QuickSilver 0 Report post Posted December 11, 2007 (edited) Hi all, I drove the work car the other day, and its a 1.3litre carby Hyundai, it was amazingly zippy for what it was... I admit it was about 12 years new, a WHOLE lot lighter and a hatch back, but never mind it got me thinking, the 320 was definitely still quicker (thankfully), this got me thinking, I still haven't changed over the diff when I did my manual conversion from the auto 4-speed to the manual 5-speed... my question, would I be seeing better pick up in first gear if I put the manual diff in? Some people have told me automatic diffs sometimes run better in manual cars due to ratios but how true is this really??? This sounds like a dumb question to me but I just dont know as i've never really played with diffs much! Cheers! Alex. Edit: Typo Edited December 11, 2007 by QuickSilver Quote Share this post Link to post Share on other sites
hotwire 352 Report post Posted December 11, 2007 Hi all, I drove the work car the other day, and its a 1.3litre carby Hyundai, it was amazingly zippy for what it was... I admit it was about 12 years new, a WHOLE lot lighter and a hatch back, but never mind it got me thinking, the 320 was definitely still quicker (thankfully), this got me thinking, I still haven't changed over the diff when I did my manual conversion from the auto 4-speed to the manual 5-speed... my question, would I be seeing better pick up in first gear if I put the manual diff in? Some people have told me automatic diffs sometimes run better in manual cars due to ratios but how true is this really??? This sounds like a dumb question to me but I just dont know as i've never really played with diffs much! Cheers! Alex. Edit: Typo Depends what diff in there currently - 320i autos varied in diff ratios between years. Being pre facelift I suspect yours is a 3.64 (see tag on rear bolt) F/L's had 4.27 & 4.45 in autos Manuals were 3.43 ( slightly taller than the early autos 3.64 but only minimal) quite different than 4.45 though, have driven a manual with 4.45 & is quick off the mark but doing well over 3000rpm at 100k Depends what you are after Quote Share this post Link to post Share on other sites
nz320i 0 Report post Posted December 11, 2007 you wont pick up faster using a "manual diff" but im surprised your not sick of the auto one already. My 3.91 is borderline too high i think. I might put my 3.65 in... Quote Share this post Link to post Share on other sites
tibbs.james 1 Report post Posted December 11, 2007 I went from a 4.45 with the Getrag 260 3100 rpm @ 100kph to a 3.91 with the 260 2700 rpm at 100kph A lower ratio would be nice but, i think the car would feel a bit slow being a 320. Quote Share this post Link to post Share on other sites
QuickSilver 0 Report post Posted December 11, 2007 Cheers guys I guess it'd be nice to be a little quicker off the line I guess so what do you all recommend? The diff is also generally worn out as it has a slow leak and needs replacing as it is, is yours a 320 or a 325 jimmy?? I find my 320 not toooo bad with power , recommendations all??? Bearing in mind I don't have $800 for an LSD Quote Share this post Link to post Share on other sites
bravo 35 Report post Posted December 12, 2007 In a 320 a 3.91 or 4.11 will give you good pickup off the mark. The 3.91 would be a good compromise for open road gas mileage as well. If you don't know what diff you have, and the tag is gone, jack the back of the car up with it in neutral, and hold one wheel still and count how many turns of the other wheel is required to rotate the driveshaft once. This number divided by 2 is your diff ratio. Quote Share this post Link to post Share on other sites
CamB 48 Report post Posted December 12, 2007 (edited) In a 320 a 3.91 or 4.11 will give you good pickup off the mark. The 3.91 would be a good compromise for open road gas mileage as well. If you don't know what diff you have, and the tag is gone, jack the back of the car up with it in neutral, and hold one wheel still and count how many turns of the other wheel is required to rotate the driveshaft once. This number divided by 2 is your diff ratio. Other way around? Count the number of times the driveshaft goes around for one wheel rotation? Edited December 12, 2007 by CamB Quote Share this post Link to post Share on other sites
tibbs.james 1 Report post Posted December 16, 2007 (edited) Cheers guys I guess it'd be nice to be a little quicker off the line I guess so what do you all recommend? The diff is also generally worn out as it has a slow leak and needs replacing as it is, is yours a 320 or a 325 jimmy?? I find my 320 not toooo bad with power , recommendations all??? Bearing in mind I don't have $800 for an LSD QuickSilver my car is a 320 and with the 3.9 it feels pretty good its not to slow. and also gets 100km to 10L(not nanna driving but not thrashing ) If i had a 325i would have gone with something like a 3.64 to be around 2500rpm at 100km/h Edited December 16, 2007 by Jimmy Quote Share this post Link to post Share on other sites
