DIFF RATIOS

spudley · Post by **spudley** » Mon Aug 30, 2010 7:34 pm

Hey guys, I can't find what spec diff came in my non turbo N12 E16 equipped pulsar.
Does anyone have an idea?
The reason for me asking is that when cruising on the freeway at 100km/h I'm finding the engine's revving at a consistant 2500rpm..
Is this normal or should I look at a higher ratio diff for lower cruising RPM, and if so, what diff can I use as a direct replacement (if there is one)

Sorry for the newb question..

Cheers,
Spudley

Post by **tassuperkart** » Mon Aug 30, 2010 9:02 pm

http://www.n12turbo.com/files/N12_gears1.jpg

BennyET · Post by **BennyET** » Mon Aug 30, 2010 9:03 pm

http://www.n12turbo.com/files/N12_gears1.jpg

i would consider 2500 5th gear low

edit: lol beat me E

Post by **shanec86** » Mon Aug 30, 2010 9:08 pm

put this together a long time ago

spudley · Post by **spudley** » Mon Aug 30, 2010 9:29 pm

sorry, i'm a bit of a noob to ratios and the like.. does the above chart mean that if I put in the diff of a N13 i'll have lower cruising RPM at 100km/h?\

cheers,
spud.

spudley · Post by **spudley** » Mon Aug 30, 2010 11:13 pm

BennyET wrote:http://www.n12turbo.com/files/N12_gears1.jpg

i would consider 2500 5th gear low

edit: lol beat me E

It might be low considering the redline is like, 5500 or 6000 or something, but having said that, i'm coming from the dark world of automatic 6cy, and V8's where cruising at 100km/h brings a RPM of roughly 1700ish..

Also, with a sports exhaust and cruising for over an hour just means I have to turn up the stereo to compensate for the drone.. god forbid if i have a passenger on board to try hold a conversation with! lol

cheers for the feedback tho.
S.

sgs · Post by **sgs** » Tue Aug 31, 2010 10:40 am

its normal, my n/a e15 pulsar does 2500rpm at 100km/h aswell.

if u think thats too low just use fourth gear, then your still only doing 3000rpm at 100km/h

spudley · Post by **spudley** » Tue Aug 31, 2010 11:06 am

nah mate, i thought that 2500 in 5th was too high cos it drones a fair bit..
all good though, it seems thats just the way they are.

like i said above, i've only owned 6cyl and V8 autos before, and they all cruise along at less than 2000rpm.

cheers.
S.

sgs · Post by **sgs** » Tue Aug 31, 2010 3:51 pm

whoops sorry i skimmed through most of this thread the first time, Yeh my racing exhaust gives me pretty numb ears on long trips aswell.

might i suggest getting some ears muffs!

spudley · Post by **spudley** » Tue Aug 31, 2010 3:59 pm

haha cool sgs, no probs

just out of interest, what size exhaust do you have and what engine?

sgs · Post by **sgs** » Tue Aug 31, 2010 4:03 pm

im a bit embassed to have to mention it, but its just the standard exhaust but with the resonator and muffler cut out. then i put a piece of straight pipe where to resonator was, welded a dumpy and a coby together and welded that out the back, hardly a racing exhaust but it sounds mean!

(sounds good without pissing of the neighbours)

spudley · Post by **spudley** » Tue Aug 31, 2010 4:27 pm

aaah cool mate, whatever suits your needs and budget

i'm booked in next sat to have a 2" full system (extractors back) so i'll see how that goes

cheers,
S.

sgs · Post by **sgs** » Tue Aug 31, 2010 4:32 pm

wicked! that one is always in my bucket list, along with cost it would intail other issues like rejeting the carb. im goona do it when i have another car tho, probly turb it etc

spudley · Post by **spudley** » Tue Aug 31, 2010 4:44 pm

BAH! rejet the carb later!

Mine's due for a tune up anyway....

Once the 'zorst and carb are done on mine, i'm keeping an eye out for a E15ET engine I can work on then drop it in with an injection setup.
Nothing spastic, just a bit better than stock, like GT28, cooler, boost controller, and the rest will be interior mods, as that's what I specialise in!

TurboZ.Dude · Post by **TurboZ.Dude** » Tue Aug 31, 2010 5:29 pm

sgs wrote:its normal, my n/a e15 pulsar does 2500rpm at 100km/h aswell.

if u think thats too low just use fourth gear, then your still only doing 3000rpm at 100km/h

Sorry for interrupting, but does that mean 100 km/h on the speedo, or the true speed of 100 km/h? At true 105 km/h (110 on the speedo) mine does 3000 rpm in fifth gear.

spudley wrote:nah mate, i thought that 2500 in 5th was too high cos it drones a fair bit..
all good though, it seems thats just the way they are.

I agree. These are small engines and need a bit more revs than bigger displacement engines in order to stay healthy (and to produce enough torque for daily driving).