Strange Single Adjustable Shock

It been a while that I needed to adjust my shocks with the new combo it is hit the shocks hard. I tighten my springs up another 1/4'' to start with to help keep the shock from bottoming out might have to change springs later I have 12'' 125s now they might not me heavy enough. When I scaled the truck when I built it that is what the guy at RJ Race Cars told me it needed. On the shock if my memory it right I think I have to turn counter clockwise to tighten the rebound up? They work good in the middle with the old combo but on the new combo I can feel the shocks bottoming out and then the tires start braking loose. Heading to the track on the 27th for some more TNT to see if I can get a good full pass with out braking loose off the starting line. Just wondering if I am heading in the right direction with my adjustments to help save some time at the track. I am going to get my gopro set up to see what is going on with the rear suspension this time to make sure what I am feeling is in the shocks.

Get that camera footage. I can hardly believe the shock is bottoming out. You probably are out of shock though as those seem to fade pretty quickly.

I think I found my bottoming out I never removed the factory rubber bumpers from the frame on each side looks like the rear end was hitting them. I didnt have but about 1 3\4" of travel the shocks has 2 3\4 " travel so just maybe that what I felt on the lanch. I am still going to get a vid of the rear end just incase this was not it.

The cars that we do separate or are neutral. They don't squat at all. That's why I was questioning that.

I had the springs loosen up more than they should have been, I loosen them up on the 460 combo it helped my 60' time but off foot brake it wasn't hitting the tires  hard. Now that I got the 552 combo with the glide and trans brake in it, it is like a whole different truck now. I went back tonight and tighten the springs to where it sets on the ground the spring is compressed to 9 1/2'' and the rear is tight again and the shocks is set about middle of the travel distance and the setting on the shock is in the middle.

If the rear suspension it's self is really squatting a ton at the launch (on either the initial hit, or the recovery period after the initial hit) it's possible you could have a number of problems. The extension valving could be too tight, the compression valving could be too loose, too soft a spring, Instant center way too long and/or way too low and/or having a real steep downhill angle on the bottom 4-link bars, not having enough power on tap for how the rear suspension is setup.

It should also be mentioned that seeing X amount of rear "bumper drop" during the launch doesn't always mean that the rear suspension is actually squating during the launch. The nose lifting & the sidewalls wadding-up during the launch can also make the back of the car "drop".

As mentioned posting some current launch video would be a good idea. And posting a current 4-link map showing I/C placement & bar angles is also something to think about.

Dave and Justin planning on going to the track Friday night I got a camera mount under the truck for my Gopro I will get some vids of it and post this weekend, as long as the rain leaves here or atleast for Friday night. I got it pointed so it shows the shocks and tire on the driver's side couldn't get it to wear I could get a shot at both tires but do have it so both shocks are seen.

Counterclockwise to soften (loosen) it............Clockwise to firm (tighten) it.

Ok thanks i put them back in the middle after i readjusted my springs and will adjust if need after a pass or 2

only one vid this time it not bottoming out now go to 4mins and that starts the run my camera bracket came off when I tried to get it to release and slide out the VHB tape came loose


https://www.youtube.com/watch?v=EbqaKkDkSRs

Looks to me like it might have had about 1" to 1.25" of extension/separation at the initial hit and pretty much dead-hooked (or close to it). Then after the initial hit it bounced on the shocks or sidewalls a few times, (and kept on extending/separating a little more with each bounce) during the recovery period. Hard to tell from the video, but the total extension/separation distance might have finally reached the 2" to 2.5" range (wild guess) before it leveled out and started to re-compress the shocks a little.

DILLIGASDAVE wrote:Looks to me like it might have had about 1" to 1.25" of extension/separation at the initial hit and pretty much dead-hooked (or close to it). Then after the initial hit it bounced on the shocks or sidewalls a few times, (and kept on extending/separating a little more with each bounce) during the recovery period. Hard to tell from the video, but the total extension/separation distance might have finally reached the 2" to 2.5" range (wild guess) before it leveled out and started to re-compress the shocks a little.  

Dave that pass my gas paddle got hung on my trans tunnel and only had carb opened about half way or a little more when I finally noticed it I was at the 1/8 put it to the floor then just got out of it. You can hear right at the end before I let out the Rs come up then I let out. On the 2nd pass it hooked and broke loose and rehooked off the line with a 1.64 60', then after looking at the 1st pass again I dropped the air to 8.5 from 10.5 to see if it would help and it did with just a little spin off the line with a 1.39 60'. Next time out I will get another shot of the rear I fixed the mount for my camera with a screw so it wont come off. I think I got it close now but another shot of the rear work will let us know.