dual shock suspension? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Suspension - Brakes - Steering
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 05-11-2006, 12:41 PM
Registered User
 
Join Date: Apr 2006
Location: arkansas
Posts: 58
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
dual shock suspension?

I'm building a 1971 Camaro SS into a stock car/roadrace style tube chassis with centerdrive truck arm rear suspension and tube type control arms in front with custom coilover front suspension.I intend to run four shocks per corner(i am replicating a race setup for SCCA Iroc style chassis from the late 90's). Only I will be using an air suspension on the second position on each wheel with the intent to run fairly decent shock and spring settings so I can use the air suspension for fine tuning for different conditions.I have it planned it out to be remote activated in the drivers seat ( all four wheels ).I wonder what some of you have to say for advice.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 05-11-2006, 12:55 PM
OneMoreTime's Avatar
Hotrodders.com moderator
 
Last wiki edit: Health and safety in the shop or garage
Last journal entry: Yard Dog pic
Last photo:
Join Date: Jul 2004
Location: Washington State
Age: 69
Posts: 7,375
Wiki Edits: 3

Thanks: 47
Thanked 151 Times in 143 Posts
Sounds waaay too complicated for me...I wouldust go with the good Pro or Koni adjustable and be done with it..

Sam
__________________
I have tried most all of it and now do what is known to work..
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 05-12-2006, 10:10 AM
Registered User
 
Join Date: Apr 2006
Location: arkansas
Posts: 58
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I need the air suspension to raise ride height for occassional use for getting around in certain parking lots in my area and to adjust for different road conditions and loads.I know it sounds complicated ,but the suspension I'm trying to duplicate used two shocks per wheel(one on control arm and one linked to sway bar linkage)with a little practice and tweaking you would be able to set the car up for almost any type of surface and still have a low ride height ,plus a decent ride.Isn't that the purpose of hotrodding?To push the envelope of what a car is capable of?If everybody took the simplest way to do things then the hobby we all enjoy would stall out and never break new ground.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 05-12-2006, 10:20 AM
OneMoreTime's Avatar
Hotrodders.com moderator
 
Last wiki edit: Health and safety in the shop or garage
Last journal entry: Yard Dog pic
Last photo:
Join Date: Jul 2004
Location: Washington State
Age: 69
Posts: 7,375
Wiki Edits: 3

Thanks: 47
Thanked 151 Times in 143 Posts
If you have it sorted out what you want and need go for it..Might work..

Sam
__________________
I have tried most all of it and now do what is known to work..
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 05-12-2006, 09:13 PM
Registered User
 
Join Date: Apr 2006
Location: arkansas
Posts: 58
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I just thought the suspension I saw in the article was cool the .The air ride shocks will have four wheel adjustability ,for tuning for different drivers and/or purposes( for example from road race to drag ,or street).The setup they had was for a SCCA road race class of some sort.I the two shock setup had exceptional wheel control .With the roads in my area I need maximum wheel travel with the lowest possible ride height.I also may want to adjust ride height or suspension stiffness.It could hold a lot of possiblities.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 05-13-2006, 02:27 AM
Member
 
Last wiki edit: Vacuum brake bleeder set up
Join Date: Nov 2003
Location: So Cal
Posts: 1,245
Wiki Edits: 8

Thanks: 0
Thanked 0 Times in 0 Posts
I can't see anything good that would come from running 4 shocks per wheel

Something like this might work for you...
http://www.universalairsuspension.co...products_id=38
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 05-14-2006, 04:13 PM
Registered User
 
