PolyBronze Bushing Install and other modifications., Lightweight V8 Options

[Mike T]

After a dismal performance plagued by random oversteer at my last AX I decided to that continuing to use the car in it's current state made no sense. I have been accumulating a bunch of suspension pieces and fiberglass body parts and decided that there was no time like the present to get to work.

This was the car on July 16th;

[Mike T]

I began with the Bushing install.

PolyBronze bushing kit comes with bushings to do both front A-arms and both rear control arms, shims and intructions.

[Mike T]

The PolyBronze Front Bushings come with 3 thicknesses of steel shim stock to be used to take up any play when fitting up the inner race sleeve on the control arm. .001" .002", .004"

The bushings are marked for "front" and "rear" meaning the front of the control arm and the rear of the control arm. Don't mix them up.

[Mike T]

Here I'm using a .001" and a .002" shim to snug up the fit. I didn't get any pictures of the operation but from here you just slide the sleeve all the way onto the bearing surface untill it's firmly bottomed against the flange. I had to straighten up the flange a little to get good contact with the sleeve.

After that I used the Loctite product specified in the instructions. About 5 to 7 drops. It wicked into the seam real slick.

[Mike T]

The finished installation.

I let it set up overnight to cure. I tried to remove it using all my strength with just my hand and it didn't budge. Here is the installed arm. Moves really smooth now. No "sticktion".

[Mike T]

When I removed the rear trailing arms I found this: Looks like the Weltmeister Polygraphite bushings were rubbing the inner ear. No cracking or pulled seams though. No "ovaling" of the mounting hole.

[Mike T]

The trailing arm and all the parts to install the bushings.



After fitting up the bushings I needed a .004" shim on one end and no shim on the other. I pulled them into place with a threaded rod+big washer.


Here is the completed control arm with grease fittings. I used a generous coating of waterproof high pressure boat trailer wheel grease during installation.The paint on this control arm is POR-15 I put on there in 1997. Held up great and is still shiny.

[Mike T]

Measure over 15/16", drill straight and you nail the grease groove dead center. I used 45° 1/4-28 fittings instead of the 5mm that came with the kit. I had a 1/4-28 tap.



Grease fitting installed.




Here is the Rear trailing arm installed with the new PolyBronze Bushings and a fresh coat of POR-15.

[Mike T]

I moved on to the chassis work. A few years ago I removed the trunk floor and added some support structure. I decided to get a little more radical.

I stole this design shamelessly from URY914... (IMG:style_emoticons/default/pray.gif) Hi Paul.. (IMG:style_emoticons/default/wavey.gif)

Begin by welding two 1.75" tubes to 1/4" steel plates and bolting them to the transaxle mounting ears.


added support tubes from shock towers and from plates welded at rear of inner suspension console.


final bar across ties the two uprights together. This tubing only supports the back of the transaxle. I replaced 16lbs of cut away metal with 9 lbs of tubing.

[Mike T]

With the rear tail light panel cut away along with all the bodywork rearward of the shock towers I lost my exhaust system hanger. I supported the muffler on a jack and made up a template for a bracket.


transfered the template to flat .09" steel plate and cut out a 2 pc muffler hanger. I welded it directly to the upright and the Bullet muffler. Light and simple. Maybe I'll drill a few lightening holes in it...

[Mike T]

I repaired the bent nose by cutting away all the sheetmetal affected by the lousy repair job. With the front end sheetmetal cut away I needed to reinforce the front end.


I added bars from the existing angled tubing to the mounting area of the front suspension crossmember. I attached them to 1/8" steel plates to spread the load.


I added a crossbar to stiffen the front of the torsion bar mounts.

[Mike T]

I replaced the entire front fender because it had been repaired by welding on a new front half with the seam just about centered over the tire. Whoever did it was careless and the front of the fender ended up 1" higher than the passenger side. I cut off the fender from a parts car and installed it in the proper location.
These will be replaced with fiberglass 1/4's when my budget recovers.


GT Racing 1/4 panel, Rennspeed Fiberglass doorskin. Retained with DZUS type fasteners.



Front IMSA Airdam fastened in place with 5 DZUS plates across top edge.

[Mike T]

Here are the Weltmeister Polygraphite bushings I took out of the rear after 9 years of service and hundreds of autocrosses. Look at the odd wear pattern in the ones on the left. There is also evidence that they deformed a little.



Front end reassembled with 22mm Welt torsion bars, 22mm Welt sway bar. I added Turbo tie rods this time around.




That pretty much brings things up to date. Still have a bunch of assembly to do. Then set ride heights and set camber, caster, toe etc.



Mike T

[J P Stein]

I'm prolly movin' to E Mod. Glad you doan live around here (IMG:style_emoticons/default/biggrin.gif)

[Trekkor]

Thanks for posting. Glad to see a project moving foward.


KT

[URY914]

Great thread and great job, Tim.

Your front trunk tubes looks like mine too. Great minds think alike. (IMG:style_emoticons/default/biggrin.gif)

I know how much work all that is, but when you post pictures of it people think you did it all in one night. Fab work is s-l-o-w when you work alone. Keep it up.

Paul

[Mike T]

Last Wednesday I bought a set of the lever arm style scales from ebay. The seller was WWW.MADONE.NET. I'm expecting them any day now. I have used the electronic style many times. A local speedshop rents a set of Rebco scales for $20.00 a day and I've rented them 4 times in the last 10 yrs. I'm looking forward to seeing how these compare and how they are to use.

[914forme]

(IMG:style_emoticons/default/popcorn[1].gif) Let us know!!!!

[Mike T]

Just an update on my project. I received the scales I bought from MADONE.NET last friday. They are well built and came well packaged. All the parts were there and the instructions look adaquate to explain operation.

The bad part is it took almost a month to get them. His ebay feedback while generally good indicated slow shipping could happen.

Anyway...

I will be using them this week and report my experience. My race season is over so I have lots of time.

Mike T

[Mike T]

Another update on the work I did to my car.

I used the MADONE.NET ebay scales and they work pretty well. Fairly easy to set up but it takes a while to get them positioned just right. Chassis setup and adjustment is a little slow because you have to crunch your own numbers. I did my car in about 3 hrs and found them to be very repeatable.

I bought the system with rollers on the frames that are supposed to allow the suspension to settle out any binding. I took 7 readings and the total weight reading varied by 2%. I consider that acceptable. I got the cross weights to 50.1% and couldn't fiddle them any closer.

I'm going to redo the car to see if the results are repeatable. Should I make a thread when I do? With pictures? Anybody interested?


Oh, by the way: After all the cutting and fiberglass body parts the total weight with fuel was 1820 lbs without driver. 56% rear weight, 49% left weight. Not bad for a V8 car with cast iron heads.

Mike T