Bracket Talk
Rear shock settings Back Half Ladder Bar

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https://drr.infopop.cc/eve/forums/a/tpc/f/80760912/m/4497084696

July 01, 2021, 06:59 AM
Holytown
Rear shock settings Back Half Ladder Bar
I have a back half ladder bar car. 14.5w x 32 x 15 slicks w/stiff sidewall. 3050 lbs with me in it. 468 BBC Iron heads. QA1 90-10's on front single adjustable.

Been 6.06 on its fastest pass

Rear shocks are strange double adjustable. 9 or 10 clicks each of total adjustment. 95 lb rear spring.

The track I'm going to go to this weekend is known to be less than mediocre. I've been reading that one an imperfect track you'd want to have the rebound tighter and compression looser. Can someone elaborate on this for me. I am trying to learn how shock settings effect a ladder bar car.

Currently my plan is to be @ 7 on the rebound and 4 on the compression to start.

Just trying to make a bracket car hook in the dirt.
July 01, 2021, 07:25 AM
Mike Rietow
Heavier springs and lead



July 01, 2021, 07:43 AM
Mike Rietow
I ran anywhere from 475 to 525 lbs of lead in the trunk of this, steel headed BBC.

Dial'd guess what? 6.41

Asphalt sealer & Coca Cola for prep, back then.



July 01, 2021, 08:10 AM
N2Ofrog
In theory the looser compression provide more bite by allowing the shock to compress more and put more pressure on the tire; tighter rebound will keep more pressure on the tire for a longer period of time as it returns back to ride height.

You could also try loosening the front shocks too.
July 01, 2021, 08:19 AM
Mike Rietow
Mount lead high, behind the tire for weight transfer.



July 01, 2021, 08:24 AM
NC3x58
quote:
Originally posted by N2Ofrog:
In theory the looser compression provide more bite by allowing the shock to compress more and put more pressure on the tire; tighter rebound will keep more pressure on the tire for a longer period of time as it returns back to ride height.

You could also try loosening the front shocks too.


I think you have this right, except the Extension is what allows the tire to "hit" the track harder and compression keeps pressure downwards on the tire after initial hit.. Extension is when rear end drops out of the car at the hit due to tire deformation, so looser E lets it drop quicker. Compression is then used to keep the body of the car from collapsing back downward, so tighter compression will help keep the tire planted.


Nick Craig

1971 Camaro Split Bumper
376ci LS3
July 01, 2021, 08:32 AM
Mike Rietow
Compression clicker adjusts how much or how little, the tire winds on the rim.

On a loose track you want the compression relatively loose to wind the tire on the rim more, for more weight transfer.
July 01, 2021, 09:19 AM
N2Ofrog
quote:
Originally posted by NC3x58:
quote:
Originally posted by N2Ofrog:
In theory the looser compression provide more bite by allowing the shock to compress more and put more pressure on the tire; tighter rebound will keep more pressure on the tire for a longer period of time as it returns back to ride height.

You could also try loosening the front shocks too.


I think you have this right, except the Extension is what allows the tire to "hit" the track harder and compression keeps pressure downwards on the tire after initial hit.. Extension is when rear end drops out of the car at the hit due to tire deformation, so looser E lets it drop quicker. Compression is then used to keep the body of the car from collapsing back downward, so tighter compression will help keep the tire planted.


I think it depends on the type of car and how it works- the shocks are just one piece of the entire package. Most door cars I've seen don't have a lot of extension at the hit - like you said you can loosen the extension to give it more initial hit, but the looser extension will not keep the weight transferred and the tire planted as long and you run the risk of it trying to spin the tire after the initial hit.
July 01, 2021, 09:41 AM
Mike Rietow
A Super Pro car that looks smooth and effortless leaving the starting line consists of a front end rising on the front side of flash stall and falling on the back side flash stall.

This is a best natural scenario.

If ya got one wheeling out to where the engine is accelerating UP to the shift, no matter how smooth the front dampers makes it look, you have an unnatural load on the engine when the tires touch down.

You use the back and front dampers, to time events on the front and back side of flash stall.





July 01, 2021, 10:03 AM
Mike Rietow
If you have one wheelying and touching down anywhere in the yellow on the back side of flash stall, it's a best natural scenario for 60ft consistency.




This message has been edited. Last edited by: Mike Rietow,
July 01, 2021, 01:07 PM
Eman
quote:
Originally posted by N2Ofrog:
In theory the looser compression provide more bite by allowing the shock to compress more and put more pressure on the tire; tighter rebound will keep more pressure on the tire for a longer period of time as it returns back to ride height.

You could also try loosening the front shocks too.

I always thought a ladder bar car seperates at the hit. Allowing quicker extension drives the slicks downward then as the weight transferred the compression is what holds the tires planted. If the car will hook at the hit loosening the front will help keep the rear hooked.
July 01, 2021, 04:10 PM
nomad
My car is similar to the OP's car. I run QA-1 double adjustable in the front and rear. Rears (24 clip range) are set full soft on compression and 19 clicks from full soft on rebound. Fronts (18 click range) are 10 clicks on compression and 13 on rebound.

I run the same tires the OP does. It takes 11.5 pounds of pressure to keep the tires from cupping at the start line.


nomad
Bruce Guertin


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July 03, 2021, 09:58 AM
Mike Rietow
The first movement shocks work to dampen is extension, the second is compression. The more the shock compresses, the more the tire winds on the rim, the longer the tire winds on the rim, the more time there is for weight transfer to occur.

The lower the pickup point relative the rearend, the more natural it is for the damper to compress, be slow reacting and to transfer weight to the rear tires.

Ride height is pickup point height (ladder Bar).


This message has been edited. Last edited by: Mike Rietow,
July 04, 2021, 10:00 AM
Al Alguire
FWIW on our ladder bar NA10.5 car at less than stellar track, whcih we ran at least weekend, looser on the extension and compression will get the tire to plant(ext)and stay planted(comp)longer. How much and how well depends on the set up and shock. FWIW we have a 2760LB SB car on a 29.5x10.5 that went 1.131 60' with on a 95 degree day with 145 degree track temp on a less than perfect racetrack(Irwindale) last weekend. Weight bias is 56/44 fwiw


"I am not ashamed to confess I am ignorant of what I do not know."
Marcus Tullius Cicero
July 05, 2021, 09:01 AM
Holytown
Started on 7 on extension and 4 on compression,
the car was initially hooking but about 100' out it looked like a pro mod kicking sideways, second time run 7 on extension and 6 on compression, a little further down track, but same result. My buddy said its not wadding the tire at all, so 3rd run I ended up at 5 on extension and 5 on compression. Car started working great! Repeated with me and him driving within 008 to the 330, 5 runs in a row. Thanks to all who contributed to this thread!