Mazda Rotary Club

General => General Technical => Topic started by: interloper393 on June 17, 2008, 05:20:15 PM

Title: Big job? rx8 box into a 7?
Post by: interloper393 on June 17, 2008, 05:20:15 PM
I know its been done a few times but does anyone have pics or a guide/idears on how hard it is to do? is there alot of fabbing involved or can it be done at home?
Also what kinda safe power can the box run?

cheers
Title: Big job? rx8 box into a 7?
Post by: RotorHeid on June 17, 2008, 05:23:27 PM
Done that!! and it\'s easy!!, and which\'s car?
Title: Big job? rx8 box into a 7?
Post by: interloper393 on June 17, 2008, 05:30:50 PM
that would be an fd bud lol, iv heard its not too bad, just checking tho b4 i buy the box..
Title: Big job? rx8 box into a 7?
Post by: RotorHeid on June 17, 2008, 05:34:13 PM
sorry cannot help you there as I don\'t know nothing aboot FD\'s chassic, only it\'s engine:(
it\'s easier on FB/FC\'s
Title: Big job? rx8 box into a 7?
Post by: hairyhoover on June 17, 2008, 05:51:26 PM
i think the major issue is the postion of the gear shifter moving forward.
Title: Big job? rx8 box into a 7?
Post by: RotorHeid on June 17, 2008, 06:35:18 PM
Peter barbon FD\'s http://www.driftworks.com/forum/drift-car-projects-builds/50275-3-rotor-n-fd.html
Title: Big job? rx8 box into a 7?
Post by: Ricco_04 on June 17, 2008, 10:39:33 PM
Think 88-GTR has one in the FC running big power :)
Title: Big job? rx8 box into a 7?
Post by: nikp on June 18, 2008, 08:50:40 AM
It\'s the position of the gear lever that\'s the bugger: it\'s a lot more forward than the FD\'s. However, something Westfield (the kit car manufacturer) did is they made a \'gear level relocation\' mechanism (for want of a better phrase!) for the Ford type 9 gearbox which moved the gear level back. Very simple, and very effective. So you might be able to do something like that for the \'8 gearbox.
Title: Big job? rx8 box into a 7?
Post by: FD3SNuttah on June 18, 2008, 09:04:54 AM
the gearbox is pretty much the same size.. my mate has one i could probably convince to sell me!

so what are the benefits apart from having 6 gears? is it stronger than an FD box? what about the ratios?
Title: Big job? rx8 box into a 7?
Post by: nikp on June 18, 2008, 10:01:08 AM
5th gear in the 8 box will probably be the same as 4th gear in the 7 (i.e. 1 to 1). I think that is the case. Therefore, the lower gears in the 8s box will probably give a better torque curve, possibly giving slightly better acceleration, and possibly better smoother acceleration too.

This is all theorisation however. Pretty certain on the 5th gear 1:1 and 4th 1:1 bit though.
Title: Big job? rx8 box into a 7?
Post by: mx1311 on June 18, 2008, 11:49:30 AM
you have to modify the fd\'s ppf and use a gen 2 clutch slave too, and as nik said the 8\'s selector sits 4inches further forward

regards

colum
Title: Big job? rx8 box into a 7?
Post by: SiH on June 18, 2008, 12:26:49 PM
I\'ve heard somewhere (although can\'t tell you ow true) that the 8\'s 6th is much the same as the FD\'s 5th - the 6 speed box would be like having an extra gear between 2nd and thrid, with third adjusted a tad.

I\'m not 100% sure it\'s worth it tbh, although i guess with a big single tub it may keep it on song better - with a  stock twin setup i would have thoguh that the ample power pread would outweigh any gains produced by the extra gear?

