Posted January 25, 200421 yr comment_65787 Hi All, I picked up my 240Z on Saturday and had to drive home with it about 150miles mainly motorway. The thing that I really noticed was that the car seemed to need to rev pretty high to get a shift on. I did some testing today and came up with these rough figures at 4000rpm: 2nd gear = ~30mph 3rd = ~45mph 4th = ~60mph 5th = ~70mph I had a look at the transmission calculator and these figures don't seem to tally with any on there. I'm assuming I have a 3.9dif which was the one used in the UK AFAIK and the closest gearset that seems to match the speeds I'm seeing is the 32010-N3201 Factory Competition (rally transmission) gearbox. The other alternative is that I have a standard box and a ~4.9 diff which strikes me as pretty unlikely. Of course I'm not discounting the fact that my rev counter and/or speedo could be whacked I guess I can check the speedo by timing over a known distance, rev counter is a bit trickier, all I can say is that the engine sounded like it was doing 4000. Any thoughts? I've got loads of bills dating back years but can't see any mention of any work done to the gearbox/diff. Cheers, Rob Link to comment https://www.classiczcars.com/forums/topic/9892-whats-your-in-gear-speed-at-4000rpm/ Share on other sites More sharing options...
February 25, 200421 yr comment_69967 Dunno if it helps, but at 4k in 4th gear I am at about 85-90 mph. My car is a '75 280 with a 4-speed. It is completely stock (just got it today). Link to comment https://www.classiczcars.com/forums/topic/9892-whats-your-in-gear-speed-at-4000rpm/#findComment-69967 Share on other sites More sharing options...
February 25, 200421 yr comment_69972 Rob,PM me with your Email and I'll send you my Excel based TransCalc spread sheet. I have models of each transmission, including the FS5C71A, installed in the European/JDM/Aussie markets Link to comment https://www.classiczcars.com/forums/topic/9892-whats-your-in-gear-speed-at-4000rpm/#findComment-69972 Share on other sites More sharing options...
February 25, 200421 yr comment_69973 By the way,Your numbers point to a 4.38 rear or even lower!FS5C71A (standard gearset), 4.38 rear, 195/60/14 tiresRPM 40001st 21.42nd 34.03rd 48.24th 63.25th 74.2 Link to comment https://www.classiczcars.com/forums/topic/9892-whats-your-in-gear-speed-at-4000rpm/#findComment-69973 Share on other sites More sharing options...
February 26, 200421 yr comment_69987 Here is a stupid question: Is a UK mile the same distance as a US mile?:stupid: Link to comment https://www.classiczcars.com/forums/topic/9892-whats-your-in-gear-speed-at-4000rpm/#findComment-69987 Share on other sites More sharing options...
February 26, 200421 yr comment_70023 They are the same. :classic: Link to comment https://www.classiczcars.com/forums/topic/9892-whats-your-in-gear-speed-at-4000rpm/#findComment-70023 Share on other sites More sharing options...
February 26, 200421 yr Author comment_70041 Thanks for the replies guys. It's still a bit of a mystery but I haven't had much time to investigate as I've been battling with rusted in headlamp bowls for a bit and now the car is blind I can't drive it - joy I'll keep you posted. Cheers, Rob Link to comment https://www.classiczcars.com/forums/topic/9892-whats-your-in-gear-speed-at-4000rpm/#findComment-70041 Share on other sites More sharing options...
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