The BIGGEST PERFORMANCE GAIN you will make - and it's NOT ILLEGAL. 

Couldnt agree more. I recommend diff gears as one of the very first mods to anyone who will listen (so not many) intakes, exhaust etc etc are great but none of them gives the very obvious improvements diff gears will/do give. Going from something like 3.08 to 3.73 or shorter or 3.45 to 4.11 or shorter makes a massive difference that everyone will feel after the change and is one of the biggest single improvements possible imo.

Congrats on the run at all Ford day mate! 12.05 1/4, in an NA 8! You did well, and so many people were watching and recording you!

Hey guys, I mentioned my T56 6th gear as .67(my memory failed me) ratio when in fact it is claimed to be .63. Although you should check with Ford as I've seen a few different claims now.

In my old BA NA XR6, 4.11 diff gears made it MUCH quicker off the line, added a 3000rpm hi-stall after that, it was good enough for it to run a 13.7 1/4 mile. If I were to do it again though I would go 3.9 gears as a good compromise between performance and everyday drivability.

I did notice being a former xr8 260 owner' that the 5.4 is s little sluggish down low under 4k, So I think the short gearing would help this motor in particular.

Another great video , albeit i found it later than the others . And an essential upgrade I'll be doing , 3.9 or 4.11 ... Not sure . But what i want to mention was the lightweight rear wheels you put on your car . That's exactly what I'm doing with my xr6 fgx , it came with 20's and they're heavy af ... Even putting konis on it didn't help much . So it's some motegi racing 18's I'm going for . Thanks again , looking forward to a better car to drive soon ... Not as quick as yours , but hey ... I haven't got that much spare money right now . All good , thanks again for your great videos 👍👍👍

6:28 Absolutely love the shiftwork.

Spitting truths mate

Hi Gap Sauce. My 4.11's are coming soon along with an old SCT tuner. Only plans I have for the SCT are to input the new diff ratio, firm up the auto if I can and I am keen to advance the timing a bit to run 98. For some reason mine has always started, run and achieved better economy on E10/94 and that's measured closely over 45,000km. Doesn't like 98 but I am keen to change that. Any suggestions on how many degrees I can safely pull back? I am thinking 2 is conservative, 3 probly OK and 4 doable but starting to ask for trouble. Street only so sees WOT for a bout 1 second, 3 times, once a month! Cheers mate keep the vids on the GT coming. Love em. (BA GTP BTR Auto - CAI, headers, Xforce full system, intake pipe)

Great video! I'll be changing the stock 2.53 gears in my BF Fairlane G8 (5.4L 3V SOHC Barra 230, ZF auto) to standard XR 2.73. This will give me a bit more boogie and stock XR freeway cruising revs. :) Can't wait!

Hi mate love your car goes and sounds wicked! Do you know if motive diff gears from eBay are any good?

Would you potentially use a S1 sequential shifter to speed up your gear changes even more?

Fully agree with you. I bettered my PB by 0.15 when I went from a standard 2.73 diff in my ZF Auto Boss 290 with 288 rwkw to a 3.45 diff. I would like to try 3.75, I think that could be optimum for me but may never happen 😊??

G'day. Ive done a couple of test n tune nights with my 6 speed auot bf gt. Best i got completely stock was 13.88. Now i have the bug and its tax time. When doing the change in diff gears to the 4.11.1 do you need to upgrade anything else to handle the extra torque that it gives in lower revs? Or is changing the diff gear ratio just applying the max torque at a shorter time?

Awesome content 💪😎👍 Better ratios “yeah yeah yeah yada yada yada “ I call BS o’l mate You’re just showing of to the rest of us mortals How good you can shift 😂🤪💥🚀💪😎👍

I learnt this when I hopped in a lazy Auto SS to a manual 3.7 HSV. And learnt more when 4.11 EVOs and other smaller cars seem to have more get up and go despite power disadvantage (taking into account obvious weight difference). 4.11 on the street, from street speeds is the go. Who cares if you’re car is geared to 270km/k lol

Would you recommend the 4.11 for the 3v g220 as it has really good low down torque

I guessed tyres. I'm still going with tyres as most important (and easily reversible) mod you can do. But diff ratios, yep, also good, especially with more modern cars and their economy focused diffs. Had 4.11 in my t56 LS1 commode. Could actually use 6th gear on hwy! Picked up 2 tenths going from 3.9 to 4.44 in my RX7 many, many years ago. Trap speed didn't change, as you'd expect. That depends on power/weight, and gears font change that. Keep up your vids, great content!

Hey man. The size issue isn’t so much actual tooth size. It mainly referring to the pinion gear. The longer the gear the bigger the pinion gear can be. The reduced thickness of the crown wheel isn’t as much a power handling problem. Also need to be making a heap of torque before it would became an issue anyway

Nice vid man, Is a tuning job or pulling your gearbox out and changing a few things?

Next time you need a set of 4.11's hit me up mate! I know a guy 😜

are you able to change diff gears on p's? Ik it doesn't change the output of the engine so it should be ok but just thought you might know something.

Hey Gap Source, my Boss 5.4 is out of action due to a a bad timing chain tensioner, oh well (any recommendations?). The reason for my comment I've noticed you love to be in the higher rpm and have subsequently built your mod 5.4 to complement that. Have you considered installing a mmr Coyote intake adapter to accommodate a boss Ford racing 302 intake. Trying to do more research on the matter but can't find anything.

Yeah I got 440rwhp but used to run 2.92 diff gears in the wagon, swapped to 3.73 gears and it really opened it up, but it did cost $1500 including the speedo recalibrated on DYNO tho

Hey mate just a quick one. What revs does it sit at while going 100km/h

Saw this dude race to at Willowbank

You officially have australia's fastest boat anchor. ;)

Great info, definitely have to do my dif... 10lt / 100 😮 , before i fixed my engine mine was at lowest 18lt/ 100, its higher now after mods

I have a auto with a mild cam and standard stall. Would diff gears make it more undrivable? Its already slighlty pushy.

What RPM do you end up at sitting on 100(ish) on the highway? Still can't decide if I want these in the XR8 or just be happy as it is.

I recently installed a truetrac diff and upped the ratio from standard 3.23 to 3.7 but notice no difference other than the revs are higher and it’s slot louder when sitting on 100kmh.

Nice to have met you at the servo this morning mate. Look me up on Facebook

100% agreed. My ute is way better with 3.23 behind the zf over the factory 2.73. Better on fuel on freeway. The car sounds and feels like its where is should be at freeway cruise revs. Still need to hit heqthcote to seen the gain on the quarter to make it official but definitely feels stronger in acceleration. Cabin drone, well its actually better now with the diff gears. Due to sitting at 2k rpmthe drone has gone. Used to drone around 1600. 60kph driving i have to sports mode and leave in gear to avoid 5th and drone lol

Going to 3.45 from 2.92 was the best mod I did

Man I went 3.45 to 4.11 6 speed and I can't get the thing under 17L per 100km now average Street driving. Before diff gears I could get it down to around 14.8L

You really know you have a long diff ratio when you can hit 90 kph in 1st. Good old 4sp auto AU XR8.

Like your videos but the music in the background might need a up grade

how expensive are 3.9 or 4.11 diff gears?