I have been looking at the synchro problem we face when using our gear boxes, namely destroying the synchros and only being left with a couple of gears out of the 5 we have.
This problem is more common when cars are pushing 500Hp and upwards, then the problem of breaking the I out shaft shows itself
A few pieces I have come across suggest a couple of things;
1, polishing the synchros
2, grinding the synchros, removing every other tooth or sometimes even more
3, extra springs, now I\'m not too clued up on our boxes to know if they use springs or not??
4, chryo treatment of parts, I don\'t know how much this is but would most certainly be the greatest cost.
All these modifications obviously require the gear box to be rebuilt. If these modifications were to work I\'m sure there would be a few people pushing higher power if they needed it instead of spending ££££\'s on a dog box etc or even on the OSGiken uprgrade.
This still leaves us with the tiny input shaft:(
Once I have done some more reading up on this I will share my thoughts. What would any body think too the modifications? Would they work?
I know we can get Gboxes for £150~ but if you constantly break them like a few people do, namely CJR(Chris) on his track day car, then having a stock box modified whilst having it rebuilt would be good if it wasn\'t to break again.
Obviously there are other ways to help the Gbox last, braces, sump plates, solid mount it to the chassis etc, all of which I will be doing/have done to my FD Gbox that I am using in my RX4.
This isn\'t just for FD Gboxes but all of the boxes we have as they are very similar.
From what I have read so far a number of cars in PR ran modified stock boxes deep Into the low 9seconds!! That\'s +-600 rwhp afaik:)
Grant i cant report back on real world experience but i have a new OSG gearkit and i cryo\'d it all before it was rebuilt....i know they supposedly use different ( stronger) material in the OSG gearkits but i thought a little extra wouldnt hurt so i got it done at the same time i did my billet E shaft and titanium engine studs:yes
The gearlkit came witha new thicker shaft too so hopefully i would like to think it will be pretty
this will be the last engine so thought might as well go all out:mmmm
How much was the OSG gear set and how much to install? Aren\'t the ratios shorter too?
Got the gearkit cheap at £1800 or £1900
Rebuild was £360......Yeh gearing is different.
That is fairly cheap but still more than what I would want to fork out. Going to learn some more about modifying the standard box and see what I can come up with and see what the costs are total.
I think the tiny input shaft will still be the down fall even if the other mods work
yep i agree....the input shaft is one of the reasons i got the kit.
i made contact with a guy in oz that made kits with interchangable gearings.....well priced to but i wanted to got the tried and tested route.....i\'ll try a find his details.
tbh...i think braCing and cryo would be your best bet grant.
or possibly get the three speed kit...but doesnt come with the input shaft.
Yeh iv got lots of bracing going into the build. Iv made one bracket out of 6mm steel, Tig welded for at the rear of the box onto my chassis using the PPF mounts as I don\'t need a ppf on my rx4:D iv also made a 6mm plate for in between between the gear box and cover plate but it extends out beyond it so I can weld or bolt more bracing to the chassis at the front are of the box, if it manages to move or twist I will be running serious power or I don\'t know what I\'m doing:(
Chryo treatment isn\'t that expensive is it?? But all parts have to be removed cleaned and seperated to do it, can\'t just it in the freezer and hope for the best lmao.
I\'m not to fussed about having interchangeable gearings as I can do that with changing the rear gear, I have options to go from a 3.9-1 to 5.1-1 on the diff, plus rear tyre size will help alter that too
got all my cryo done for cheap....about £140...for e shaft, suds and gearkit with shaft
by cover plate do you mean sump?....does the fd box have a sump?
yep all have to be clean and seperate....thats why i did it all when i did.
Quote from: Ed_RX7parts;859184got all my cryo done for cheap....about £140...for e shaft, suds and gearkit with shaft
by cover plate do you mean sump?....does the fd box have a sump?