Join Date: Apr 2006
Location: arkansas
Posts: 58
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
If you read my post you noticed that one of the shocks per wheel were attached to the sway bar linkage.I,m still trying to find the article so I can say for sure exactly how they were linked up.I gathered from the article that the chassis builder that used this setup had great success at setting chassis for a whole range of different track conditions.For lots of tight curves to long straights with high speed corners.As I stated before I wanted to be able to compensate for weight distribution and ride height as well.The site mentioned in previous post was informative.It was configured for 2.5" coilover .It seems to me that you would have to use a shorter springs (ie a 7" in place of a 10" spring)if that is the case you give up quite a bit of wheel travel and lose some of the longer springs ability to soak up bumps without harshness.I think that is the idea behind the four shock arrangement.You have one shock to do the main part of shock absorption with the other providing stiffer damping for the bigger bumps.They're car wouldn't have as many compromises as far as handling would be concerned.As a matter of fact lots of rockcrawlers and 4x4 /offroad racing people use dual shock suspensions with two different rate shocks per wheel.I'm trying to have that same versatility on a smaller scale with ride height adjustability as well without getting under the car for any of the adjustments.I mean is it that unusual for someone to use race technology to push street car envelopes to the limit?
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 05-14-2006, 04:52 PM
Member
 
Last wiki edit: Vacuum brake bleeder set up
Join Date: Nov 2003
Location: So Cal
Posts: 1,245
Wiki Edits: 8

Thanks: 0
Thanked 0 Times in 0 Posts
I would need to see a diagram about how the shocks would be attached to the anti-roll bar...do you mean using shocks instead of end links?

Are you thinking of something more like this
http://www.kinetic.au.com/techno.html
Note: the end links are hydraulic rams and not dampers

The off road guys often use bypass shocks for the 2nd shock at each wheel. With them you are able to get both velocity sensitive and position sensitive damping. They also often use "air bump" bump stops (but bypass shocks can be valved so that bump stops aren't needed.

As for the "air/coil-over" that I posted earlier what you will end up with is a dual rate, non-linear, spring. The spring rate of 2 springs in series is found by:

K(series) = 1/((1/K1)+(1/K2))

In this case one of those springs will have a linear rate while the other (the air spring) will have a non-linear rate (it will get much stiffer as you squish it). The available travel should change because you use the air spring...but yes you might want to get longer shocks than normal to have room for it. For performance driving you would be able to let all the air out of the bag (maybe?) lowering the car and also raising the spring rate (because you will now only be using the 1 spring rather then 2 in series). That sounds like a good thing to keep it stable at high speeds and for performance driving. Around town you would be able to air up the air-over and have a softer spring rate as well as some more ground clearance.

Have fun with your research...
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 05-14-2006, 06:48 PM
Registered User
 
Join Date: Apr 2006
Location: arkansas
Posts: 58
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
You may be onto something there as I've seen a similar type of mechanism for circle track racing.They are hydraulic in nature and don't work quite the same way but as for ride height they could be made to work ,but they are more expensive to setup my car with them.Wouldn't you get a stiffer spring rate as you added air pressure to the shock attachment?They are just a small air bag configured to have a shaft to pass through them aren't they?I would think if aired down you would get a softer rate at that point,or am I thinking backwards?Would it be the same as two separate shocks?The ones i want to use are of pretty soft dampening rate so you could still get a decent ride with the proper choice of primary shock and adjustment of the same.I wish I could find the article so I could scan the photos and post them for you.I was very intrigued when I read it .It was done on a 92 camaro road race car.Four convential shocks and four coil-overs.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 05-14-2006, 09:29 PM
Member
 
Last wiki edit: Vacuum brake bleeder set up
Join Date: Nov 2003
Location: So Cal
Posts: 1,245
Wiki Edits: 8

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by jamesinark
...Wouldn't you get a stiffer spring rate as you added air pressure to the shock attachment?...I would think if aired down you would get a softer rate at that point,or am I thinking backwards?...
How about an example of 2 springs in series (stacked on top of each other):

Say the coil spring is 600# and the air spring is 800#.

When you put them in series the combined spring rate would be:

K(series) = 1/((1/600)+(1/800)) = 343#

As you can see it got softer even though the other spring was stiffer. This is because each spring has the same load on it and each spring deflects based on that load. When the air spring bottoms out the spring rate will go back to being 600#.

