1dirtyZ

iTrader: (1)

i'm posting this by request from TNTAddict,

last race we had an issue with the car wanting to stand on the bumper everytime he launched it .
we tried everything , we even relocated the lower control arms to the upper hole in an attempt to make it spin and not hit as hard ( the result is the fifth launch in the video ). most runs were filmed from multiple angles)

http://www.youtube.com/watch?v=oVlZ74XI9X4


the only difference from the last time out was the tires ( fresh hoosiers, and much colder weather)


quick list of whats on the car :
427 with solid roller , cary's perf. intake , huge solid cam , th400 with ati converter, 4.11 rear gear, 28x10.5 slick, sphon torque arm , qa1's all around , travel limiter set to 1 inch of travel , and a pretty light car.

like i said , we played with the rear shocks , lca angle and pinion angle but nothing seemed to make it better (lca relocation made it wheelie longer ! )

what do you guys recomend or or notice from the videos? the only time it didn't lift was when he completly letoff the pedal and waited till it went down then floored it , which killed his et .

can it be that the converter is too loose?

1dirtyZ

iTrader: (1)

forgot to mention it was cutting low 1.3 times then.

we were debating over getting a shorter torque arm vs a new converter .

MADMAN

iTrader: (4)

Looking at the video you have more than an inch of travel. Tighten the limiter some more. Also tighten the front shock all the way. How much air in the rear tires?

TNTaddict

In all 5 runs: (N/A LS7)
--------
Pinion Angle @ (-2)
skinnes 35 PSI
Slicks 10 PSI
--------

In the first run:
didn't change any thing in this vid,,,except for Fresh slicks and coolder weather..
front shocks @1
travel limit. @3"
rear @ 8
LCA (lower hole @ +2)
http://www.youtube.com/watch?v=Mxu14A_v1_k


----------
2nd run:

front @5
travel @2"
rear @8
same lca
---------

3rd run:
front @7
travel @1" (almost Zero travel~ the last hole)
rear @5
same lca
--------

4th run ( LCA to the upper hole,and back to #1 setup)
front @1
travel @3"
rear @8

and completly letoff the pedal and waited till it went down then floored it again got 9.4@143 mph
--------

5th run:

didn't change any thing fron the 4th run but thought changing the lca to the upper hole worked (from the vid it seems she will go stright with the front end alittle bit in the air)

so, i thought i'll not letoff the pedal and will try to hit the 8's but i got the longest wheeli..(1.42 60" on the back tires,,,best 60" was 1.29)

Ed Wright

iTrader: (1)

I'm with Madman, that car has more than 1" of travel. He needs to get it going straighter also. My little na 383" has stayed on the bumper all the way through 2nd gear. Ain't hard to make these cars do that. Lifting like he was in the videos sure tears a lot of stuff up with those hard landings. It needs to go straighter than that on the rear tires. Best to just drive through those. Limited travel and tight shocks usually takes care of that stuff. Maybe another lb or two in the rear tires?

If not, training wheels come next.

Edit: Needs to go straight without the training wheels (Wheelie bars).

Zmg00camaross

iTrader: (11)

That thing is a little out of shape on the back tires like stayed above. what bar you using in the rear?

1dirtyZ

iTrader: (1)

the class he runs in doesn't allow wheelie bars.
and if i recall correctly i think he has a bmr bar in the rear.

luckily he was just lifting enough to "try" and stop the car from going any higher , most landings were relatively soft
only one landing was harsh , and that resulted in a small ding in the headers ( thank you save your *** bars ! )

anyhow , we talked to mad steve from madman racing last night and will be ordering a ner torque arm and some afco's soon

tektrans

iTrader: (23)

You could try the front shocks full tight, that's what I do when the track it grabbing the way it is in the vid.
Stiffer springs up front also will store less energy in them and not transfer weight so dramatically.
You could also run your rear tires at a higher psi.

tektrans

iTrader: (23)

car is outta shape because the rear bumper is steering the car not because of his sway bar.

just watched it again, nope I was wrong car is steering itself like you said.

ty_ty13

iTrader: (42)

if you need help not hooking i can help... i seemed to have perfected that last year....

looks like you have a good problem that should be able to be fixed relatively easy with the new TA you have coming and shocks

airforcemanss

iTrader: (23)

define: 1" of travel?

what is the difference between the long tq arm and the one that you bought from madman?

i enjoyed those videos. i gotta say the guy was balzy to run with you on the last pass after all them outta control tuning passes

JL ws-6

iTrader: (50)

First thing I'd do, is tighten the limiters one hole, tighten the front front shocks up all the way, and see what that gets you. If that doesn't fix it, add 1 lb of air to the rear tires....

I'm not sure how you're measuring your travel, but get the car at ride height, then put a jack under the k member and lift up on the car and see how much the car comes up without the tires leaving the ground. That shouldn't be mroe then about 3 inches TOPS, probably 2 with the way that car wants to come up.

If you have new parts coming, then get them on the car and start fresh... but if you have time and want to try something before they get there do as suggested above

airforcemanss

iTrader: (23)

thank you sir!

btw op sorry for the hijack. but if you could explain the difference in your previous tq arm to madman that would be koool duuude

Ed Wright

iTrader: (1)

I measure from the top edge of the wheel to the edge of the fender opening with the car sitting at rest, then jack it up or pick it up with the lift and measure it again. Difference is "travel". 1" to 1.5" is usually plenty on a sticky track. More, of course, when it is slick. Slowing the front shocks down also makes a huge difference. Slowing the shocks down helps prevent red lights. Loose shocks and near-zero tire drop and you can ****** the tires out of the beams. Ask me how I know. Not ususually a problem with a 3000# door car on a 4/10ths pro tree, but is on a 5/10ths pro, or when using a blinder on a full tree.

If you can buy or borrow borrow some scales, and check your wheel weights (driver in place), then jack the front tires off the floor with the jack centered under the front cross member and recheck the rear tire weights, you may find some of the "car-not-going-straight-on-the-rear-tires" problem. It should go straight down the track on the rear tires. Dragging the bumper, or not.

I use a modified version of PeteZ bars, which allow me to make rear steer corrections easily. 1/2 turn on one side will correct the car being nearly a car width off at 60'. Just pull one rear wheel to adjust it. No anti-roll bars, I still use the factory torque arm. It now does little more than smooth things out.

Top Fuel

iTrader: (8)

he runs the spohn arm right now which is mounted where the tunnel brace goes and has no front mount adjustment.

the madman arm is a little longer, which will cause less hit to the car, and has front mount adjustments above and below the cross member. using the lower mounts will take even more hit out of the car.

1dirtyZ

iTrader: (1)

thaks for explaining that top fuel , and ed that is something that we definatly will have to do with the scales and jacking the car from the center.

jl, he measured travel from wheel edge to fender then jacked the car up and remeasured.

airforce, we actually asked to run alone , but somehow we got that guy next to us ( i'd like to see the look on his face right after the launch )

1dirtyZ

iTrader: (1)

i'm thinking cut the floorboard out where his feet are , install a lexan panel and indiviual left/right handbrakes ( like sand rails have) , and go have fun ,,,, problem solved !

Zmg00camaross

iTrader: (11)

^^^ still wish i had this problem, video is one of my favorites

1dirtyZ

iTrader: (1)

i remeber when we first started , we would get real excited if one tire pulled from the ground by a fraction of an inch ( soo little that you had to zoom in a bit till you "might" see it ) , we would brag about it all over the place ,,,,, and now we call it a problem

ahhhhh,,,, the irony of life

Zmg00camaross

iTrader: (11)

Maybe one day it will do that, Let us know if the new parts improve your issue.