Yeh the sump bit, it has a magnet in the bottom to catch all the broken synchros and input shafts when they pussy out. Lol
It has a plastic piece on the inside that I think helps the oil cover all the gears when spinning
if you added rigidity to this would it not help?....might be worth someone knocking one up in billet...possibly with cooling fins. pretty sure the guru box was like this.
I have made a plate to make it rigid, 6mm steel to go between the sump cover and the box, I think I should have made it a little thicker but its will take a lot to force to bend 6mm steel and the aluminium all bolted together.
There\'s someone on rx7 club that has made a 3/4" plate like I have but that\'s just getting really thick, not sure if he milled it CNC\'d it??
Will see I f I have a picture of the box sump sandwich plate and post it up in here, would be nice if anyone else had any ideas on this or any info about how the gear boxes work etc.
This is what I have done
(http://i1215.photobucket.com/albums/cc507/grantmonkhouse/1F043013-309A-4A26-B37C-94A07254E3A2-21736-00002C3EAACE58D2_zps96176764.jpg)
I per powerfully left it protruding like like so I can extend it out and bolt it too the chassis and possibly hold the exhaust up into the tunnel if there\'s room.
Think I have got a picture of my other bracket/brace somewhere too. Even though its for my rx4 I bet I could use/make something similar on an FD and get rid of the ppf and make a beefier diff brace/girdle.
(http://i1215.photobucket.com/albums/cc507/grantmonkhouse/1ad089eb.jpg)
Here\'s what I made for the rear of the box
all looks cool...would love a larger billet sump though...just thinking why no one has done it tbh?........casing also being noted as a weak point...in hindsight maybe i should have done tnat aswell as a precaution....oh well only time will tell. in the meantime a sandwich plate seems like a relatively inexpensive way of adding some sxtra strength as well as fluid capacity to the old girl!
Ed, there\'s a couple of billet gearbox sumps on RHD from the usual RX7 tuners.
Richard
Quote from: Ed_RX7parts;859193all looks cool...would love a larger billet sump though...just thinking why no one has done it tbh?........casing also being noted as a weak point...in hindsight maybe i should have done tnat aswell as a precaution....oh well only time will tell. in the meantime a sandwich plate seems like a relatively inexpensive way of adding some sxtra strength as well as fluid capacity to the old girl!
thanks for the heads up mate....i\'ll have a gander.
Attain or Feed.
http://www.rhdjapan.com/attain-extra-large-transmission-oil-pan-fd3s-fc3s-21229
So I have order this book, worth having a look at and read. I will post up on here anything useful I find in the book and any other info i come across from other sources
http://www.amazon.co.uk/gp/aw/d/0760320470/ref=mp_s_a_1_fkmr0_1?qid=1370954200&sr=8-1-fkmr0&pi=SL75
Right iv come across a relatively cheap way to upgrade the stock box. There\'s a thread on rx7club that gives possible upgrades for the FD box, all are expensive apart from this option.
1350-2500 dollars. This gets you a larger Input shaft polished gear and synchros for smoother shifting, full rebuild. This option is being used by a guy on his 20B track car, 650whp 500rwtorque! For a full dog box race box it\'s the higher end of the price range.
So for £800, plus shipping you can get an awesome rebuilt gearbox that shouldn\'t break for a long time. And especially with most of us mere mortals only running 2rotors it looks like a good option.
I will email the people that do it and post up any replies I get.
I know people like CJR and possibly Clive would be interested in this, especially at the rate CJR has gone through boxes like a fat kid through cake. Now he has a powergains half bridge motor and Jay mapping it I imagine he will be buying up all the spare boxes around.
Just pulled these prices off their website
(http://i1215.photobucket.com/albums/cc507/grantmonkhouse/998DEA33-3B81-4710-9012-17182ACCCE41-10480-00000D0B56C5DA68_zps19bd6cc2.jpg)
From their website on what they do/change with the gears.
