Sean's RCR GT40 build

Randy Folsom

Supporter
Its mostly life getting in the way these days, job has me traveling alot now. Also doesnt help I decided to learn how be a machinist... although I have a very long way to go before I can call myself one.

I plan to build a Cobra next, the wife is really wanting one. Ive been looking at the FFR ones, they seem like they have a nice product. What are your thoughts on that kit?

The wife really wants me to get the Superformance one vs a kit. :oops:
Mine is a Mk3 from 2007. My understanding is that the Mk4 is much improved. All my parts are scattered in boxes with no labels and it still seems fairly easy to figure out. I think the FFRs are probably easier to build than the GT40s especially if you buy the complete kits and stay away from donor parts. Just like any other kit, the money is in the engine and paint. One of the other advantages to the FFR is the almost overwhelming community of support available and of course the endless list of upgrades.
 

Randy Folsom

Supporter
#30 drill bits are just a few thousandths larger than 1/8” and make rivet insertion a breeze…
Having built a half dozen FFRs teaches a few tricks! FFR kits are a great learning tool.
Thx for that tip. I am just now preparing my panels for installation. I am still working out which panels to screw down so I can retain access and which panels to coat or leave bare because they will be hidden.
 

Neil

Supporter
Thx for that tip. I am just now preparing my panels for installation. I am still working out which panels to screw down so I can retain access and which panels to coat or leave bare because they will be hidden.
#30 drills are often available as aircraft surplus items. Manufacturers use them by the zillions and sometimes sell off their excess due to contract terminations, etc. A "split-point or a 135 degree point is particularly good for sheet metal. I drilled 451 holes for rivets in my chassis so a good sharp drill was much appreciated! On this subject, let me rail against using hardware store pop rivets. These are low-strength, low-quality fasteners. AVEX blind rivets are far better and have a very wide grip range. For critical areas there are Cherry Max rivets that are excellent. Most blind rivets are available in different head styles and in different materials. Don't just grab whatever is
451 Rivets.jpg
on the shelf.
 

Chet Zerlin

Supporter
Neil, that's an impressive series of rivets! I'm assuming you used some type of template to get them is such straight lines and drill the holes so evenly spaced?

Chet
 

Neil

Supporter
Neil, that's an impressive series of rivets! I'm assuming you used some type of template to get them is such straight lines and drill the holes so evenly spaced?

Chet
Thanks, Chet. No, I just used a ruler and a T-square to lay out the rivet pattern. It is tedious but care in the spacing and alignment gives nice looking results. BTW, at every car show here in Tucson, some US Air Force guy asks me if I'm an aviation mechanic. :) I take that as a great compliment as I have only taken our local Pima Community College "Airframe & Powerplant Mechanics" course. I did belong to the Experimental Aircraft Association years ago- both were very worthwhile learning experiences that I recommend. My thought was that race car technology is just old aircraft practice. Zinc chromate primer and rivets just have a certain "look".
 
Did you use aluminum rivets or stainless? I was wondering if stainless would be a better choice attaching aluminum to carbon steel.

I've drilled a ton of holes in the bottom of mine, but at present have it on with a couple of zip screws and cleacos until I have everything welded up in the nose.
 

Neil

Supporter
Did you use aluminum rivets or stainless? I was wondering if stainless would be a better choice attaching aluminum to carbon steel.

I've drilled a ton of holes in the bottom of mine, but at present have it on with a couple of zip screws and cleacos until I have everything welded up in the nose.
My chassis is a mild steel with 7075-T6 aluminum stressed panels. I used mostly 1/8" (#4) aluminum AVEX rivets. They have a steel stem which increases their shear strength over plain aluminum/aluminum blind rivets. In places, I used 5/32" (#5) rivets and some 3/16" (#6) rivets. To fasten some 6Al-4V titanium sheet I used Huck fasteners.

The yellow zinc chromate epoxy primer is helpful for minimizing electrolytic corrosion between the aluminum and steel. You will need one of these...

Rivet Gun 1.jpg
Rivet Gun 2.jpg
Rivet Gun 3.jpg
Rivet Gun 4.jpg


And maybe..

Primer 2.jpg
 
My chassis is a mild steel with 7075-T6 aluminum stressed panels. I used mostly 1/8" (#4) aluminum AVEX rivets. They have a steel stem which increases their shear strength over plain aluminum/aluminum blind rivets. In places, I used 5/32" (#5) rivets and some 3/16" (#6) rivets. To fasten some 6Al-4V titanium sheet I used Huck fasteners.

The yellow zinc chromate epoxy primer is helpful for minimizing electrolytic corrosion between the aluminum and steel. You will need one of these...

