Jesse's MK4 build in Braselton, GA - Gaps at Rear Differential bolts?

[RogerRoger88]

Since I got the call from Stewart Transportation that my roadster kit will delivered on Sunday morning, I figure it is time to start my official build thread. I have wanted a Shelby Cobra since I was about 10 years old when I saw one at Georgia Tech’s annual Ramblin’ Wreck parade.

I have spent many, many hours reading through build threads and normal threads. I have even had the opportunity to visit a few local builders and view their Cobras which were in different stages of the build – from just starting out, half-way through, and completed.

This roadster will be my first automotive build of any kind. I have a wife and 2 kids (pre-teen). Building it with them, and learning important automotive things as we go will be a great opportunity for all of us. Just to warn everyone, I will probably be asking many dumb questions.

I will be going with a blacked out theme, including both interior and exterior. Here is what I’m looking at so far. I know this list will grow exponentially. Maybe the preferred vendors should start a rewards program to help us builders out.

FFR:
Complete roadster MK4 kit
Powder coated chassis
Power steering
Black leather seats
Dual roll bars powder coated black
Willwood brakes 12.88” black – front and back
17” Halibrands – these will be powder coated black along with all of the aluminum panels
Roadster body with cut-outs
Carbon fiber dash
Wind wing set
Sun visor set
Trunk gas strut kit
Brake duct wire mesh set
IRS front and rear swaybars –
Seat tracks for driver and passenger – with the height difference between my wife and I, this will be needed
Assembled side louver set


Forte:
351W based 427 – in process of building so not 100% sure on HP/TQ but close to 500
TKX trans with .81 5th gear
IRS kit
Earls oil cooler kit
Edelbrock Pro-flow 4
Mechanical linkage
External hydraulic slave kit
Other misc parts


Gas-N:
Black ceramic coated Touring side pipes
Black ceramic coated long tube headers

FFmetal firewall forward kit

Some stuff that I haven’t ordered yet but plan to:
Cobra Valley seat heaters
Custom gauges from Speedhut
Battery mounting kit for engine compartment
Driveshaft safety loop
E-Stopp emergency brake set up
LED headlights
i.e.427 Turn signal
Drop trunk kit
Considering a quick release steering wheel
Battery cut off with removable key
USB chargers
Cup holders
Lots of other misc parts will be ordered


A few questions already:
Is it advisable to use the rear swaybar with IRS? It seems I read in a thread that it was not needed or desired.
Ordered the forward kit when I thought I would be doing AC and heat. However, I’ve changed my mind on that and probably won’t be doing either. Is it okay to still use?

I must admit, I’m about 70/30 excited/scared ****less. Eh, maybe 30/70. Either way, looking forward to beginning this journey.

Thanks in advance for everyone’s assistance and opinions on my build!

Jesse

[jklapp]

Good luck! We have very similar specs. Also going full blackout as well. Enjoy! Joel

[RogerRoger88]

Good luck! We have very similar specs. Also going full blackout as well. Enjoy! Joel

Thanks Joel! I've read through your build thread, and your build does look similar to mine. And we're somewhat alike in that we're not exactly automotive experts, but we do woodworking. We also prefer to learn by experience.

I see you're going the blackout route too, but you're not using black fuel and brake lines. Any particular reason why? I initially thought about using black for everything in the engine bay, but I'm wondering is the SS lines would look good against the black.

[Mike.Bray]

That's going to be a nice build, congratulations! Don't get overwhelmed, it's a marathon not a sprint. Enjoy the process. If you have to step away and regroup it's okay. I've said this before and it's served me well for many years, projects like these are like eating an elephant, you do it one bite at a time.

I would agree with everything you're ordering from FFR except for the anti-sway bars. Unless you're planning on some serious track time you don't need them.

I love pushrod V8 engines, yours is going to have the period look and a nice rumble. You'll be happy with the Pro Flo, it's a nice unit.

Do the firewall forward and thank me later. Not only does it give a little more space but it's also thicker. And you can run your wire harness out the bottom of it instead of the front to clean up the engine compartment some.

