How do you get a Suspension to hook, when the track surface is marginal at best

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Cudafever

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I have reached out to you guys and gals before for opinion on this. But now, with my new converter, I have to do something this Winter. Wanting to make what i have work better, and maybe learn something instead of just throwing on a bigger slick......which may be what i have to do in the end...........
I don't know how many pass i made, and i video them all. Most from the rear of the car(under the car) and a couple in car passes at the first and last of the video.
They don't do justice as to how bad my car was skating around on the top end. had to lift sever time. The best ones that show me spinning off the line are at the 4:30, 5:30 and 7:30 minute marks.
Take a look and tell me what you see.

 
Pinion seal is leaking ? Not a traction issue but you are dropping oil on the track?
 
Did you see those springs turn into pretzels?
And the pinion angle winding up on the start-line and back down on decel?
And I see little or no rise on take-off, the power instead going into twisting the springs.

I'm no drag-racer, but I see new springs, softer T-bars and all new shocks in your future...... and maybe some gears.
The twisted up springs may be steering your car at speed, but more likely it's in the camber curves,and accompanying toe-change, or a combination.
 
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Just wached upto the first run under the car. I see you clamped the front section already.
Maybe adding a front half-leaf section, or just a complete leaf per side would help a lot, or just step-up to CalTracs.
Also think the right side of the axle seems a tad bit looser then the other side.

The energy that's now being wound up into the spring at the spring, will also unwind again after take-off, which perhaps could unsettle things on bad tracks.
 
AJ/FormS said:
But would you put Caltracs on those springs? They might last a couple of runs............... but what if they break?
Click to expand...
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Since the caltrac is designed to put down force on the front of the leaf spring I would think the leaf springs would last longer with the caltracs than without them.
 
I hear you, but those springs are like jello. I think they will just become permanently deformed by the Caltrac lever-arm, or worse just snap off.
You can see even just the idling engine is twisting them into an S-shape
 
It looks like not enough air pressure. Rolling over the tire.
 
First off, Thank You all for your thoughts, keep then coming!!! I didn't want to set your focus on what i saw, but your seeing the same things i am.
These are Very Old SS Spring in the back(brand new in the mid 1990's) has an adj pinion snubber in the back. About an 1-1/2 off of the floor pan. It does have rear lift under load, but is probably wasting some of it in the leaf bend. My stock torsion bars are 318 vintage and i have put smaller tire up front so that i could lower the from suspension to get more suspension travel.
I like the idea of adding an additional leaf section up front.

Here is a link that show me launching from the tower.



Caltrac does not recommend the use of a SS Springs. I think mostly, because the right side spring pressure is higher than the left. messing with it's tune ability.

As far as air pressure goes, if it's at 15 psi, it just slips more, if I go to 13 psi then it's all over the track at the top end.

Thanks everyone, keep them coming!!!
 
Agree with the pinnon snubber. Touching or even slightly preloaded.
My co-worker got his '67 GTX to rise nice on slicks with the snubber up tight. He also broke some things before he learned that...
After that he got many, many passes before twisting the axles. I wish I had pictures - this was all pre-internet and digital camaras LOL. The pictures his kid took were B&W - but they were good.
Are the pinnion angle and shackles setup to account for the movement at launch?
 
Things we can't see,pinion angle,shackle angle,age condition of shocks,rear of leafs clamped.Springs look weak,get that pinion snubber up by the floor to let it work,unclamp the rear of the springs,pinion angle 5-7 nose down and a decent rear shock,now the front end,how much travel look for 5",shocks 90-10?.What tire wheel combo are you using and what kinda of et,60' are you getting.
Note: some of these suggestions are for track use only.
 
Been out of drag racing since the late seventies but.. my car builder ran a 68 Camaro small block, 4-speed with 2800 lb super stock springs and Dana 60 with adjustable pinion snubber, and 10" M&H Racemaster tires. It ran 6.70s in 1/8 mile. His car and my ladder-bar car both hooked hard and carried the front wheels, and tracked straight on slick local tracks. One thing I remember was he modified the front suspension upper control arm mounts to bring down the front mounting position. With the factory anti-dive braking setup, as the front suspension rises under acceleration, the positive caster goes away. By lowering the front mount or raising the rear mount, you could lessen this effect. Driving either of these cars, I never thought about steering. It seemed as though the steering wheel was just a place to rest your hand. Best I remember, we had around 7 degrees positive caster. My ladder bar car used 14 x 32 Firestones at 6psi.
Btw, it looks to me like your left spring does have too much bend when you launch at full power. May just need a new set of springs.

