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4.12 vs 3.88 transmission
ashbaxter - August 10th, 2012 at 03:06 PM

I have been looking at these freewayflyer tranmissions on the net in order to get a better top speed out of the Ghia without revving the guts out of it.
I have a twin port 1600 and would like to be able to cruise comforably at 60-65mph when need but am concerned that I may loose too much off the start if I pick the wrong one.

Any opinions or experiences please?


1303Steve - August 10th, 2012 at 03:48 PM

Hi

The stock 4th gear speeds in both boxes workout about the same at about 31 KPH per thousand with a 24 inch tyre.

What ratio do the freeway flyers use?

Steve


Joel - August 10th, 2012 at 06:03 PM

It depends which gearboxes you are looking at, as some places just call Lbug boxes freeway fliers as a marketing wank and as Steve says the difference between the Lbug 3.88 box and the 1500/Sbug box at 100km/h is only 50rpm.

You don;t want to slow the revs too much as it will only cause overheating and crap fuel mileage.

Some "freeway fliers" put a taller 4th which is fine with a big HP motor but will load up a stocker too much.

A 1600 twin port in a ghia with a 4.125 or 3.88 stock box will cruise all day at 80mph, have you got a 1200 or 1300 box in there at the moment?


ashbaxter - August 12th, 2012 at 08:16 PM

Mate I'm not sure what it is I need to get under and find the number to work out what it is.


grumble - August 12th, 2012 at 09:07 PM

Ash my Ghia with a std 1200 box and 1600 single port revs at about 3000rpm at 60mph (100kph) and runs happily at that,on the expressway we ran it up to 65mph most of the way to Newcastle with no problems,as Joel says you don't want to slow the revs too much.


Klaus - August 12th, 2012 at 11:43 PM

ghias have a different ratio box dont they "ao" code