All total hypothesis though, not based on any fact :D
Title: Big job? rx8 box into a 7?
Post by: AshRX on June 18, 2008, 12:40:37 PM
Chris Impey was running one on his drag FD
Title: Big job? rx8 box into a 7?
Post by: interloper393 on June 18, 2008, 03:28:35 PM
Quote from: SiH;509611I\'ve heard somewhere (although can\'t tell you ow true) that the 8\'s 6th is much the same as the FD\'s 5th - the 6 speed box would be like having an extra gear between 2nd and thrid, with third adjusted a tad.

I\'m not 100% sure it\'s worth it tbh, although i guess with a big single tub it may keep it on song better - with a  stock twin setup i would have thoguh that the ample power pread would outweigh any gains produced by the extra gear?

All total hypothesis though, not based on any fact :D


yeah been reading up on it on rx7club and they say the same thing, 6th gears is the same as 5th plus the gear stick sits abut 3"`s forward, o well thats that idear scraped lol..
Title: Big job? rx8 box into a 7?
Post by: RotorHeid on June 18, 2008, 05:45:55 PM
Quote from: AshRX;509615Chris Impey was running one on his drag FD

That\'s right,  
 Chris (FD) ,88GTR( FC) and Carl(FB), Peter Barbon(FD)and myself (FC)

any more??
Title: Big job? rx8 box into a 7?
Post by: hairyhoover on June 18, 2008, 06:44:28 PM
does this 3" hamper the driving position much?
 
do you need to mod the dash at all?
Title: Big job? rx8 box into a 7?
Post by: nikp on June 18, 2008, 07:37:49 PM
This is what I was talking about regarding the extension. Obviously not suitable for the RX-7 gearbox, but an example of what is possible

http://www.westfield-sportscars.co.uk/shop/uploads/html/Sierra_type_9_gearbox_gearlever_extension_249_1.htm
Title: Big job? rx8 box into a 7?
Post by: Timrxmotors on June 18, 2008, 09:02:20 PM
5th gear is the same as 4th on the FD box,6th gear is lower than 5th on the FD box.Your hand needs to go in where the stereo was to change gear.
Title: Big job? rx8 box into a 7?
Post by: interloper393 on June 18, 2008, 09:29:06 PM
Quote from: Timrxmotors;5097875th gear is the same as 4th on the FD box,6th gear is lower than 5th on the FD box.Your hand needs to go in where the stereo was to change gear.

yip tiz like that in all the pics iv seen lol, very cramped it looks lol, and due to the dash board i doubt i cud fad up a new midsection in F/G to tidy it up..
Title: Big job? rx8 box into a 7?
Post by: RotorHeid on June 18, 2008, 09:49:00 PM
Quote from: interloper393;509795yip tiz like that in all the pics iv seen lol, very cramped it looks lol, and due to the dash board i doubt i cud fad up a new midsection in F/G to tidy it up..

If that\'s me, I wouldn\'t be brother with it and better keep FD\'s box in as most of mofry RX\'s with RX8box goes racing!;) e.g RX8\'s no speedo cable and how to install on???
Title: Big job? rx8 box into a 7?
Post by: interloper393 on June 18, 2008, 09:55:34 PM
yip guna stick with the 7 box lol, just get it rebuild and made stronger :)
kool cheers for the input peeps :)
Title: Big job? rx8 box into a 7?
Post by: Timmy on June 18, 2008, 10:05:57 PM
surely the 8 box only makes sence for drag. On track your revs would drop quicker and drop out of boost on a single, makes more sence for twins if anything. I think switching to 6 speed takes alot more math than people give it credit for. As for the length thing couldn\'t you use an extention plate between g/gox and engine and shortened prop shaft. expensive probably.
Title: Big job? rx8 box into a 7?
Post by: mx1311 on June 19, 2008, 08:46:33 AM
Quote from: RotorHeid;509710That\'s right,  
 Chris (FD) ,88GTR( FC) and Carl(FB), Peter Barbon(FD)and myself (FC)

any more??

james willday

anyone wanna by a trust dog box :chat