Lol, g series transmissions don't like 300whp :)

[JWMotorsports]

I've read on a thread I found that the Mazda 3 gearbox is a new beefy G-Series box. Kaaz also has a LSD out that is supposed to fit G-Series box. Can anyone one here (Yoda...Kiwi) verify this? If it is true then...how close is the Mazdaspeed 3 gearbox to the G-Series? My wife has an 07 Mazda 3 and BOY do things look awfully close and similiar with mounting points (rear trans mount looks like 95-98ish Protege). To bad she won't let me play with it...hahaha.

As for the G-Series box not liking 300whp...two of mine held up fine until I dropped the hammer at 6000rpm and hooked it. Twisted 3 sets of axle splines, sheared the custom stub shaft, and exploded the clutch pack in the Mazdaspeed LSD all in about 30ft. However I have yet to break a g-series gear. In 3rd gear my car puts down around 485+ ft/lbs of torque (on a conservative timing curve). I'm also running 245/50-R16 tires deflated to 15psi to get it to have traction...any smaller it just blew the tires off all the way up to 130mph. The open diff gear box had 10,000 HARD miles put on it with no failure...I never wheel hopped it (hint...hint). I use 80w-90 Lucas Gear Oil with 1 bottle of Lucas Trans Fix in them, which helps things a little I also don't have my exhaust running under the oil pan either, which I'm thinking could also be contributing to the unusual life I'm seeing compaired to others. With the exhaust moved and thermal wrapped I'm not radiating anywhere near the heat into it that others are.


Here is the thread I found on G-Series gearbox data: http://www.specialstage.com/forums/show ... 59&page=29" onclick="window.open(this.href);return false;
They talked about Kaaz LSD (which I knew was in the works but never heard when it was tried n worked...Corksport), Also possible to modify a 1st Gen RX-7 LSD to go into it, etc...

[se7en]

Ya ya, I know...wheel hop isn't good....I had a small problem with that last year....I knew third gear was weak now...

also, there was a time when I first did the swap when i didn't have a clutch....I only drove it like 10 miles like that, but afterward, the trans didn't seem to be the same....the next gearbox will be fine I think LOL.

[tehbrookzorz]

You sir, must confirm this information for us!

[kiwimx3]

JW

I have a RX7 diff and are looking to fit that in the next gearbox, as the quaife is not a cost option
either is the kazz for me. Its going to take a bit of machining to get the ring gear to sit in the right place.
Personally in your case Id look at fitting a mini spool.

Eliminating wheel hop saves the gearbox! ( yep massive hint to everyone out there! ) keep your
axles as straight as possible as well by using limitstraps so the car will not lift the front end!

Polishing and shot peaning the gears seems to work for a lot of peaple. I might go down this road myself.
However strenghting the external parts of the gearbox and changing how the mounts locate have
certainly saved gearboxes.

Oh the other thing was the gear that blew had already done over 150,000kms so I really can't complain.

I honestly have no idea if the mazda3 gearbox internals will interchange.

Its not been my year in general. In and out of hospital four times and under the the knife
five times, and have spent well over 10K in health care and god knows what in lost earnings
due to not being able to work and given the stupid goverment support structure I get nothing
due to having assets!

Update, Breaks all my rules but someone has made me a offer for my car and i can't refuse.
however what I have learn't so far will go into the next build which will be photographed
from start to finish.

[kiwimx3]

http://forums.neons.org/viewtopic.php?f ... &start=275

Its a bit of a long read, but could the ATX from the KLZE be modified to perform
to the same specs , sure the KLZE ATX is a monster in size and weight but call me
a tight a-- after having a conversation with someone who has a PAR engineering
dog set for a GM25 ( My eyes watered when he told me how much! ) and then the
added words of they don't last that long!

The general consenses of gears is re heatreating them to a lower RC point and then
polish and shot peaning in the long run the gears will "stretch" but not shatter. Still
after a season of racing just pull the box and replace.

