You neglected to mention they are running wider tires as well... Imagine that. I run with many SuperMiata guys and they do not run rediculous stretch on their tires.

Saying that a 1 inch wider wheel is worth 1 second unilaterally regardless of track type and length is a rediculous statement.

Again, im sure it may run a little better on 10s or even wider, but I'm not going to gain a second for the extra spend on wheels.

I was more stretched before on 255s and the car feels better now with more tire, and ran the same times with 50+ degree higher track temps. Again, FCs don't respond to tire stretch like some other chassis do.

I didn't write that, Urge engineers did.


They mean 1 second per 1 minute of lap time.

so 3 minute lap = 3 seconds faster.

LOOKatme-

The FC does not respond well to a low profile, stiff sidewall, flat tread surface tire

because it has crap suspension.

----------------------------

On the FC chassis the tire's contact patch has to be able to deform to stay flat on the ground DESPITE what the suspension and chassis is doing to it.

If you want to go really fast in an FC its going to be big sidewall bias ply slicks on 16x12s.

Yeah, they feel gross to drive- but its fastest.
-----------------------------

Having a tire with a stable contact patch predictably located relative to the wheel as you are arguing for only works when the suspension is doing its job.

What part of the job aint the suspention on the fc doing right? i have not yet driven it since my last version of the suspention (pillowballs evrywhere and groundcontrol/konis and wide ass tires) but last year i had poly bushings and tein type HA and 235 yokohama semis and i thought the car drove well....a little pushy in the corners but nothing major....

The FC suspension is what it is. It's a Mac strut front and a semi trailing arm rear so nothing about it geard toward race inspired handling.

To really oversimplify it, all you need to do to make it work is plant the front tire contact patch on the ground as best as possible and let the trailing arms articulate in the back.

It ain't the best but it's far from the worst and it still works pretty well relatively speaking.

Well is sounds like you are on the right track. What is your setup and alignment?

Mine is all solid bushings, 275s all around, Custom coilovers etc. I have about 7000 track miles on the car developing it from a nearly stock NA FC with basic mods to a 400WHP track focused setup. So you can listen to people like Eage8, BlueTII, and myself and others who actually have experience with the FC on a track, or Lookatme that just reposts irrelevant conjecture and jargon.

While you are learning about suspension, aero and 20B trailing split here is some inspiration to keep you going on your pursuit of Time Attack FC3s.

Super Motobei and SuperNow FC3s are the ones to watch.

Current fastest Time Attack FC3s?

Super Motorbei FC3s-
FC???????FC3S?Blog?????Minkara - The Car & Automobile SNS (Blog - Parts - Maintenance - Mileage)

Relevant to this thread, note Super Motobei FC3s tire and Tsukuba lap time progression.

February 2014 current of the original Samurai ☆ FC specs

https://cimg8.ibsrv.net/gimg/www.rx7...643afb8c97.jpg


F spoiler Tamon design
F fender Tamon design-based one-off + 60㍉ (Auto sonic processing)
R Quarter 〃 + 60㍉ (ditto)
F lip Tamon design base
Canard auto sonic one-off [m: 66]
Undercover Tamon design
Side Tamon design
Bonnet Tamon design
Rear Diffuser over manufacturer unknown (not served by only brackets?)
GT wing super ☆ Now (Garni w bought in 1800㍉ + hardware store)
Door hatch FRP + acrylic (SK SERVICE processing)
Engine 13-B base Bridge port Top Fuel Racing (TFR)
Turbine Trust 07-25G (2009. December change)
Westgate third TypeJ gate silencer (auto Sonic one-off)
Computer V professional (TFR setting 500ps)
Intercooler TFR one-off
Oil cooler auto Sonic both sides distribution (one-off) (2010. March)
Radiator TFR one-off
Clutch Exedy twin metal
Transmission FD3S genuine (super ☆ Now conversion kit) + circuit shifter
Engine mount super ☆ Now (rigid)
Differential mount super ☆ Now (rigid)
Underbody Super ☆ Now "羯徒 毘" ← this Onunume! !
Spring Rates F11.6k R8.0k (2012. December)
Upper sheet super ☆ Now
Stabilizer bracket Super ☆ Now
R undercarriage (pyro) Super ☆ Now (lateral, scan Con main, Kyankonsabu, Tokon)
LSD Cusco RS (1.5wey)
Muffler GP Sports (propeller canceled)
Catalytic converter KTS Tyco
Dash Four site-based FRP (SK SERVICE one-off)
Meter Defi white (octopus, oil temperature, oil pressure, water temperature, boost)
Full backet of sheet D sheet ... Brit
Seat belt Takata 5-point

