Viper, Cortina rear suspension.

[Dixie]

I have not been happy with the handling of the rear end on my Viper, at best it is very hard and doesn't install me with much confidence. Today I took it to a locally renound suspension expert for his opinion, he had the car all day, set the front geometry which was "All wrong" and also tightened up a loose wish bone???

The rear axle has little or no adjustment, and also bottoms out on the chassis at the full compression of the springs, hence makes a banging noise when I go over bumps. It only has 2 inches of usable travel, he tells me that it looks as though it's been built well, but the actual design is fundimentally flawed!!!!!! He say's the best thing to do is to remove the springs and arms, and make the whole assembly stronger to take coil over shocks and a panard rod. I must confess that I need to look on the net and find out what a panard rod is!!!??? He also suggests trying to retro fit a Searra back axle and suspension, but I am unsure just what work is involved with that.

Any of you Viper guys have any comments on his suggestions.

Thanks

Mark

[osgood]

Mark a panard rod is fixed to one side of the chassis and the other end to the opposite side of the axle this stops a live axle moving from side to side when cornering, much like anti tramp bars stop the axle trying to wind up like a spring under acceleration, you should also consider making & fitting these to improve handling re your live axle.

Osgood

[kevchard]

We also have the Corty rear end, but have not got to the finishing stage yet.
After the SVA the rear end will be coming off and a Granada Cosworth setup will be going on. It will not be a straight swap by any means, and the work will be done by my welder mate and me during our spare time.
What about coil over conversions, are there such a thing for cortinas?
Variable rate dampers would be a simpler rate to go down, whereas you can adjust ride height, stiffness and travel. Dampertech do such a beast.
The strongest route would be the complete axle swap but would involve the following at least :-
Brackets for arms
brackets for diff (including being able to adjust for camber)
Changing brake lines from drum to disk
Hand brake mods for disks
Damper brackets
Changing hubs from 5 stud granada to 4 stud cortina/sierra
Modifying of propshaft

Not a job for the faint hearted or economically challenged but best overall route.
All the above routes are my opinion only.
Cheers
Kevin

[steamyrotter]

From review of mine i think it would be rather hard to strengthen the rear shock mounts sufficiently with the body on. Also the tubes going rearward from the main chassis are slightly smaller and hence more flexible so would be less than ideal anyway.

You may be able to fit coilovers where the springs originally fit but would need lower bracketry on the trailing arm, which admittedly you could take off to do, and a bracket in the top mount position. Bit easier than where the shocks are at the mo but you would still end up with not a lot of travel.

You could always try to find stiffer springs and or spring assisters for the current setup to avoid the bottoming out. However actual rates would be a trial and error job i think.

Conversion to sierra rear is always possible but you may need to make your own arms as the sierra subframe will not directly fit (as far as i can remember) unless you modify the rear corners of the main chassis (ie just behind the seats on the outer corners) again not easy with body on. This is possibly what i may do once registered and have a bit of time on my hands!!!! Although you could always modify the subframe until it does fit within the confines of that particular hole.

I may be a bit loony but cannot see how a panhard rod will work on or help the original cortina setup as there is some triangulation in the layout of the rear arms which do the work of the panhard rod anyway. Perhaps i have misread that bit?? will have another look! (Ignore this bit... read it again, thought about it and can see some benefit if done correctly. Would still be a pain to fit depending on what has already been done back there though!)

ps As these are vipers then there always is a way to get anything to fit......

[kevchard]

I am going to go down the route similar to to what is already holding the rear lower arms on (eg a tab welded to the corner of the chassis behind the seats).
I am planning to take complete axle assembly to an engineering shop and get them to make the 'tabs' and tack weld them together off of the viper chassis. That way i can get the 'tab subframe' welded to the chassis without the incumberance of the axle assembly. Then bolt in axle assembly, work out bracketry for diff assembly. Remove axle assembly, make brackets for diff and fit them, then bolt it all back together again.
This way i can do a lot of the measuring/fabrication work and my mate can come and weld when he has a few minutes .
As far as i can see the sierra and granada are very similar, so i was going to go for broke and fit the strongest option, which in my opinion is the LSD granada.
Does anyone have any pics of the sierra setup on a viper? Is it Declan or Ceejays that has the Sierra rear? This way i can rougly gauge where the tabs need to be fitted.
Cheers
PS Has this put you off yet Dixie?

[Deck]

I've got the sierra...and am all alone in the world with it by the sound of it!!
I'll take some pics as have none of it and am changing the rubber brake hoses soon, hopefully tonight! I'll warn you though, I (accidently) discovered that its the estate rear end so don't know if it'll be of any help.

Sorry Mark, don't know about the trouble you're having cos i'm a long way from driving, and from a Corty...
Personally, I'd probably keep on driving until there'as something actually wrong with the car, enjoying the car and all the fun I can only imagine! Now you know the setup you can get used to the handling and take confidence in what your mechanic has said about the quality.

I imagine mine's going to have handling issues too but its the trade off between dreaming about an Ideal and affording a reality.
Happy Driving
Dec

[jools]

A quick short term solution to get more travel would be to use 19mm thick rear spring to lower arm seats from Superflex. Part No. SPF0208-19 @around £9 each. I have done this on my Sumo Mk2 with Cortina rear end & it's made a hell of a difference, it now doesn't bottom out at all.

[kevchard]

Hi Dec
Some pics would be great. Especially showing where the front mounts are on the large 79x39 box section chassis. I am hoping they will roughly be where the existing corty mounts are.
How far is yours these days Dec?
Cheers
Kevin

[steamyrotter]

you could always start with something like this:-

http://cgi.ebay.co.uk/IRS-rear-suspe...QQcmdZViewItem


or not.

[kevchard]

Hi Dean
Does that look substantial enough for a Cobra? I like the idea and the probable weight saving, but not the cost.
We already have the granada donor parts, but your ebay link looks more flexible (hopefully not in the bending sense tho ).
As always full of different ideas Dean, thanks for confusing me further .
Cheers
Kevin