Home 
Home Search search Menu menu Not logged in - Login | Register
> Jensen Healey & Jensen GT Tech > Suspension > Coil-Over Shock/Spring Conversions

 Moderated by: Greg Fletcher Page:    1  2  Next Page Last Page  
New Topic Reply Printer Friendly
Coil-Over Shock/Spring Conversions  Rating:  Rating
AuthorPost
 Posted: 12-02-2006 05:47 pm
  PM Quote Reply
1st Post
James Wilson
Member


Joined: 11-01-2006
Location: Glasgow, Scotland, United Kingdom
Posts: 34
Status: 
Offline
I'm think of upgrading the suspension components by going to coil-over shocks with stiffer springs.

Has anyone done this, and how successful was it? What shocks and springs were used, and was there any additional fabrication or strengthening required?

Useful information I need: Spring Lengths with/without load. Shock length: maximum and minimum extension.

TIA

James

 

Last edited on 12-02-2006 05:48 pm by James Wilson

Back To Top PM Quote Reply  

 Posted: 12-02-2006 06:37 pm
  PM Quote Reply
2nd Post
Judson Manning
Member


Joined: 03-14-2005
Location: Atlanta, Georgia USA
Posts: 406
Status: 
Offline
 

James,

There really isn't enough room for a typical coil-over set-up to fit inside the JH crossmember and lower arm without significant modification.  You can see the modifications I had to make on my E-prod car to adapt a set of coil-over Konis.

Judson

 

Attachment: 05Jul06-001.jpg (Downloaded 569 times)

Back To Top PM Quote Reply

 Posted: 12-02-2006 07:10 pm
  PM Quote Reply
3rd Post
James Wilson
Member


Joined: 11-01-2006
Location: Glasgow, Scotland, United Kingdom
Posts: 34
Status: 
Offline
That's useful information.

The alternative then is to use something like the Spax or Bilstein shocks and have the springs modified. It seems the front hasn't enough clearance to be lower but would there be benefit to increasing the rate. The rear seems to offer a fair bit of room for lowering and increasing the rate.

I have a front anti-sway bar from a GT that I'll use and I'd think about fitting one to the rear, if I can find a UK supplier.

Back To Top PM Quote Reply  

 Posted: 12-03-2006 03:34 am
  PM Quote Reply
4th Post
Art DeKneef
Member
 

Joined: 03-12-2005
Location: Mesa, Arizona USA
Posts: 338
Status: 
Offline
Judson,

Is that rotor attached to the normal healey spindle or is it something else. It would be nice to have a 5-bolt rotor on the car.

Thanks, Art

Back To Top PM Quote Reply

 Posted: 12-03-2006 05:52 pm
  PM Quote Reply
5th Post
Judson Manning
Member


Joined: 03-14-2005
Location: Atlanta, Georgia USA
Posts: 406
Status: 
Offline
No such luck Art.  What you are looking at is all custom and by no means a bolt-on solution.  I'll reveal all my 'secrets' in a future series of articles Greg has invited me to write for the JHPS monthly. 

Back To Top PM Quote Reply  

 Posted: 12-05-2006 11:41 am
  PM Quote Reply
6th Post
normv
Member


Joined: 08-07-2006
Location: Sydney, Australia
Posts: 46
Status: 
Offline
James

I have just measured a Set of Spax they are as follows

               Min                  Max

Fronts      218                 307

Rears        308                 494 ( from the center of the lower eye to the lower mounting washer)

I also measure the koni rears 303 to 472 (this is with the 15mm bumpstop installed)

Sorry I have just installed the Koni fronts but I will measure the next set when they arrive if you want.

Back To Top PM Quote Reply

 Posted: 12-06-2006 12:35 am
  PM Quote Reply
7th Post
James Wilson
Member


Joined: 11-01-2006
Location: Glasgow, Scotland, United Kingdom
Posts: 34
Status: 
Offline
Thanks Norm. That should help.

Now all I need are the spring lengths- particularly the rear since I a "spare" front sub-frame to play with.

 

 

Back To Top PM Quote Reply  

 Posted: 12-06-2006 08:11 am
  PM Quote Reply
8th Post
normv
Member


Joined: 08-07-2006
Location: Sydney, Australia
Posts: 46
Status: 
Offline
James

I have just measured a rear coil from a JH5 it is 265mm uninstalled excluding the insulator rubber, the wire diameter is 12.3 and it is 4.5 coils with 110 internal spacing. I don't have the spring rate but I will be getting a set of coils made in the new year so I will measure this beforehand to work out what I need. Don't forget if you decide to go coil over you have to factor in the fulcrum point of the original spring , you will also need to allow clearance around the shock for the spring to clear the body.

