Kubs

Over a year ago I took apart my street car to begin building it for full time track duty. It has been on jackstands since September 2010 as I re-did the suspension, and installed some home made control arms and redesigned the way the spring mounts. Today was the first time in over a year that the car has held its own weight! Not a big deal, but it made me happy and I thought I would share.

This is a week before I took it part:


I removed the interior, engine, and front suspension to begin my project. I work on it as money allows (which is why it is taking so long).

Here are the front upper control arms I made:




Here is my custom way of mounting the front spring to get it low enough with all the weight out. I used the Banski spring mount kit and drilled holes in the spring and control arm:






Here it is today on the ground finally! (The Black Rose C4 is my dad's '92 all stock street car)












This is how low I can get the car with no engine, trans, or interior! I have room to raise it up more.


Not too much to show, I still have to finish the engine and paint it, and put a cage in, but this was a big step today and I wanted to share.

383vett

Way to go Kubs.

Rob31

Is that spring mt. kit new from Banski ? Pretty slick .

Kubs

The mount is made to be used on the rear here. I bought the kit and adapted it to the front spring. When I removed so much weight from the nose it shot up in the air pretty high. I had already removed the rubber pads in the middle, and the rubber on the ends of the spring so there was nothing left to lower it. When Tom at Banski showed me his new rear spring mount I bought one with the intention of putting it on the rear, but once in my hand I had the idea to use it up front. I have to get another one for the rear now.

JackDidley

Got a bump on the hood.

leesvet

Good Job !

Thats what a "project" is supposed to look like ! ....progress, improvement, upgraded, personalized with a purpose. Still the same basic car, on steriods.

Did you consider the steering geometry when building those A arms? Thats one of the ways GM got the tight precise handling of the C4 was to offset the spindle a few degrees off center of the arm travel/center. I'm sure curious what a little more or a bit less would be like. Moving it rearward or forward...nice looking fab job !

I'm curious...why did you elect to weld one side ( A-arm) and use a bolt in the other? I'd be a little concerned about that welded stud cracking at the plate junction....

PLRX

Ive never seen the monospring mounted the way you did it. Wow thats is impressive.

DIY UCA and modified LCA-AWESOME

383vett

It'll be interesting to see how that front spring holds up. Normally, they are pretty delicate and don't even like being knicked let alone drilled on. If it works, we've got a new way to lower these things. A suggestion is to use a plate with rubber insulation below the spring so the force is spread out as much as possible instead the current rubber donut. Not criticizing, just observing. Willie

Kubs

Yes. That is to make room for the new engine to come at a later date..

Yes the arms actually follow the factory arms very closely. I believe what you are talking bout is Caster. Caster changes the ball joint location. It is more helpful in autocross but not felt so much in road racing. That is also the reason for welding one side of the arm. By making one side of the arm longer and one shorter it will move the ball joint forward and back. If both ends could pivot it would just rotate the ball joint in the center and not change caster.

Thanks!

Willie, I used a very sharp bit made for wood cutting, and it actually cut right through without splintering the fiberglass at all. I know some guys have drilled the eds of the spring to add a bolt to help adjust corner weight, but they were still mounted in the top of the control arms. I believe the springs will work in this orientation, but I will be sure to report back when I get it on track.

The donut you speak of is actually made of delrin and is incompressible. The bottom diameter of it is actually almost the width of the spring at the mounting location so it does distribute a lot of load. I thought about putting a large fender washer under it, but I dont think it is needed.

USAsOnlyWay

Awesome work, gotta feel good to get it back in the ground. Looking forward to hearing how it works out.

j-wireman

WOW! Congratulations. Good Job.

BrianCunningham

Nice fab work on the suspension

96GS#007

Nice work I am curious, why not use coil-overs so that you'd have a lot of adjust-ability and no worries about the spring coming apart?

Kubs

Thanks!

For my race class you have to take points for every modification you do. Each type of modification is worth a different number of points. For instance changing control arms is +6points, and using heim joints instead of rubber bushings is +3 points, etc etc. The more points you acquire the higher up in class you go (from the base class of the vehicle). Every 20 points you get puts you in a new class. Going to a coilover would cost more points than using a different rate leaf (+4 vs +2). The class I am trying to stay in is the fastest class that still uses the points system. The next class up is unlimited points and only controlled by a wt/power ratio. Basically deepest pockets wins that class. And probably the biggest reason I did this, Im poor. Therefore I make things I cannot afford.

engle1147

Lookin' good!

I will say I am a bit leary/wary of that hole you now have in the spring...what was wrong with the old slip/pinch stocker style mount?

Kubs

I took so much weight out of the car that thw stock style of mounting the spring couldn't get the car low enough. Obviously where it is adjustes in the picture is too low, but i now have that adjustablility also.

engle1147

I see. Well the rear spring has holes on the ends so I guess the holes in the front won't/wouldn't really matter. Keep us posted.

383vett

Good point. I didn't even think of the holes in the back springs.

Kubs

Thats what I was trying to replicate. Like I said, I ordered a spring mount kit made for the rear, and used it on the front. The rear however does have metal around it on the bottom, much like Willie suggested a few posts back, but the delrin covers a good amount of the bottom of the spring to help distribute the load. I will try to get better pictures of under the spring this weekend.

I will be sure to update this when the car hits the track.

engle1147

Ahhh - I did read it all but I missed that little rear spring tid-bit in the posts above. I seems pretty clear that you've given each portion of this project a good amount of thought before diving in - well done!