Logan's Gen 3 Coupe-R Build

[Logan]

Logan, I see that you have the nose dive planes on your list like the Snap On build. Can you tell me where you sourced these as I can't find them on FFR parts list.

Firstly, congrats on joining the forum and ordering your kit! You used your first post on this forum in my build thread... I am honored. Lol

To your question, the canards (dive planes) are available from FFR. You can call and ask for them, made in their composites shop. A word of warning though, they're not the quality you might expect of a high-end carbon fiber race part from someone like Anderson Composites, APR, Seibon, Speedkore, etc. They're raw carbon straight out of the mold, weave imperfections and fringed edges included. They are NOT clear coated and pretty like what you see on the Snap On car. So expect to do plenty of body work on them (and any other composites received from FFR, the main body included) if you wish to go that way. Had I known, I would have simply made my own. They are not overly difficult shapes even for a beginner.

Logan, Did you get your wheels ordered yet?

Rsnake, I planned to order wheels during Black Friday sales of 2020.... but things were/are tight so didn't place the order. Thank goodness too! Forgestar just released a new wheel profile for the F14 which I will be going with. I was already expecting to be on the extreme end of their available offset on the SDC (Super Deep Concave) wheels, but they have now released a profile called UDC (Ultra Deep Concave) that is available in negative offsets....finally! I will still wait until I put the body on my car to measure for exact fitment. Should be ordering them sometime this Spring though.


Now, update time.

My daily driver 2017 Mustang GT Premium w/ Performance Pack has been a GREAT car, but I knew all along it would be replaced with a truck so I can haul the FFR as needed. So the day after Christmas I drove the Mustang up to Tennessee and traded it in for a 2021 Ram 1500 Big Horn Level 2 Night Edition. Cross the tow vehicle off the list! Now I need a trailer... considering building my own from scratch with a lowering deck that requires no ramps (yes I have a problem).





On the FFR Daytona front....the video a few posts back left out some detail. I had fabricated a bead-forming tool and used it to great success on my aluminum upper radiator tube. Then, ordered the Boig lower aluminum tube after trying half a dozen ways of routing the rubber hoses, with and without a spring inside which tries but doesn't always prevent hose collapse. Plus the amount of hose sticking into the wheel well was too much for comfort, especially considering the amount of wheel and tire I have to stuff in there. Highly recommend the Boig cool tube... nice product and fits perfectly. Filled the Gen3 Coyote with Motorcraft coolant and purged air through the Moroso tank. Just like an OEM Mustang setup, couldn't be simpler. Ran the car for 30 minutes going through multiple radiator fan cycles. All systems looked good. Since then, I have been driving the car here and there. Put about 30 (loud) miles on so far, and need about 100 miles on the clutch for break-in before I can race it. Between this and the tune status, it's the reason I didn't get to race it in 2020. So close!!



During the 30 miles worth of driving, a clunking noise was identified. Turned out to be the bearings I installed in the control arms, one per arm was backwards, so the longitudinal loading caused the retaining rings inside to be forced from their groove, and the captive spherical bearing to move within the shell. Unfortunately, they are easy to press in, but there are no fixturable points with which to press them back out, so I had to weld a tab onto each end to press the incorrectly oriented bearings out and press them in from the other side. As a note, to anyone using bearings in place of the polyurethane bushings... press them all in from the OUTSIDE of the arms, facing in. I had pressed mine all from the same side (from the rear, in my case, all pointing forward). They are all replaced now and solid as a rock, no clunk. Glad to catch that in a test drive before reaching max lateral loading of the chassis mid-corner at an autocross!



I have also been working on seats and harnesses. Believe it or not, this has been one of the hardest parts of my build. Placement, alignment, getting the 6-point harnesses to work with the Kirkeys, sliders for the drivers seat, height with my helmet on, centered to the steering wheel, seat back braces, seat heaters, added side foam (I'm as small as a jockey), and more.... it's been quite the debacle. Getting to a point where they'll work now I hope. Welded some brackets to the bottom of the chassis for the sub straps to bolt into, behind the seat as intended by all racing sanctions.

I also got the last of the exhaust components I spoke about in the previous update, the laser cut flanges. I only needed two, but ended up getting 8 total; 6 plasma cut from stainless steel, and 2 laser cut from mild steel. Once the body is on my chassis, I will fab the custom pipes and hopefully quiet it down some.... many racing organizations have strict noise limits.



