Re: Shock tuning effects of adding rebound
[Re: 03heavy]
#2622933
02/18/19 03:13 PM
02/18/19 03:13 PM
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Joined: Jan 2003
Posts: 19,544 Las Vegas
Al_Alguire
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I Live Here
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Tightening the rebound/extension on the shock will slow down the rear housing, thus not pushing the tire as quickly or hard into the track surface. Loosening compression will not help much if you cannot control the hit on the tire. To over simplify it extension will control the hit and compression will control how long it stays there. Lots of factors play into this, suspension type, track conditions, power level, rear tire type etc
"I am not ashamed to confess I am ignorant of what I do not know."
"It's never wrong to do the right thing"
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Re: Shock tuning effects of adding rebound
[Re: 03heavy]
#2622938
02/18/19 03:23 PM
02/18/19 03:23 PM
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Joined: Mar 2018
Posts: 52 Texas
03heavy
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At this point the slow motion videos show the tire Being hit hard and fast then the pressure is released From the tire Not much and it’s not blowing the tire off But slightly slipping I’m right on the verge of getting it right Sounds like the rebound adjustments may be the The Ticket
Last edited by 03heavy; 02/18/19 03:37 PM.
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Re: Shock tuning effects of adding rebound
[Re: 03heavy]
#2622958
02/18/19 04:21 PM
02/18/19 04:21 PM
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Joined: Dec 2005
Posts: 12,318 Fulton County, PA
CMcAllister
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Mr. Helpful
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So many factors involved - suspension type and geometry (IC), power/torque, stroke, gear ratios, tire type, car weight, stick vs. transbrake vs. footbrake, track prep....
All of these factors determine what the housing is going to do when the torque hits the pinion, the shock controls how fast it's going to happen.
Rebound affects the initial hit, bump affects what happens after that initial action. These affects can be observed by videoing with at least 30FPS, 60 is better, and watching it frame by frame. Much of what you want to see happens before the car moves a foot or 2.
My advice - run the shock as tight as you can. Some tracks can be rough to the point where tight compression settings will upset the car, and the settings become a compromise. High and low speed adjustable or electric shocks - where they are tight initially, then are softened after the car leaves the starting line - are being used more by fast bracket, pro tree guys these days.
If the results don't match the theory, change the theory.
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Re: Shock tuning effects of adding rebound
[Re: 03heavy]
#2623064
02/18/19 09:27 PM
02/18/19 09:27 PM
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Joined: Jan 2003
Posts: 5,487 SoCal
Brian Hafliger
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If I understand correctly adding rebound will actually soften the hit on the tire Correct?? I’m using a Transbrake and a set of menscer da socks When I leave at a lower rpm everything is good ( 1.39 60 foot ) But hard to cut a good light and I as expected as I raise the two step The 60’’s slow I would load a video but guess I need to work o that also I’ve added compression almost to point of being out of adjustment And not much of a change I ran out of time last time out before I got a chance to add rebound I know this had been beat to death and I appreciate anyone sharing There knowledge/experience I’m guessing menscer has been busy with lights out 10 Because they haven’t answered there phone in the last week Is this a ladder bar car?
Brian Hafliger
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Re: Shock tuning effects of adding rebound
[Re: 03heavy]
#2623113
02/18/19 11:22 PM
02/18/19 11:22 PM
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Joined: Dec 2005
Posts: 12,318 Fulton County, PA
CMcAllister
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Mr. Helpful
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Fulton County, PA
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If you raise the RPM (make it more aggressive) and it slows down tighten the shock to control the housing. You don't want to punish the tire, just manage it.
If you run out of clicks before the car shows you it doesn't like the tighter settings, or it's still separating like that with the shock dead tight, then it's time to revalve the shock.
Last edited by CMcAllister; 02/18/19 11:25 PM.
If the results don't match the theory, change the theory.
