Dak

So from this old thread Could an FC be made to handle as good as a stock FD or near its level ? - RX7Club.com - Mazda RX7 Forum we know the FC's handling won't ever be as good as the FD or RX-8 but how does it compare to current model cars? Lets say Mustangs and Camaros now that they have independent rear suspension though admittedly I haven't looked into the actual designs. Does the lighter weight of the FC make up for any shortcomings in its suspension design vs these heavier cars? If the FC is a modified TII to be closer to the power to weight ratio of these cars. What about the Toyota/ Subaru FR/BRZ they are of more similar weight/power output to a stock TII or highly modified n/a. Oh I almost forgot the Nissan 350/ 370z's. Of course there is the Miata but I think they are universally known as great handling cars even if the early ones had chassis stiffness issues. I'm really more concerned about the previously mentioned cars. Not thinking of getting rid of the FC or anything, just curious.

WondrousBread

I was thinking about this earlier today actually. I'm assuming the BRZ would handle better due to similar weight and a more advanced suspension design. Probably Rx8 like.

Mustangs and similar may still face a deficit due to the extra weight, but recent models now have a vastly better suspension design than the older ones, so who knows.

Miatas are something else. My mum's NC is crazy nimble. I can take a turn absurdly fast in that thing and stay glued to the road, even on average tires. It's underdamped and a bit too high IMO but with slightly stiffer shocks and a 1.5" drop it would be perfect.

Food for thought though:

- NC Miata track width is only about 1" wider than FC.

- NC Miata subframes can accept Rx8 diff, brakes, etc as a drop in swap.

- NC Miata has hydraulic PS (not electric). At least NC1, not sure of NC2.

- NC Miata already has 5x114.3 wheel pattern like FCs do, the only Miata to do so.

- NC Miata has dual wishbone front and multi-link rear, just like the Rx8.

Obviously it's harder to make it a reality than to talk about it on paper, but there's potential for a swap there if someone is a skilled fabricator and has the time and money.

The FC is still very good as-is though. The suspension may be outdated but it's still fun to drive.

Dak

I had once wondered what it would take to put the RX-8 rear subframe in an FC. This was back when I was doing the RX-8 rear end swap. I don't remember why, it may have been the track width but I decided to not even investigate it further. The NC stuff you mention sounds interesting though. A quick Ebay search for the rear makes it look like a pretty big undertaking.

WondrousBread

The biggest problem is the different shape fuel tank and floor IMO. First, the fuel tank in the NC seems to sit directly above the diff nose and have a tunnel shape over the nose and driveshaft. On the FC it sits way out back. If you were to swap the NC subframe in, to my eye it would want to occupy some of the space the fuel tank lives in. Which means custom fuel tank. The whole NC subframe assembly looks "taller" as well, which combined with the fuel tank issue means that raising the cargo floor might be required. Then there's modifying the subframe for clearance (possibly the chassis frame too), adding mounting provisions in the appropriate places, shock mounts, etc.

Anything is possible, but it's a Project Binky level of complexity. Not quite Binky scope of course, but Binky complicated. It would require not just experience but expertise in multiple areas, and I know my limits. Maybe one day though

If installed with an Rx8 transmission too, you could get even wilder. Move the engine further back with lower profile oil pan and custom mounts, or even further back with custom intake. Fabricate a custom PPF to integrate NC diff and FE trans all together for stiffness.

At a certain point though, the limitation is the FC chassis stiffness. Maybe stiffening foam, stitch welding, some strategic welded bracing, I'm not sure.

Obviously this is a very deep rabbit-hole, but one day if I have the time, experience, and financial flexibility, I'd love to grab another FC as a rolling shell and give it a try.

DR_Knight

iTrader: (23)

Just as I said in your old thread………………


It is all relative….
put enough money, time into adjusting the fc suspension and it will be a top notch driving sports car.

$35k total spent on a fc and upgrades
$35k to buy a stock car

………………………….

Dak

That's pretty much how I feel but I have no hands on experience with other/ newer cars. Some of the people I occasionally talk cars with at work act like I'm delusional for thinking that about my car. To them it's just a 30 year old Japanese car. Why don't I get something newer instead of wasting money on that old car. This is a little off topic but there is a double standard. If it was an old American muscle car then people wouldn't question it, but since it's from Japan why bother. I mean it was designed IIRC to compete with the 944. I bet if I had a 944 people's attitude would be different because It's a "Porsche" Okay rant off.

