R32 Gtst, 5th Gear Is Very, Very Short?

[CanadianGTST]

Greetings, SAU. After lurking for way to long, I have decided to make my first topic, asking questions and just being a general nuisance. My car, a 5mt 92 gtst, seems to be.... Rev happy?

After a recent cruise with a bunch of other skylines, I finally got around to getting an accurate calculation of speed vs rpm on the highway. I was kind of surprised:

5th gear, 4000rpm = 123km/h GPS verified. As far as I know, I have the stock 4.3 diff. However, I also have noisy gears, 1st, 2nd, 3rd, and 5th all have a "straight cut" gear sound. It's not dogbox levels of whine, but it's definitely audible in the first few gears (less so above 3rd gear, as my exhaust is way too loud). From what I've gathered, my highway RPM's seem much higher than everyone else that I know who also drives an r32 gtst around my parts. Did Nissan really gear these cars so aggressively, or do I have aftermarket gearing? As it stands, if I'm booting it and I shift from fourth into fifth, the way it pulls in 5th makes it seem like there really should be a 6th gear, like 5th is purely an acceleration gear, rather than an overdrive.

I don't really mind cruising along at 4000rpm, don't need to downshift to pass. But it absolutely rapes my highway fuel economy! As a result, I tend to do the speed limit on the highway, since it's never any higher than 100km/h until you get out of the city (the city being Vancouver, if anyone's interested).

Thanks for your time ;P

[ClutchBurndout-:(]

Greetings, SAU. After lurking for way to long, I have decided to make my first topic, asking questions and just being a general nuisance. My car, a 5mt 92 gtst, seems to be.... Rev happy?

After a recent cruise with a bunch of other skylines, I finally got around to getting an accurate calculation of speed vs rpm on the highway. I was kind of surprised:

5th gear, 4000rpm = 123km/h GPS verified. As far as I know, I have the stock 4.3 diff. However, I also have noisy gears, 1st, 2nd, 3rd, and 5th all have a "straight cut" gear sound. It's not dogbox levels of whine, but it's definitely audible in the first few gears (less so above 3rd gear, as my exhaust is way too loud). From what I've gathered, my highway RPM's seem much higher than everyone else that I know who also drives an r32 gtst around my parts. Did Nissan really gear these cars so aggressively, or do I have aftermarket gearing? As it stands, if I'm booting it and I shift from fourth into fifth, the way it pulls in 5th makes it seem like there really should be a 6th gear, like 5th is purely an acceleration gear, rather than an overdrive.

I don't really mind cruising along at 4000rpm, don't need to downshift to pass. But it absolutely rapes my highway fuel economy! As a result, I tend to do the speed limit on the highway, since it's never any higher than 100km/h until you get out of the city (the city being Vancouver, if anyone's interested).

Thanks for your time ;P

4000rpm @ 123kmph? what is it at 100kmph?

[_Ryan_]

4000rpm @ 123kmph? what is it at 100kmph?

and what size tyre

[CanadianGTST]

and what size tyre

sorry about taking so long to reply :X Car was down and out for a bit while I was doing some stuff to it so I couldn't test on highway. Speed in 5th gear at 3000rpm is 95 km/h indicated, 94km/h on GPS.

Tire sizes are stock HCR32 front and rear, 205/55/16. Pressures are 36psi front and rear, although I don't think that would have an effect at all... is my speed/rpm in 5th gear normal?

[jiffo]

FS5W71C gearbox 5th gear is 0.83:1 overdriven.

Diff ratio is 4.3:1

205/55 R16's are 505 revs per K.

Do the maths and at 3000rpm you're doing 100kph, or near as.

Are you sure your tacho is correct?

[Galois]

gps readings can be a bit tricky cos of accuracy restrictions (within a few metres) and hills, wouldn't be relying on the gps. can you test your speed driving along with a mate?

[KiwiRS4T]

The answer is yes it appears normal 4.3:1 is quite short - would drive me bananas but some people who are more interested in dragging from the lights seems to like it. My Stagea has a 4.1 final drive which I find too short. I am looking to change it for a 3.545:1 off a R34GTR which should be fine when my RB30 is fitted.

[jiffo]

4.1 V's 4.3 makes very little difference, about 2950 at 100 for the 4.1 and an Rb20 certainly feels more lively with the 4.3 ratio.

But the O.P.'s numbers don't add up.

Your first post said 4000 = 123kph, via GPS.

Something is wrong, it's just maths.

3000 at 100kph equates to 4000 at 133kph.

[CanadianGTST]

I'm going to be on the highway tonight, so I'll come back with hopefully more accurate #'s. Perhaps my tach is a bit out as someone mentioned. Since it doesn't sound out of the ordinary, I can't really complain. It certainly is lively in the first three gears

Thanks for the replies everyone

[TurboDoseBro]

Yeah, seems to have very short gears. I find them short even for an NA, would feel even shorter in a FI i would imagine. Mine also sits at roughly 2950RPM at 100km/h (GPS reading). Feels like 4th gear sometimes.

Edited July 28, 2010 by TyresBro