Also I am not sure if these were different to the early springs as the bumpers on these are quite heavy

Back To Top PM Quote Reply

 Posted: 12-09-2006 03:51 pm
  PM Quote Reply
9th Post
Ron Earp
Member


Joined: 03-12-2005
Location: Cary, North Carolina USA
Posts: 339
Status: 
Offline
I seriously looked at the coil over solution too, because that is legal for me in IT.  But, I didn't see how I could make it work with the existing A arms.

I did put on re-valved shocks and made a lot of springs for the front and rear. On the rear I went to a common 2.25" ID race spring because they are cheap and readily available. I'm running a pair of 250lb springs now and I think they will be about right.

Up front I had a few sets of specific springs made from:

http://www.coilsprings.com

They are good, and cheap. A set of custom front springs with 3.25" ID at 600lb rate was right at $150 a pair, think they were 11" overall length. I made some at 500lbs, 650lbs, and I think the last set was 450lb. All are slightly different lengths and the set on the car now gets the A arm about 1.5" off the bump stop, actually, there is no bump stop so 1.5" off the subframe. I think it is too close and I'll have to go to a slightly longer spring.

Morale of the story is if you need some spring made call those guys at coilsprings.com.  Much less expensive than any race spring places, they do good work, and as a family business are easy to work with.  No, I don't get kick backs just pleasantly suprised to find a good place like that to work with.

Ron

Back To Top PM Quote Reply  

 Posted: 12-13-2006 08:21 am
  PM Quote Reply
10th Post
James Wilson
Member


Joined: 11-01-2006
Location: Glasgow, Scotland, United Kingdom
Posts: 34
Status: 
Offline
Thanks Ron.

So it sounds like you're running 250 Lb. springs on the rear and 450 Lb. on the front (presuming the last ones were the ones you settled on using).

What lengths are these? Do the rear springs lower it any?

Shipping can sometimes be a killer (along with import taxes- VAT at 17.5%).

Back To Top PM Quote Reply

 Posted: 12-13-2006 12:50 pm
  PM Quote Reply
11th Post
Ron Earp
Member


Joined: 03-12-2005
Location: Cary, North Carolina USA
Posts: 339
Status: 
Offline
The car is by no means dialed in. But, up front at the 650 lbs springs and they felt good with the limited track time it has had, which is under 20 laps unfortunately. I liked the "flatness" of the cornering and the front felt very good. The front shocks are some shocks off of a light truck that cost like $15 each, but they work in a pinch.  The front is quite low, so the standard Koni's and Blisteins I had were too long.  clearly shocks will have to be looked at, but they are typically the last thing to adjsut after dialing in the springs, settings, bump, etc.

The rear is using 250 lbers and they are much shorter than stock thus lowering the rear considerably, but not as much as the front. The rear felt great on track, it has a panhard rod and as welded axle, very planted. I don't plan to change anthing back there right now.

I can measure the lengths of the springs and post them if you like.

You can get an idea of what it looks like in this thread:

http://www.jensenhealey.com/forums/view_topic.php?id=679&forum_id=2


Back To Top PM Quote Reply  

 Posted: 12-15-2006 11:33 am
  PM Quote Reply
12th Post
James Wilson
Member


Joined: 11-01-2006
Location: Glasgow, Scotland, United Kingdom
Posts: 34
Status: 
Offline
It would be useful to know the lengths of the springs too, and how much the rear has been lowered.

I believe Judson Manning in another posting mention you were using 250 Lb. 8 inch springs on the rear, and he recommended 175-200 for a street car. I'll be using mine on the street and not racing it... its being re-built as what the British call a "fast road car"....

I'm doing the engine and hope to get 180-190 hp or thereabouts from it, going to the Toyota 5-speed and want an uprated suspension to suit it.

I've thought about going to 15 in. wheels, mainly to improve the tire selection; but that's pretty expensive (I reckon on £1000 for a full set of 5 wheels & tires ~ $2k) and the money can be spent more effectively elsewhere and I can live with the limited range of tires available.

Back To Top PM Quote Reply

 Posted: 12-15-2006 02:51 pm
  PM Quote Reply
13th Post
Ron Earp
Member


Joined: 03-12-2005
Location: Cary, North Carolina USA
Posts: 339
Status: 
Offline
I'll check them for you, but, if you don't lower the front you'll have an odd looking car.  The stock fronts are quite tall and certainly jack the car up.  I have a number of rear sets, I want to say I have the 6" springs on now, but it might be 8". I'll figure it out.