Also found this. May be some adjustable tubular control arms to help get more caster.
www.allpar.com/history/mopar/front-end-alignment.html
 
Some good reading here
BaselineSuspensions.com.........Launching A Drag Car
and here
https://www.yellowbullet.com/forum/showthread.php?t=582861

I would start with some good shocks and an adjustable pinion snubber. If you go with Caltracs you will need good shocks anyway. I would suggest something like QA1 double adjustable on the front and single on the back (double on the back if you can afford it). If you still can't get it to hook then you can decide if you want to go with Caltracs or new springs. But do read the thread on yellow bullet, lots of good info on there, tuning the front end is super important too.

Garth
 
Thanks again to you all!
I can answer some of you question but some i will have to get back to you tomorrow night!
Rear shackle is rear word 1 inch, as in the left spring part of the shackle is 1 inch back.
Rear shock are MP " race shock (purchased also in the late 1990's)
Front shock are standard worn out shocks
Rear segment of the SS Spring are not unclamped
When i installed the pinion snubber it was at the highest spot without having to raise the body to get the pin in it. (also installed back in the 90's)
This is a full Dressed car that hasn't see the street in over 10 years. It's a race cars...just a heavy one. Aka track us only car.
Front travel......just went and check. I have exactly 5" of travel. I have threatened to cut the bumper off to get me a little bit more travel.
Rims are a 8" x 15 finned alu wheels. fronts tires are 165 80R 15 and backs are 26 10 15 M/T ET Slick with tubes
When the track has some teeth in it, my best 60' was a 1.707 "Disclaimer" I race at 1/8 mile track and the elevation is 6600 feet.
best ET to date, is 7.86@87 mph 1/8 mile.
I will have to jack it up to check my pinion angle......and find my angle gauge
 
dartgarth said:
Some good reading here
BaselineSuspensions.com.........Launching A Drag Car
and here
Shock Sticky - Yellow Bullet Forums

I would start with some good shocks and an adjustable pinion snubber. If you go with Caltracs you will need good shocks anyway. I would suggest something like QA1 double adjustable on the front and single on the back (double on the back if you can afford it). If you still can't get it to hook then you can decide if you want to go with Caltracs or new springs. But do read the thread on yellow bullet, lots of good info on there, tuning the front end is super important too.

Garth
Click to expand...
Thanks Garth
I will get to that read tomorrow:)
 
tinman2 said:
Been out of drag racing since the late seventies but.. my car builder ran a 68 Camaro small block, 4-speed with 2800 lb super stock springs and Dana 60 with adjustable pinion snubber, and 10" M&H Racemaster tires. It ran 6.70s in 1/8 mile. His car and my ladder-bar car both hooked hard and carried the front wheels, and tracked straight on slick local tracks. One thing I remember was he modified the front suspension upper control arm mounts to bring down the front mounting position. With the factory anti-dive braking setup, as the front suspension rises under acceleration, the positive caster goes away. By lowering the front mount or raising the rear mount, you could lessen this effect. Driving either of these cars, I never thought about steering. It seemed as though the steering wheel was just a place to rest your hand. Best I remember, we had around 7 degrees positive caster. My ladder bar car used 14 x 32 Firestones at 6psi.
Btw, it looks to me like your left spring does have too much bend when you launch at full power. May just need a new set of springs.

Also found this. May be some adjustable tubular control arms to help get more caster.
www.allpar.com/history/mopar/front-end-alignment.html
Click to expand...

First time I`ve read of someone running lower air pressure than I did, use to run 6 3/4 on 14 and 16 x 32`s.
 
I think using a pinion snubber is just a bandaid to the weak spring. If it were mine I would add leaves to strengthen the front segment and clamp them. Then pitch the pinion snubber and add a good d/a shock and Caltracs with your stronger front segment. Then play with your air pressure.
 
furrystump said:
I think using a pinion snubber is just a bandaid to the weak spring.
Click to expand...
I agree with this now only because of the age of the springs and probably, there worn out. The pinion snubber was fine when it was introduced. It still is. However, as all things, time marches on and improved items appear over time.

On the cheap ...... New springs and readjust the snubber. In concert, the snubber stops axle wind up so the front springs can do a better job (Same job) more effectively because it is more focused on controlling just that one side instead of the entire rear. You can see the left and right sides of the rear going up and down independently. It is still old tech and not fool proof and the last word in control. It did just fine in the early days.

If there is money to spend, an entire new set up would be a good investment IMO. The Cal Trac set up is worth looking into. FWIW, I would use sliders on the springs rear.

Ether way, it looks like a fun car. I miss driving my E body Cuda
 
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