5 speed conversion

Discussion in 'Modified Shizzle' started by redoxide, Feb 21, 2015.

  1. redoxide

    redoxide Guest

    I think your still fighting against the high final drive numbers... the old laycock od were bolted the back of the box if i remember right, I dont know about the ones you mentioned ? probably be an issue with rotation ? but, as you can see, Im definately no expert on gearbox stuff .. but doing my homework ... :)
    Poptop2 likes this.
  2. Poptop2

    Poptop2 Moderator

    Me neither. I had a bit of a lecture about boxes when I first started out, but never really got to grips with them theoretically. But. I do remember a friend who raced bolting one to one of his sports cars and waxing lyrical about the top end difference. I never understood how it worked though!
  3. Moons

    Moons Moderator

  4. Moons

    Moons Moderator

  5. An overdrive unit is a smaller epicyclic gearbox that fits after the normal gearbox and before the propshaft/finaldrive. A relatively easy task on a front engine rwd car but pretty much impossible on a bus. A lot of British cars of the 50s and 60s had them as it was a lot simpler and cheaper than designing a 5 speed box from scratch. They usually operated on the top two gears only, effectively giving 6 gears. They usually were operated via a switch on top of the gearstick, driving along in normal 4th flicking the switch would drop the engine revs just like shifting into a higher gear.
    Moons and Poptop2 like this.
  6. Poptop2

    Poptop2 Moderator

    Okay got that now. Thanks Phil. :thumbsup:
  7. Well having gone down the ej20 path coupled via rjes bellhousing to a six rib 091 in a bay I can say it works well, will happily cruise at 70 and uses less fuel than my old 1641 with progressive weber ( this was coupled to a 1700 box). The old set up used to top out at 80 i've not had the current set up over 95 yet as still settling in new front suspension set up. That said I picked up a subarugears box etc a little while ago and plan to fit that over winter so hopefully il be able to compare. Studying up on fitting the box you have to mod and fabricate linkage coupling.The chassis/firewall mod has to be made to fit the scooby lump whatever box you use.

Share This Page