View Full Version : New 5 link suspension on Viper

28-09-08, 08:55 PM
I have finally got around to putting 5 link suspension with Panhard Rod and coil over's on my Cortina based Viper.

Photos are crap due to taking them on my phone.

28-09-08, 08:57 PM
Some more photos

29-09-08, 12:44 AM
Hi Dixie

You've been busy.

A little question though
Are you sure the top strut mounts are strong enough to take the full suspension loads?
I wouldn't trust mine (similar design) so erred away from the coil over route and used something different.

Don't know if you have any cross bracing in the boot but might be worth considering??


29-09-08, 10:08 AM
Hi Mark
I love the 'fourth bridge' approach underneath :). Your welding definetly looks better than mine :).
I will be nicking the coil over approach eventually (after i have sorted my front end out).
If you are right Dean, would you suggest the 'triangulation' approach to the front and rear of the original bracket?

29-09-08, 12:33 PM
Hi Dixie.
You have been a busy boy under there.
You should not use a panhard rod with that set up. Because the upper trailing arms are at an angle to the lower arms this will in effect triangulate the set up. Adding a panhard rod will try to alter the way it all works, conflicting with the the stresses on the bushes/rose joints. If you have rubber bushes in the top trailing arms this might help eleviate the stresses the panhard rod will induce.
A Watts linkage would not induce the stresses, but would almost certainly have no appreciable effect.;)

29-09-08, 08:01 PM
I basically wanted to keep the origional Cortina triangulation because I couldn't see any problems with it, except that it was difficult to adjust. Bob Busbridge has put Panhard rods on his Vipers with great success.

I have measured the amount of lateral movement on the axle using a LASER, and with a maximum up and down travel of only 3", it seems that the axle moves less than 0.25mm over the total travel, more than acceptable. The arms are located on Poly Bushes supplied by Superflex in Wells, they have a "Kit Car" set of bushes specifically for making up your own arms( Cost 64 for 4 bushes and shells), the other ends are aircraft grade 14mm rose joints with PTFE liners, these bushes give a fair amount of movement, one end of the Panhard rod has a rubber bush.

The 300 Lbs Coil/Overs have been put on strengthened brackets, I did not trust the origional ones, although Viperjim has done it and they work fine. I have welded some more plate onto the side of the existing brackets and followed them around the bottom of the chassis in one piece and put extra webbing in place, you can't see it from the photos, also I have dropped the position of the damper by 3 inches to stop any flexing and reduce the moment force, there is so much new metal there it can't go anywhere.

I have now moved the axel over by 10mm to make wheels equal both sides, moved it back 15mm so that the wheels are in the center of the arches and lowered it by 30mm, with my new wheels it should great.

The frame was Viperjim's idea, he did this to his Pinto Viper a number of years ago, seems to work well. I will take some better photos tomorrow when I paint it.

Thanks to Viperjim for all his help and ideas and where to get the shocks

29-09-08, 08:11 PM
I take it all back, that 0.25mm is more than safe. I was expecting much much more.:D
Have you tried it without the panhard to see how much side to side there is? I should imagine quite a bit if you put a little presure on the nylon bushes.:D:D

29-09-08, 09:04 PM
Some more photo's of Panhard rod. This was made before I altered the arms, so photo's out of sinc with rest of posts.

29-09-08, 09:16 PM
I did look at the Watts linkage, but couldn't be arsed with making a mounting bracket up to take the 180deg arm that the rods fit to. Ralley Design had one, but wanted over 200 for it, so paid 45 and brought the Panhard rod, may not be the best but should be fine for my limited use.

29-09-08, 09:21 PM
Hi Dixie.
I have just noticed something on one of the last set of pictures:-
http://www.cobraclub.com/forum/attachments/viper-tech-forum/6407d1222718653-new-5-link-suspension-viper-panhard-rod-4.jpg (http://www.cobraclub.com/forum/attachments/viper-tech-forum/6407d1222718653-new-5-link-suspension-viper-panhard-rod-4.jpg)
The lower trailing arms seem to be at an upward angle as then run from the chassis to the axle.. This can cause severe rear axle steer over bumps. I had this problem with a chassis i made for cortina running gear some years ago when i tried to lower the ride height.
This rod (And the top ones for that matter) need to be in a horizontal position at normal ride height to correct this) Have you either raised the height of the front mount or lowered the mount on the rear axle since then to resolve this? Feel free to give me a ring if you like on 07785 702005 (Before 10:00 PM);)

Happy Jim
29-09-08, 09:22 PM
I have now moved the axel over by 10mm to make wheels equal both sides, moved it back 15mm so that the wheels are in the center of the arches and lowered it by 30mm, with my new wheels it should great.

Hats off to you Viper guys, you really are the "Builders" amongst the remainder of us "Assemblers".

Nice work


29-09-08, 09:23 PM
You're not kidding.


29-09-08, 09:35 PM
Hi Dave.

I did notice this when I started the mods, but other than putting on new brackets on the axel I couldn't find an easy way of changing it. I could have made shorter top arms, but that would of meant welding new brackets on the car, plus I didn't know what effect this would have on the geomertry, believing that Mr Ford new a thing or 2 about Cortina's, I chose to leave them, may live to regret it.

The new arms are also at this angle, but don't seem to have made alot of difference in the handling as they are at the same angle as the orional Cortina items, but as I actually don't know much about all this stuff I will take your word for it.

Can I call you tomorrow evening please?



29-09-08, 09:41 PM

Have a look at this photo please. It is the new arms after the mods. These are more horizontal.


29-09-08, 09:45 PM

Have a look at this photo please. It is the new arms after the mods. These are more horizontal.


Hi Mark.
The pivot points on the Cortina were horizontal to one another at normal ride height. (That's how old I am, Had loads of Cortinas back in the day....:(
Is this picture taken with the rear wheel off the ground?
Anyway, feel free to give me a bell.;)

29-09-08, 09:53 PM
Good point, wheels were off the ground.

What a bummer, I will drop the shocks off and move the axle up and down and see what interaction there is.