We actually have very similar builds except I have bling and not blackout. Blackout for me is when I stand up too fast:)

[jklapp]

Thanks Joel!

I see you're going the blackout route too, but you're not using black fuel and brake lines. Any particular reason why? I initially thought about using black for everything in the engine bay, but I'm wondering is the SS lines would look good against the black.

I used black flex lines and fittings, but saw the polished stainless and just had to have a little shine. :-)

[RogerRoger88]

That's going to be a nice build, congratulations! Don't get overwhelmed, it's a marathon not a sprint. Enjoy the process. If you have to step away and regroup it's okay. I've said this before and it's served me well for many years, projects like these are like eating an elephant, you do it one bite at a time.

I would agree with everything you're ordering from FFR except for the anti-sway bars. Unless you're planning on some serious track time you don't need them.

I love pushrod V8 engines, yours is going to have the period look and a nice rumble. You'll be happy with the Pro Flo, it's a nice unit.

Do the firewall forward and thank me later. Not only does it give a little more space but it's also thicker. And you can run your wire harness out the bottom of it instead of the front to clean up the engine compartment some.

We actually have very similar builds except I have bling and not blackout. Blackout for me is when I stand up too fast:)

Hi Mike, I've read through your build thread, and yours looks amazing. Beautiful blue color.

Yeah, I wasn't 100% sure about the sway bars. I do have Road Atlanta about 5 minutes away that I plan on driving on from time to time.

I knew I wanted the thicker firewall, but it sounds like having the forward kit will make things a little easier.

I'm the same way. I stand up too quick, and I'm seeing stars.

[Fman]

Welcome and nice build! I am running the Pro Flo 4 setup, so far after 6300 miles it has been really good. I also don't think you need sway bars unless you are going to be tracking your car. I am also running a 427 based stroker block (dart), I have never had issues with oil temps, infact during cooler months the oil temps almost seem on the low side.

Have fun with your build, looking forward to seeing it all come together.

[RogerRoger88]

My kit was delivered without any issues yesterday afternoon, just in time for many neighbors to ride by and inquire about what we were getting. The neighbor across the street walked over and we chatted for a little while. He did a quick search and ordered a brochure for himself.

For my POL, it appears there is only 1 item - brake reservoir parts. The Cert of Origin and Nameplate are listed, but I believe they get mailed separately. I'll start working on going through the inventory to confirm we received everything they listed. We are currently on the tail end of a master suite remodel that we expected to have been finished by now, so part of the garage is being used to store materials for that. Once that is complete, I will be able to remove and suspend the body from the ceiling and begin the build process.

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[M22_COBRA]

Congrats! I used to work for FOX Factory and live in Loganville, so I'm very familiar with Braselton. Looking forward to your build, looks like you got allot of the same items and direction I have going on my build. I'm getting closer to putting together the Estop soon, definitely a big upgrade.

[egchewy79]

welcome and good luck on the journey.
I have a regular firewall and have a heater, which is nice when the mornings dip into the 30s here in Ohio.
Get familiar w/ the vendors and try to batch your orders to save on shipping.
Breeze has a ton of good functional stuff (fan shroud, battery box, radiator mounts, lower radiator tube mounts, seat mounts, etc) and Mike Everson @replicaparts.com has some good finish parts (radiator aluminum, trim bezels, weatherpak connectors, etc). Forte is great to work w/ as well.
plus, all these vendors will actually answer a phone call, which is refreshing these days.
keep us posted on your progress!

[RogerRoger88]

Congrats! I used to work for FOX Factory and live in Loganville, so I'm very familiar with Braselton. Looking forward to your build, looks like you got allot of the same items and direction I have going on my build. I'm getting closer to putting together the Estop soon, definitely a big upgrade.

Yeah, I know there are a couple Fox Factory locations near us. I may be reaching out to you to see how you did your Estopp setup. I wanted to get rid of the e-brake handle, and this looked like a good product to do that.

[M22_COBRA]

Yeah, I know there are a couple Fox Factory locations near us. I may be reaching out to you to see how you did your Estopp setup. I wanted to get rid of the e-brake handle, and this looked like a good product to do that.

