Technical Manifolds

[Uno driver]

Which do you think is better? First one is from uno 60S, second one is from Uno 1.0ie 1998 (SPI). I have also punto 55 manifold that is almost the same as uno 60 (+ water temperature sensor). 1.0 manifold has slightly bigger ports than 60S.

Which exhaust manifold is better, with dual downpipe or with single downpipe?

 

[alexGS]

Interesting quiz. I'd think the second one is better - more equal path length to all cylinders. And a long path length, which is supposed to give better torque characteristics (in general).

As for the exhaust, I'm a believer in dual downpipes for all four cylinder engines. My Spider has a single downpipe (1978 model) and it's well known that the earlier and later dual-downpipe versions give better performance at high RPM. The old 128 saloon had a single downpipe and single-barrel carb, 55bhp. The same engine with a twin downpipe and twin-barrel carb, 65bhp. Every bit helps.

Looking at the size of the exhaust on the Uno 45 (and its dual downpipes), I've always thought it was more than sufficient for 45bhp. Look at a Mini 1000 and you'll see what I mean...

-Alex