Ke70 Question

[Teddy]

Hey all

 

On the ke70s, the final drive gear ratio is 4.300 standard - The came optional as 3.889

 

How do i know which ke70 would have which ratio ? - Is there a way of telling ?(besides from driving on freeway at 100 Kmh in 5th and seeing revs)

 

& - Which ratio would keep the revs lower @ 100 kmh in 5th - The 4.300 or the 3.889 ?

 

Thanks All !!!!

[andrew]

on the back of the diff there is a tag that has the ratio stamped in it

[Teddy]

Swwwweeeettt - Thanks !

 

& Which ratio would keep the revs lower @ 100 kmh in 5th - The 4.300 or the 3.889 ?

[Super Jamie]

actually ke70 standard is 4.11

 

a higher ratio (4.3, 5.0, etc) gives you more acceleration but lower top speed. it keeps the revs higher in all gears for any given speed

 

a lower ratio (3.9, 3.6, 1.8!) gives you less acceleration, but higher top speed (if your motor has the torque to fight wind at 200km/h). it will keep the revs lower in all gears for any given speed

 

circuit cars use high gears (4.3, 4.5, 5.0) for acceleration. you're probably not going to top out in 5th around say, QR. big yank tank cruisers use low gears (3.6, 2.x, 1.8 with a big block) for fuel economy, because they aren't quick anyway, and because their old v8 motors don't like to rev high. it's not unusual for one of these cars to be doing say, 1400rpm in 5th at 100km/h. that's just off idle

 

in a corolla, because they have fairly gutless motors, you need a high ratio to get any sort of performance out of them. you can really feel the difference even changing down 0.1 of a ratio, my locker's a 4.2 (compared to my open 4.3) and the difference is noticeable

 

a 3.9 would make your car VERY slow. stick with 4.11s. the borg warner diff in ke70s makes ratios very hard to change too. you pretty much have to disassemble the center out thru the housing. the earlier jap diffs are frontloaders, you pop the axles and the bolts holding the center, and it just comes out. you can change a center in about 35 minutes with practice

 

import ke70s (not aussie ones) had a jap diff and little ke30-type drums. i know where one is at a wreckers if you're keen on driving down to lismore to pick it up, apparently the 3.909 center is f@$ked too. personally i wouldn't bother changing it :)

[Teddy]

wow - thanks jamie!

 

i just got those 2 figgures "4.300 standard - The came optional as 3.889" From the origional sales brosure thingie.

 

Great info, really helps !!

 

Thanks again jamie for yet another great indepth answer !!!!

 

Teddy

[demuire]

I have heard that the AE86's in Japan (T-series diff) came standard with 4.3

[Teddy]

oh ok - (gah so many different bits, so many different measurments lol)

[andrew]

i think they only had a 3.89 ratio with the 4a engine. as this would be to high for a 4k. 4.1:1 is good for your car

[irokin]

my cars getting a KE30 4.3 diff :)

[demuire]

I'm running a 4.3 in Hal at the moment and absolutely LOVING it. But yes, Andrew is right - for a stock 4K you'd probably want a 4.11 cause they don't like to rev too much. I'd hate to have a 4.3 in Pinky, driving down the highway would be torture!

 

In a worked 4K like Doug's or Jamie's on the other hand... :)

[andrew]

yes true. a 4.1: in 5th will rev at 3000rpm wich is good

[Teddy]

ah ok coolies

 

just got the idea, coz ure in mums hyundi automatic, on freeway revs are at 2000 or what eva, cars hardly trying, but now that i think of it - its much more powerfull than my 4k heheheh

 

I'm happy with my ratios then, leanrt something new again :) !!

 

ThAnKs All !!!!!!!!!!