What RPM= what speed?

[slownslurious]

hey guys, speedo isn't working, and I wanted to know what rpm=what speed in 5th gear. I was messing around on a really long flat straight stretch in the middle of nowhere, and I got up to 6500 rpm in 5th without breaking a sweat, I think the motor could probably redline in 5th if I had the room and the balls. How fast is that? Also how fast is 55, 65, 75, etc? Might come in useful on the highway.Anyway I've talked to a couple other guys with ca's and nonworking speedos, so maybe the info could be in the FAQ. Thanks!

[r34 gtr]

im thinking that 55mph in 5th would be about 3200rpm. i know you do about 48 at 3000 in 4th... 75 you would be doing about 4050rpm in 5th. this would make 65 about 3700 or something. i used to know them all but its been awhile since i had a nonworking speedo.

- tim

[slownslurious]

nah its got to be faster than that, the speed limit is usually around 70 around here and I keep up with traffic doing 3500 rpm's in 5th. Out in the country traffic moves around 80 mph and I seem to keep up doing about 3800-4000 rpm (ok, so, more than keep up. :-)

[c-rad]

Uhh.....70mph in 5th is almost exactly 3000 rpms. The gearing in the CA transmission is the EXACT same as the KA. Only the SR has a slightly taller 5th gear.

[Dattebayo]

Actually, I dont know where this myth keeps coming from, but all the S13/S14 transmissions have the same gearing!

The only thing that is different is the final drive (the differentials!). Its just weird.

[float_6969]

Not entirely true either. The JDM CA (I think the UK is different) has a shorter 5th gear than the KA. Otherwise, yes, they are identical.

[float_6969]

hey guys, speedo isn't working, and I wanted to know what rpm=what speed in 5th gear. I was messing around on a really long flat straight stretch in the middle of nowhere, and I got up to 6500 rpm in 5th without breaking a sweat, I think the motor could probably redline in 5th if I had the room and the balls. How fast is that? Also how fast is 55, 65, 75, etc? Might come in useful on the highway.Anyway I've talked to a couple other guys with ca's and nonworking speedos, so maybe the info could be in the FAQ. Thanks!

Have you considered simply correcting the cause of the problem, instead of dealing with the effects of it?

[boost_boy]

hey guys, speedo isn't working, and I wanted to know what rpm=what speed in 5th gear. I was messing around on a really long flat straight stretch in the middle of nowhere, and I got up to 6500 rpm in 5th without breaking a sweat, I think the motor could probably redline in 5th if I had the room and the balls. How fast is that? Also how fast is 55, 65, 75, etc? Might come in useful on the highway.Anyway I've talked to a couple other guys with ca's and nonworking speedos, so maybe the info could be in the FAQ. Thanks!

6500rpm in 5th gear will equate to roughly around 144-6mph. I could be a little off by +/- 3-5mph, but I do know it's close enough.

Dee

[NeedCAforS13]

Not entirely true either. The JDM CA (I think the UK is different) has a shorter 5th gear than the KA. Otherwise, yes, they are identical.

I agree. I've had people tell me (mostly people without running CA's in their car ----> Chris and 2BN for example) that the KA and CA transmission gearing are the same, but I'm POSITIVE 5th gear is different. I never used to cruise at this high RPM on the highway with the KA.

Sean

[Dattebayo]

(mostly people without running CA's in their car ----> Chris and 2BN for example)

Alright, alright. I'll admit its true. But to make sure, I am going to compare the two transmission gear sets when I remove the KA from my 240sx. Then we will know for sure (at least for the KA > CA issue).

[WeldingHank]

i get 70mph at exactly 3000RPM, just like my KA.

[mbmbmb23]

http

Actually, I dont know where this myth keeps coming from, but all the S13/S14 transmissions have the same gearing!

The only thing that is different is the final drive (the differentials!). Its just weird.

http://www.nissansilvia.co.nz/...e.htm

[slownslurious]

thanksdamn so I was going 144 mph? well, its gonna be off a little too cause I have 195/50 15's so that would explain why I gotta cruise a bit higher. Interesting stuff about the transmissions, it seems like my ka cruised at a lower rpm but I never paid much attention.

[slownslurious]

working on it, but its hard because I don't know the problem. I have the USDM speed sensor installed, and my HUD worked perfectly fine before the swap, and a guy did the wiring that has done it many times before. The only thing I can think of is to wire the speed sensor directly to whatever wire it goes to at the dash....

Have you considered simply correcting the cause of the problem, instead of dealing with the effects of it?

[float_6969]

I thought HUDS were infamous for problems like this? Are you sure it's not the cluster?

[slownslurious]

yeah, when I first got it the hud didn't work so I replaced it, its worked fine since then, worked before the swap, didn't work after it.

[Dattebayo]

So I read that list or ratios and it proved my point. It says all S13 and 14 factory transmissions have the same ratio with different final drive {differential) ratios.

Edit: I would be interested as to how you eventually solved this little problem as my motor is going in very soon...