View attachment 134109View attachment 134110View attachment 134111View attachment 134112

And maybe..

View attachment 134113
PPG, also makes a good Aluminum anti-corrosion paint scheme using P99 wash primer and PAC33 anti-corrosion primer. It is a zinc chromate as well.

I also etch and alodine before painting.
 
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Neil

Supporter
PPG, also makes a good Aluminum anti-corrosion paint scheme using P99 wash primer and PAC33 anti-corrosion primer. It is a zinc chromate as well.

I also etch and alodine before painting.
Etch & Alodine is a good idea if you have the facility to do it.
 

Sean S.

Supporter
I had made up my mind to remove the roll cage, but I decided to try one more thing before I started to cut.

I reclined the seats a little more. I moved the bottom cushion about 2” farther forward. This netted almost 3” more headroom. The roll cage is still close to my head, but I think I have something to work with now. If I move the center bar in slightly, it should stay clear of my head.

I will need to move my pedal box slightly forward now to compensate, but think this was the overall best solution to my problem of being too tall ‍.

Seat belt mounts went well and they look great.
 

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Ron McCall

Supporter
My chassis is a mild steel with 7075-T6 aluminum stressed panels. I used mostly 1/8" (#4) aluminum AVEX rivets. They have a steel stem which increases their shear strength over plain aluminum/aluminum blind rivets. In places, I used 5/32" (#5) rivets and some 3/16" (#6) rivets. To fasten some 6Al-4V titanium sheet I used Huck fasteners.

The yellow zinc chromate epoxy primer is helpful for minimizing electrolytic corrosion between the aluminum and steel. You will need one of these...

View attachment 134109View attachment 134110View attachment 134111View attachment 134112

And maybe..

View attachment 134113
This is one of the best purchases that I've made in the past 5 years.
 

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Chris Kouba

Supporter
I reclined the seats a little more. I moved the bottom cushion about 2” farther forward. This netted almost 3” more headroom.

Sean,

Have you split the base from the back? I have mine split and it worked out great (6' 2", no bubble; can wear helmet if wanted). The upholstery insert still fits as well due to it being longer than needed. If you haven't tried it, I would recommend it. I bolted the base directly to the floor and made simple "L" brackets to mount the seat back.
 

Randy Folsom

Supporter
#30 drill bits are just a few thousandths larger than 1/8” and make rivet insertion a breeze…
Having built a half dozen FFRs teaches a few tricks! FFR kits are a great learning tool.
Randy, I am starting to make some progress on my FFR Mk3 Roadster. I am about to start putting on some of aluminum panels. Have you used a pneumatic rivet gun? Do you know if they work better or worse than battery powered guns?
 

Sean S.

Supporter
Sean,

Have you split the base from the back? I have mine split and it worked out great (6' 2", no bubble; can wear helmet if wanted). The upholstery insert still fits as well due to it being longer than needed. If you haven't tried it, I would recommend it. I bolted the base directly to the floor and made simple "L" brackets to mount the seat back.
Thanks for the suggestion Chris, I hadn't thought about splitting the seats like that.

I will give it a shot and see how it works. Thinking about it now, I would bet it gives close to another inch of head room.

Thanks,
Sean
 

Randy Folsom

Supporter
Thanks for the suggestion Chris, I hadn't thought about splitting the seats like that.

I will give it a shot and see how it works. Thinking about it now, I would bet it gives close to another inch of head room.

Thanks,
Sean
Sean,

From Chuck’s build log. He needed to accommodate both himself and his son:


Brackets were fabricated from flat aluminum stock to extend the connection between the seat bottom and seat back about an inch. This simple modification puts one’s bottom further back and thus lower, increasing the head room. But here is the neat part. You can flip the lower portion of the seat back either forward or backward. For Ryan, who needs the extra height, we set it backwards. For those a bit more vertically challenged, we set it in the forward position. In the rearward position the seat back sets just under and even with the horizontal roll cage bar. In the forward position the seat back sets just in front of the roll cage. This effectively give one an easily adjustable seat for different drivers.
 

Randy V

Moderator-Admin
Staff member
Admin
Lifetime Supporter
Randy, I am starting to make some progress on my FFR Mk3 Roadster. I am about to start putting on some of aluminum panels. Have you used a pneumatic rivet gun? Do you know if they work better or worse than battery powered guns?

I've never used an electric rivet gun. Only manual and the one here (using Neil's Pic) which is identical to mine. I have used the smaller pneumatics and the el-cheapo Harbor Freight ones with marginal success.. To my recollection, I've not had any jams or misfires with my Pneumatic..
Rivet Gun 1.jpg
 
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