I have an 86.5 N/A supra. Recently i had the 1jzgte engine installed with the supra turbo gearbox. Changing the gearbox has changed the gear ratio to slightly taller than it was originally. At 240km/h(150Mp/h) the car is almost at 6000rpm. It seams to still have plenty of go left in it at that speed. The engine redlines at 7000rpm which suggests to me that the gear ratio is a bit high for quarter mile drags. Only been once pulling high 13's. Was wonderin if anyone knew the standard diff ratio of an N/A 86.5 supra and if they can be changed without too much hassle.

lol
yup you hit the nail on the head
your diff is a 4.3 from memory and the 87-88's use a 3.9 lsd and 89-92 use 3.7's
find a diff from a manual 7mgte or 1jzgte and she should pop right in :)
should help you out anyhow ;)

In that case i would have thought i'd need the diff i have in it. I want a lower top speed not higher. Also i'm not 100 percent but my car seems to have an LSD diff?

i'm not sure what diff you have... have a look at the id tag in your engine bay should read either G254, G255, G313, G314, G315, you get the idea
even numbers are open diff
odd numbers are lsd
let me know what one you have...
well you're in a catch 22 then...
you want lower speed so you need a higher ratio diff
but you don't want as high gearing so you need a lower ratio diff..
i think you need to make a sacrifice there somewhere hehe

G285? Sorry my understanding was the higher the diff ratio, the lower the top speed. Is this not correct?

yes you are correct but you were also saying that your rpms were too high?

and yes it's a 4.3 4 pinion lsd :)

I don't think my rpm is too high. i think it's too low for the speed i'm doing. It used to be higher before i changed the gearbox. It definatley says W58 then G285.

ahhh
are you using the stock gearbox?
you should really use a R154 if you're doing drag racing... w58's aren't known for holding up to high hp :P

here is a link for all manual gearboxes and their ratios if it helps :)
http://www.geocities.com/MotorCity/Pit/997.../Gearboxes.html

Cheers, you rock! just wanna keep playing with it and hopefully get under 13sec one day. dunno much about the 1jz's. had the 7MGE then the 7MGTE, so i'm kinda new to this engine. Is the R154 the same ratio as the W58?

hehe kool
i've got a 7mgte and planning to prove to the world that we can do it too lol
i do mid 13's at the mo but that was on a bhg engine... have fresh rebuild and got 278rwhp now which is about 30rwhp more than what i had before on 5psi less ;)

the r154 seems to have very different ratios than the w58... i think if you got the jz diff and gearbox your ratios would sort themselves out... but i think first get an r154 and see what your ratios are like... if they're still not suitable try changing the diff

what made you go 1jz?

Something different... Was just more accessable at the time. I know you can get some serious power out of a 7mgte. I have a magazine with one with 565Kw(730Hp) the the wheels! The plates on it was BLCJET. if you do a search on it you might find it. it's pretty shit hot though. good for nines they reckon.

*drools*
sebastians 7mgte
that is total drool material hehe
yea i got that fast fours mag too... i plan to annialiate his power tho hehe
this engine i only want 500rwhp
forged engine 800rwhp
should be interesting lol

well good luck with ur 1j and keep us posted :D
would like to hear ur progress ;)

My car originally had the W58. I changed the gearbox with the engine. I assume i have the R154 gearbox in it now if thats the supra turbo gearbox. And yes, the ratios between them are a fair bit different. thats why i wanted to change the diff to counteract the change.

ohhh sweet
that's good
can you send it here lol

they're really rare here and cost alot usually like 1500nzd or more
well check out http://www.geocities.com/MotorCity/Pit/997.../AxleCodes.html
there's the diff codes as well
so you could probly over time work out the perfect diff ratio to suit gearbox etc ;)

Mine i got for 700 aussie dollars. aparently was around 1500 but i'd already spent an absolute fortune at this place so i got a good deal. Cheers for your help... Good luck with the killer 7M...

yep you got R154..like the shifter???

i have a toyota supra 7mgte 3ltr turbo auto. but i also have a manual car the same as the auto. does any on now what the diff ratio would be in the auto and manual

It differed based on year, not transmission. 7M-GE = 4.30:1 (all models and years), 7M-GTE = 3.91:1 for 87 - 88 models and 3.73:1 for 89 - 93 (no difference depending on transmission A/T vs M/T).