R

Back To Top PM Quote Reply  

 Posted: 12-19-2006 10:24 pm
  PM Quote Reply
14th Post
Tom Thomson
Member
 

Joined: 03-18-2005
Location:  
Posts: 33
Status: 
Offline
Guys

  Twice in this thread I have seen mention of Koni Shocks.  The Koni importer says no listing exists for the JH.  What application are you using?

                                                     Tom 13753

Back To Top PM Quote Reply

 Posted: 12-20-2006 10:24 am
  PM Quote Reply
15th Post
normv
Member


Joined: 08-07-2006
Location: Sydney, Australia
Posts: 46
Status: 
Offline
Tom

Your importer is correct the Jensen Konis have not been available for some time and there is no direct replacement, the valving is always way out if the length is correct, I have had a couple of sets made up recently however this is a little expensive as they have to revalve and rebush some others and they know how to charge for this, unfortunately the hardest part was finding someone with the original specs for the Jensen so I cannot shop around. I am looking at a few options to reduce this including doing the modifications myself as I do have access to koni spares and have revalved my race shocks for years, I just need to find the correct valving My supplier wont tell me but I do have a set they have done. They currently work out to be a to be a little more expensive than the Bilsteins

I am in Australia but if you really want Koni’s I can get them done and post them to you. ( I consider they are the best, although I do also like my Spax but they cannot be rebuilt).

Norm

Last edited on 12-20-2006 10:25 am by normv

Back To Top PM Quote Reply  

 Posted: 12-20-2006 04:06 pm
  PM Quote Reply
16th Post
Greg Fletcher
Administrator


Joined: 03-11-2005
Location: Lake Nacimiento, California USA
Posts: 430
Status: 
Offline
I had Konis on my JH for years and always thought they were too stiff for a road car, so I suppose it depends what you're after. BTW, Koni will be happy to rebuild an old set of JH shocks for $140 per shock. No idea what the valving is on those. Despite the cost of the Bilsteins, you get a lot of shock for your money.

Back To Top PM Quote Reply

 Posted: 12-21-2006 10:54 pm
  PM Quote Reply
17th Post
Tom Thomson
Member
 

Joined: 03-18-2005
Location:  
Posts: 33
Status: 
Offline
Greg

  Do you still have the old Koni's around and if so would you sell them?

                                       Tom 13753

Back To Top PM Quote Reply  

 Posted: 12-23-2006 03:32 pm
  PM Quote Reply
18th Post
Pat Connor
Member


Joined: 03-12-2005
Location: San Dimas, California USA
Posts: 21
Status: 
Offline
Ron great info about custom springs from http://www.coilsprings.com .  What is their turnaround time on custom springs?

Back To Top PM Quote Reply

 Posted: 12-24-2006 01:10 am
  PM Quote Reply
19th Post
Ron Earp
Member


Joined: 03-12-2005
Location: Cary, North Carolina USA
Posts: 339
Status: 
Offline
Pretty quick in my experience. About 3-4 weeks tops, just make sure you phone back about 5 days after order to make sure it sticks. I had four good experiences, and one bad experience when my order was lost. It is a small family company and things happen, but I am pleased with them.  Out of KS if I remember right.

I've got a couple of sets of Konis that have rebuilt by TrueChoice. I might sell a pair, let me locate them.  The thing about shocks is to get your spring rate dialed in first - they are the primary spring in the equation and must be right. Shocks are dampeners, and they do just that - dampen the primary spring with respect to the suspension system.

Smart money goes to getting the springs right first, shocks second. I'm running a set of $15 truck shocks at the moment and they seem quite good.  I'll definitely change them out for something else once I know the springs are right, or re-valve my Blistens to match the springs once settled.

Ron

Last edited on 12-24-2006 01:14 am by Ron Earp

Back To Top PM Quote Reply  

 Posted: 01-02-2007 03:06 am
  PM Quote Reply
20th Post
Art DeKneef
Member
 

Joined: 03-12-2005
Location: Mesa, Arizona USA
Posts: 338
Status: 
Offline
Since we were talking about shocks and springs, is there away to tell in what shape a shock might be when it isn't installed on a car?

I have some shocks that I can can compress and uncompress by hand. That kind of tells me the shock is worn. But by not havingany new shocks, I can't tell if that is correct. Checking around didn't offer any help other than testing with the shocks on the car with the old bumper bounce test orsome other test.

The shocks aren't leaking but the bushings look old. I'm just trying to decide whether to use these for a while or buy some new shocks.

 

Thanks, Art

 

Back To Top PM Quote Reply

Current time is 09:22 pm Page:    1  2  Next Page Last Page    
> Jensen Healey & Jensen GT Tech > Suspension > Coil-Over Shock/Spring Conversions Top




UltraBB 1.172 Copyright © 2007-2011 Data 1 Systems