of the 4 link bars in relation to that line, above/below, will cause different reactions in body/chassis. Bob has good suggestions.

http://www.how-to-build-hotrods.com/tuning-4-link.html

When the front hits your UCA bump stop, it kills weight transfer. Maybe trim 1/2" off the upper stop.

Keep at it! :cheers:

 

[clinteg]

A change in the IC of the rear suspension will cure the squatting. Search the net for tuning. There is an Anti-Squat line that runs from the contact patch of rear tires to horizontal center of gravity line at the front axle point on your car. The lift point of the 4 link bars in relation to that line, above/below, will cause different reactions in body/chassis. Bob has good suggestions.

http://www.how-to-build-hotrods.com/tuning-4-link.html

When the front hits your UCA bump stop, it kills weight transfer. Maybe trim 1/2" off the upper stop.

Keep at it! :cheers:

Very insightful read! I'm going to have to go back and measure the angle of the bars and see if I can figure out where I'm at. My bump stops are just flat stops that are only about 1/4" thick. They are low profile enough that I can get the torsion bars out without removing them.