The rad will not be a problem, plenty of room at the front

Been doing some primary school maths (but cheated and used a calculator).

1900cc = 0.0671 cubic feet.

Assuming 1.5 bar boost, total air consumed = 2.5 times that (including the 1 bar atmo.)

Engine revs to 4500 rpm. However each cylinder ingests air every other revolution, so half it.

Multiplying this out, I get 377CFM flow required to run the engine at 4500rpm.

Is there anything wrong with this assumption? Why is it likely to be high or low (or just plain wrong)?

J.

Thought I'd drag this one up again.

Assuming 2.0 bar of boost instead of 1.5, the engine would ingest 452.4 CFM. Though maybe 4.5Krpm is a little high and it assumes 100% efficiency.

If I assume 80% efficiency and peak power at 4Krpm instead of 4.5Krpm, the engine eats 321CFM.

As an armchair project at the moment, trying to figure out the pros and cons of turbos. Assuming one left the original turbo installation but ran a second unit "outside". What cheap but larger turbo would make up to 1 bar and flow 321CFM?

Assume inlet flow of maybe...

Filter -> LP compressor -> MAF -> HP compressor -> IC -> engine.

Exhaust flow of...

Engine -> HP turbine (or bypass) -> LP turbine (or wastegate) -> exhaust pipe.

Trying to think if adding a 2nd turbo makes any sense at all. I think that the trick is to control the acceleration and forces on the wee-little KKK unit. Letting it see a full 2 bar on the overrun would potentially be very messy.

J.