horsepower vs front shock settings

[AMXstocker1]

we have a 69 amx so pretty pitch happy car with a 97 inch wheelbase that has all calvert rear suspension mono leafs, bars, and sliders and shocks and a trz anti-roll bar and we run a 28x10.5 mickey Thompson pbr. the front has suspension limiters and viking crusader shocks with ak valving and the car has been setup like this for 8 years now. what I've noticed is the more horsepower we have the tighter i can set the front end and the car still work. in 2017 when the car was running 10.60s if i tighten the front shocks more than 6 clicks from full loose on rebound it would spin, get the car running 10.30s-20s a couple years later it 6 clicks wheel stands a bit to much for comfort and find out 7 clicks works just fine. and after pulling the biggest wheel stand i've ever been in yesterday i try 9 clicks from full tight and it leaves nicely and goes 9.83. the rear has been set the same way for years bars just touching in top hole, arb neutral and single adjustable Calvert shocks on 7. we also haven't played with the front suspension limiters they have the same 4 inch's of travel they've had since 2016. my question is should i be playing with some of these other tunable factors or if it works just leave it and let it work. i feel like i'm missing something or should test things just to see what changes the car 60 fts well that 9.83 was on 1.35 60 ft 3.98 at the 330 and 6.22 to the 1/8th. is there a point when i'm going to find slowing down the front more and more just doesn't work?

any suggestions or thoughts are helpful

[Wesman07]

My racing experience is primarily with off-road motorcycles but I’ve set up suspensions for a few trucks as well.

I understand that drag racing is very different but if there is something you can do to make the car run better and you decide not to, you’re willing missing out.

It sounds to me like you are experiencing “shock fade”, that is with use the shocks start to become softer. Oil breaks down, they may loose pressure, etc. It is not uncommon that going one click firmer will get you back to where you liked it. More power probably makes it more noticeable.

Keep good notes and make one change at a time. If you ever get those shocks serviced, your preferred settings may be closer to where you started.

What adjustments do you have?

[AMXstocker1]

Just rebound and compression and on this particular valving each click is a noticeable difference. And I've thought about fade as the shocks get some age on them, I do back them off when the car goes in the trailer we don't race that much maybe 50 passes a a season

[AMXstocker1]

This what I would call an average pass

[Wesman07]

I looked up the shocks you have. The adjustment simply adds resistance to fluid flow, so backing them off won’t do anything. Your rear shock adjustment will affect both compression and rebound. It’s a big compromise but may be beneficial to try it.

Cool car. I always like those AMX

[AMXstocker1]

On the front or rear because I can say the fronts definitely change when changed

[Wesman07]

I did not mean the adjustments are ineffective. The adjustments have no bearing on the life of the shock, especially when not in use. So, there is no need to back the clicker’s off.

I’m glad to hear that the adjustment is noticeable. There is a long of snake oil suspension components on the market.

[AMXstocker1]

Ah sorry for the misunderstanding. Viking says to do it when the car is being trailered, so we have been.

I would like to get a good double adjustable shock on the back I'm curious if it would be worth et, I've often thought it hits thr tire pretty hard.

[ijames]

Ah sorry for the misunderstanding. Viking says to do it when the car is being trailered, so we have been.

Just thinking out loud. If that sets the shocks to maximum stiffness, or closer to 50/50 than 90/10, I wonder if that is to reduce the amount of bounce the car experiences going down the road in the trailer. Would save wear on the tie down straps and the springs and suspension of both car and trailer, and could make a small difference in how the trailer handles on rough roads.

[Wesman07]

Two separate circuits would be beneficial. A compression adjustment will help control rear squat. Rebound will affect how your tires stick to the ground after it squats.

Try it on the trailer, you won’t hurt anything. Most trailers don’t have shocks so they inherently bounce like a sob.

[AMXstocker1]

Ah sorry for the misunderstanding. Viking says to do it when the car is being trailered, so we have been.

Just thinking out loud. If that sets the shocks to maximum stiffness, or closer to 50/50 than 90/10, I wonder if that is to reduce the amount of bounce the car experiences going down the road in the trailer. Would save wear on the tie down straps and the springs and suspension of both car and trailer, and could make a small difference in how the trailer handles on rough roads.

It sets them to there loosest setting ie 10/10

[AMXstocker1]

Two separate circuits would be beneficial. A compression adjustment will help control rear squat. Rebound will affect how your tires stick to the ground after it squats.

Try it on the trailer, you won’t hurt anything. Most trailers don’t have shocks so they inherently bounce like a sob.

Leaf spring drag cars typically seperate not squat as ours does the idea being to shove the tire into the ground not pull it up into the chassis.
Your point is still valid you still need to control the seperation and and when it comes back to rest

[Wesman07]

I find the best traction to be the least amount of rebound damping needed. It allows the wheels stay in contact with uneven ground, or accommodate for factors such as side wall deflection. Too little and it will pogo. We want the rear wheels to stay weighted and react as fast as possible without the negative side effects.

[Rick!]

is there a point when i'm going to find slowing down the front more and more just doesn't work?

The simple answer is yes.
First, inspect and/or disassemble the Caltrac stuff and see if the aluminum bushings need to be renewed and the slider bearings are free. Correct as needed.
Since the rears are rebound adjustable only, you are missing out on loosening up compression to get a bit more squat. Double adjustable rear shocks will allow more adjustment and may improve on your 60ft which will translate into a lower ET.
You mention the tire gets hit hard at launch - you want to stick the tire with just the right amount of "wrinkle" but don't get hung up on if it looks ugly or not.
The video shows very little squat but it is also at a poor angle so a video from the side in slo-mo will help understand what is going on at the launch.
Along with the video, a movie viewer on your laptop that can advance frame by frame is really helpful.

Lastly, since you increased power with the "new" heads, you should to track RPM drop between shifts. If you raised your shift points significantly, you may want to consider a higher stall narrow up the RPM drop and soften the launch.

[Dragsinger]

My experience shows that setting down from the wheels up is a critical happening. It needs to be a relatively gentle motion because it has potential to upset the rear suspension. Visualize the front having some compression as it sets down, but the shock must control the rebound, so it does not bounce. Watch other super stockers of around your ET range. In reference to your video, I think it would be OK for the front to rise slightly more. And I like the above posted ideal about disassemble and check and lube the rear parts.