Probably going to seem pretty stupid, but does the capacity of an engine have any bearing on how much power it can make with a particular turbo strapped to it (providing it can get it to spool of course.) ??

As an example a well set up and tuned 2 litre yb with a t4 running 2 bar should make around 500 bhp.

If the same t4 was fitted to say a 5 litre v8 and again was well set up running 2 bar would it still only make 500 bhp?

Or another way to put it - once a turbo has maxed out on flow of air (xx lbs per min or whatever) is it irrelevant the capacity of engine it is on and will only make whatever power that xx lbs of air can make whether it is a 2 litre or a 5 litre engine?

 

i believe your staitment is correct i am sure that to make x hp at x rpm requires a certain amount of fuel and air, i belive if you give the same amount to a bigger cc engine then the power will be the same

im sure someone will correct me if im wrong but thats my understanding

 

oh to add the @ x bar i dont think is correct as the v8 engine will potential consume more air so will make the maximum power for the amount of air flow at a lower pressure

 

Far too much in an engine to be able to generalise it into something so simple but a turbo will have a maximum amount of air it can supply and therefor if everything was 100% efficent a fixed amount of power available.

JAmes.

 

The pressure will be different, but the flow will be the same and this airflow controls power. Therefore the same turbo on any engine for which it is suitable should manage broadly similar power figures.

This is talking peak figures of course... Imo if you take something like rods engine, and fit the turbo to a 6l V8, you would still get your 840bhp but the area under the curve would be greater and it would be a generally nicer engine to live with (although useless for a cosworth top speed event!)

As far as taking any one engine and increasing the power, capacity isnt the limiting feature, strength is. Bigger engines make more power with less stress and hence dont need to be as strong, but look back into F1 for aomr 1500cc 1500bhp engines.....