(//From%20left%20to%20right:%20Stock%20Gear,%20Pro-Shifted%20Gear,%20Face%20Plated%20Gear%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20Liberty%5C's%20High%20Performance%20Products,%20Inc.%206390%20Pelham%20Road%20Taylor,%20Michigan%2048180%20USA%20%20%20PHONE%20313-278-4040%20%20%20FAX%20313-381-2411%20%20%20EMAIL%20%5Bemail%5Dlibertysgears@aol.com%5B/email%5D%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20Pro%20shifting%20and%20face%20plating%20eliminate%20the%20need%20to%20worry%20about%20missed%20shifts.%20%20This%20is%20made%20possible%20by%20%20removing%20the%20stock%20synchronizers%20and%20opening%20up%20the%20engagement%20window%20for%20faster,%20higher%20rpm%20shifting.%20%20%20%20%20Initially,%20the%20cost%20of%20face%20plating%20is%20slightly%20more%20than%20pro%20shifting,%20but%20in%20the%20long%20run%20you%20will%20%20find%20that%20face%20plating%20is%20more%20cost%20effective%20due%20to%20less%20wear%20on%20engagement%20components.%20%20%20%20%20With%20pro%20shifting,%20the%20shift%20lugs%20engage%20on%20the%20inside%20of%20the%20slider%20and%20as%20the%20pro%20rings%20wear%20from%20normal%20%20use,%20they%20burr%20up%20and%20require%20dressing,%20deburring%20and/or%20replacement%20to%20maintain%20smooth%20shifting.%20%20%20%20%20%20With%20face%20plating,%20the%20engagement%20lugs%20are%20on%20the%20face%20of%20the%20slider%20which%20will%20not%20allow%20them%20to%20burr%20%20up%20and%20require%20maintenance.%20%20The%20design%20of%20the%20face%20plate%20shift%20lugs%20give%20them%20much%20more%20contact%20area%20%20which%20makes%20them%20much%20more%20durable,%20so%20longevity%20is%20increased%20dramatically%20(about%20three%20to%20four%20%20times%20longer%20than%20a%20pro%20ring)%20and%20there%20is%20virtually%20no%20chance%20of%20them%20popping%20out%20of%20gear.%20%20%20%20%20Pro%20shifting%20and%20face%20plating%20does%20NOT%20make%20your%20transmission%20clutchless.%20%20The%20%20shock%20load%20of%20shifting%20without%20the%20clutch%20will%20cause%20severe%20damage%20to%20your%20transmission%20%20%20%20%20Parts%20or%20complete%20transmissions%20can%20be%20sent%20in%20for%20face%20plate%20or%20pro%20shift%20modification.)
Interesting stuff Grant and Ed.
I\'m obviously interested what this investigation concludes.
For my next box swap I managed to source a late FD box with low miles. A good friend had it stripped by a gearbox specialist and the gears de burred.
I have another box as a spare, so depending on your investigations I may look at upgrading that one.
Other plans will result in the motor putting out more hp for next year, (http://www.mazdarotaryclub.com/forums/images/icons/icon12.gif)so I need to find a solution that lasts longer than two day track sessions.
Quote from: C J R;867353Interesting stuff Grant and Ed.
I\'m obviously interested what this investigation concludes.
For my next box swap I managed to source a late FD box with low miles. A good friend had it stripped by a gearbox specialist and the gears de burred.
I have another box as a spare, so depending on your investigations I may look at upgrading that one.
Other plans will result in the motor putting out more hp for next year, (http://www.mazdarotaryclub.com/forums/images/icons/icon12.gif)so I need to find a solution that lasts longer than two day track sessions.
Which option would you be looking at? Would you want to go full bore dog ring or just upgraded shaft and internals too keep it as a road car/track car?
Just going to send them an email now.
Prob the uprated shaft and internals.
What are you thinking of ?
