I know that the FC has McPherson struts and is more of a heavier gt car from the 80s and that the FD is considered to be god-tier when it comes to handling but could it be made to handle as good / almost-as good as the FD ?
thanks

 

Yes and no.

There are plenty examples of FC's running extremely quick times in GT racing and super lap battle. The biggest issue is the suspension design for the FC was never meant to be super "competitive," in comparison to the FD with it's double wishbone suspension. That said, nearly any car with proper suspension tuning will outperform one with worn out or bad suspension tuning.

Keep in mind, the biggest difference in making a car handle as good as another is the driver. If the driver is unskilled, no amount of suspension parts or tuning will allow the car to compete against skilled drivers.

 

What do you consider good handling?

When we start out racing a good handling car is one that is forgiving and doesnt try to kill us when we make a mistake (car does what we want it to do despite our inputs).

When we are more advanced racers a good handling car is one that tries to kill us when we make a mistake (car does what our inputs told it to do).

 

First time coming across that analogy. Love it!

 

Realistically, it’s all relative. You can spend $15k on a stock fd, or spend $7k on a fc that will destroy a stock fd.....

my fc handles better than my Hawkeye sti, but I have upgraded everything suspension wise on my fc and only have coilovers/sway bars on the sti. But I have about the same amount of money in them.

You’ll learn once this hobby shreds your wallet.

 

A) Racing is a little unusual because all we care about are lap times, its not very common you do something that has such a simple metric like that.

B) that second thing is true! this one time one of the drivers, Mario (he does have a red suit), was complaining about the car being twitchy, but you look at the in car camera, and he's wiggling the steering wheel, and the car is just twitching because he's twitching....

 

Well, to be fair, twitchy cars are actually a thing. His steering inputs could be reactive to the vehicle and constantly making micro-corrections or he could be actually causing the twitching. Hard to say without more telemetry.

 

My actual FC vs FD experience is a follows.

Watched Video Option #92 where RE Amemiya builds up FC2000 and got inspired.

Built my $1,500 FC TII in 2001 with about $15,000 in parts and raced it till 2014 spending much much more along the way. Final evolution of FC was EFR 7670 turbo @ 26psi making 420rwhp/420rwftlbs, weighing 2,500Lbs.

Bought my FD in 2008 for $14,500 and put wheels/tires, coilovers, downpipe and catback (~$6,000). Making probably 250rwhp.

250hp FD was 5 seconds faster on hillclimb (1,160ft elevation change in 2.2 miles) and 2 seconds a lap faster on the kart track I race on in 2013.

 

he was wiggling the wheel going down the straights... we did have the telemetry, he was ~2 seconds slower. to be fair he made it look exciting, the other driver looked like he was gong to the store or something

 

With the experiences I've had with the FC, other cars with better suspension designs, and having read both of the RX-7 development books by Jack K. Yamaguchi cover to cover, I would have to say that even with fairly extensive modifications the FC would not out handle a stock FD (assuming of course that both cars are in good running order.)

The FD's suspension design is world class.
In stock form, it was engineered to keep the tire at an ideal toe/camber setting at every forseable stage in a corner. Mazda poured many, many hours and tons of money at the FD; a luxury they simply didn't have with the FC. Also the suspension in both cars was engineered for two completely different purposes...

The FC was intended to be more of a Grand Touring car with the intention of out doing the Porsche 944, 80's 300ZX, etc.

The FD however was a completely different approach; more of an all-out, raw, sports car intended to take on the likes of the NSX, Skyline GT-R, Corvette, 911, etc.

 

Here’s a thought, double wishbone suspension on a FC. Yes I know easier said than done. But still possible.

 

FC handling deficits are not just down to strut front end. So, even if you could adapt double wishbone and get it to integrate properly with the rest of the chassis/suspension set-up to work well with the strut front compromise- you would still have the issues below to deal with.

Rear suspension is very heavy trailing arms so they suffer over bumps.

The weight distribution of the FC chassis is nearly 50% weight directly over front axle and nearly 50% weight directly over rear axle.
Sounds good, but provides higher Polar Moment of Inertia compared to FD where they made the car a bitch to work on by trying harder to get as much weight into the middle of the car as possible to lower the P.M.l.

Then you would want the FD ABS (or better ABS) and bigger rotors.

That is to get FC up to stock FD level. Then you have FD upgrade potential to deal with...

For that you would need a complete suspension redesign so you can run a widebody on the FC and have proper scrub radius with the new wider lower offset wheels because the FD can run 295s on 10.5" wide wheels on stock offsets (or 315s on 11" wide wheels with 5mm less offset than stock).

Then you have to have a company engineer and build you race coilovers because no company makes decent coilovers for the FC, whereas FD has cheap Ohlins or Aragosta or more expensive race oriented Moton/JRZ/whatever available right off the shelf.

Not that the FD is the ultimate Mazda chassis.

The newer RX8 chassis is even better and despite some unibody rigidity loss the NC and ND Miata might be better as well.

RX8s sure are cheap and ugradeable...

 

Part of the fun of having an FC (or any car) is that it is what it is. If you need to redesign the whole car to do x/y/z, why bother to start with it at all?
my friend has a T2 with springs and shocks, and on the street it feels great to drive, and rides better than any FD i've ever been in. obviously its not a track car and we have no numbers, but who cares?

semi rant, i live in an urban area, and its actually rare (pre pandemic) that people drove the speed limit....

 

^^
And also,
An old car like AE86 Corolla, S-chassis, Skyline GTR, FC or FD might not be the fastest/best handling/whatever superlative car anymore, but if it inspires the owner to drive and modify their car to an extraordinary level- great things can still be achieved (but mainly you are just going to have a fun time trying).

 

i got to drive a stock AE86 once, and it was fun, even though it is amazingly slow. actually the most fun FD i drove was stock, it wasn't fast either but you could actually get into it a little before you were doubling the speed limit

 

As far as going to a double wish bone suspension I believe that is the redesign, but if you want a widebody kit to accommodate wider wheels and tires, not a problem. If you get wider wheels for an FD and keep the stock offset the scrub radius will move from O.E.M. specifications, so what would be the proper scrub radius?

 

Scrub radius is the measurement of the intersection of the steering axis through the contact patch to the center of the contact patch.

So, if you keep factory offset you have factory scrub radius no matter the wheel/tire width.

It really helps wide wheels and tires drive well in my experience.