Done many searches but no find. Is there any final drive ratio change possible from standard?

Looking for any possibility of a taller set up 10% taller or even 15%. Have previously fitted taller typres from 295/50R15 to 275/60R15 but am looking now at the diff.

Thanks



http://www.youtube.com/watch?v=HXwh4z8d66o 

The only other ratio is from the 411/412 which is shorter so not what you wanted.

Type 3 - 3.67
Type 4 sedan 3.73
Type 4 wagon 3.91

thanks Mackaymanx thought so. and the Subaru auto boxes are 140mm too long. oh well. bigger tyres is best I can do. lowers revs by 150rpm at 100kph down to 3100rpm.

a 4 cylinder car needs to be at around 3000 so that it will pull up hills and your not changing back all the time.

The trikes ea81/SC12 draw thru will be getting sPFI shortly and the SC taken off. If that is enough powerI'll be happy. If it isnt I will install a supercharger again in a blow thru set up with on/off switch. Then taller gearing would be ideal.

Think then 16 inch wheels (up from 15) might be on the cards and raise the guards.



Thanks

Didnt realise that tyres are available in a size 275/65/r15. at ebay site

http://www.ebay.com.au/itm/Brand-New-265-70R15-275-65R15-255-70R15-High-Quali...

This will change the tyre circumference 8.5% eg adds 8.5 kph to 100kph at the same revs. Means at an actual 100kph you drop about 240 rpm down from 3100 to say 2860.

As you say Ian you need the power to keep you from slowing on the hills and when towing with tall a gear you will need to change up earlier. But if the Sc is installed this woldnt happen.

Just as a matter of interest....when new the trike had a 1916cc engine that, upon climbing a small mountain near us would slow to 60kph in 2nd gear (auto). After the EA81 NA engien was fitted it would get down to 80kph in second gear. When the SC12 draw thru was fitted it would romp up that mountain at 105 kph in top!! with all the low down power anf torque you wanted. Dyno showed 30% power and 33% torque increases. So taller gearing then should be quite ok IMO.

Why are you removing the SC?

purely economy Pete.

Light foot or heavy foot it achieves 19 mpg 14L/100kms and worse with towing. Not good for a 550 kgm vehicle. Of course the cruising range has dropped to 300kms from 500kms. On a long tour it means carrying fuel. It just drinks it. This is regardless of a dyno tune and even after that I put in smaller jets to try and lower the consumption. That helped a little but not enough.

So SPFI will not replace the 100+hp I get now but it might be in the middle of that and the weber NA engine. Say 90hp, the same as the ea82 with sPFI that came out in the USA. I'd be happy with that. However the clutched SC12 blow thru might be considered if more power is needed- hopefully not.

The dyno was itneresting. That VW auto zaps 14hp off the engine. Much more than I anticipated when I first went ea81.

have you checked the stall rate in the convertor?I think standard tye3 convertor with vw1600 is 2100 rpm where a convertor for a kombi which is exactly the same is about 2500rpm.I had one made with a lockup plate in which locked the convertor up at about 80kmh.this did widen the convertor so required a spacer plate between the motor and box.we where looking at about 300rpm drop when the plate locked.we where running a v6 motor behind this box and changed the stall to 1600rpm.geoff

thanks Geoff. most interesting.

I dont suppose you got pics of that lock up plate? Tony

my van is not green.mine has been off thr road for 3yrs now.has been changed to full drag with full cage,supercharged motor and an alloy front beam.Idont have any photos off the convertor.the plate fitted was from a kc ford laser which is centrifical in action.in checking the ea81 manual the stall rate for this motor was between 1800 and 2100 rpm.maybe lowering the stall will help.sometimes,if the convertors are different sizes,oil capacity is different and this can have the same effect as changing the stall rate.Im no mechanic but having done many different conversions using the vw auto the convertor is critical to the performance

Good points. thanks again.