Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post

mauricio · 01-13-2010, 09:47 AM

Hi OldBeaver,

I'm trying to fit a RD28 in an old Nash 1956 (rambler model). This car has an original rear ratio of 4.2 (too slow, I thought) and I bought a Dana 30 with 3.07 ratio. Here there are no hills but maybe this ratio is too fast. How was your car with this relation in horizontal terrain? Have you some technical information about laurels and skylines gearbox and differential available? I've a 5 speed gearbox, and you have an automatic gearbox. Is it relevant? You say that in the original car it was a 4:1 final ratio, isn't? It is the only available ratio or there are also faster? I thought that RD28 are similar as a naturally aspirated merc. 300D (88hp) and this engine comes with a 3.0:1 final ratio. But maybe the RD28 has less moment and higher rpm?! Maybe i must try the car first with the original ratio (4.2:1) and if it is too slow, I must change for the 3.07:1. What do you think about? Thanks and best regards,

mauricio.

01-13-2010, 09:47 AM	#6 (permalink)
mauricio EcoModding Lurker Join Date: Jan 2010 Location: montevideo Posts: 1 Thanks: 0 Thanked 0 Times in 0 Posts	RD28 in an old Nash Hi OldBeaver, I'm trying to fit a RD28 in an old Nash 1956 (rambler model). This car has an original rear ratio of 4.2 (too slow, I thought) and I bought a Dana 30 with 3.07 ratio. Here there are no hills but maybe this ratio is too fast. How was your car with this relation in horizontal terrain? Have you some technical information about laurels and skylines gearbox and differential available? I've a 5 speed gearbox, and you have an automatic gearbox. Is it relevant? You say that in the original car it was a 4:1 final ratio, isn't? It is the only available ratio or there are also faster? I thought that RD28 are similar as a naturally aspirated merc. 300D (88hp) and this engine comes with a 3.0:1 final ratio. But maybe the RD28 has less moment and higher rpm?! Maybe i must try the car first with the original ratio (4.2:1) and if it is too slow, I must change for the 3.07:1. What do you think about? Thanks and best regards, mauricio.