Does anybody know the diff ratio for a 1.8 sierra h reg.
Thanks Gordon
Is it pinto engine,cvh engine,
estate,auto,manual?
Its the CVH - Manual - Saloon/Saphire
It's around 3.89 I believe ,i will look it up when i get home , ( I'm doing a NED!!)
Thanks.
Whilst you are looking could you let me know what options I have to go to a lower ratio ie more speed. Because if your right with 3.89 then the top
speed will be very low.
Thanks Gordon
Gordon,
I know someone who ran a 4.1 and topped out at 98mph (zx9r engine), I know 3.62 and 3.38 difs exist as I have one of each...
Ned.
Ned
What donors did your diffs come from, I think I will have to try and find one. I will be running a ZX9R and they seam to have low output speeds
Gordon
On the subject of diffs,
How do you ID the diff?
Is it all down to numbers on the casing? and matching these up to a predetermined list?
Is it acceptable to count the number of revolutions of the prop flange are needed to give one full rotation of the drive wheel?
Am i also correct in thinking that the higher the first number in the ratio the quicker acceleration you will have and lower top speed?
Col,
Normally the (sierra) difs have a tag on one of the bolts on the backplate (well, at least both mine do) stating the ratio.
Yes, the higher the number the quicker acceleration, lower top speed eg 3,9, 4.1, 4.4. lower numbers are slower acceleration/higher top speed eg 3.38,
3.62.
Ned.
but don't rely on the tags
be best way is no of revs input vs no of revs output that way you can be certain
From Haynes Sierra book...............
1.3
3.77:1
1.6
3.62:1 (except ecomony) , 3.92:1 (saloon ,hatchback) , 3.38:1 (estates)
1.8
3.62:1 (4 speed and auto's), 3.92:1 (5 speed)
2.0
3.62:1 (manual), 3.38:1 (auto)
2.0inj
3.92:1 (manual), 3.62:1 (auto)
P100
4.625:1 ( mega acceleration up to 50mph on a bike engine)
Higher the 1st number = higher the engine revs for a given speed..........From what I've seen on here bike engines need a diff around 3.5 or
probably lower , ask Jasper how many mph per thousand revs he gets in top with his 3.54 diff.
Dont forget to take into account wheel circumference.........................
Thanks Dave
Looks like I need to start looking for a new dif or use 20" dia wheels.
Gordon
i have a push fit driveshaft type 3.38 spare...
Ned.
Ned
Sounds good, how much, when, where, etc etc
Gordon
sorry to sound dim but what is the sierra 4x4 diff gonna be like with the fireblade engine i intend to fit? (when my garage is finished and kit bought..........)
quote:
Originally posted by scotlad
sorry to sound dim but what is the sierra 4x4 diff gonna be like with the fireblade engine i intend to fit? (when my garage is finished and kit bought..........)
Mmmmmm donuts....
(we have a 3.62 Sierra LSD and 220lbft )
It's a bit annoying that our gearing will only get us to 48mph in 2nd though :/ Could maybe just not use first...
Could try removing the V8 lump and inserting a screaming bike engine!!
Maybe in the next one... 
This might help ID all yer bits - but only if they are the original bits:
VIN decode
very useful, thanks geoff...