Jump to content
SAU Community

Recommended Posts

I know there are lots of variables but was just wondering what other older Nissans/Datsuns show on the tacho at 100kph.

My result is:

Skyline MR30, L24E, 3 speed auto (!), 83 series 1, 3500 RPM

Not so good on economy but hums along nicely on a good day.

cheers,

JH

Link to comment
https://www.sau.com.au/forums/topic/355831-rpm-at-100-kph/
Share on other sites

I know there are lots of variables but was just wondering what other older Nissans/Datsuns show on the tacho at 100kph.

My result is:

Skyline MR30, L24E, 3 speed auto (!), 83 series 1, 3500 RPM

Not so good on economy but hums along nicely on a good day.

cheers,

JH

Hi John,

Your problem is the 3 speed transmission because top gear is 1:1 and not overdrive as in the later model 4 speed.

Have a play with this link and you will see what you have got.

http://www.testarossa.jp/utility/gear.html

Your gear ratios are: 1st: 2.458, 2nd: 1.458, 3rd: 1.000 and at the bottom after 6 is diff ratio: 3.9

Cheers, D

Link to comment
https://www.sau.com.au/forums/topic/355831-rpm-at-100-kph/#findComment-5695789
Share on other sites

Thanks Dennis,

Looks like I'm 'spot on' then. Not so bad for a car with 260,000km on the clock.

I'll be interested to see some real-life figures from a 4 sp auto and 5 sp manual. (Maybe you can take the PNV for a run.)

cheers,

JohnH

Link to comment
https://www.sau.com.au/forums/topic/355831-rpm-at-100-kph/#findComment-5695814
Share on other sites

Just by using the Testarossa link and the right gear ratios the 4 speed auto has 0.686 overdrive and does 111kph @ 2500

The 5 speed MR30 with 3.9 diff & 0.833 od it does 92kph @ 2500 and 110kph @ 3000 in top gear.

The PNV however has an od of 0.813 just a tad higher, but with lower diff ratio of 4.11 and it does 89kph @ 2500 and 107kph @ 3000.

As a result of this, my modified L20et (umm 2818 L20et) PNV will have an 3.7:1 diff with a modified R32 GTSt gearbox with an 0.759 overdrive so that it will be a much better cruiser just chugging along on 106kph @ 2500 rpm off boost.

Cheers, D

Link to comment
https://www.sau.com.au/forums/topic/355831-rpm-at-100-kph/#findComment-5696022
Share on other sites

The most crytical part of kph @ rpm is your tyre size. Just changing from factory fitted 195/60 x 15 on an R30 to 205/60 x 15 which is the common & norm here in oz, it makes an incredible amount of diferrence to the end result.

D

Link to comment
https://www.sau.com.au/forums/topic/355831-rpm-at-100-kph/#findComment-5697151
Share on other sites

speedo doesnt work. have new speedo cable, just have to put it in.

When i sit with traffic on camden bypass at 100km/h, im doing 4000rpm!

so i sit on 3500rpm for economy's sake, and everyone is overtaking me

Took the air filter element out, held engine speed at about 3000rpm, spayed throttle body cleaner

up the air flow meter for about 30 seconds. No difference performance wise, but uses a lot less fuel and a bit smoother

(not that it wasnt smooth before)

Link to comment
https://www.sau.com.au/forums/topic/355831-rpm-at-100-kph/#findComment-5697809
Share on other sites

Its JAPANESE but its discernible through context..however i cannot find the ratio specs for the r30 4sp auto gearbox. Who has?

Thanks in advance.

EDIT:

I punched in 0.686 ratio for gear 4 with a diff of 3.9 - gave me 96k/h @ 2000 rpm and 121 k/h @ 2500 rpm - ABOUT RIGHT! guess she pulls her weight alrigght, considering she's done 140k since 1984.

Edited by samkhan86
Link to comment
https://www.sau.com.au/forums/topic/355831-rpm-at-100-kph/#findComment-5699017
Share on other sites

Its JAPANESE but its discernible through context..however i cannot find the ratio specs for the r30 4sp auto gearbox. Who has?

Thanks in advance.

EDIT:

I punched in 0.686 ratio for gear 4 with a diff of 3.9 - gave me 96k/h @ 2000 rpm and 121 k/h @ 2500 rpm - ABOUT RIGHT! guess she pulls her weight alrigght, considering she's done 140k since 1984.

4 speed auto >>> 1st: 2.842, 2nd: 1.542, 3rd: 1.000 & 4th: 0.686. Reverse: 2.400 Diff: 3.9

Cheers, D

Link to comment
https://www.sau.com.au/forums/topic/355831-rpm-at-100-kph/#findComment-5699233
Share on other sites

I noticed no one is putting down what there miles per gallon is, since this is where the saving is,

I'm running a L24 inter-cooled Turbo, running EDIS ignition (waste spark), Megasquirt II using the version 3.0 board, running the latest MS Extra firmware,

3 inch mandrel bend exhaust, with a free flowing muffler, and 7 PSI for normal driving, switchable to 10, and 15 PSI

I just came back from a trip, 290ish kilometers, I sat on between 105-115k's 80% of the way,

and I'm getting 34.34 miles per gallon, or 8.22 liters per 100k's.

