HOME FORUM RULES CONTACT
     
   
   

Go Back   CLASS RACER FORUM > Class Racer Forums > Stock and Super Stock Tech
Register Photo Gallery FAQ Community Calendar

Reply
 
Thread Tools Display Modes
Old 08-08-2013, 11:42 AM   #1
Bobby Fazio
VIP Member
 
Bobby Fazio's Avatar
 
Join Date: Nov 2009
Location: Egg Harbor Township, NJ
Posts: 1,468
Likes: 1,448
Liked 4,365 Times in 501 Posts
Default Rear Suspension Video

I am looking for advice for the rear suspension on the SS/L Mustang. Here is a run from Atco this past weekend. Changed springs three times 110lb, 130lb, and in this video 150lb. The front end was not moving much due to coil over setup with not enough shock travel. The car tends to drive the right rear tire down and the left front tire up no matter where the shocks are set. The shocks in this run were set 12 clicks on the rebound and 7 clicks on the compression. When I try the stiff compression and soft rebound the rear tires bounce like a basketball and the sixty foot is very slow. These tires are M/T 29.5/10.5stiff sidewall. Lastly the ladder bars are in the bottom holes for maximum weight transfer. Thanks!

__________________
'65 Mustang SS/L & L/SA
DriverInterviews.com | App.DragInsights.com
Bobby Fazio is offline   Reply With Quote
Old 08-08-2013, 12:12 PM   #2
Dyno
Senior Member
 
Dyno's Avatar
 
Join Date: Dec 2002
Posts: 916
Likes: 1,135
Liked 682 Times in 203 Posts
Default Re: Rear Suspension Video

The spring just supports the weight of the car, the shock controls the movement. The spring should compress about 25% of the spring height. I think the 130 & 150 spring are to much. The shock moves much less than you think. The shock will first go into a rebound/compression movement, about .25 - .40/.60 - .80 A rear shock sensor tells alot. With the stick, you need a different setup than an auto. Talk to Randy Mans at Fastshocks, he can help you out. 612-306-5387
Dyno is online now   Reply With Quote
Old 08-08-2013, 02:15 PM   #3
Robert Simpson
Senior Member
 
Join Date: Aug 2004
Location: Jacksonville, Florida
Posts: 808
Likes: 7
Liked 20 Times in 12 Posts
Default Re: Rear Suspension Video

Bobby, what a great video. I do not pretend to know anything. But, I would assume that with a stiff sidewall tire it would rebound (bounce very quickly). I would assume it would be the shock adjustment and the clutch setting on the hit vs the importance of the weight of the springs. By the way what camera did you use, it is very clear. I like the car. Thanks again.

Robert
Robert Simpson is offline   Reply With Quote
Old 08-08-2013, 03:48 PM   #4
njk53
Senior Member
 
Join Date: Jul 2007
Location: East China, MI
Posts: 504
Likes: 0
Liked 0 Times in 0 Posts
Default Re: Rear Suspension Video

It was hard to tell and correct me if I'm wrong, it looked like the spring was not compressing much if at all.
__________________
Nelson Kowal
Stock 345
njk53 is offline   Reply With Quote
Old 08-08-2013, 03:56 PM   #5
Bobby Fazio
VIP Member
 
Bobby Fazio's Avatar
 
Join Date: Nov 2009
Location: Egg Harbor Township, NJ
Posts: 1,468
Likes: 1,448
Liked 4,365 Times in 501 Posts
Default Re: Rear Suspension Video

Thanks Robert, it is a Go Pro 960 that I purchased back in 2011. My uncle and I made a mount for under the car. I just realized that the video looks kind of weird because YouTube has a smoothness enhancement on. That's why the camera is doing weird zooms and what not. I just turned it off and hopefully soon it will be back to original. Also, Thanks for your input Dyno.
__________________
'65 Mustang SS/L & L/SA
DriverInterviews.com | App.DragInsights.com
Bobby Fazio is offline   Reply With Quote
Old 08-08-2013, 11:50 PM   #6
Jeff Lee
VIP Member
 
Jeff Lee's Avatar
 
Join Date: Jul 2007
Location: Anthem, Arizona
Posts: 2,766
Likes: 0
Liked 3 Times in 3 Posts
Default Re: Rear Suspension Video

" Lastly the ladder bars are in the bottom holes for maximum weight transfer. Thanks!"