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Re: Shock tuning effects of adding rebound
[Re: 03heavy]
#2623155
02/19/19 12:45 AM
02/19/19 12:45 AM
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Joined: Dec 2007
Posts: 12,593 Great Neck,LI,new york
hemi-itis
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If I understand correctly adding rebound will actually soften the hit on the tire Correct?? I’m using a Transbrake and a set of menscer da socks When I leave at a lower rpm everything is good ( 1.39 60 foot ) But hard to cut a good light and I as expected as I raise the two step The 60’’s slow I would load a video but guess I need to work o that also I’ve added compression almost to point of being out of adjustment And not much of a change I ran out of time last time out before I got a chance to add rebound I know this had been beat to death and I appreciate anyone sharing There knowledge/experience I’m guessing menscer has been busy with lights out 10 Because they haven’t answered there phone in the last week Share that vid,it will be informative!
HEMI-ITIS has no cure. My condition is fully BLOWN!!
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Re: Shock tuning effects of adding rebound
[Re: 03heavy]
#2623166
02/19/19 01:00 AM
02/19/19 01:00 AM
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Joined: Jan 2003
Posts: 19,544 Las Vegas
Al_Alguire
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I Live Here
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Las Vegas
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Tighten them up first thing...
"I am not ashamed to confess I am ignorant of what I do not know."
"It's never wrong to do the right thing"
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Re: Shock tuning effects of adding rebound
[Re: dthemi]
#2623197
02/19/19 02:41 AM
02/19/19 02:41 AM
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Joined: Oct 2011
Posts: 3,036 bean town ....Ca
WHITEDART
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bean town ....Ca
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Slow motion 1.19 60ft . With the same shock that you mentioned Outback.. oh and I would look at the front of the car https://youtu.be/ddVLS0nreuM
Last edited by WHITEDART; 02/19/19 02:42 AM.
In the 8s N/A.with Brett miller W8's 5.07 at 133 at 2700lb
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Re: Shock tuning effects of adding rebound
[Re: WHITEDART]
#2623226
02/19/19 07:55 AM
02/19/19 07:55 AM
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Joined: Mar 2018
Posts: 52 Texas
03heavy
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Slicks with tubes I’m still having trouble loading the video not sure why it’s being a pain But after the index race on this Saturday I will try get a few test passes with the shocks tightened up Likely will not make it past the first round
Last edited by 03heavy; 02/19/19 10:28 AM.
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Re: Shock tuning effects of adding rebound
[Re: 03heavy]
#2623335
02/19/19 03:05 PM
02/19/19 03:05 PM
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Joined: Jul 2006
Posts: 4,319 Puyallup, WA
StealthWedge67
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I’m a novice at best with this stuff, but that video looks to me like you’re controlling the extension pretty well. It looks like the axle rotated some by watching the wheelie bars, but it’s not extending/separating much at all. I do see a little bounce in the car just after the hit (about 3 tire rotations out), but it again doesn’t appear to be reflected in the axle position relative to the car. Smart guys are here to reel me in if needed, but it looks to me like axle rotation may be your issue, not axle extension. With this in mind, I might suggest to look at preload on the bars more than shock setting (??). How much preload is in them now, and what hole are they in?
LemonWedge - Street heavy / Strip ready - 11.07 @ 120
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Re: Shock tuning effects of adding rebound
[Re: 03heavy]
#2623652
02/20/19 12:27 PM
02/20/19 12:27 PM
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Joined: Mar 2018
Posts: 52 Texas
03heavy
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Guys the video you are watching is from a car that works And in completely different league then mine I can’t load and videos not pictures of mine But after reading the comments I have an idea of what I need to do
I will run the front on full loose And adjust the extension to full tight on the back and back off if needed Roughly 3000rpm off the Transbrake And see if that will work I feel like it will do the trick And if not I will get with menscer see about revalving the shocks Thanks guys Just needed to get it put into perspective
Last edited by 03heavy; 02/20/19 12:36 PM.
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