The 14 Car Performance Therapy Project Rushforths, Baers, Yokohamas, and more

[WSSix]

I'm curious to see how the spoiler turns out. That's something I've thought of doing in the future. Thanks for the updates John.

[NOT A TA]

Originally Posted by WSSix

I'm curious to see how the spoiler turns out. That's something I've thought of doing in the future. Thanks for the updates John.

More on the spoiler!


The rear spoiler is a focal point on a lot of 2nd gen F bodies and very easy to see. Since they're 35-45 years old now most have deformed or been damaged over time. The plastic slowly drying out and shrinking causes them to become wavy and crack. Some are worse than others of course and I'm lucky the two I'm working with were in pretty good condition to start with.

The tall one I'm making was from a 76 and needed some stripped threads repaired and missing studs replaced so I welded some small washers on 1/4" X 20 threaded rod and made several replacement studs (since I couldn't buy any locally). While I was making them I made the threaded part that screws into the spoiler a little bit longer to grab virgin threads at the bottom of the holes. Several drops of fiberglass resin in the holes before installing the new studs carefully and problem solved.

Next issue with spoilers is getting them to line up as well as we'd like. Often we're dealing with used or aftermarket quarters, deck lids, tail panels etc. which may not be the same as original. Our standards for panel alignment and gaps has raised quite a bit over the years since these cars were new and even when new the alignment/gaps weren't all that great from the factory. Here's my way of bringing old rear spoilers back to usable condition with better fitment and gaps than stock. I'm sure others have different ways of accomplishing the same goal and there's more than one right way to do things.

Strip the spoiler with 80 grit and clean old paint, sealers etc off the inside of the spoiler around the mounts and pads it sits on where it meets the body. Then install center section on trunk lid (trunk lid aligned previously). Clean old paint, sealers etc off the inside of the spoiler where it meets the body. If the mounts on the inside of the spoiler have to be modified by grinding a little off so the spoiler sits nice, so be it. Also, the holes in the decklid may need to be ovalized a bit to get the center section where you want it. Once happy with the center section, snug up the nuts on the ends to hold it in place. Then install end caps and see if you can get them lined up pretty well with the center section with the nuts snug. Again, may need to slot holes or modify the inside of the spoiler cap so it sits nice on the fender. Be patient, take your time and shuffle the pieces a little one way or another to get the pieces to sit as nice as possible on the sheetmetal and have the best gaps. If necessary move the center section a little and try again, when satisfied tighten the nuts. Then...

The ends of the caps and center section have often been sanded for previous repaints and the plastic has shrunk and deformed so after 35-45 years they're usually not very flat anyway. Apply a coat of your favorite body filler over the gaps between the end caps and the center section, don't try to fill the entire void, just bridge the gap. Ya, I know, it just seems wrong. Then use a hacksaw to cut a slot centered where you'd like the center of the finished body gap between the center section and end caps to be. Next use a thin file like a saw and cut the gap wider. Then use thicker and thicker files to widen the gap till it looks the way you want. Using the files keeps the slot straight and even because they don't flex much. If you want to move the gap a bit one way or another just apply pressure to the file as you're cutting with it. Once you've got the gap where you like it open the trunk and apply filler to the voids on the ends where the filler used to bridge the gap didn't go. Then close trunk and use the file again, repeat as needed till the ends just have little voids and pinholes in the bondo.









Because the spoiler plastic has shrunk, warped etc. over the years They're not straight anymore. At a minimum they'll need high build primer and block sanding. I'd hoped that would be all I needed to do for the one below but as you can see after some blocking on the one in the pic below I've already cut through the primer to the plastic and haven't even removed the guide coat in the low areas where the mounts hold the spoiler to the car. This was on a spoiler that spent 99% of the last 25 years in a garage since I did the car the first time. I've seen the same pattern before and apparently the mounts pull enough so the spoilers deform as the plastic gets old. The cure is to skim coat the whole spoiler with filler (front and back) then block sand the filler with the spoiler attached to the car so you can have the center section line up with the end caps by sanding across the gap. then prime/block/prime using a guide coat till you're happy.





Here's my tip for making a uniform edge where the spoiler flows into the decklid. A flat block with sticky sandpaper and a spacer to keep the block on the same angle as you slide across the spoiler. Don't forget tape so you don't mess up the trunk lid.

[NOT A TA]

I've now got both spoilers in final primer and will move on to other things. When I mounted them to do my sanding etc. I mounted the stock spoiler forward and the tall spoiler slightly back so that the stock spoiler would always cover any foot print marks, or fade lines from having the tall one. The tall version is about 1 1/4" taller than stock and mounted to the car in the pics below where it will stay a while so I can admire it while doing other stuff ahahaha.











