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Coil over shocks convo

Posted: Mon Feb 17, 2014 5:41 pm
by itawolf
Anyone running a conversion on the rear
That eliminates the torsion
Etc etc

I would like to see pics
But on a street bug

Also anyone running stock x stock
Chromoly trailing arms
On same street bug

I want to eliminate my dual spring plates

Re: Coil over shocks convo

Posted: Tue Feb 18, 2014 3:04 pm
by itawolf
no 1???????

Re: Coil over shocks convo

Posted: Wed Feb 19, 2014 8:57 pm
by FJCamper
Hi Itawolf,

Torsion bar replacement kits do exist that allow you to bolt a ball joint onto the torsion bar housing. The joint bolts to an adapter that in turn bolts to your diagonal arm.

You then need a reinforced lower shock mount on your diagonal arm to bolt the bottom end of the coil-over shock to, the top end bolting to your original upper shock mount.

The entire weight of the rear of the car is now on your upper and lower shock bolts.

The advantages of this modification is you get full control of your ride height, and with the right shock, compression and rebound adjustment. But, you still have the (relative) limitation of the diagonal arm geometry. You don't get F1 geometry.

For dune duggies, replacement of the torsion bar suspension helps by allowing greater suspension travel, but for a street car, it's a very complex operation for too little gain --- other than bragging rights.

FJC

Re: Coil over shocks convo

Posted: Thu Feb 20, 2014 8:01 am
by Dale M.
Also shock towers where never designed to support the weight and or pressure exerted on them for full support of suspension.... You might be headed for eventual shock tower failure by changing the loading on them....

Dale

Re: Coil over shocks convo

Posted: Thu Feb 20, 2014 8:31 am
by Ol'fogasaurus
Both Pileldriver's and Dale' 'puts are good but Dale's, especially the latter one on the shock towers, should be considered.

You didn't say just what you have in mind which could make a difference as to the advice given. If you want to mod the suspension for ride there are IFS kits for the front (a couple of companies sell the conversion but it is $$$) and I guess you could change-out the rear torsion bars for coil overs (Dale's warning) but there must be a reason you want to do this; there are/maybe advantages to doing it but it could be a lot of work depending what the potential gain/outcome is. Remember you are dealing with either a 80" or 95" wheel base with the former being harder to setup ride wise because of the inherent short choppy ride.

Lee

Re: Coil over shocks convo

Posted: Sun Feb 23, 2014 11:51 pm
by 4agedub
I have thought about doing something similar, but only to assist the torsion bars. So leave the torsion bars and add coil overs to make the rear end harder. Maybe something like they used on the old Formula vees might work.

Re: Coil over shocks convo

Posted: Mon Feb 24, 2014 1:38 am
by helowrench
4agedub wrote:I have thought about doing something similar, but only to assist the torsion bars. So leave the torsion bars and add coil overs to make the rear end harder. Maybe something like they used on the old Formula vees might work.
Yes, that is possible, but it is relatively easy to put stiffer torsion bars in.
Fairly cheap, also, if you are willing to consider used torsion bars.

rob

Re: Coil over shocks convo

Posted: Mon Feb 24, 2014 6:52 am
by Ol'fogasaurus
I would think this over a bit. Both the 4ager and Helo's points are valid but to add to it the spring rates of the two suspensions are going to be different and will probably react differently. Think of a coil spring as nothing more than a torsion spring (twists) in a compact area (diameter); it is going to twist as it compresses or extends while the torsion bar is just going to twist; the coil over is supposed to support the torsion spring not take its place which it would/could end up doing during the suspension's limited travel.

As far as the suspension package goes: I would focus in hard on shocks/dampeners as that is where the support for the torsion bars is. Not to augment but to properly dampen the unwanted movement or loading/unloading reactions.

My opinion is worth slightly less than you paid for it so react accordingly.

Lee

edit: changed "... coil spring is ..." to "... coil spring as ...".

Re: Coil over shocks convo

Posted: Mon Feb 24, 2014 9:05 am
by Dale M.
4agedub wrote:I have thought about doing something similar, but only to assist the torsion bars. So leave the torsion bars and add coil overs to make the rear end harder. Maybe something like they used on the old Formula vees might work.
Simply reindexing rear torsions will give you stiffer rear suspension (or adjustable spring plates) ....

Image

Not only does raise or lower rear it changes preload on rear suspension...

Dale

Re: Coil over shocks convo

Posted: Mon Feb 24, 2014 4:48 pm
by PhillipM
Preload doesn't stiffen the suspension however, the spring rate and ride frequency is still the same ;)

You just tend to run out of droop and drop into holes instead, ends up riding like crap.

Re: Coil over shocks convo

Posted: Mon Feb 24, 2014 5:09 pm
by Ol'fogasaurus
When I went to 30°s of preload the ride got down tooth jaring! It does stiffen up and going with less softens it up.

Re: Coil over shocks convo

Posted: Mon Feb 24, 2014 5:10 pm
by PhillipM
Probably because you'd run out of droop!

No good having soft springs/bars if you drop the chassis into every hole it goes over because the wheel can't go down :lol:

Re: Coil over shocks convo

Posted: Mon Feb 24, 2014 5:17 pm
by itawolf
Boy you guys have given me alot to think about

What are most autoX peeps running??

I'm looking for a good turning ride
We r talking sharp sharp turns
Like in mountain racing in the alps


Like the

2013 Formula Renault 2.0 ALPS

Re: Coil over shocks convo

Posted: Mon Feb 24, 2014 5:20 pm
by PhillipM
Fiddle brakes :D

Re: Coil over shocks convo

Posted: Mon Feb 24, 2014 5:40 pm
by Ol'fogasaurus
PhillipM wrote:Probably because you'd run out of droop!

No good having soft springs/bars if you drop the chassis into every hole it goes over because the wheel can't go down :lol:
I am running the full suspension travel that I allow myself based on the max CV angles allowed for what I am running http://blindchickenracing.com/How_to/CV ... ts_101.htm; I am running bus CVs inner and outer. I don't recommend running more than 26° to 28° as the ride gets very stiff after that. I have been running on the sand this way for many years w/o a problem.

Image

Riding on top of the whoops (top to top not dropping down into the whoops)

Getting back on to subject, the more preload you put in the stiffer the ride and conversely so. By using less preload and a stiffer/bigger dia. bar you may get better suspension action w/o too stiff of a ride at non off-road settings.