My Cobra Build Site

Another pretty productive weekend with lots of different activities. It’s hard to concentrate on one particular area of the car as there’s always one thing that needs to be done while you work on other stuff.

Most of the waiting time is for paint-related items. Lots of spray paint flying around the shop right now as I paint all of the aluminum panels for the engine bay, the rear end parts we’ve been working on, and the brake booster setup.

More detailed info:

Rear End:

I made the decision that for autocross (which I’ll be doing in this car), the 4-link suspension setup was going to be wholly inadequate. That means I need to upgrade it to a 3-link setup, which uses the original 4-link as the base. Fortunately, FFR sells a retrofit kit that includes the panhard bar, cross members, braces, and all necessary hardware. All in all, the upgrade is reasonable at $550. Considering the 5-link is $1700, this isn’t a bad option. This is going to be my birthday present this year (and probably most of Christmas!

Since the original 4-link was going in, the lower control arms are designed for it, and have brackets and perches we don’t need. We decided to be both anal and brave at the same time, and we broke out the grinder and get rid of the extra stuff. Michelle made quick work of it as a start, and I finished up the first one. We also cut off the quad-shock mounts from the axle housing and drilled holes for dv/dt’s possible bracing mode using the upper ‘ears’ on the axle.

Unfortunately, I also finished up my cheap grinder. A combination of using the wrong wheel, and not cooling it adequately…I let out the magic smoke.

Pics:

Driver’s Side Footbox, Brake Booster, Pedal Box, Engine Bay Aluminum:

This is a multiple-personality set of projects. I’m putting the footbox together, putting the master cylinder and brake booster together, and putting the pedal box together as well.

Everything has to be painted before going in. I’m using Hammertone on the panels, and although it looks nice, I’m not that happy with how it all goes on. It does not touch up well as it more or less has engineer “orange peel” so you get high and low spots as you try to touch it up.

Other parts like the brake booster and pedal box are getting just a metallic aluminum paint, and I like it much better.

Brakes:

I decided after driving Mike’s non-powered brake car, I definitely wanted to go with the boosted system. Whitby Motors puts all of the necessary parts together for you, and the kit is top notch. Since you have to cut the frame to make room for the big booster (the car is designed for manual brakes), they even include a well-designed frame brace to make it possible. If you want power brakes, this is the way to go.

You do have to make room in the footbox metal to get the booster’s boot and push rod assembly through. This was a bit of a challenge for me, and I ended up kind of hacking it up a bit, using my sawzall. If I had it to do over again, I would have bolted in a piece of wood or metal as a backing, and simply used a large holesaw instead. You need the backing so you have something to guide the holesaw.

You also need to move the steering shaft bracket to the inside of the firewall. Despite the spacers, the booster will still hit. This is a very easy movement though, so not a big deal.

A bit of bad news, as I assembled the pieces, I discovered the booster is broken. The good news is as I was doing this entry, Jeff got back to me. I’m shipping him the booster and he’s replacing it. He’s a good guy!

Pics:

Bench Bleeding – since I hadn’t done this before, I had to look it up. A lot of guys say it’s more trouble than it’s worth, but after doing it, I can see the value. This includes filling the reservoirs, hooking up the tubing, and then actuating the push rod piston manually until you get all of the air out (AIR IN YOUR BRAKES = BAD.) The basic procedure is to clamp the master cylinder in a vise, get it totally level so the bubbles will come out, and then push the piston in and out until it gets the air out (this primes the system). This is easier said than done. I ended up removing the plugs one at a time, and mounting the resevoirs to a board high above the bench. I used 2 3/8″ socket extensions to push the piston in. You’ll start with more than 1″ of travel, and eventually when it’s primed, you’ll get less than 1/8″. It took me maybe 100 strokes to get it there. Much better than doing it with the pedal and pushing air through the whole system.

Engine Bay Aluminum – This was a pain. The guy I bought it from was not going to paint his stuff, so the f-panels and firewall have all already been sealed and riveted into position. I’m doing all hammertone as mentioned already, so in order to paint what’s there, I could either drill out and remove the panels, or tape and mask around them. The 2nd was the lessor of 2 evils, but it took forever, and was a pain. The good news is that the frame (powered coated) cleans up easily with goof off (lots of over spray, despite my efforts).

If you want to see what white engine bay panels look like, see the in progress pics, the primer I’m using is white.

