chrisp

Just wondering if there is some sort of scale. I guess its dependent on fueling, air flow, ecu and size of turbo but anyone got an ideas on how much boost on the VF series turbo translates to engine power.

Not sure if that very clear but I just thought it may be useful eg.

On a VF23 turbo :

{Note this figures are WRONG just to illustrate my question ]

0.8 bar = 220bhp
0.9 bar = 240bhp
1.0 bar = 260bhp
1.1 bar = 280bhp
1.2 bar = 300bhp
1.3 bar = 320bhp

It probably a stupid question but I thought I would ask it anyway .

Cheers

ChrisP

john banks

You might be better asking the question how much airflow for a given pressure ratio at different efficiencies for different turbos? The original question as you suggest has too many uncontrolled variables.




Thanks to Mark V (EMS). You can find various guides as to how to read them in books and on the web. Basically it requires a few circular assumptions as to turbo, intercooler, volumetric efficiencies and then you work out airflow from RPM and boost pressure, (PR 2.2 = 1.2 bar gauge), and work out the efficiency. Not ideal, but at least you can compare turbos this way, well the compressor wheels anyway, but the exhaust side of the turbine has an effect on back pressure and airflow so you cannot take the compressor wheel in isolation. Gives an idea though. Also, turbo compressor maps are very difficult to source for a lot of turbos.

chrisp

Thanks John, I guess I knew it wasnt a simple answer but I have now have something to go on

Cheers

ChrisP