Hooked pulling front wheels then spun

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"I have an extra clamp on the front segment of the spring and I've removed the back segment".


A friend of mine who runs a 440 roadrunner with SS springs single adj shocks took the rear clamps off for whatever reason, the car bit and then unloaded the 275 tyres, I suggested he put the clamps back on and no more unloading. all too loose, axle hit too hard and came back up as it will do, no proper rebound control settings on shocks or springs as designed to keep tyres planted and this was only a mid 12 sec 3700lb car., he does not use 90/10's on front....my 2c's
 
I am running Mickey Thompson ET Street SS drag radial. 275/60/15 with about 19 lbs of pressure.
 
Hot Metal said:
"I have an extra clamp on the front segment of the spring and I've removed the back segment".


A friend of mine who runs a 440 roadrunner with SS springs single adj shocks took the rear clamps off for whatever reason, the car bit and then unloaded the 275 tyres, I suggested he put the clamps back on and no more unloading. all too loose, axle hit too hard and came back up as it will do, no proper rebound control settings on shocks or springs as designed to keep tyres planted and this was only a mid 12 sec 3700lb car., he does not use 90/10's on front....my 2c's
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That is very interesting. This set up worked flawlessly when the car was slower and lighter. Now it's 3600 with me in it and running a ton more power than before. I'll definitely take some clamps to drag week to try if needed. I added weight with the procharger, roll cage and Dana 60.
 
Walker434 said:
I am running Mickey Thompson ET Street SS drag radial. 275/60/15 with about 19 lbs of pressure.
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Same tyre with 18psi, @SPR with concrete track/good hook, just goes to show, track bite/torque/weight/set up etc. etc. and how each car wants what it wants. He's going to a Dana next year along with a 10:1 589 wedge motor with 750ft lbs... changing to mono's/caltracs and better shocks, never ran a car that has the potential to go skywards!!..should be interesting.
 
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I've seen video of drag radials and you need to slow down how hard they plant because they don't crush like slicks do but instead will push against the concrete and unload, like a bounce.
 
Calvert's Website says "Dial primarily adjusts rebound, enabling driver to control excessive rear body separation". So the single adjustment is just adjusting rebound? I believe these are the same shocks as the old Rancho 9000 single adjustable that some people were using.
 
Walker434 said:
Calvert's Website says "Dial primarily adjusts rebound, enabling driver to control excessive rear body separation". So the single adjustment is just adjusting rebound? I believe these are the same shocks as the old Rancho 9000 single adjustable that some people were using.
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They are the old rancho 9000 with a different label.
 
Walker434 said:
Calvert's Website says "Dial primarily adjusts rebound, enabling driver to control excessive rear body separation". So the single adjustment is just adjusting rebound? I believe these are the same shocks as the old Rancho 9000 single adjustable that some people were using.
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LOL. Yep. Primarily to me means it also affects bump (compression for the technical types) and it sure does change the bump.

If you can only control rebound, you can only control the hit the tire sees.

It's a tough deal. Calvert doesn't do a very good job explaining how to tune with them for sure.
 
yellow rose said:
LOL. Yep. Primarily to me means it also affects bump (compression for the technical types) and it sure does change the bump.

If you can only control rebound, you can only control the hit the tire sees.

It's a tough deal. Calvert doesn't do a very good job explaining how to tune with them for sure.
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Yeah I agree. I'll be going to Viking double adjustables next year just wasn't in the budget for this year.

I spoke with a tech at Calvert yesterday and told him my set up and what the car was doing. He said to try them on 8. If that doesn't work go to a 9 setting. He said the higher the setting the longer it takes the shock to separate. He said if I go with an 8 setting it will either fix the problem or take longer for the tires to unload. ( meaning they would unload farther down the track or not at all)

I will have a chance to test and tune at Dinwiddie VA on Sunday after I get through the tech line. I'm going to try these shocks on 8 and see what happens. I also bought some spring clamps yesterday so I can re-clamp the rear of the springs if changing the shock settings doesn't get this thing to hook.
 
Walker434 said:
Yeah I agree. I'll be going to Viking double adjustables next year just wasn't in the budget for this year.