I worked at the one at the race track. That's the Engineering R&D center. I think the new assembly plant is up the road in Flowery Branch.

That is exactly why I picked it also. I am considering the LR outboard mount that others have done. I am currently reverse engineering the rear chassis bars so I can print some prototype mounts. I think I can get 3 of the 4 or maybe 2of4 hard mounted to the bars. At that point I'll figure out if I want to print some in Nylon PA12 or Nylon CF with steel inserts or go the send cut send method.

[Blitzboy54]

From one Jesse to another. Welcome aboard! Looking forward to following along.

Jesse

[RogerRoger88]

After a month of not being able fully use my garage due to a reno project, I am finally getting started. I've gotten the body off and suspended from the ceiling using a couple sets of kayak hoists.

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I have started marking and removing the aluminum panels, and then drilling. Since I'm a rookie, here are a few questions.

Where does this aluminum panel go? It was taped to the floor of the PS. I've looked through the manual with no luck.
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Is it normal to have this much of a gap (1 1/4") between these two panels? This is the DS footbox area. I can force the left panel against the right panel, but it's not exactly flush.
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Should these panels be flush with the frame? I'm assuming they should be. Mine stick up 1/4".
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Thanks as always!
Jesse

[Blitzboy54]

After a month of not being able fully use my garage due to a reno project, I am finally getting started. I've gotten the body off and suspended from the ceiling using a couple sets of kayak hoists.

204910

I have started marking and removing the aluminum panels, and then drilling. Since I'm a rookie, here are a few questions.

Where does this aluminum panel go? It was taped to the floor of the PS. I've looked through the manual with no luck.
204911

Is it normal to have this much of a gap (1 1/4") between these two panels? This is the DS footbox area. I can force the left panel against the right panel, but it's not exactly flush.
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Should these panels be flush with the frame? I'm assuming they should be. Mine stick up 1/4".
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Thanks as always!
Jesse

The panel on the floor is the rest of your fire wall. There will be a block off plate as well in your box aluminum if you decide to use it. It has a hole in it to be used as a wiring pass through. I looked through my first build thread but I don't have a real good picture of it. It goes on the passenger side

The gap is normal in so much as nothing is properly attached so there is slop. Once you start fitting things in per the manual the fit will be better

Yes, they absolutely should but again you don't have it properly fitted yet. I had to trim one just a touch on my current build but it's not common.

[RogerRoger88]

I'm slowly getting minutes here and there to work on things. Decided to put the Koni shocks together. What is the preferred shock orientation for installation? Body on top or body on bottom? Or does it matter? I have seen it done both ways.

Thanks,
Jesse

[Blitzboy54]

I'm slowly getting minutes here and there to work on things. Decided to put the Koni shocks together. What is the preferred shock orientation for installation? Body on top or body on bottom? Or does it matter? I have seen it done both ways.

Thanks,
Jesse

The red ones can go either way. It’s really up to you.

[RogerRoger88]

The red ones can go either way. It’s really up to you.

Thanks! That’s what I was thinking but wanted to make sure. Your build threads are a couple of the many I’m using for reference and I saw how you had them oriented but then I saw a couple others that were different.

Jesse

[RogerRoger88]

Forte Engine Dyno

I got a link for my engine dyno - https://www.youtube.com/watch?v=nb0x6M3Bhbk

It dynoed at 491HP @ 5368 RPM and 511 lbft @ 3558 RPM.
Final specs are:
- 351/427W Boss block
- AFR heads
- Edelbrock Pro Flo 4 EFI
- Aeromotive 13129+ fuel pressure regulator
- Tremec TKX transmission 2.87/.81

Now I need to pick up the pace and get to work.

[gbranham]

Forte Engine Dyno

I got a link for my engine dyno - https://www.youtube.com/watch?v=nb0x6M3Bhbk

It dynoed at 491HP @ 5368 RPM and 511 lbft @ 3558 RPM.
Final specs are:
- 351/427W Boss block
- AFR heads
- Edelbrock Pro Flo 4 EFI
- Aeromotive 13129+ fuel pressure regulator
- Tremec TKX transmission 2.87/.81

Now I need to pick up the pace and get to work.