The same. Iv sent them an email. Hopefully hear back soon. It\'s just a shame it\'s probably cheaper to send a gear box too the states, have the work done and have it sent back for cheaper than it would be to have a company here in the uk do it:(
The faceplates gears look awesome though. No maintenance required
good luck with liberty\'s customer service, its done when its done and you cannot speed things up
still waiting for a set of drop gears and a motorplate (6months and counting)
I would be up one for one set, when it comes to placing an order Grant. I am already working on a gearbox upgrade....So please keep me posted....
Mir
Quote from: colum;867380good luck with liberty\'s customer service, its done when its done and you cannot speed things up
still waiting for a set of drop gears and a motorplate (6months and counting)
Iv heard they\'re slow. Lol. But f they can possible supply the bits and get the gear boxes rebuilt here then it might work out better. I\'m really just trying to find a good solution for everyone and share any info I come up with. Seen as there isn\'t a good source of info for people to find easily I want to do the leg work myself and have all the info in one place and easily searchable on here.
A lot of people can not afford a T56 etc such as myself so for under £1,000 it seems like the best option for a more reliable oxidized stock box.
Also with the HKS box being not only expensive, but also the scarcity of parts available to recon them people aren\'t willing to use them. Quaife is another option but then again its expensive.
I looked into this Liberty option a few years, it be fine up to 650hp, after that it will break the case or the main shaft, spoken to a few guys that run this mod, in terms of circuit racing this option is fine. I think for drag racing if you looking for more then 650 then go for a proper dog box eg Gforce etc
Oh yeah good luck when getting stuff done, few guys in the states have to wait for a few months turn around.
Do you need to change the rear end around if you want to run a Gforce t56 or can you get away with just a different prop?. :)
I was not talking about the Gforce t56 btw, I was talking about the clutch assisted GF5R box, I think you specify which car you have, they provide you with a yoke and then you make your own custom prop I should imagine probably get your existing one modified
Quote from: BlitzBoy;867409I was not talking about the Gforce t56 btw, I was talking about the clutch assisted GF5R box, I think you specify which car you have, they provide you with a yoke and then you make your own custom prop I should imagine probably get your existing one modified
I only want a consistent reliable 10/maybe 9 second car. That box is way too much. Nice though.
What do you think too a stock modified box coping with... Let\'s say a 75hp wet shot of nitrous? That stuff is amazeballs.
Quote from: Grant Monkhouse;867412What do you think too a stock modified box coping with...
consistantly?
from experience... high to mid 10\'s
you can run the numbers with fd and t2 boxes (some as far down as high 8\'s) but after 3 or 4 passes, they like to crap out
chris seemed to do well on the rx8 box for a few years running multiple high to mid 9\'s
Quote from: colum;867413consistantly?
from experience... high to mid 10\'s
you can run the numbers with fd and t2 boxes (some as far down as high 8\'s) but after 3 or 4 passes, they like to crap out
chris seemed to do well on the rx8 box for a few years running multiple high to mid 9\'s
That\'s impressive stuff, I guess running low weight in the car helps prolong the life of the box as there is less mass too get moving. My car should be sub 1,000 kg, in know this as another rx4 iv been in, no turbo but had a full roll cage weighed 960kg full tank of petrol too. Doors still complete with door cards etc, and I can tell you this rx4 doors are heavy, so is the bonnet
got this reply from them.
Grant,
We do offer an upgraded main shaft for the Rx7, as well as the faceplate modification if you feel it will be applicable. The faceplate modification will allow you to shift at high RPM\'s without relying on the brass blocking rings to function properly. We can also perform a cryogenic treatment, thermal stabilization, and shot peen in order to add strength to the gear set. It really depends on what results you\'re looking for as to what I would recommend. If you\'d like you can contact Paul at (313)278-4040 to speak to him directly for more information.
Thanks,
Rocko Khoury
So I will try get in touch with them and see what costs are etc. Just need to find out what time difference is and call them when it\'s reasonable for them.