spitfun None
Dec. 14, 2012 4:15 p.m.

I am building a rotary powered Spitfire for autocrossing. I believe I need to stiffen up the rear as I have already went to 450 lb. spring up front,by either finding a stiffer race spring (anybody have one they want to sell by the way?) or I was thinking about coilovers with maybe 100 lb. springs on them,is there any problems going this route? I figure I want to be around 300-350 in the rear and with the stock spring and a lowering block I should be close. Thanks Rich

93EXCivic MegaDork
Dec. 14, 2012 4:34 p.m.

You will probably need to stiffen the shock mount if you go that direction since the stock ones are not meant to take spring force. Or you could go to a spring shop and have them re-arch and add a leaf to stiffen the stock spring.

Ian F PowerDork
Dec. 14, 2012 5:48 p.m.

Contact Ted Schumacher at TSI automotive in Ohio. He can direct you towards where you need to go.

erohslc HalfDork
Dec. 14, 2012 7:45 p.m.

The shock mounts actually handle much greater loads than the spring mounts, and so are perfectly adequate for your needs.
You can have a spring shop make a custom spring that is stiffer, but I'd really consider going the coilover route with the current spring.
To achieve the needed ride height, you will have to either re-arch the spring flatter, or get a spacer block to fit between the spring and top of the diff.

Is this a swing axle car? What is your solution for preventing jacking and tuck-under in the corners?

I ask this, because the leaf style Camber Compensator can be configured to act as additional spring stiffness, thus solving 'two birds with one stone'.

Also, most organizations will not let you race a swing axle Spit without some kind of camber control device.

Carter

spitfun New Reader
Dec. 14, 2012 8:22 p.m.

The car will have a 1" spacer to combat the positive camber problem. It is a swing spring 1500 car. I would like to find a race spring and be done with it,but no one makes them anymore (off the shelf anyway). Rich

spitfun New Reader
Dec. 15, 2012 5:47 p.m.

bump

bearmtnmartin Reader
Dec. 15, 2012 7:01 p.m.

I have a composite mono leaf on my gt6. Can't remember who made it though. I will give it some thought.

erohslc HalfDork
Dec. 15, 2012 8:48 p.m.

Since you have a swing spring, no Camber Compensator required to prevent the condition.

Note that it's been reported that some AutoX Tech Inspectors will still demand to see one before they let you run.

BTW, I have a copy of the BLMC Spitfire Competition Preparation guide (4th edition) here in front of me.

On p.37, it says:

'Before installing the spring assembly, have it de-arched by a spring shop to 1";i.e.with the main leaf spring resting on the workbench, it should measure 1" from the bottom of the leaf to the bench. Next, cut off the second leaf at the point where it wraps around the eye. This is to prevent it from bottoming when it flexes.'

Thus spake Kastner ....

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