12 replies to this topic

[Bounce]

Im having my engine out soon to have a SW5 cam fitted and was thinking. While its out, is there anything i can do to my standard gear box to make motorway cruising a tad more friendly on my engine? Maybe a different box is needed, but if its possible id like to get away with the standard box.


Its a 1995 SPI, Im quiet happy to put some money into this as it 'should' extend the life of my engine.



Cheers
Bounce

[RacingGreen]

you could change the diff so it is better for motorway cruising

[Bounce]

Any ideas? I have no knowladge about diffs, only a very basic idea of how they work.

I was thinkin changing ratios on the gearbox to keep the revs down, maybe even shelling out for a 5 speed box

[Sprocket]

you could fit the 2.7:1 final drive from the likes of the MPI. Im sure there is some one with one they dont use and have lying about.

[Bounce]

Sorry, im a leckie, i dont do engines. are you on about gearbox or diff?

[RacingGreen]

the 2:7:1 is the final drive ratio of the diff, it should help on the motorway.

[Bounce]

Cheers for the help guys

[Bungle]

good old guessworks

[Guess-Works.com]

I would go 2.95 minimum, unless you have a seriously torquey motor 2.7's just kill any acceleration you once had... I think the SPI's have 3.1's as standard which is not such a bad diff ratio anyway...

[THedooBZ]

agreed a 2.7ratio will kill your acceleration, its what i have fitted to my mpi, i dont generally thrash about anyway so acceleration aint a problem, it still goes enough though, while on motorways it is quite quiet at 70mph ( well for a mini anyway)

[blacktulip]

i think my old spi had a 3.44... 70mph @ 4k so id check first, my car was a k reg

[Bounce]

I get around 70 @ 4k not fantastic for the motorway. I like my acceleration, but i drive on the motorways a fair bit, is there an in-between soulution??


A 5th gear perhaps?

[blacktulip]

i would think a 3.2 would be better for u, i want to have one when i get my new engine. only problem u will have is to recalibrate your speedo.