is there a taller ratio diff for sunny than 3.89
as we are valve bouncing at 7700 and would like to drop about 700 revs we run 13inch wheels with 80 series tyres and would like to drop these down to keek car a bit more stable

wot speed u doing

The WB310 [Sunny Sportswagon] that came with the A15 engine also came with a 3.7 to 1 H150 differential.

This wagon model was made right near the end of the B310 model run.

If you are able to, another way is to get the complete axle housing from a Stanza, the type with the removable diff centre,not the Borg Warner style. You can get 3.7:1 ratios from the manual stanza's or early 4 speed bluebirds. I can only assume you're doing speedway & are using 2nd or 3rd gear. Have you fitted twin valves springs to the engine, or isn't it allowed? You should also change the suspension rubbers to urethane as this cured the axle tramp I was getting in my Sunny.

Not a bad idea to use the stanza assembly: you have more variety and choice of diffs including LSD. The downsided it is heavier H165 assembly instead of lighter H145 assembly.

yep doing speedway
no double valve springs as not aloud in rules running second gear as third is to big a gap and it takes to long to wind up we did try 4.11 but we prun out of revs 20 meters out of turn have changed all rubbers on car front and rear

great info ? do you know how much wider stanza diff housing is as we can only go 50mm over sunny with.

we have a top average speed on clay 440 meters of 76.8 kph and thats pulling 7200 round corner and 7700 down straight

do you know where I might find one.

i hear they guy's in the west running 4.4's so must be using 3rd gear..