Pics:

Pedal Box and Pedals – I put in Russ Thompson’s go-pedal and brake and clutch pedal covers, which required a lot of cutting of the stock mustang pedals, but it came out nice. The throttle pedal is aluminum, so you have 2 options for paint (if you want them to match), either paint that one black, or paint the other 2 aluminum. I chose the latter. I’m not sure if I’ll keep it that way, it might be too much contrast on the back carpet, but I’ll give it a dry. It’s easy to brush on the black latter.

The main issue I’m facing now is my size 11 feet. The pedals are pretty close together like a race car, which isn’t a big deal, but the gas pedal is only about 1″ from the side wall panel. Greg M did a nice bump out to give him more room, and I’m waiting on measurements to do the same thing. Hopefully, that’ll give me the room I need.

Pics:

Next Up:

I’ll wait for the new booster to show up, and work on the bump out on the DS box. I’m also going to mount the steering shaft in place so the booster will go in and stay there. I also need to figure out where to mount the reservoirs (probably on the firewall) and get the hole drilled out for the heater (actually need to modify the one that’s I did already for the ffr heater…I switched to a summit one instead.) So…big fun and continuing on…

Man, it’s been almost a month since I’ve done an update. It’s been pretty busy around here. Making some progress here on the build, but it’s been a little slow.

It seems like with every step, I spend a couple of hours researching, clarifying, and modifying the build step.

What I’ve been working on:

Engine:

I have the engine about 90% completed. I installed the intake manifold, carb, distributor (temporarily), coil, water pump, and alternator (complete with Mike Everson’s bracket.) I need some parts to finish things up, then I’ll be able to get it all assembled and ready to put in the car.

Pics:

Test Fit with Headers:

I was able to put the engine in the car and put the 4 into 4 headers on so I could verify my passenger foot box modification. I was pretty pleased with the results. With just measurements to build from, I managed to fit it with about 3/4″ of clearance to spare.

Pics:

Front End:

Some of the parts were already assembled, and I had already painted the rotors and put the brakes on. Michelle and I got the steering rack installed (we installed and uninstalled it 3 times to get it right.)

After spending hours and hours learning about SAI, bump steer, caster, camber, toe-in, toe-out, etc., I finally felt like I could put all of the components together for the front end. My steering rack is an 18:1 manual rack from Mike Forte, and I also got my solid offset bushings and my bump steer kit from him.

Bump Steer Kit and Offset Bushings:

There are many different configurations for installing the bump steer kit. The tie-rod ends can be installed on top of or below the spindle, and you have a varying number of spacers. As a starting point, I used the “parallel to the LCA” configuration, and ended up with my tie-rod ends on bottom of the spindle arms with one spacer on top. I also added a washer for protection on the bolt head. To get the right angle and to get the rack centered, I put the bushings so that the rack was as high as possible. I also used the bump steer kit to pull the wheels in so they are marginally in pre-alignment location.

Once I’m ready to align, I’ll end up measuring bump steer throughout the top to bottom of the wheel stroke, and adjust as needed.

Pics:

Rear End:

I had my 3.55’s put in locally since I didn’t have all of the tools needed to complete it. I figure it was $300 well spent, as it was all ready for me to prepare the rear end for installation.

The first step was to replace the old axle seals. Getting them out was a bit of a challenge, but a carefully placed hammer (claw end) worked well to pop them out. Getting the new ones in was even more challenging as they are pressure fit. I placed them in the housing, tapped them with the hammer, and used a pulley I found that was the right size to pound the new seal in place. A little touch up spray paint, and I was ready for the axles.

After this, I removed the rear cover, removed the pinion shaft bolt and pinion, and put both axles into the shafts. The original owner didn’t give me the c-clips to hold the axles in, but I had picked up a set (they sell them in 4’s for some reason) from Ford. You basically just push the axles in all the way, put the clips on, and pull the axles back out to seat the clips in place. Pinion shaft and retaining bolt back in, then I used some rtv to seal the rear cover and gasket, and torqued the bolts down.

One thing that didn’t go well was getting the drain plug out for the rear end. You just use a socket extension since it’s a 3/8″ square plug. Someone in the past had really put that thing in well, so I managed to bend my extension a little. Nothing the grinder can’t fix. Unfortunately, it was my long extension, which I don’t have 10 of like I do the short ones.

