4 replies to this topic

[087dave]

HI ALL is the 3.44 62/18 the best diff for a modified 998 i have a stage 1 kit stage 3 head sw5 cam and ligthened flywheel and was told the a few years back copper works had a 998 kit with a 3.44 diff which is a copper s diff instead of a 3.65 62/17 diff and had great results is this correct? has any body changed there diff ratio lately to a 3.44??

THANKS IN ADVANCE!!!!!!!!!!!!!!!!!!

[wilp99]

my metro motor came with a 3.44 diff and i like it most of the time. getting off the line is great, and if i keep on the throttle i stay in the power band. all the way thru 4th gear. however when im cruising at about 75 ish on the motor way, im sittin about 4700rpm. so it makes my motor scream while cruising.. so in that aspect i wish i had 3.10's but i dont go on the motor way enough to change it.

[tuktuk]

i have a 3.44 on the 1330, great round twisty roads, acceletares like stink but come to motorways ect its a pain.

jordie has this diff too and in the turbo it just had lots of power but kept running out of gear too quickly

[Ethel]

Tuned normally aspirated engines need to turn at higher revs to make the extra power (all things being equal, if you were to get the same power as a 2L engine out of a 1L one it would need to be turning twice as fast to consume the same amount of air in a given time). Open the throttle in a 2L engine and it will instantly start to draw in twice as much air as a 1L engine can that's turning at the same speed - changing down gear is the only way you could get the same instant hit out of the smaller engine. Have a look at guessworks site or download WinSU and have a play around with various ratios, once you know where the power band of your engine is, to best match it to where you'll do most of your driving.

[Jordie]

3.44 diff is a good comprimise for town and motorways. As said above, a loud noisey engine sitting at high revs on the motorway is a problem to some.

A 2.9 or 3.1 diff would make the revs lower at 70mph for example. but it will be slower off the line.

a 3.9 diff would be amazing off the line, but 70mph would be like 8500rpm for example.

The 3.44 was great in the turbo, it accelerated like stink with the power off the turbo and the diff ratio. But again, higher revs at the top end of the speedo. Turbos useually run a diff like 2.7 or 2.9 because you can use the boost to get the power for the standing starts and keep on boost for a longer range.