Circuit time until now

TC2000 only

1 minutes and 15 seconds 2 (01R F225 / 40/18 R245 / 40/18) 2008. April
1 minutes and 10 seconds 8 (55S / F225 40 17 R255 40 17) 2009. April
1 minute 09 seconds 6 (55S / F225 40 17 R255 40 17) 2009. October
1 minute 05 seconds 0 (050M / F235 40 17 R255 40 17) 2009. November
1 minute 04 seconds 9 (undefined undefined) 2009. December
1 minute 03 seconds 4 (undefined undefined) 2010. January
1 minute 02 seconds 9 (11S / RS F245 / 40/17 R255 / 40/17) 2010. February
1 minute 01 seconds 086 (050M / F255 40 17 R255 40 17) 2011. January
1 minute 00 seconds 731 (050GS / F255 40 17 R255 40 17) 2011. February
59 seconds 321 (050GS / F255 40 17 R265 35 18) 2012. January
58 seconds 322 (050GS / F295 30 18 R295 30 18) 2013. February
57 seconds 866 (050GS / F295 30 18 R295 30 18) 2013. December
56 seconds 495 (050GS / F295 30 18 R295 30 18) 2014. February

My setup as of today is:
Supernow pillowballs everywere
Fully seam welded
Full racing cage(to come next month)
Groundcontroll/konis 11k/8k (on its way)
Supernow tie rods
Re amemiya diff
Evo 9 front brakes/large FD rear brakes with yellowstuff all around and dual MBC
Fc2000front bumper/w home made splitter (150mm allowed only)
600hp 20b
Bmw 6speed gearbox
Speedway style swaybar up front
Manual rack
Very very lightened

Thats where i am now....alignment will be done after wheels are bought but i have last years figures somewhere

Thanks for the porn ;-) i can definatly see the pattern in tirewidth/lap time!

My setup as of today is:
Supernow pillowballs everywere
Fully seam welded
Full racing cage(to come next month)
Groundcontroll/konis 11k/8k (on its way)
Supernow tie rods
Re amemiya diff
Evo 9 front brakes/large FD rear brakes with yellowstuff all around and dual MBC
Fc2000front bumper/w home made splitter (150mm allowed only)
600hp 20b
Bmw 6speed gearbox
Speedway style swaybar up front
Manual rack
Very very lightened

Thats where i am now....alignment will be done after wheels are bought but i have last years figures somewhere

I would also suggest-

A rear wing (which you probably just didn't mention):nod:

Roll center correction at the lower front suspension arms if they aren't already done from the SuperNow parts.

Some form of positive location on the rear "subframe" to unibody (such as Powered By Max sub frame risers) and use the individual SuperNow or Powered By Max camber links to adjust camber if you don't have this already.

You might find you need to upgrade the the front spindle/bearing to something with wider spacing because of brake pad knock back issues when you go to the 295mm or wider front tires.
____________________

Sounds like your aero is actually pretty limited for a Time Attack series with just a 6" front splitter.

Are you allowed additional front canards and or splitter fences?

How much rear wing area allowed?

forgot to mention the rear wing....its limited only be the width of the car and height of the car and mounts must not protrude past rear bumper, so a 2d-bigass apc wing is probably what ill get

ill look into the roll center corrections but im not sure what u mean with subframe risers? mine is alu mounted (diff and subframe) and i got ronin links in the garage for camber, pbm toe adjusters and so on, i do have supernow hubs up front so i hope thats enough, otherwhise there is a guy in sweden that had porsche gt2 hubs and spindles on his fc and i might cooy it :-)

as for canards i can have 4 of them 50mm wide, cant find restrictions as of splitter fence or rear wing area....i do think front end downforce will be the biggest issue

the porsche/fc hybrid front end, claims 0 bumpsteer and very low rideheight, also gives you porsche brakes and struts...to expansive for me (since i built mine on fc parts already) but an epic setup!

