Another "Help me with my ladder bar setup thread! (w/ video)

[forcefed86]

Quick Rundown.

79 rx-7
Turbo 5.3 LS engine
Traps around 150
Car is 2800lbs with me. I’m sure it’s nose heavy don’t have the ability to weigh it on 4 corner scales.
1.76 Glide with trans. brake
3.25 gear 9” rear
28x12 MT drag radial
Both rear shocks are at 70/30 full firm with 150lbs springs.
Adjustable competition engineering ladder bars
Oem struts up front. (stuck with it for now!)

Should be able to put this video on 1080p and slow it down to .25 to really see whats happening

https://www.youtube.com/watch?v=AdA0Ip4 ... e=youtu.be



From what I’m told and have seen in pictures the car launched nice and straight. Previous owner was pretty much my exact height/weight. 6’4 and about 210 lbs. This chassis originally had the forward sway bar installed, I removed it. Other than that the suspension hasn't been touched. I’m thinking of reinstalling it to help with the front end “twist”. Is this a big mistake? Should I be looking at trying to straighten the twist with the rear suspension and some sort of front end limit strap instead? I did drop the tire size 1", and switch from a slick to a drag radial. Currently the pass. side wheel barely leaves the ground while the driver side comes up quite a bit.

I believe the car is setup neutral at this point. Ladder bars appear to be level. Car pulls left on the launch. But doesn’t pull left down the track, almost like it points left initially then tracks straight if that makes sense. Should I only adjust the ladder bar preload if it constantly tracks to one direction? I seem to be hitting the tires well initially, then tracking left out of the “groove’ and spinning 20ft out or so.

Included some old pics that how how straight the car picked up the front. And how much twist I'm getting now.

I tried lowering the front mount location one notch and have not been back to the track yet. Any input much appreciated.

Thanks!

[bracketchev1221]

I would put the sway bar back in the front. It is possible that the twist now is loading the passenger side tire harder and then driving it left. 150 springs in the rear seem a little stiff for a 2800 lbs car.

[forcefed86]

I would put the sway bar back in the front. It is possible that the twist now is loading the passenger side tire harder and then driving it left. 150 springs in the rear seem a little stiff for a 2800 lbs car.

Thanks for the input... I ordered a FWD sway bar. What are the symptoms of a spring being too stiff? What pressure would you suggest?

[bracketchev1221]

I would check some of the shock websites for spring recommendations like QA-1 or maybe Strange, but my car is 3160 with me in it and I use 130 springs. It generally 60's around 1.27-1.28.

[forcefed86]

I should add I was pulling constant 1.3x's last year and didn't seem to have issues with launching straight. With the new motor making more power I've managed a best of 1.51 and constantly pull left and spin.

I was able to work on the car a bit last night. I was mistaken on the springs. They are 125lb springs.

I removed the CE 3 way adjustable shocks and played with them a bit. I tried to adjust the firmness and I was unable to tell a difference pulling and pushing on them manually. This type of shock you bottom out manually and twist it to the left or right to adjust firmness. I can hear/feel it click, but I have no idea of knowing what position it is in. As far as I can tell I have the pass side now at 70/30 (full firm) and the driver side at 50/50 (full soft) Hoping this may help the car initially launch straight. New rear shocks will be added soon. I’d like to be able to adjust them clearly and installed.

I moved the forward ladder mount down one hole.

As far as preload goes I want to try my current changes first without touching that. If the car still pulls left initially will adjusting the ladder bar only effect the launch? Or will this affect how the car tracks the entire run?

Thanks!