Maximum power FC gearbox can take?

m1tch · March 08, 2011, 10:04:00 PM

Hi all,

What is the most power the FC gearbox can take, I have heard about 500bhp is and at least the diff won\'t explode like the FD ones lol should I save for uprated internals? I know I can get an OS Geiken gearset for it but those are Â£Â£Â£s.

I know that you can swap out the 5th gear and drop it into the MX5 gearbox to get a longer 5th in the MX5, so I am guessing that they are standard Mazda fit components etc, are there any higher powered Mazda gears that I could run?

Please note that I wouldn\'t launch at full power lol I would set the AVC-R to delay the boost and lower the boost in the first 2 gears and then only go full boost in 3rd onwards.

Is the FD box any better and keeping the gears inside the box?

Upgraded close ratio gears:

http://www.rhdjapan.com/os-giken-5-speed-close-gear-kit-w-input-shaft-fc3s-fd3s-60624

antnicuk · March 08, 2011, 10:11:28 PM

FC gearboxes are so cheap, i would just replace it when it breaks. I ran a stock one at 460 bhp for 2 years, drag, drift and track work with no problem.

m1tch · March 08, 2011, 10:15:58 PM

Hmm thats probably the T88 power on spring boost lol wonder if its worth seeing if I can get a dog box made up? or a Lenco box

najiru · August 21, 2011, 05:02:44 PM

M1tch - what did you do in the end?
I\'ve just broken the rx8 box in my fc and am looking at the options. Still want the close ratios and will basically be track only so trying to decide what\'s best.

m1tch · August 25, 2011, 06:10:47 PM

Quote from: najiru;783612M1tch - what did you do in the end?
I\'ve just broken the rx8 box in my fc and am looking at the options. Still want the close ratios and will basically be track only so trying to decide what\'s best.

I will be keeping the stock box at the moment, will be limiting the power in the lower gears via my AVC-R, what power is your car at? I can then see at what power the RX8 box can take! Perhaps keep with a stock box but change to a different ratio diff?

I know there is an OS Geiken gearset on RHD japan for a close ratio set, think its Â£1200 though.

12at · August 25, 2011, 09:05:45 PM

my mates cosmo back home made over 600 rwhp through one and never had an issue.

m1tch · August 25, 2011, 09:31:47 PM

Quote from: 12at;784598my mates cosmo back home made over 600 rwhp through one and never had an issue.

How much stronger is a cosmo box though? Surely thats uprated to take the extra power and torque for the 50% extra rotors?

antnicuk · August 25, 2011, 10:08:31 PM

i would wait til you actually get 500 hp, then when the box breaks, fix it with something stronger!

B.Martin · August 26, 2011, 07:51:28 AM

Quote from: antnicuk;784614i would wait til you actually get 500 hp, then when the box breaks, fix it with something stronger!

He\'s right Mitch!

Grant Monkhouse · August 26, 2011, 08:20:19 AM

Quote from: m1tch;784605How much stronger is a cosmo box though? Surely thats uprated to take the extra power and torque for the 50% extra rotors?

I do believe the Cosmo 20B\'s came with an auto gear box, not a manual.

najiru · August 27, 2011, 08:27:48 AM

Mine is 530fwhp and has lasted a good while. Which is considered stronger the fc or rx8 box?

m1tch · August 29, 2011, 07:44:25 PM

Quote from: Grant Monkhouse;784668I do believe the Cosmo 20B\'s came with an auto gear box, not a manual.

Well at least we know the autobox is strong enough, would just need to mod the autobox ECU to fit paddle shifters lol

antnicuk · August 29, 2011, 08:31:36 PM

Quote from: m1tch;785288Well at least we know the autobox is strong enough, would just need to mod the autobox ECU to fit paddle shifters lol

the cosmo auto box is your typical slushy jap crap and they dont last long on a stock cosmo