Now, I just need to find time to keep working on it! I'm schooling for Mechanical Engineering on the side, and these courses are not easy... I spend more hours sitting at the computer than I get in the garage. Not an excuse, just a factor. I bought HP Tuners MPVI2 and am sort of learning to tune on the side, with help of course... but that's a whole lot of time I don't have right now, so considering calling in some professional help to jump start the process. Lots of other little details over the past few months, but this covers the highlights.

[Snowman]

...Forgestar just released a new wheel profile for the F14 which I will be going with. I was already expecting to be on the extreme end of their available offset on the SDC (Super Deep Concave) wheels, but they have now released a profile called UDC (Ultra Deep Concave) that is available in negative offsets....finally! I will still wait until I put the body on my car to measure for exact fitment. Should be ordering them sometime this Spring though.

Super cool they added another profile! I know I want Foregestar wheels, I really like the CF5. I was going to copy your wheel stud setup and run spacers like you've described, but now I need to rethink that and stare at the F14s more to see if that's the route I want to pursue. I really like the idea of not running spacers, but I do like the look of the CF5 better. Decisions, decisions...

Question: When you drilled your hubs for the ARP wheel studs did you also have to drill out the rears?

[Logan]

I really like the idea of not running spacers, but I do like the look of the CF5 better. Decisions, decisions...

Question: When you drilled your hubs for the ARP wheel studs did you also have to drill out the rears?

I also really like the CF5. I ran that face-style on my Mustang for the past 3 years and absolutely loved them. Classic 5-spoke look, simple yet elegant, easy to clean... On the other hand I also like the look of the F14s, but it pretty much came down to available sizes that made that decision for me. SDC profile and 12" to 13" widths available in the F14, previously with as low as +6 offset, but now with UDC profile they go as low as -50 offset which is nice. I would not hesitate to use a spacer with CF5s or SDC-profile F14s if needed.

As for the hubs, remember the rear hubs (if you go with IRS) are already M14x1.5 studs as they are S550 Mustang spec. FFR would have you replace the beefy M14 rear studs to match their 1/2" studs in the SN95 front hubs... but I prefer to keep the larger of the two. Especially since it's standard issue on many (most) performance cars today. Better clamp load, higher yield strength, handles frequent torque cycles better, etc. To achieve this, you only need to ream out the front SN95 hubs to roughly the size of the rear hubs holes. There's science behind knurl diameter, material displacement, and so on. But long story short, I have done the science and have confirmed results. Buy a 0.612" diameter reamer from McMaster Carr, and within 5 minutes at the drill press you're ready to press in a 0.625" knurl-diameter M14-stud of any length you desire. The reamer is $50, and has little other use besides this, but very much worth it to do it right. Cuts the hub material like butter. Do NOT take a regular twist drill to your hubs!

[Snowman]

I also really like the CF5. I ran that face-style on my Mustang for the past 3 years and absolutely loved them. Classic 5-spoke look, simple yet elegant, easy to clean... On the other hand I also like the look of the F14s, but it pretty much came down to available sizes that made that decision for me. SDC profile and 12" to 13" widths available in the F14, previously with as low as +6 offset, but now with UDC profile they go as low as -50 offset which is nice. I would not hesitate to use a spacer with CF5s or SDC-profile F14s if needed.

As for the hubs, remember the rear hubs (if you go with IRS) are already M14x1.5 studs as they are S550 Mustang spec. FFR would have you replace the beefy M14 rear studs to match their 1/2" studs in the SN95 front hubs... but I prefer to keep the larger of the two. Especially since it's standard issue on many (most) performance cars today. Better clamp load, higher yield strength, handles frequent torque cycles better, etc. To achieve this, you only need to ream out the front SN95 hubs to roughly the size of the rear hubs holes. There's science behind knurl diameter, material displacement, and so on. But long story short, I have done the science and have confirmed results. Buy a 0.612" diameter reamer from McMaster Carr, and within 5 minutes at the drill press you're ready to press in a 0.625" knurl-diameter M14-stud of any length you desire. The reamer is $50, and has little other use besides this, but very much worth it to do it right. Cuts the hub material like butter. Do NOT take a regular twist drill to your hubs!