I spoke with a tech at Calvert yesterday and told him my set up and what the car was doing. He said to try them on 8. If that doesn't work go to a 9 setting. He said the higher the setting the longer it takes the shock to separate. He said if I go with an 8 setting it will either fix the problem or take longer for the tires to unload. ( meaning they would unload farther down the track or not at all)

I will have a chance to test and tune at Dinwiddie VA on Sunday after I get through the tech line. I'm going to try these shocks on 8 and see what happens. I also bought some spring clamps yesterday so I can re-clamp the rear of the springs if changing the shock settings doesn't get this thing to hook.
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Can you post the results? I'm anxious to see what that does. I get they are slowing the shock down in rebound. Just don't know what's going to happen in bump, because it will change that too.
 
I'm in the shock learning camp, and just not grasping the hole tuning theory behind it all. And I like these kind of thread that gets the ol mind working.

so, removing the rear clamps (on a SS Spring in this case) allow it to bite harder.........Faster?

Does this mean that you are cause the spring to be a lighter weight spring under load(with rear spring clamps removed) AKA push the spring harder and faster like a weaker spring woud act.

If i understand this correctly, then removing the rear spring clamps is just like setting your rears shock rebound (shock extenting) to a softer setting........ AKA like turning the dial on the shock from 9 firm to 1 soft.(suspension loading, shock extending)
 
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B3422w5 said:
Where is the pinion angle
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No one has answered your question, so i'm going to ask a question on top of it.

If the pinion goes nose up, compared to drive shaft this is a bad thing.
But is there more torque or load potential from more or less degrees pinion angle
 
Cudafever said:
No one has answered your question, so i'm going to ask a question on top of it.

If the pinion goes nose up, compared to drive shaft this is a bad thing.
But is there more torque or load potential from more or less degrees pinion angle
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All i know is having a 4-5 degree down angle on pinion is super critical to making power work with S/S springs
I had 3350 pound 9.80 car, uncut, unminitubbed, that would hoo on ice with 002/003 leafs.
Another thing is throw the pinion snubber in the garbage. If its still on, it can unload the tire
 
Got me thinking, have many video of my rear suspension working, from the back......Thinking i might be interesting to see it working from the front. If for no other reason then to see if i'm eating up all of my pinion angle. don't have any vibration on anything like that.

Yes i have an adj pinion snubber, but i think i will keep it until i have a true Double Adjustable Shock.
3860 pound car but only high 11 sec car.

Mine is hooking for the moment, but as i get my carburetor and engine dialed in more, it may be a problem again.
 
Walker434 said:
That is very interesting. This set up worked flawlessly when the car was slower and lighter. Now it's 3600 with me in it and running a ton more power than before. I'll definitely take some clamps to drag week to try if needed. I added weight with the procharger, roll cage and Dana 60.
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I went through this same scenario. Put in a bunch of power and everything went to ****. This is what I would suggest if your looking for opinions.

- First. Are you sure your rear end separation isn't excessive? A video would tell. And slow motion really shows what's going on. The more power you throw at it the more the rear wants to separate.

- Check your pinion angle to make sure it is still what
it was. If it has changed, then,

- Do you have your spring perches boxed? If not, check them, make sure they're not flattening out. If you can see any air gap at either end, they're starting to curl and your pinion angle is changing on launch. If good, your lucky but get them boxed if they're not.

- Get some dble adjustable shocks on the front.

What finally got my car to hook was with the rear shock rebound on full tight and front shock rebound added. I ran QA1's on the front with 18 notches and where things settled down was when the fronts were Increased to 7. 7 rebound, 18 compression.

With front shock rebound added my front end rise slowed down, which kept the rear tires planted long enough to get me out further without spinning.
I wouldn't have thought, but it made the difference for me. Front shock rebound can play a big part with leaf springs and lots of power.
 
The car hooked for all of dragweek. Of course, that meant great tracks, great track preparation, and a TON of rubber down on the track before my run. Anyway, I went to an 8 setting on the driver's side and a 9 setting on the passenger side. We'll see if it still hooks at some smaller tracks this fall.
 
Cudafever said:
I'm in the shock learning camp, and just not grasping the hole tuning theory behind it all. And I like these kind of thread that gets the ol mind working.

so, removing the rear clamps (on a SS Spring in this case) allow it to bite harder.........Faster?

Does this mean that you are cause the spring to be a lighter weight spring under load(with rear spring clamps removed) AKA push the spring harder and faster like a weaker spring woud act.