Well yea you are certainly on your way. Is your front sway bar custom or the AWR one? I am looking to go to a speedway bar this year.

Also notice that the FC BlueTII posted does not have a ton of tire stretch...

i just want to add, that Mazda's stock fit is a 205 on a 7" wheel, 225 on an 8" wheel, and this hasn't varied since the FC came out. we are running a 205 on a 9" wheel, but hoosiers run wide, so its really more like a 225 tire

we've tuned a few suspensions at the track with pyrometers and such, and we've found that even the double wishbone cars want about -3 camber in the front, the FC isn't that different. i will grant you that we're tuning cars that are running 205 or 225 tires, i would expect a 295 to be different.

i did measure the FC camber curve, and found that there isn't one, its basically a flat line through most of the travel.

its been a LONG time since we ran an FC at the track, and we've learned a LOT since then, it would be really fun to set one up, they are great race cars, its like a big happy dog. like a labrador with some st bernard in it, or something.

On the FC we have in our group he stretches a 225/45/17 on a 17x9 wheel on the front. he pulls 1.1G on extreme sport street tires with a peak of 1.2G observed. only gets better with wider wheels. I should mention that this person ran the 4th fastest time at autoX last year in a field of 148 people, he beat some very good drivers.

The Miata that races in our group of people runs a 205 on a 9" wheel and runs 225 on 9" depending on the tread width. We both started stretching some years ago.

The group has many many many miles on track.

one vid for fun. He pulls 1.3G peak or so on extreme street tires with this set up. runs very fast laps as well with a miata at high altitude (not much power).

The perfect tire width sweetspot for timeattack FC?
 

Any miata examples you have are completely invalid. You can't get normal 23" tires in wider than 225s, so of course they're going to throw wheel width at it to make them as wide as possible.

There are a thousand examples of race classes being limited by wheel width and everyone running silly wide tires on narrow wheels because it's faster than narrow tires.

Bottom line, both tire and wheel width are important, get over it. You should fit the widest wheel you can with the widest tire you can in that order. If you're tire is too big for the wheel you did it wrong. If you can fit more tire, you did it wrong. Please stop distracting every thread you're in from more important discussion points.

the thread is about the perfect tire width.


its completely on topic. and many other cars can be used to help us determine what could be the fastest. my vote, fit the widest tire, exactly, then figure out the widest wheel width for the tire.

The perfect tire width for an FC is as much as you can reasonably fit on a given wheel. I'd stay on the wider wheel size of a given tire MFG recommendation.

Something to take note of is that the further you stretch the tire the snappier the car can become. I've noticed the car tended to snap loose whit less notice than when I went with a larger tire. This is also a function of running a smaller tire.

Since you are still on this jihad of misinformation, he would be even faster with MORE TIRE on that rim.

I ran 235/40/17s on a 9 inch rim, then ran 255/40/17s on the same rim. I was faster on the 255s. Both sizes were NT05s.

rx7jocke

but im not sure what u mean with subframe risers? mine is alu mounted (diff and subframe

Yes- same thing. You have what I was thinking of to keep the rear subframe from moving.:icon_tup:

rx7jocke the porsche/fc hybrid front end, claims 0 bumpsteer and very low rideheight, also gives you porsche brakes and struts...to expansive for me (since i built mine on fc parts already) but an epic setup!

Customized Porsche parts do sound expensive!

Your aero limitations sound a lot like my autocross class (street modified).

I'm running a ciro designs racing wing on my car. it uses custom length (to get exactly close to the width of the doors) APR GT-1000 elements. my current uprights fit all your rules except they go 6" above the roof, he can easily made some 6" shorter for you.
Wing | CiroDesign Racing


https://cimg6.ibsrv.net/gimg/www.rx7...d187aeffd1.jpg

eage8 thanks for that wing tips! i will definatly look into it!

This simple concept even a rotard could understand. If I hear anyone argue to the contrary I will find you; and I will kill you.