Thanks for the heads up on the reamer and confirming only the front hubs would need to be reamed out! ARP actually recommends a 39/64 drill bit for their longer S550 wheel studs. The reamer seems like it would be easier to keep the holes centered up.

Still haven't made up my mind yet, I like the sounds of keeping things simple without using spacers on the new F14 profile, but I prefer the look of the CF5. They both look great honestly so i really don't think there is a wrong decision, lol. Ultimately I think I'll let the price of either path guide me. Those ARP studs are NOT cheap! I guess I need to ask Forgestar for quotes and see where that takes me. Plenty of time to get that figured out.

[Logan]

ARP actually recommends a 39/64 drill bit for their longer S550 wheel studs. The reamer seems like it would be easier to keep the holes centered up.

39/64” would leave just over 2 thousandths more material in the holes than the 0.612” reamer I used. Either of those sizes will work just fine, as there is a small allowable range for spline press-fitments. I prefer a reamer to a twist drill because it leaves a perfectly round hole with parallel sides, perpendicular to faces, etc. Machinists use reamers to clean up and perfect the rough hole made by a twist drill. I’m sure you could find a 39/64” reamer too actually.

I agree you can’t go wrong with either the CF5 or the F14. Looks like the UDC profile is about $280 more per set of four ($70 per wheel) compared to the SDC profile, for a given size. UDC is only available in 19” diameter, while F14 SDC and CF5 are both available in 18” if that influences your decision at all?

The ARP 100-7733 studs are about $60 per pack of 5 (There are cheaper options for extended studs, such as Dorman, but not the same strength as ARP). You would only need extended studs if you planned to use a slip-on spacer between 0-1” thick. If you need more than 1” of spacer, you’d be better off using standard length studs and a bolt-on spacer. For track or racing use, a slip-on spacer is preferred to a bolt-on. However, a wheel with the proper offset which requires no spacer is naturally the best method if possible.

[Shakey]

39/64” would leave just over 2 thousandths more material in the holes than the 0.612” reamer I used. Either of those sizes will work just fine, as there is a small allowable range for spline press-fitments. I prefer a reamer to a twist drill because it leaves a perfectly round hole with parallel sides, perpendicular to faces, etc. Machinists use reamers to clean up and perfect the rough hole made by a twist drill. I’m sure you could find a 39/64” reamer too actually.

I agree you can’t go wrong with either the CF5 or the F14. Looks like the UDC profile is about $280 more per set of four ($70 per wheel) compared to the SDC profile, for a given size. UDC is only available in 19” diameter, while F14 SDC and CF5 are both available in 18” if that influences your decision at all?

The ARP 100-7733 studs are about $60 per pack of 5 (There are cheaper options for extended studs, such as Dorman, but not the same strength as ARP). You would only need extended studs if you planned to use a slip-on spacer between 0-1” thick. If you need more than 1” of spacer, you’d be better off using standard length studs and a bolt-on spacer. For track or racing use, a slip-on spacer is preferred to a bolt-on. However, a wheel with the proper offset which requires no spacer is naturally the best method if possible.

Any idea if the Forgestar F14 UDC in a 19in would fit? I'd guess a 325/30r19 tire. I agree it would be great to get a F14 on there with a 315+ width tire and no wheel spacer.

V/R

Shakey

[Logan]

Any idea if the Forgestar F14 UDC in a 19in would fit? I'd guess a 325/30r19 tire. I agree it would be great to get a F14 on there with a 315+ width tire and no wheel spacer.

V/R

Shakey

The wheel itself is just a 19” x 11” or 12” (however wide you choose). Between the SDC profile and UDC profile, you can now get the offset you want built into the wheel so no spacers are required. Even for FFRs where we need low or negative offsets, that’s where the UDC profile comes in.

It’s the tires that are critical for total fitment. Average 18” tire options are 25.5” diameter for 315/30, and 25.9” diameter for 335/30. Moving up to 19” wheels, tires from 315/30 to 325/30 to 345/30 are 26.5” to 27.2” in diameter. So a total of 0.6” to 1.3” taller in diameter, and half of that in radius. The first point of contact with large tires is the short angled square tube of the Coupe chassis behind the seats. Set the wheel offset such that the tire has good clearance to this tube and you should never have any problems. I still really wish they would offer the UDC wheel in 18” as I prefer the tire options there.