Wednesday, July 05, 2006 - 12:10 am, by: Nenmar Bisso(Lexply)
hey guys, ive been looking through some of threads from before and havent seen anything rlated to this. I have a trimatic 3 speed transmission, and wen im on a freeway, at 100kmph, im sitting on about 3800 rpm, is there any way i can reduce this. Also my o/d is always off, i dont have the normal soarer stick in, so is there any other way i can turn it on. Any info would be great, thanks
Wednesday, July 05, 2006 - 08:04 am, by: Tai Johnsen(Privatejohnsen)
I think the O/D button is just a latching switch (push-on, push-off) which grounds the over drive wire.. So you could wire up a separate button somewhere..
That's probably the easiest way... Other than that, change diff ratio or tyre size, both of which will stuff up your speedo
Someone more learned than me may have know some more.
Thursday, July 06, 2006 - 11:37 pm, by: Nenmar Bisso(Lexply)
Hey guys, sorry about the late reply, um ive got 19 * 7.5 inch rims on my car. I took out the black part where it shows the gears you ar in, and i noticed that one of the three wire clips arent plugged in, could this be my o/d. If so, do you think i could wire it up to a switch, ie as in a rocket switch or something??
Friday, July 07, 2006 - 08:29 am, by: Chris Davey(Chris_davey)
You need to know the exact tyre size but by the sounds of it there probably isn't much bigger you could fit if they are on 19's.
If you have a trimatic gearbox (th350, th400 etc) then they are only 3 speed gearboxes. The stock wiring will not be doing anything as the trimatic is not electronically controlled. So therefore, plugging an od into something will not do anything as it is not controlling the gearbox.
I would be looking into a jza80 manual diff swap.
What you need to do Is search the net for the following:
Gear ratios Tyre diameter
Look on your build plate and find what diff code you have and work out what it is (search here and toymods)
Then find out what ratio the jza80 tt diff is.
Then google for speed/rpm calculator.
You input your tyre size and gear ratios and you can input your current diff ratio and it should come up with how your car currently drives. Then put the jza80 diff ratio in and see what the difference is. If you are swapping from 3.9 or so to 3.2 it will be a huge difference.
I used to have 4.875 and I changed to 4.625. This is just noticeable but I am also putting tyres that are 2 inches taller than the old ones. This effectively brings the ratio down to around 4.2 or so.