now when speaking to Rod he mentioned to me that i would need roughly 630-650bhp to achieve 200mph, now thats in an ideal situation, ie im making that power at exactly 200mph, this brought me on to how much power do i actually need, the first thing to do is have a look around at a few compressor maps and also a few examples from the US/OZ

Now there is a thread on here about compressor maps by scooby slayer, perfect thing to work out what turbo i would need.

Now the problem with rotarys is they are very un-efficient with the airflow that they recieve, for every 10lb of air they recieve they only make use of a max of 7.5lb of it.

So to make say 750bhp ill need a 1000bhp turbo if everyone follows me?

because of this un-efficent process the forces are not used fully for movement and are passed onto heat, hence why rotarys run so hot and also produce really high EGTs in turn because of the high EGTs the energy is passed out of the engine and into spooling a turbo, hence you can run a very large turbo for its engine capacity.

I did look at the garratt range of turbos but since this is very limited in budget i decided to discount them.

This left with me with a few other brands, mostly american diesel turbos. Now a company a few people may have heard off called Borg Warner are becoming increasingly popular in the performance market

Ill type up the next bit on my turbo choice in a second