Hello all -

I'm in the middle of doing a lot of suspension mods for my 1800 race car. I've done a lot of reading and research and think I know how I want to proceed. I would like to point out the mods I am doing to solicit feed back from those that know about suspensions.

I have listed the mods in the form of stages, however, I'm already at various points within all the stages, and plan to build at stage three for all my changes.

All comments are welcome...I've never had thin skin and never will.

Thanks, Tremmelle

MOds:

Stage one:
Limited slip or welded rear-end (mine is welded, but I'm going to slip)
800 pounds 9" front springs, 200 pound rear springs (not sure of the height yet)
Carrera Shocks - model 3146 (144/101 rebound/compression) for fronts.... model 3275 (98/76) rears (or shocks to the same valve specs)
7" wheels as close to original offset as originals.
Derin bushings
Adjustable sway bar in rear, with rod end connectors, and sway bar with rod end fitting in front. (rod ends make it easier to account for twists or preload in the bars).
Corner balance car with shims without the sway bars connected, than connect the sway bars and insure they don’t have a preload to upset the balance just done.

Stage two:
all rear arms links converted to rod ends (no rubber or derin)
steering column replace with Borgeson “double D”rear rod and u joint

Stage three:
Convert shocks to rod end type (have to modify the mounting points on the car)
once shocks are converted, use the coil over function in front. To convert the rear to coil over, eliminate the stock shock mounting position (at an angle) and move the shock to the mounting position that springs are in (vertical) and convert to coilover.
Convert all control arm bushings to bronze, with zerc fittings.
reinforce the flanges on the front cross member where it attaches to the frame rails. By now, the suspension is more rigid than the car frame/cross member, which is bad...the car frame can flex. (note: my roll cage is extremely well designed…there are two roll cage connecting bars connected to the frame near the front suspension (both sides of the frame)on each side of the car back to the main cage inside the car)
make thinner engine mounts (mine are solid aluminum today). This will lower the engine by almost an inch and you can move it back about 1/2 inches. This should have a similar effect to lowering the car.

I don’t plan to reposition pivot points of the control arms. The steering box may have to move because it is connected to the frame. If the frame moves, the box moves…if the box moves the idler arm moves…and so on. The steering column gets in the way, the frame rail gets in the way, and so on.

I would like to know if anyone see any blaring mistakes in the making.

Tremmelle,

Some comments.

Too much is left out for anyone to make a lot of specific recommendations.
What tires for instance, makes a huge difference on springs, shocks, sway bars, etc.

Some of us that you might be looking for info from do this as a business,
so most of the detailed info goes to those who buy parts, etc, from us.

I usually recommend changes in stages, as someone used to stock 250 lb. springs, for example, would be very uncomfortable jumping to 1000 lb. springs. So we really need to know where you are, what problems you are trying to cure, before making recommendations. Not one word said about how the car handles now, spring rates now, etc. Times at known tracks would give an idea where you are now with your current setup, driving skills, etc., and can help with recommendations as to where to go from there.

Some changes will make the car illegal for vintage racing with most organizations, such as going to coilovers, and for what advantage?

Why adjustable sway bar in the rear and not in front?

Bushings are in the rear suspension for a reason. Unless you change the geometry
the stock 4 link suspension will tend to bind with solid rod ends. You can work this out on paper.

KISS - "keep it simple, stupid". Some changes are a lot of work ( and $$$ ) for little result.

Fix problems first before doing "go fast" changes.

I know that you saw me race at the Road America Volvo meet. Fastest Volvo there based on qualifying and race times, and the suspension was entirely stock except for front upper and lower suspension bushings, shocks and springs - eventhough I had raced earlier in the year with different setups. Should give you an idea what can be done without a lot of radical changes.

Just some thoughts.

John
V-Performance.com

I cant comment on the 1800 chassis but it sounds like you are doing the most important part the handling extremely well. I noted that you weld diffs, when i raced hot rod and stock cars a hundred years ago we filled hemisphere with lead, seal potential leaks and preheat metal to prevent spatter, pour in molten lead. Never had anything break and you reheat and use parts again.