ok, our take on this is as follows:


Modified pumps:
There are two options:

• 1 - Standard pressure + Higher flow.
• 2 - Increased pressure + Higher flow.

The standard pressure uprated pump needs bigger injectors than your 550cc's to make over 400bhp. The higher pressure uprated pump (Ie: Mountune) will make the 400 and more with the 550cc injectors.


In essense, your 550cc's should do 380/390BHP safely but we would prefer to see bigger injectors in there for safety.


We use the Bosch injectors (some use Siemens) and we far prefer the higher pressure pumps that Mountune supply. But they are far from a cheap solution Jay.

All the above info is using our own calibrations. Why does that matter?
It matters because the fuel system is fixed pressure non return and the more boost you run, the less the fuel injectors can flow. Others tunes may vary due to boost pressure used to achive similar end results.

Example:
Our 420PS conversion only uses 22/23 psi.