I started thinking the other day about the effect that a lower ratio diff would have on my XF. At the moment it is 2.77 single wheeler and I would like to get a 3.23 or 3.9 :1.
Would the car go a crap load better with a 3.23 or would i be better with the 3.9??
The car is a 5spd so I would hope that when cruising at speeds its not yelling. Does anyone have any experiences with this ratio change or could someone point me in a direction where i could get some info?? One last question, what revs would the motor do at 120kmh in 5th with both the 3.23 and 3.9?
Some simple arithmetic says that with the 3.23 you revs will rise around 1.2 times and with a 3.9 they will rise around 1.4 times everthing else remaining unchanged.
So if you do say 2500rpm now at a given speed and gear you would be doing ~2900rpm with the 3.23 and ~3500rpm with the 3.9's.
I would suggest 3.23 for an everyday driver with minor engine mods. The 3.9 would be more suited to a very rev happy engine and short sprints (not happy on the highway).
From what a guy at work said with his XF, it's doing 2700 somethin at 100km/h. I got a 3.23 in my baby and she turns 1950rpm at 100km/h.
Oh yeah acceleration will be heaps toey with the 3.23, if you want a good compromise get the 3.45 (XR's have got em)stronger takeoff and at 100 you'll be doing 2200rpm.
I have a friend who replace his 3.45:1 gear set with a 4.11:1 unit. At 100 km/h on the highway I think he was doing around 2600 - 2700 rpm in fifth gear.
I've got the BTR T5OD, which is an evolution of the T5, ratio's can vary from gear to gear. By the sounds of things it looks like i've got a taller 5th gear than yours which is offset by the shorter diff ratio.
I've got the BTR T5OD, which is an evolution of the T5, ratio's can vary from gear to gear. By the sounds of things it looks like i've got a taller 5th gear than yours which is offset by the shorter diff ratio.
I was going to go for 3.45 as there's not enough jump from 2.92 to 3.23 to justify it, but I've heard that 3.55 are more readily available and cheaper, but I haven't looked into it yet. Then again, the 2.92 moves pretty well once it winds up a bit and I've started to wonder whether I might leave it in and just put more punch into the donk. Decisions, decisions.
I started thinking the other day about the effect that a lower ratio diff would have on my XF. At the moment it is 2.77 single wheeler and I would like to get a 3.23 or 3.9 :1.
Would the car go a crap load better with a 3.23 or would i be better with the 3.9??
The car is a 5spd so I would hope that when cruising at speeds its not yelling. Does anyone have any experiences with this ratio change or could someone point me in a direction where i could get some info?? One last question, what revs would the motor do at 120kmh in 5th with both the 3.23 and 3.9?
If you haven't checked it , just type diff in "search",can't be easier. Only problem is it shows all ads including complete cars if the word diff is mentioned. Best part is that it is local for us,sandgropers.
Best of luck with your diff.
Regards Jon (dragonV8)
I pretty much buy the quokka every thursday anyway. I'd say that 99% of the diffs that people are selling are the usual open wheel 2.77's or 2.92's. No one seems to be selling any LSD 3.23/3.9
Ok, so which diffs from other Falcons (either the whole diff, or just centre) would fit straight onto an '86 XF Falcon sedan?
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Ford Forums
1.4M posts
115.4K members
Since 1999
Ford Forum is a community to discuss all things Ford. Check out our discussions on the Ford Escape, Mustang, Edge, F-150, Raptor, Explorer, Focus, Fusion, Fiesta and more!