WondrousBread

This is something I've run into more than once. I bought my car in high school, and most of my friends were not car enthusiasts. I can think of literally one person who genuinely liked my car (and still does). Everyone else either said things like "Oh, it's not so bad!" (implying they thought it's all I could afford) or gave me a plainly forced "I like your car." Even now, some of my extended family are open about the fact they have no idea why I like my Rx7 in particular compared to other cars.

I think that American muscle has way more name recognition amongst laypersons than Japanese cars. Unless it has an obvious characteristic people want (Miata is a convertible for example), non car-people will never understand why we like them. Meanwhile if you tell someone you want a Mustang, they know exactly what you mean and why you want it.

Dak

My wife's brother is always trying to get me to LS swap it. He's domestic guy for the most part.
On the other hand I have been getting more comments from strangers in the past year or so saying they like my car. This even in it's current state of being in bad need of a paint job. These are mostly people in their late teens or early 20's. Apparently the FC is becoming popular with the younger generation.

driftxsequence

iTrader: (8)

I think one of the big things is chassis stiffness. When you jack up one corner the car flexes so much compared to a modern car where a similar height jacked up will lift both the front and rear wheel on that same side. McPherson struts and trailing arms are still somewhat relevant suspension designs, but modern material science focuses on applied forces in a certain direction.

Black Knight RX7 FC3S

iTrader: (7)

as with what driftxsequence said, the chassis rigidity is what set the current cars from the FC. I have driven 3 of my FC on track and drift, and have tracked a 370z, s2000, 2018 mustang, and a 2020 camaro ss 1le, and a short stint with a 2020 civic type R. While these cars have wider stickier tires than what I am using on my FC, what these newer cars have vs the FC is chassis stiffness, The flex in the FC is just very noticeable, I mean its an open air hatch, it will flex. Installing an xbar or a 4point bar on the B pillar greatly increase the rigidity of the car, bolt on ones are ok but the welded on ones are much safer and provides better structural support. I welded my own basic "chassis stiffener brace", I wouldnt even call it a roll bar, it tied the B pillar to each other and it also tied into the rear shock tower. It was just 2 bars high and low on the B pillar that formed a box to the rear. Just from that, it made drifting much more controllable.

In the front of the car, you need to stiffen up the points between the shock towers, and the firewall. In the past I welded my own strut bar that is also bolted to studs I welded on the firewall so it doesnt interfere with the turbo/intake/powersteering, and it was pretty good, but steering still felt not precise, so I bought Himni lower arm bar and a fast left to right transition was pretty on point.

WondrousBread

I just looked up that Himni piece, it's pretty nice. I currently have the Cusco version on my car, can't feel any difference with / without. Probably due to the hinged joint on it. I've been looking a lot into strut braces and similar lately (since I would like added rigidity but don't want a cage on my street car) and it seems like unless you have a one-piece brace it likely isn't doing much.

Dak

Have you got any pictures of that? I'd really like to see that setup. I've been thinking about a rear stiffener bar of some sort for a long time and just haven't done anything about it yet.

I have front strut tower bar but it only ties the towers together. Mazdatrix used to sell this 86-92 Strut Tower Braces (archive.org) I envision your bar is similar to this. You have made me think since the mounts to my brace are steel I should weld up something similar to that old Mazdatrix one to them. Also that Himni brace does look nice. I may think of adding one of those to my to do list as well.

WondrousBread

That brace is really cool, especially since it also had an option for an engine torque brace. It's unfortunate it's not made anymore.

Black Knight RX7 FC3S

iTrader: (7)

sadly, I have zero pictures of that car lol. I spent entire month of fabricating the rear bars and the car got into a rear end crash that pretty much was not repairable. It was my drift car too, had it for a total of 3 months. Junked the shell and swapped almost everything I could to my GTUs that I had at the time. In my GTUs, while I never did the full rear bar setup like I did in the previous one, I did make it much more simpler. I saw a japanese car that had a lower B pillar bar which goes on the lower section right behind the seat and a basic xframe strut bar for the rear, and I just copied that.