I'm very happy with this, good fuel economy, and plenty of power, when I put the foot down a little.

to get it running this good, I run it lean (2500 - 3600 RPM), AFR sits between 15 and 16.5 (light cruise), EGT sits about 770ish just before the turbo.

Nigel

Edited by noddle
Link to comment
https://www.sau.com.au/forums/topic/355831-rpm-at-100-kph/#findComment-5701472
Share on other sites

Spec figures from carbuddy.com for L24E:

4sp auto 13.5L/100km city and 8.5L/100km highway.

3sp auto 14L/100km city and 10.5L/100lm highway.

5sp manual 13.5L/100km city and 8.5L/100km highway.

I'd like to try bigger wheels, only running 14's at the moment (195/65HR14). The speedo reading will be out with larger rims/tyres. My guess is that 5% larger outer diameter means 5% lower reading on the speedo - so when it says 95, actual speed is 100.

JH

Link to comment
https://www.sau.com.au/forums/topic/355831-rpm-at-100-kph/#findComment-5702395
Share on other sites

Spec figures from carbuddy.com for L24E:

4sp auto 13.5L/100km city and 8.5L/100km highway.

3sp auto 14L/100km city and 10.5L/100lm highway.

5sp manual 13.5L/100km city and 8.5L/100km highway.

I'd like to try bigger wheels, only running 14's at the moment (195/65HR14). The speedo reading will be out with larger rims/tyres. My guess is that 5% larger outer diameter means 5% lower reading on the speedo - so when it says 95, actual speed is 100.

JH

Ummmm now we are talking tire sizes, well factory fitted 14" tires were 185/70 x 14 & 195/70 x 14 or Ti 195/60 x 15.

185/70 x 14 have a dynamic radius of 299mm

195/70 x 14 have a dynamic radius of 306mm

195/60 x 15 have a dynamic radius of 297mm & optional fit 205/60 x 15 is 303mm

And it's the dynamic radius that counts when it affects the speedo numbers.

And John, your 195/65 x 14 is 295mm

(figures compliments of http://www.toyo.com.au/Tyres.htm)

Cheers, D

Link to comment
https://www.sau.com.au/forums/topic/355831-rpm-at-100-kph/#findComment-5702552
Share on other sites

Ummmm now we are talking tire sizes...

Yes, we're wandering off the topic slightly but it's all related. Thanks for the tyre figures. I found this tyre calculator on a VW site: http://www.club80-90...0calculator.htm

I'll check my fuel economy and post some figures as well.

Meanwhile, it might be interesting to see some figures from even-earlier Skylines. The figures from '73 to '83 are all very similar.

cheers,

JH

Link to comment
https://www.sau.com.au/forums/topic/355831-rpm-at-100-kph/#findComment-5702766
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

    • Plazmaman 76mm Pro Series, done. Data to back it up, I posted up somewhere here a few years back
    • So.....wire it up appropriately. You can't use the resister pack with those injectors anyway.
    • that’s the thing i’m on ID1050s and haltech not getting power due to the injector resistor 
    • ahh okay cheers, i was thinking of just going for the m073, think m079 would be way too overkill considering they are same size. 
    • My first car was a HG. I'm very familiar with them. A mild cam upgrade is a good idea. The 186 is a very flexible engine - meaning it has good torque from down low. You can give up a little torque down low for quite a lot more excitement in the mid range, and a bit more up top - but they are not exactly a rev monster. You need to upgrade valve springs at the minimum. For a bigger cam, you'd want to make sure it wasn't still running the original fibre cam gear. That would be unlikely, given that most of them shat themselves in the 70s and 80s, but still within the realms of possibility. Metal cam gear required. Carbies are a huge issue. The classic upgrade was always a Holley 350, which works, but is usually pretty bad for fuel consumption. The 186S had a 2 barrel Stromberg on it that was very similar to the one on the 253, and is a reasonable thing if you can find one, and find someone to help you get it set up (which is the same issue with setting up a 350 to work nice). The more classic upgrade was twin sidedraught CD type carbs, or triples of same, or triple Webers. The XU-1 triple Webers being the best example. You can still buy all this stuff new, I think, but it's a lot of coin to drop. And then the people able to set them up are getting fewer and further in between. There's still some, but it used to be everyone's** dad and uncle could do it. **Not everyone's! But a lot. All in all, I wouldn't get too carried away with the engine. Anything you do to it without a full rebuild for power and revs will only make it slightly faster. I am all in favour of a complete teardown rebuild, with nice rods and pistons, 10 or 10.5:1 compression, and a clean port job with at least a big enough cam to run 98 with that compression, if not bigger. And if I did that to a dirty old red motor, I'd want to inject it too, which I'd struggle to fight against the devil on my shoulder that would argue for ITBs and trumpets. But the bills would start to mount up, and it will still never make stupid power. OK, a few people still know how to build absolutely mental red motors, courtesy of the work that went into HQ racing and modern knowledge being applied. But even a 300HP red motor is no match for an RB20 with a TD06. So you have to decide what it's worth to you. I'd just put a set of 6>2>1 extractors, a 2.5" exhaust and an electronic ignition conversion/dizzy on it and just run the old girl like the fairly slow old girl that she really is.
×
×
  • Create New...