Help 67 Barracuda drag racing setup help

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Sean1105

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So everyone I need some help tuning the front suspension optimal on a slow bracket car to I'll give you a run down what has I will post some pictures also.
- 67 barracuda w/ stock 440 out of 69 charger nothing fancy done to engine
- low gear for drag racing
- Stock but rebuilt front suspension
- Superstock springs on rear
My question is mostly in the front end in reguards to travel / torsion bar adjuster that kinda stuff as it sits right now from alignment shop wheels do some wild turning in stuff by it may not be optimal for racing as it doesn't see the street. I just want a optimal setup that I dont have to throw a ton of money into

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I posted this in the racers forum but looking I probaly should post it here I'm kinda new to all this forum stuff

I need some help tuning the front suspension optimal on a slow bracket car to I'll give you a run down what has I will post some pictures also.
- 67 barracuda w/ stock 440 out of 69 charger nothing fancy done to engine
- low gear for drag racing
- Stock but rebuilt front suspension
- Superstock springs on rear
My question is mostly in the front end in reguards to travel / torsion bar adjuster that kinda stuff as it sits right now from alignment shop wheels do some wild turning in stuff by it may not be optimal for racing as it doesn't see the street

20200524_214109.jpg


20200524_214039.jpg


20200524_214002.jpg
 
six cylinder torsion bars, an inch gap between lca snubber and frame, a nice pair of semi-worn std. shocks.(never got to try my Koni adjustable drag shocks)
 
six cylinder torsion bars, an inch gap between lca snubber and frame, a nice pair of semi-worn std. shocks.(never got to try my Koni adjustable drag shocks)

The MP Chassis manual recommends starting with a 1/2" gap.
 
On the launch, travel is good.
The shop manual front suspension chapter is pretty good. Start with that so you see what the foundation is.
T-bars in the FSM are set by the hieght difference between the bottom of the lower ball joint and the bottom of the control arm t-bar socket.

Moparts on the Web - Main Index
In Bulletin 15, p. 13 starts the drag race front suspension info.
There is some ambiguity in what the 1" mentioned on that page is in reference to - I would say the chassis, not the Chrysler 'ride height'. The point is to set the alignment at the hieght the chassis will rise to on the track.
 
My car 1.65 60', high 11 low 12.0 car, street/strip. I run the Competition Engineering 90/10 up front with lower bump stop 1/2-3/4 inch clearance. Upper control arm bump stops cut to 1/2" to allow front end to move down more to barely keep front tire on the track. Alignment was done with me sitting in the seat and fuel level I race with, 3/4 full. Get someone to photo car launching and accelerating down the track with an old paint stir stick taped to the fender you can see index marks you made. Front end alignment is done with car front end raised in acceleration height. I have my toe set to minimum for street driving. I'm lucky that a good front end guy is local to me. Ask around at your track where people have gone for a good alignment shop.
dart launch.jpg
000_0306.JPG
 
That would be lowering the tosion bar adjuster right? When lowering do you have to loosen the pivot shaft nut or is that only when raising

Yes, loosening (counter clockwise) will lower the front. With the front lowered it will have more travel than with it cranked up. The slower the car the more it needs the travel in the front to help transfer weight to the rear tires.

I've never loosened the nut on the pivot shaft. Normally I just bounce the front after making an adjustment and check the measurement after a drive.

If your goal is to drag race the car you'll need a loose front shock too, something like a 90/10 or a set that is worn out. With worn out shocks it will have some bounce on the street.
 
Drag racing alignment specs; Camber 0* Caster +1.5*-2.0* Toe in 0-1/16". Three way or more adjustable shocks will help with the weight transfer & rebound.
 
Dont adjust the T bars with weight on them !
Lift the front of the car . Might want to oil them first.
 
Upper control arm bump stops cut to 1/2" to allow front end to move down more to barely keep front tire on the track. View attachment 1715534735 View attachment 1715534736

THIS!!!

Cutting the upper bump stop and make sure the shock has sufficient extension travel to accommodate that longer swing.

You want a weaker spring/torsion bar that is wound up tighter/more preload. Slant bars tend to work well in race applications. I like my stuff low with a ton of travel. Easier to limit travel than it is to find it when you need it.

There is usually a lot of time locked up in the front end of these cars. Most spend hours on the back, that's the easy end!
 
crackedback is correct, a lot of time goes into getting the front suspension set just right. Just remember not to make more than one change at a time & keep good records of the changes so if you have to back up, you know how much.
 
C8976C9D-9653-4B00-B0C8-1A90C5722E4C.jpeg
I run original 340 from bars. I have no bump stops at all with QA1 R’s on the front. Set on the softest extension. The only thing is with the aftermarket shock I had to clearance the bottom bump stop mount or it would hit the body of the shock. Buddy of mine had the same issue on his b body
 
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That's a hell of a lot of travel from UCA to bump stop does car react good lights? stop
My car 1.65 60', high 11 low 12.0 car, street/strip. I run the Competition Engineering 90/10 up front with lower bump stop 1/2-3/4 inch clearance. Upper control arm bump stops cut to 1/2" to allow front end to move down more to barely keep front tire on the track. Alignment was done with me sitting in the seat and fuel level I race with, 3/4 full. Get someone to photo car launching and accelerating down the track with an old paint stir stick taped to the fender you can see index marks you made. Front end alignment is done with car front end raised in acceleration height. I have my toe set to minimum for street driving. I'm lucky that a good front end guy is local to me. Ask around at your track where people have gone for a good alignment shop.View attachment 1715534735 View attachment 1715534736
 
I would start with a 90/10 shock and go from there. At your power level it may be all you need. I'm not a fan of using old worn out shocks because they bounce (disrupting the chassis)...a 90/10 will extend quickly and come down slowly, keeping your rear tires planted.
 
I forgot to mention, I'm also running a 67 Barracuda (notch-back, small block). How slow are you talking?...and is this 1/4 mile or 1/8 (just curious). Just asking, because I have been dialing in my car for many years, and used to do so on a stock suspension setup.
 
When i started out it was SS spring and worn out front shocks
Then lowered front end
then lowered front end some more to get 5" of UP Traval
The 90/10 shock.................Front end so stiff 90/10 shock didn't work so well.

The ordered these
QA1 52311 Dynamic Adjustable Strut Bar, Mopar A-Body
alone with upper control arms with heims joints and lower control arm bushing with urethane bushing and greased well.

If you can get it to hook with the Previous set up, i would bother with this last step. especially if it still street driven.
 
7.80's 1/8 mile nothing to fast

I forgot to mention, I'm also running a 67 Barracuda (notch-back, small block). How slow are you talking?...and is this 1/4 mile or 1/8 (just curious). Just asking, because I have been dialing in my car for many years, and used to do so on a stock suspension setup.
 
If it has good rear tires, it should basically be dead hooking with everything nearly stock at that ET.

If it’s not spinning on the line, messing with the front suspension won’t yield much of any ET gain.
 
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