Jump to content
SAU Community

Recommended Posts

I have a R32 GTST auto and will be changing it to manual soon,

At this point in time the over drive is at 3000rpm at 100km/h, i am wondering when i change to manual what the rpm will be at 80-110km as this is the avg speed i do driving around. i would prefer it to be around 2500rpm for 100km/h.

any one know of any aftermarket 5th gears that are in diffrent ratios or will i have to get a custom one made.

I have the stock diff too.

Link to comment
https://www.sau.com.au/forums/topic/331290-5th-gear-rpm/
Share on other sites

Why do you think you need to be running that low in the rev range?

Nissan will have set the tune of the engine to be optimised with the gearing of the car. Changing the diff ratios will upset that balance.

Link to comment
https://www.sau.com.au/forums/topic/331290-5th-gear-rpm/#findComment-5380004
Share on other sites

yea the rb30 would still pick up good from 2500rpm, the old saying "no replacement for displacement" is mostly true.

if your simply after better economy on the highway then personally i dont think it'll happen, if you gear it down to 2500 or so then you'll find you have to spend more time on the gas to overtake (or you may even have to chop it down to 4th, also a good way to use more gas) and even at normal cruising, the rb20 wont maintain 100kph as easily, meaning the throttle needs to open further to maintain 100kph, injector duty cycles go up and fuel economy goes out the window. same reasons why you shouldnt use 5th gear at 50km/h. i'm sure you've tried that. it's shit.

like jiffo stated above, Nissan got it right. there are good reasons why most engines 2000cc and below do ~3000rpm at 100km in 5th gear, it provides optimal fuel economy and optimal driveability. the general rule of thumb for factory vehicles is the bigger the engine, the lower its rpm at any given speed, simply because it can (i blame physics).

and yea, factory diff ratio for auto r32 (2wd) is 4.3. factory manual diff 4.1

Edited by jonboy
Link to comment
https://www.sau.com.au/forums/topic/331290-5th-gear-rpm/#findComment-5384286
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • A few small updates since the previous post and lessons. I decided to do a little interior light upgrade on the 110. I quite like the iilumo items, even if they're a bit of a premium over other brands. You'll also note the Stedi Fogs, that will go into the S15 fog lights as I needed to match the bulbs since I got the new ones earlier. I hope they fit as the body is quite a bit longer than your normal bulb.  Annoyingly, I managed to trip the fuse, which normally wouldn't be an issue until I located the fuse. I can't say I've ever come across this. I had lucked out that someone nearby had a spare, but oddly enough Toyota dealerships seem to keep this in stock. I ordered some to keep in my stash and as luck would have it, someone else nearby tripped the same fuse so I passed on the favour.  I also did a little service on the 110 ahead of some additional work coming up. It's been annoying that Goleby's stopped carrying this particular HKS filter for the 110, so now I need to keep them on order from Japan. I also took the opportunity to install a bash plate and number plate riser. The plate riser is such a cheap but nice fix to help really tidy up the car. I'm tempted to now also replace my headlights, on this car. Both items were from Project Aero.    I also needed to replace the rear tyres on the 110, and after trying to get it aligned learnt that I need to replace some bushes in the front end, so that's next.  Closing out this update with a nicer picture as always! 
    • Yeah mate, never miss it.
    • Any going to watch World Time Attack at SMSP this year?
    • Appreciate the correction on the "ground", that will make a huge difference to looking at this. That makes complete sense about AF70/AF71 which is what I had come down to being the issue, one of these. I'll have another look in the ignition wiring when I get a chance next week. I'll also make up a jumper wire for running that AF73 test.  ECU is fine, relay itself is fine, pump harness is fine and the pump itself is fine. I am going to upgrade the Walbro 255 anyway with a DW300 I have since I need to replace the fuel sender and I'm going to upgrade the FPR with my chasebays kit ready for new plenum/injectors/dbw, but I'll get this working first. That's why this is so frustrating. 
×
×
  • Create New...