It would be nice to cruise on the motorway at 70 without reving the nuts out of our engine, what are the options of box or diff changes i can do to our 74 1800 bus.
Whereas I think you should add more sound proofing. My 1700 was only just happy at 70 - a little faster and it got too hot. Over-gear it and same result IMHO - more effort per rev = more heat. At that speed you won't save petrol by reducing the revs either, as you'll have to press the accelerator further down - again, more effort per rev needed.
If you're doing about 3500 rpm then that's about right - I think I read somewhere about that being in the optimum rev range for getting enough cooling air through at speed.
Next option is porsche 915... not cheap, but it will get your cruising rpm down... The heating system will need tweaking about if you're running stock heating!!
I'd love a porsche box but its a fair amount of work and the boxes dont come cheep. I've got the engine out at the moment and the box is a tiny bit noisy so i am just weighing up my options thats all, just wondered if there is another bus box or beetle box worth finding to rebuild with slightly higher ratio's. The bus holds 4th on hills unless they are massive so was only thinking i could happily sacriffice dropping into 3rd on hills if it cruised better on the flat a bit, which is where the bus spends most of its time. And it would be nice to go back down in tyre profile purely for looks.
I found the box in my 74 1800 ok, it was a little quicker than the 2L 091 boxes too ( as we found out in convoy) I think the 002? box has a longer 4th gear that the 091
Might be its got a higher final drive diff cos i thought most boxes had the same ratios just the diff's changed but i'm not 100% on that, good to know that a 74 1800 might already have one of the highest gearings anyway, cheers for that.