I disagree with this statement. As I've never had a car like yours, a 4-speed with a little engine, all I can do is offer an opinion. I'm guessing you only have low 400HP and torque is as bad as it gets because it's a little 289 with low compression and all. That being said, I would think I would place the ladder bars further UP and then make my shock adjustments using the lighter 110# springs. I don't think a car like yours has enough "giddy up and go" to warrant having the IC way up front and attempting to carry the car. I'd hit the slicks harder with the ladder bar moved up. Then you might see some changes with shock adjustments. And of course, I'd have the shocks dyno'd to make sure all is well with the shocks. No matter how new or old they are.
__________________
Jeff Lee 7494 D/S '70 AMX
Jeff Lee is offline   Reply With Quote
Old 08-09-2013, 11:15 AM   #7
Bobby Fazio
VIP Member
 
Bobby Fazio's Avatar
 
Join Date: Nov 2009
Location: Egg Harbor Township, NJ
Posts: 1,468
Likes: 1,448
Liked 4,365 Times in 501 Posts
Default Re: Rear Suspension Video

Quote:
Originally Posted by Jeff Lee View Post
" Lastly the ladder bars are in the bottom holes for maximum weight transfer. Thanks!"



I disagree with this statement. As I've never had a car like yours, a 4-speed with a little engine, all I can do is offer an opinion. I'm guessing you only have low 400HP and torque is as bad as it gets because it's a little 289 with low compression and all. That being said, I would think I would place the ladder bars further UP and then make my shock adjustments using the lighter 110# springs. I don't think a car like yours has enough "giddy up and go" to warrant having the IC way up front and attempting to carry the car. I'd hit the slicks harder with the ladder bar moved up. Then you might see some changes with shock adjustments. And of course, I'd have the shocks dyno'd to make sure all is well with the shocks. No matter how new or old they are.
Ahh ok good point Jeff, thanks. That makes sense. Why then would you choose the 110 springs as opposed to the other 2?
__________________
'65 Mustang SS/L & L/SA
DriverInterviews.com | App.DragInsights.com
Bobby Fazio is offline   Reply With Quote
Old 08-09-2013, 11:32 AM   #8
ss3011
Senior Member
 
ss3011's Avatar
 
Join Date: Feb 2002
Location: Southeast Michigan
Posts: 909
Likes: 70
Liked 239 Times in 114 Posts
Default Re: Rear Suspension Video

It is very hard to tell what is going on at full speed. You can take the video and slow it down using Microsoft Live Movie Maker, its part of the Windows Essentials package. You can slow it down to 1/8 speed and do a better analysis of what is going on, Cool Video !!
ss3011 is offline   Reply With Quote
Old 08-09-2013, 11:43 AM   #9
FED 387
VIP Member
 
Join Date: Jun 2006
Posts: 3,419
Likes: 525
Liked 332 Times in 180 Posts
Default Re: Rear Suspension Video

springs look as if they are "almost" totally stationary little to no compression or expansion at all on the initial launch leads me to believe they are too stiff--- look at the video if you can put it in "slow motion" things hapenning to fast on the normal speed hard to see whats really going on in 1-2 seconds--I would put ladder bars all the way up to top hole to preload the chassis just to see if it likes it--- if it does then tweak the shocks a bit a little at a time to see what happens if it likes that then go to changing the springs go from the softest or the firmest all the way to the extreme opposite--- I would only do maybe 100-150 foot long plus squirts to see your results--- dont waste time doing anything longer you just want to get the car to launch who cares what it does in the 1/8 or 1/4 work on that later--- just remember for every .01 in the 60 foot usually means .02 in the 1/4---you are not looking for subtle differences now you want radical changes then you can fine tune what ever it is you are trying to do by changing shocks, locating points or spring rates and even rear tire pressure to---- you are not gonna solve this in 2 minutes unless you get lucky and hit the right combo right away----my 2 cents ---FED387
FED 387 is offline   Reply With Quote
Old 08-09-2013, 04:41 PM   #10
Jeff Lee
VIP Member
 
Jeff Lee's Avatar
 
Join Date: Jul 2007
Location: Anthem, Arizona
Posts: 2,766
Likes: 0
Liked 3 Times in 3 Posts
Default Re: Rear Suspension Video

Quote:
Originally Posted by Bobby Fazio View Post
Ahh ok good point Jeff, thanks. That makes sense. Why then would you choose the 110 springs as opposed to the other 2?
Primarily be because your car is so lite. Springs just hold the car up, if not enough, pre-load them which works better anyways. I bought 110# springs for my AMX as I thought I was going SS. And that would have been 3160#'s with driver and well over 600 HP with a stick.
You may want even lighter than 110# springs.
__________________
Jeff Lee 7494 D/S '70 AMX
Jeff Lee is offline   Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 07:57 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
Copyright Class Racer.com. All Rights Reserved. Designated trademarks and brands are the property of their respective owners.