Next:

I’m now ready to get the rear end installed in the car. Michelle and I will likely work on this tomorrow night for date night!

I’m about 2 1/2 weeks from picking up my kit, and I’ve been searching hard for all the little goodies I need to complete the car. The ffcobra.com forum and the corral.net forum are great sources for used parts.

So far, I’ve picked up some quad shocks for the rear, a Cobra oval air cleaner, and today, my Cobra valve covers showed up for the 5.0L. I’ve gotten some great deals from the guys, and everything has been top quality, for roughly half of retail. Lots of stuff to still get, so I’ll keep looking.

The other good parts news is I made 100% profit on my transmission purchase after a little clean up and paint, so I’m just about dead even for sold vs. bought (well, not including the kit money, of course!)

Pics of the valve covers:

Well, after spending a few days searching for suitable donors and trying to decipher all of the necessary information on what donor parts are actually required, what donor years give you the parts you need in the right configuration, etc., I came to the realization today that I still know very little.

What I do know is that it seems that I should no longer keep looking for a donor. Since I don’t need the engine and transmission, a donor won’t give me much in the way of value, and the extra parts won’t really have enough value to make it worth it.

Here’s some of the stuff that I learned about donors for FFR kits, I thought I’d put it here for archiving and if someone else is looking.

What years started disc brakes on the rear? – 1994

Can I use a V6? Yes, but it’ll have a weaker 7.5″ rear end, not advisable

Can I use a 4cyl? No.

Any reason not to use a 94+ donor? Yes, the axle width is wider, which will mean more limited wheel options (backspace) or you will need to change the axles.

Will the stock rear end have the right gearing? For most applications, no, the stock 3.08’s and less gearing will want to be replaced to 3.55’s or 3.73’s at least. This will help the relatively mild stock motor get a little more punch and put more power to the road, so to speak. As horsepower increases through add-ons and upgrades, wheel spin could be come an issue with the 3.55’s, etc., and it will likely prove useful to go back to using 3.27’s or 3.08’s to ensure the rubber continues to meet the road effectively.

What Year is the best of all worlds? 87-93 5.0 Mustangs, they have the 8.8″ rear end

I’m going to start researching individual parts now, and see what I can come up with.

Some 302/5.0L Stock Engine Build Up Info I found (thanks to Oldtymeflyr):

Go with a 85 Mustang Duraspark distributor, rebuilt it might go $50.

Recently there was a discussion comparing intakes, the Edelbrock Performer worked better than the RPM manifold.

Cams, with a E303 cam, an early Performer type intake and with a set of stock GT40P heads, I am right at 300 RWT. Also, I run a vacuum Holley 600 and 4 into 4 exhaust.

My thoughts are do a little work on a cheap set of GT40P heads, pick your cam right and you should be a little over 300 RWHP.

Some More Donor Info:

From 66fstbk:

I wouldn’t do a “single” donor. Just get the parts you want from a couple different vehicles. You can do it very affordably if you shop at the right yards.
98′ T-Bird IRS Complete with posi and discs $250 (requires IRS FFR option)
95″ spindles and brakes in excellent condition $100
04′ fuel tank with plastic shiled and filler tube like new $100
95′ 5.0 engine and trans 74k mi. $1,000 (only needed shortblock and trans, did not need rebuild)

If I had purchased a 87-93 it would likely have needed an engine rebuild, would not have used front hubs or brakes, rear end (because I used IRS). So there was no point of a single donor for me.

True the kits were origionally designed for Fox single donors but a lot better parts from different year cars plus the age of these donors make this a less and less optimal solution every with passing year.

From Sergio:

I’ve used a 1991 donor to build a FFR MKI and a 2003 SVT Mustang Cobra to build a FFR MKIII .

I think I am qualified to say that the Best Donor for these cars is The Terminator (also Known as the 2003/2004 SVT Cobras.)

87-93 donors come with stock 225HP while the 03/04 cobras make 420HP stock.

While you couldn’t probably use a 03 Cobra as a donor for a MKI (unless you do tons of modifications), you can use any 87-2004 Mustang V8 to build your MKIII, except that (thanks to me), Factory Five modified their literature to read: You can use any V8 Mustang from 87 to 2004 (except 03/04 Cobras).

The 03/04 Cobras can be used as donors as I have proven, with some sensible modifications, a handful of others have done it too now.