Chris, R180 diffs are out of C110, C210 (240K, Skyline), Zeds and some 4WD's. 3.9 is the standard ratio for a C210 Skyline with 5 speed box, 3.7 and 3.5 are more common in the 240K.
Nissan auto diffs can be both higher or lower, but there is a pattern. On a 1600 the Aus spec 4 spd man has a 3.7:1 diff, the auto has 3.9 (which is lower) but other markets have 3.9 as the standard diff. On a model that has a 4 or 5 speed manual and a 3 speed auto such as the 240K, the 4 speed has 3.7, the 5 speed has 3.9 and the auto 3.54, which for this model the auto is a higher ratio. If there was a 4 speed auto available for this model the OD ratio would be around .75:1 and the diff ratio would be around 4.4:1, so the overall gearing would be 3.3:1 which is pretty tall for cruising but in theory much better acceleration than for the 3 speed auto. When applying a diff ratio to a stock powered engine with an auto trans you have to take into account the HP, torque (very important), weight, and a few other variables like the ratios of the box, tyre sizes etc. Another interesting Nissan to look at gearing wise is the Stanza SSS second edition. The L16 engine is exactly the same as the GL/GX 4 speed with a 3.7 diff, but the so called SSS performance model had a 4.3 diff with .865 OD, so acceleration was better than the GL but the overall gearing in top gear is almost identical. You can vary the overall gearing by +-4% just by changing the tyre size and there's around 4% difference between ratios. Say for a 3.9 diff with 195/55x15, you can lower the overall gearing by 4% by fitting 195/50x15 or raise the gearing by 4% by fitting 195/60x15 so a 3.9:1 diff is about right for a L20B in a 1600 with a 5 speed box. The baseline tyre size in 14" would be 195/60x14 and 13" is 185/70x13. regards Terry -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Chris Williams Sent: Tuesday, 13 November 2001 9:39 PM To: [EMAIL PROTECTED] Subject: RE: L20 & R180 Probs? R180 diffs are out of 240K's yes? if so are the auto diffs higher or lower ratio? What is standard 1600 diff ratio and what is a good ratio for a mild L20B in a 1600 with a 5speed dogleg box and a 240K fly wheel? thanks Chris W > R180 diffs come in ratios from 3.3:1 to ~5:1 > > In 5th gear 3900 - 4100rpm @ 100 kph (depending on tyres and 5th gear > ratio) is a 5.1 diff, you'll need to change it before you fit the Turbo > (3.7 - 4.1) is recommended. > > 4th gear in most Nissan L series 5 speed boxes is 1:1 except some > Option boxes. > > regards > Terry > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]]On Behalf Of nifty nigel > Sent: Tuesday, 13 November 2001 5:47 PM > To: [EMAIL PROTECTED] > Subject: L20 & R180 Probs? > > > Howdy all, > I have decided that the turbo can wait but I >still want power now!! So the L20 will be done. > Are there any mods required to fit an L20? > I have an L18 already in. > Could I beat a standard falcon with the L20?? > > Oh yeah and does any one know what ratio the R180's > come in?? I was told mine is 3.9 but it is not! > 4000rpm at 62 mp/hr 5th gear!! > I worked it out to be about 5.2 > And maybe the ratios of a 260 z 5 speed is 4th 1.0?? > > __________________________________________________ > Do You Yahoo!? > Find the one for you at Yahoo! Personals > http://personals.yahoo.com > > --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/[email protected]/ ---------------------------------------------------------------------