What are your cam and head specs?

[RogerRoger88]

What are your cam and head specs?

Here is the cam: https://www.edelbrock.com/rollin-thunder-camshaft-for-small-block-ford-351w-v8-2281.html

Here are the heads. Using the 72cc option. https://www.airflowresearch.com/220cc-sbf-competition-cylinder-head/p543
(https://www.airflowresearch.com/220cc-sbf-competition-cylinder-head/p543)

[RogerRoger88]

I finally got some time to make a little progress on the front suspension, and of course I need the resident experts to view my work to make sure everything looks good. One issue I ran into is that FFR sent one correct castle nut and one incorrect castle nut for the spindle. I’m hoping they can put the correct one in the mail.

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I did purchase the Energy Suspension ball joint boot replacements. Just to confirm, I’m supposed to use the taller one on the upper ball joint? Do the other 2 boots get used anywhere? The FFR supplied lower one looks fine.

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One issue I was running into was the upper boot was slipping off where it was supposed to seat creating a large gap when I started tightening the castle nut. I think I created the issue by already having the upper control arm sleeves set to 9.75” (front) and 8.5” (back). I moved the back one’s measurement closer to the front one’s measurement, re-seated the boot, tightened the castle nut, and moved the back sleeve back to 8.5” The boot seems to be staying seated. And just to confirm, there isn't a washer for the upper?

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Let me know if anything seems off. Thanks!

[RogerRoger88]

I think in my previous post, my steering arm was wrong. Based on some posts from other build threads, this is something I want to get correct the first time and it seems to be something that is easily installed incorrectly for first time builders. I switched the steering arm around, and this is how it looks now. Does this look correct? Thanks!

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[RogerRoger88]

Just finished installing the rear differential, and I've got gaps on all four corners. I didn't have gaps at the back bolts until I tightened down the front bolts to attempt to close up those gaps. While I made the gaps in the front smaller, it created slight gaps at the rear bolts. Should I put washers in for all 4 bolt locations to close the gaps? All 4 were tightened to 100 ft-lbs.

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[cv2065]

I had a 1/16” gap on the right rear bolt. FFR said it was normal and to proceed with the build. With a search you’ll see many are the same.

[RogerRoger88]

I had a 1/16” gap on the right rear bolt. FFR said it was normal and to proceed with the build. With a search you’ll see many are the same.

Yeah, I've seen others have gaps, but I've got 1/4" gaps on both front bolts and about 1/16" gaps on both back bolts. That seems a little excessive.

[Grubester]

I sized some thickness-appropriate washers to close my gaps for the IRS differential unit.
I was just figuring that 400+ HP is flowing through that assembly, so why not have it firmly positioned.

I also had gap issues with the way the control arms and their respective polyurethane bushing assemblies fit into the frame mounting ears. Grease wasn't flowing properly up the faces of the bushings and was leaking out the ends of the hexhead bolt and nut in a few cases. I designed S.S. shim stock, laser cut washers (5/8" I.D. x 1-3/4" O.D.) in thicknesses 0.005", 0.010", 0.015", 0.020". Also, used some precision "die button shims" from McMaster-Carr to effectively "extend" the length of the steel sleeves inside the poly bushings. I did that because when I removed the sleeves and put the 5/8" bold through them in position where the control arm mounts, there were gaps of 0.020" - 0.070" inches. You could slide the bushing sleeve back and forth. Just torqueing the bolts to 100 ft-libs doesn't effectively close the gaps, because the steel mounting "ears" have to bend slightly to reach the sleeve, causing a very slight gap on part of the face of the steel sleeves. The sleeves must seal effectively against the mounting ears so that the grease pathway is ensured for the faces of the bushings.
I'm attaching a drawing as example. (Full disclosure: I also submitted a .PDF paper to Dave V. at FFR and talked with him and Dan G. but it wasn't a major point for them.)

Point is: I'm guided by trying to understand what the engineering design intent is. Then, is that being carried out in manufacturing and later in assembly.
My whole career in hi-tech in the semiconductor equipment industry in Silicon Valley was informed by that principle.
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