If i understand this correctly, then removing the rear spring clamps is just like setting your rears shock rebound (shock extenting) to a softer setting........ AKA like turning the dial on the shock from 9 firm to 1 soft.(suspension loading, shock extending)
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Removing the rear leaf spring clamps lets the axle separate from the car easier as the axle tries to rotate pinion up. Pushing up on the front spring eye and pressing the tire into the track. Too much or too violently and the tire compresses too much and bounces, unloading the tire. So its a hook and spin deal. So you tune/time it with the extension setting of the rear shock. If it bounces the tire, stiffen up the extension to slow the impact and delay it until the car is moving faster. So you really want it as soft as possible to get the highest downward pressure on the tire without bouncing it. You should have already established what tire pressure the car wants because it will dramatically change how bounce prone the tire will be. I have cheap non adjustable kyb rear shocks and the rear just rotates pinion up but doesn’t separate. So if I spin it is right at the hit, not after. I really need a double adjustable rear shock to loosen up the extension and get more bite on the hit.
 
furrystump said:
Removing the rear leaf spring clamps lets the axle separate from the car easier as the axle tries to rotate pinion up. Pushing up on the front spring eye and pressing the tire into the track. Too much or too violently and the tire compresses too much and bounces, unloading the tire. So its a hook and spin deal. So you tune/time it with the extension setting of the rear shock. If it bounces the tire, stiffen up the extension to slow the impact and delay it until the car is moving faster. So you really want it as soft as possible to get the highest downward pressure on the tire without bouncing it. You should have already established what tire pressure the car wants because it will dramatically change how bounce prone the tire will be. I have cheap non adjustable kyb rear shocks and the rear just rotates pinion up but doesn’t separate. So if I spin it is right at the hit, not after. I really need a double adjustable rear shock to loosen up the extension and get more bite on the hit.
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I agree with all of this, but if you have a double adjustable shock, and the tire is bouncing back into the wheel well, you can stiffen the shock in bump and keep hitting the tire, rather that remove hit by slowing down the rebound.

Unless of course you are hitting the tire too hard in the first place.
 
furrystump said:
Removing the rear leaf spring clamps lets the axle separate from the car easier as the axle tries to rotate pinion up. Pushing up on the front spring eye and pressing the tire into the track. Too much or too violently and the tire compresses too much and bounces, unloading the tire. So its a hook and spin deal. So you tune/time it with the extension setting of the rear shock. If it bounces the tire, stiffen up the extension to slow the impact and delay it until the car is moving faster. So you really want it as soft as possible to get the highest downward pressure on the tire without bouncing it. You should have already established what tire pressure the car wants because it will dramatically change how bounce prone the tire will be. I have cheap non adjustable kyb rear shocks and the rear just rotates pinion up but doesn’t separate. So if I spin it is right at the hit, not after. I really need a double adjustable rear shock to loosen up the extension and get more bite on the hit.
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Drag radials will actually bounce where slicks will crush so the drag radials need a softer hit...
There was a guy on moparts posting slow motion videos of this showing how the radials would come back up after the hit and unload....
 
My father took a slow motion video on my car with an M&H musclecar DOT tire on it. It wrinkled enough that you could see the bottom section of rear half of the leaf spring separate and pop back each time it ran over a wrinkle. So I thought I needed a couple lbs of air pressure. Nope, I guess it wasn’t running over the tire too much, because it hooked much better slightly running over the wrinkle.
 
furrystump said:
My father took a slow motion video on my car with an M&H musclecar DOT tire on it. It wrinkled enough that you could see the bottom section of rear half of the leaf spring separate and pop back each time it ran over a wrinkle. So I thought I needed a couple lbs of air pressure. Nope, I guess it wasn’t running over the tire too much, because it hooked much better slightly running over the wrinkle.
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just a thought and probably not the problem but when mine was making a bump as i launched it wasn't the wrinkle wall slick but the off set shackle binding.

off set shackle bind..PNG
 
All I can add is that the pinion angle down insures it doesn't go to zero when the axle rotates.
The idea is to keep the transmission output and the diff pinion parallel.

Some illustrations here, along with text from the DC Chassis Book.
Moparts on the Web - Tech - Pinion Angle
 
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