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View Full Version : Aftermarket, front, rear or both - Mopar A Body



Boony405hp
08-03-2011, 03:53 AM
Ok guy's I'm asking the common question. I've done some research but it's all a bit hazy. Aftermarket front ends and rear ends...I'll give you the background on my car first:

I currently have an A body with the factory torsion bar front end .890 torsion bars (is currently a 6 cylinder/265 hemi), and leaf spring rear (retempered/extra leaf added). I am doing the new 5.7 Hemi conversion. I currently have the car set up with Koni shocks all around, 30mm sway bar up front,, all good condition bushes, and sits on a set of 235/45/17 American Racing torque trusts.

https://static1.pt-content.com/images/pt/2011/08/car-1.png

Now I think the car handles pretty good as I've put it around the a few circuit tracks, it's just on the road the ride can be quite bumpy harsh on some streets in comparison to a which rides much softer on the bumps but still handles quite well.

If you had to change one end of the car to make it a smoother ride would you do the front (alterktion) or rear (IRS from a jaguar for example which I've seen done or a 4 link). I think true IRS would be best as apposed to a solid axle but there are no real off the shelf IRS kits other then HEIDTS.

I've never really seen any what I believe fair comparisons (XV maybe the closest). I understand there is a compromise between handling and comfort. But your modern cars even the modern cars which ride much softer can still handle very well (in comparison).

http://www.reillymotorsports.com/store/product.php?productid=16184
http://www.reillymotorsports.com/store/product.php?productid=16172&cat=263&page=1


What are you're thoughts??

Uhcoog1
08-05-2011, 10:37 AM
A lot of questions there! I vote for keeping it torsion bars and leaf springs. I think you can get the desired ride with a lighter rear leaf spring (take out your add a leaf) - that's probably overkill. I'm planning on running my factory replacement rear leaf springs (or an equiv spring rate of 130 lb/in leaf springs) to get the roll rate couple I need, and that will be with either 1.04" or 1.14" torsion bars and a 1.25"-1.5" sway bar up front.

I'm doing the 5.7 hemi with tko600 right now myself. I've seen some very good running mopars with factory type suspensions, one of which is the hotchkis e-max challenger. They've finished very well in events, with upgraded components.

A lot of the mopar guys run 1.04-1.14-1.24 torsion bars (~250, 350, 450 lb/in wheel rate torsion bars). Compared to your .89 bars, which are probably ~120? (I don't have the chart handy)

I know you're looking to go to IRS in the rear and/or coils up front, but I don't think that will neccessarily accomplish the ride you are after. Also, have you welded in subframe connectors?

exwestracer
08-05-2011, 02:20 PM
Where does it feel like the harshness is coming from? Front, rear, or both? I would think about swapping some leaf spring out for a rear sway bar. Also, if you've gone to urethane or delrin bushings, you're going to have to live with it. Possibly look into some digressive shock valving (best) or double adjustable shocks (2nd) so you can soften the compression damping to suit.

Bjkadron
08-13-2011, 08:54 AM
Mopar Suspensions are a great design right from the factory. To be honest, I was going to trash the whole stock setup and go to coilovers before I researched the geometry of the stock mopar stuff. Now I'm just taking the flex out of the bushings and tuning the spring, shock, and swaybar rates.

If you like the way it handles, but are concerned with the ride, why not go with adjustable shocks? They control much of the feeling of the ride and with adjustable all you have to do is switch to the stiffer settings for the track.