[/QUOTE]

[NOT A TA]

With the spoilers in final primer I moved on to mocking up all the pieces of the tail panel and bumper to get the best fitment, gaps, etc.

I had my bumper welded up to eliminate the bolts and jack slots many many years ago. I took a used bumper (no repros available back then) that still had the mounting brackets attached to it and sent it to a shop where the brackets were tack welded to the bumper, the bolts removed, plates welded over the holes on the backside, and the bolt holes plug welded from the front. Then the bumper was sent for smoothing and rechroming.

The bumper never really fit quite "right" due to the brackets being adjusted for the car it came off of and the ends had the side droop seen so often on 70-73's. So now was the time to fix things. I ended up making spacers and tack welding them to the bumper brackets to even up the gap along the back and modifying bolts and almost all the bolt holes so the ends can be adjusted properly during final assembly.



This is the rubber isolator often missing on the center bumper support bracket. Held on by 2 plastic T clips.



Here's a tip for masking off an edge you can't cut easily with a single edge razor. Rub a file on the tape.



You can see the spacers tack welded to the brackets to create an equal gap to the tail panel in the pic below. Car had no previous rear end damage and none of the sheet metal had been replaced and although the bumper itself had been repaired and replated at least once before I ever owned it it's pretty straight. So I have to assume the fit wasn't very good from the factory judging by the thickness of spacers required and other 70-73 birds I've seen and dealt with.

[NOT A TA]

Back in the fall Holley introduced a new product at the SEMA show, the Holley Hydramat. It's a product that mounts in the bottom of a fuel tank and if the fuel in the tank touches any part of the Hydramat the fuel will be sucked in even if no gas is touching the rest of the hydramat. https://www.youtube.com/watch?v=yfE1v65fNZI

Holley started shipping about a month ago so I ordered one and got it a couple weeks ago so I thought I'd show it here. Will post about it again when I get it set up in the tank. Cost of mine was a couple hundred bucks. Seems expensive but to save the same weight (on track) with lightweight parts would cost more

This looked like a good product for me to try in my stock unbaffled gas tank until I can install a properly mounted and protected fuel cell. It'll allow me to save weight by keeping less fuel in the car on road courses without risking sucking air in high G corners, reduce the pendulum effect of fuel sloshing in the tank, be safer if there's a fire because less fuel in the car, and since it's also a filter I eliminate the canister fuel filter I've been using also saving weight.

I got the magnet kit for mounting the mat in the tank and will need to install submersible fuel line instead of the stock tube and sock strainer in the tank. Holley makes other sizes and shapes of the mat as well as types of mounting setups for tanks made out of other materials.

[NOT A TA]

Back in the 70's when we ran air shocks with big and small tires on F bodies I always noticed the crappy job GM did on the pinchweld under the rear splash pan because the rear of the cars were jacked up. Well those fugly looking pinch welds are still there on most of the cars and haven't gotten any better. They got bent on ice mounds in the north, rusted, repainted without being sanded smooth or stripped, and so most look worse than they did from the factory. I'm going to make a rear diffuser for my car and folks will be looking under there taking pics etc. so I figured now's the time to even it up and make it more presentable and finished looking while getting the whole tail section in final primer.

So I gave myself a guideline and used a 4 1/2" cutoff disc to cut a thin slice off. Then ground it pretty even with a 4" grinder stone, filed it straight, and got rid of the sharp edges.

[NOT A TA]

With the rear of the car in final primer I spun the car around (Go-Jacks are awesome!) and turned my attention to lining up the doors and front end sheet metal. I'd loosely assembled everything to determine if I'd be able to use the 81 subframe, 70 steering, and 70 core support with the solid body mounts. There are differences in the subframe front horns that affect the position of the bumper brackets and steering but with various modifications it looks like I should be able to get everything to fit.

The door hinges were installed bare metal to bare metal at the factory on the 2nd gen F body cars I've worked on. If the area where the hinge mounts is covered in primers/paint it's a lot more difficult to line up the doors because the paint sticks together when the bolts are snugged or tightened. Then if you try to move a hinge just a little while aligning things it usually jumps farther than you want it to move once you get it to pop free.

So I sand down the area on the cowl and door as well as the hinge surfaces to make adjustments easier. Then because I'll be leaving the hinges on the cowl when the doors come off for the cut ins I sanded down the final primer that was already there to 320 for paint because it's easier to sand without the hinges in the way (they'll also get the Scotchbrite scuff before paint).

Once sanded, a little spray lithium grease gets shot inside where the plate slides around in the cowl and door and a thin film of grease where the hinge touches the cowl and door. This allows easier adjustment of the doors and a bit of corrosion protection. Careful attention to keep grease off areas that will be painted is a must and after the hinges are mounted wax and grease remover used all around hinges to remove any possible residue.