KLZE vs MX3 gearbox



  • Can anyone tell me what speeds you're doing at 4000 rpm on an mx3 V6 gearbox?

    I'm thinking of swapping myMX6 KLZE gearbox and rarely have the need for top speed so I'm hoping the ratio's are shorter on an MX3 box to get better acceleration on track.

    I've done some googling, but cant find a definitive answer. If anyone has facts/figures please let me know.

    Also, if anyone has a spare gearbox with no issues get in touch. Cheers



  • **5th is 19.5mph/1krpm on stock 205/55R15 wheel/tyres, so 78mph.

    If you have different tyres/wheels, your mileage may, literally, vary. I can easily do the maths for you though - I've got gearbox ratios to hand following similar calculations here.

    Hub speed at 4,000rpm in 5th on the K8 G25M 'box is 1,146rpm.

    And yes, I have a wholly spare MX-3 gearbox which I believe to be in excellent condition, 86k miles old.**



  • 5th gear on a mx3 box does work well for drag, it gets to the 118mph ze limiter very quickly!!, then scares the shit out of you, and the cars behind by fireing flames!.



  • Yeah but i'm running it in a de-limited J-spec MX6 Garfy!

    I dont want it for drag, I want it for trackdays. The MX6 box suffers in 4th/5th gear as theyre too tall so I want better acceleration up to say 120/130mph

    Will a K8 box do that, or are the ratios about the same?

    I read that a KLDE and KLZE have a different final drive ratio so the theoretic top speed of a DE is 158 mph whereas a KLZE box is geared to 168+

    Just not sure what the differences are between the 3, K8, DE, ZE?



  • **Let me know what wheel & tyre size you're running and I'll run it through the ratios I have.

    The K8 box should certainly do what you're asking and since the 'boxes are largely the same I don't think the extra torque will cause it much issues beyond potentially shortening its life a bit.

    Edit: On an MX-3's stock wheels at 4,000rpm the road speeds are:

    K8 - 81.45mph
    ZE - 96.42mph

    Call the redline 7,200rpm and you're looking at 146mph to 173mph, so yes, the overall effect of the K8 box would be to shorten the gear ratios and improve acceleration over the ZE box. I'd need your wheel and tyre sizes to be more accurate for your application.**



  • thanks mate, i'm running 205/40/17's instead of the standard 205/55/15's



  • will try and get a 0-118mph video, there is a very straight section of clear road local, and also is mostly deserted so no risk.

    As far as i knew the mx6 only has a taller 5th gear. All other gears should be the same.

    oh and im running same size tyres, although the alloys are really heavy Bk racing ones. :( need some rotas or team dynamics. or better yet some ray wheels. :D



  • I'm on BK's too Garfy, i've got Jamo's old MX6 from MX6.com



  • ah sweet, well should be a good idea then!, what tweeks has it got? dont think you have a project page do you??

    not been on mx6.com for ages, most people seem to have moved on!



  • have a look here mate

    http://www.mazdamad.forumwise.com/mazdamad-thread423.html

    and here

    http://www.mazdamad.forumwise.com/mazdamad-thread449.html

    Basically, I sold my old mx6 and bought this one then took it to the Nurburgring 10 days after I bought it. When I got back it went to a mate in Essex to get a full engine rebuild

    Then ran the engine in for 1000 miles and set about sorting other things.

    Its got, full powerflow exhaust system and stainless headers, thermoblock IM and TB spacers, uprated FPR, CAI kit, Tokico Illumina's and lowering springs, shortshifter, Fidenza flywheel and stage 2 clutch, Prosport gauges, etc etc.

    Getting megasquirt fitted at the end of the month then i'm either going Turbo or NOS depending on budget. I know the ZE is high compression so i'll have to look into what is safe to run with.

    Heres my rather eventful lap of the Nurburgring!

    http://www.youtube.com/watch?v=2T7CUAtxNXA



  • ive got megasquirt sat on top of my kitchen cupboard not fitted yet, also looking at forced induction but with a difference!!!, trying to think of something thats not been done yet, turbo, supercharged,ITB conversions all been done now :( there is even a v8 conversion on youtube, type v8 mx3 in.



  • Twin engine mate!

    5 litre, 400 bhp, 4 wheel drive!



  • @ab4c086206=Garfy1981:

    As far as i knew the mx6 only has a taller 5th gear. All other gears should be the same.

    **The ZE has a longer 5th and Final ratio.

    Also, those tyres will make the speeds 1.6% higher, give or take. Should still be good for 150mph at the top end.**



  • @eea6bd0927=Famine:

    @eea6bd0927=Garfy1981:

    As far as i knew the mx6 only has a taller 5th gear. All other gears should be the same.

    **The ZE has a longer 5th and Final ratio.

    Also, those tyres will make the speeds 1.6% higher, give or take. Should still be good for 150mph at the top end.**

    150mph on a ZE?? No way you'd get that out of a K8 box, reckon mine will do 130mph - 135mph tops, Stu, we will have to have a drag race LOL



  • @e4bc9bdbff=mx3gulf:

    150mph on a ZE?? No way you'd get that out of a K8 box, reckon mine will do 130mph - 135mph tops, Stu, we will have to have a drag race LOL

    **It's all down to the tyres.

    I've had 141mph (indicated) on Red. Gear ratios suggest that to be the maximum the gearbox will give. Tyres with a larger rolling radius lengthen the gearing.**



  • speedos are not accurate, I have hit 120mph and road angel was saying 112mph, i'm on standard 15" rims



  • Thats what i'm after, lower top speed but gets there quicker.

    Might have to just bite the bullet and try it, should be fun.

    Paul, you're about 300kg lighter than me and mines only pushing out 188 bhp mate so you'll whip my ass.

    Once i've got the megasquirt on, and a shiney bottle of nos, then come and see me :D



  • **Preaching to the choir - I don't even read my speedo in Red. But do the math.

    K8 5th - 0.795:1
    K8 Final - 4.388:1
    Engine speed 7,000rpm = output shaft/hub speed of 2006.62rpm

    205/55R15
    Tyre diameter = 23.877"
    Tyre circumference = 75.015" (distance per revolution)

    2006.62rpm * 75.015"/revolution = 142.54mph @ 7,000rpm

    205/40R17 tyres are 1.6% smaller, which is good for 140mph (140.03mph). Push the revs to 7,200 and you have 144mph (144.03mph). Close enough to 150mph for my likes - and the ZE should have enough power to overcome the MX-3's aero limit.**



  • i'm on 205 40 17's mate, whats that calc at?

    Also, I have no limiter but according to my dyno run I make peak power at 6250 rpm so would only take it past 7k in 5th anyway.



  • Sorry, mistype - that is for your 205/40R17s.


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