Making HP is not the issue, getting it to the ground is!

[JWMotorsports]

The ATX would be fun with a high stall converter...kiss lag good bye. The hardest part is getting the aftermarket bands, friction, metals, & pumps to bring the hydralics up high enough in pressure...then hopefully the valve body will hold up. Red Eagle frictions are where it is at!

Custom gear sets for the G25 I'm guessing in the 8,000-12,000 USD range for shafts & dog gears. Where I work we have 5 axis grinders, 5 axis bed mills, EDM, etc... I just have to get the guys in the tool room to do the machining for me in their spare time. I've done a lot of material research and have found an alloy that has a tensile strength of 300KSI and nearly DOUBLE the impact strength of 300M! As your guessing the price is astronomical...but broke parts get their too. I'm actually looking at doing a different design for my axles than normal which will increase strenght significantly (shear carrying capacity) while lowering the rotation mass and cost. I'm eyeballing the Kaaz LSD because I like to drive it on the street still but am seriously considering a spool or custom LSD.

Lowering the Harndes of the material isn't what you are after...hardness actually doesn't tell you much, as most believe. This is something I've learned in my metallurgy class from a professor who's experimented with all kinds of different methods. The microstructure is what you need to know about and the processes used to get there in VERY detailed depth. Ideally you want to anneal the shafts and gears and then reheat treat and temper them to the proper microstructure (in this case as much Martensite as possible). The problem with doing it to the stock gears and shafts is the distortion that will occur, so your limited to what you can do to them...shy of welding them up, annealing them, rough machining them, heat treating them, tempering them, then final machining them to the proper specs. If you had access to everything to do it your self (VERY few do) it might be feasable...other than that you might as well bye better materail and go from there.

Bottom line...reliability in anything costs mega $$$'s !!!

Some times I'm tempted to put it all in my 2nd Gen RX-7...which now has a TII tranny, ACT Pro Lite Flywheel, GTU LSD, couple Racing Beat Goodies, couple Mazdatrix Goodies....contemplating a 4 rotor since I have the facilty for making an E-Shaft for it

[tehbrookzorz]

It strikes me as funny that you speak of reliability, and then change the topic to RX-7s..

[kiwimx3]

JW,

I was quoted $4k USD for a dog gearset, given current exchange rates thats $8k NZD
( I can build a compete KLZE 323 for that cost! and have it run 12's all day!)

I used to have access to all that machinery, Id wire cut the final gear shape as you can
heatreat first then wirecut. I did a set of timing gears once for a small block very smooth.

RPM Engineering Have been making three peice four rotor shafts for a long time, google
http://www.youtube.com/watch?v=Au7F2ttEXWU
Thats my "home" track, "fourre" now has a airshifted four speedbox

With a ATX, kiss goodbye lag, be able to set differnt boost settings for each gear
gain well over a second if not two due to the autobox being able to shift faster
than a human on a MTX. ( proven fact guys )

Though when I go turbo It will be a RWD car and a autobox more than likely a manualised
C4 as they are cost effective and bullet proof!

Im going to build another N/A KLZE 323, though this time it will be more focused on being
a pure FWD drag car than a street car and try and get the weight down to 800kgs minus driver
though still be low volume certified for street use.

I still Impressed ( or rather put the fear of ???? ) with the old 323 considering the old tart was
900 kgs on the scales ( not including my lard a-- of 75kgs ) and no aerodyamic mods at all!

Its one thing to sit infront of a computer model programme and move figures about to doing it
in real space and time is another. still its interesting!

However, the current fastest FWD pro import in NZ currently stands at 9.88 @ 236 kmph
Its one record that I would love to have a go at! hence the ATX
( though there are weight rules around power units and power adders, body shapes and other
silly stuff! )

I think the last gearbox failed not due to Hp or torque ( as my motor makes a misserable 200 FTlbs on the dyno )
but more the synco breaking and going west ( or east ) through the box and jamming the gears.