RT195 with original Taffy expansion- gearing recommendations

[Bidsy]

I’m after bit of advice from you guys if possible please. I’m building a small block RT195 ( piston ported) and have an original Taffy expansion to go with it plus Italian LI150 gearbox and 46 crown wheel. Could anyone recommend what final gear ratio I should be aiming at for a good touring setup (13 stone and a bit of luggage ) I want to be able to sit comfortably on a motorway at 60mph but still have a bit left in the tank of overtaking. Also recommendations of carb size. Thanks

[Rich Oswald]

I have a Taffy Mk 4 on my Muggy 225. I had an Italian GP200 box on at first, so same FDR ratio as LI150 (5.2) but went to 19/46 (4.8) FDR which I stayed at when I went 5 speed. Pulled great for me but i'm only 11 stone. Defo go at least 16/46 but may pull 17/46 which is what I have on my RT225 reed (5speed). May be trial and error.

Rich'

[Bidsy]

Does the Original Taffy produce its power high up or low low the power range?

[GP Kevo]

If it's their road pipe then the power is pretty low down with the peak power at around 7,000 RPM. The road exhaust is in two parts not including the silencer. The down pipe connects to the exhaust flange. Then that connects to the main expansion pipe with two springs

If it's like a JL4, really fat, one piece and with a really long stinger leading back to the silencer, then it's their race pipe. That exhaust makes power much higher up in the revs.

Hope that helps.

[Rich Oswald]

Does the Original Taffy produce its power high up or low low the power range?

Low down the power range. It's a touring pipe with plenty of torque.

[Bidsy]

Look like I have the road version, So am I right to assume it delivers power similar to that of a box pipe and would be better suited to a FDR of around 4.9 rather than 5.2?

[Rich Oswald]

Look like I have the road version, So am I right to assume it delivers power similar to that of a box pipe and would be better suited to a FDR of around 4.9 rather than 5.2?

IMO yes.

[ULC Soulagent]

Me personally I’d settle for 5.2 fd with the expansion pipe
Everyone is different though so case of suck it n see
30 phbh delly as well

[hullygully]

I had Taffy exhaust for years, got bored with hitting the invisible wall, then changed to a Franny tourer , then upped to a super tourer