If however you had the springs in parallel (if you had an air spring and a coil spring both mounted to the frame and control arm) the rates would add up.

K(parallel) = K1 + K2 = 600 + 800 = 1400#

In this case when you lift it up to drive around town it will also get a bunch stiffer. While that might be good on the back end of a truck hauling heavy loads I don't think you would be happy with it.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 05-15-2006, 12:31 PM
Registered User
 
Join Date: Apr 2006
Location: arkansas
Posts: 58
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I understand you now.The air over coil-over shock would be better for my purposes.Just one or two more questions ,if you don't mind.How much ride height adjustment do you think that setup would give me?Also ,do you think the shock length should take into account the actual amount of ride height adjustment ?for example,if the air bag has a range of 3" of movement should the shock be 3" longer ?I appreciate you taking the time to converse,I never came across that product in any research I've done.I will probably use them as it would be alot simpler and work better as well.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 05-15-2006, 02:38 PM
Member
 
Last wiki edit: Vacuum brake bleeder set up
Join Date: Nov 2003
Location: So Cal
Posts: 1,245
Wiki Edits: 8

Thanks: 0
Thanked 0 Times in 0 Posts
I haven't ever worked with them or even seen them in person. They are fairly new to the market. I think now would be the time to call them up and ask them some questions.

You will have to ask them:
Can they take bottoming out (being driven at low to zero pressures)?
How much load can they handle?
What kind of pressures will they operate at at the loads you will be putting on them?
Can they handle the motion ratio of being installed midway down the control arm?
How much travel do they have?

And the big kicker (I bet you $$ they won't have a clue)...
What is the spring rate at different pressures and amounts of deflection.

Post up the info you get out of them because I would like to know too
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 05-16-2006, 02:47 PM
Registered User
 
Join Date: Apr 2006
Location: arkansas
Posts: 58
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I will contact them and see what they have to say and will post results when they get back to me.you thinking about using their products?If so what kind of project you have in mind for them?Very good questions.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 05-16-2006, 02:55 PM
Member
 
Last wiki edit: Vacuum brake bleeder set up
Join Date: Nov 2003
Location: So Cal
Posts: 1,245
Wiki Edits: 8

Thanks: 0
Thanked 0 Times in 0 Posts
I'm not sure that I would have a use for them...but If anywhere I might put them in the front end of my 71 K5...I would have to get coilovers first though...
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 05-20-2006, 09:22 AM
Registered User
 
Join Date: Apr 2006
Location: arkansas
Posts: 58
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
The car I mentioned before (the one with the dual shock setup I'm considering replicating) was an IROC chassis made in the early nineties.I may end using the coilver airbag setup after I give it more comsideration.The thing I'm stuck on is that you were saying (if I understand you right) that if aired up the suspension rate would actually be softer?If this so this may be the right setup for me.I really want to be able stiffen the suspension a little at different for different situations.what do you think of my predicament?Haven't had the time to sit down and call the place with the questions you suggested.
Reply With Quote Quick reply to this message

Recent Suspension - Brakes - Steering posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hotrodders Knowledge Base: Suspension - Brakes - Steering Jon Suspension - Brakes - Steering 0 11-26-2005 06:29 PM
Rear Shock Placement, Angles ZipZ28 Suspension - Brakes - Steering 22 10-08-2005 01:52 PM
Shock compression at installation? Arcuden Suspension - Brakes - Steering 3 08-24-2005 04:30 AM
Lever Shock is in the way! rwruther Suspension - Brakes - Steering 0 06-11-2004 02:20 PM
Brake / Suspension Upgrade - 75 Chevy Pickup dwstevenson Suspension - Brakes - Steering 0 12-31-2002 07:42 AM


All times are GMT -6. The time now is 11:37 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.