Martelius exhausts for sale

[oldskull]

@Gtsi-R: You mean WHP right? PK is in dutch?

[Speedline]

Separate topic? (moderator?)

If you start with lets say the basic engine of around 120hp. 600mBar of boost pressure in theory gives a 60% increase in power. (Density, temperature of supercharged intake air should be equal.)

With a good engine design this power increase should be attainable. Even a little bit more than the 60%. Reason is that the boostpressure in the intake actually reduces engine pumping losses by pushing on the piston on the intake stroke.

The only way to go for high power supercharged engines is to tune the engine to a high mean cilinder pressure (high power and torque) and then supercharge the sucker. Just to be clear, you need lower compression to keep peak cylinder pressure down to a managable level. The torque comes from a shitload of extra mixture giving more pressure over a large amount of degrees of crankshaft motion. Even optimised with better conrod length to stroke ratio. (Longer conrods.)

Many people think that you have to change cam phasing and reduce valve timing overlap for supercharging. Because this is what the oem's do? You don''t have to. Oem's tune for mid range grunt, not power. But power and speed is what you want.

For example. Take engine for example 2-litre 240hp with strong engine block design. If you change engine design with good piston/ head combo and supercharge the engine you should get over 480hp in a trick design at 1 Bar of boost. You want high mean pressure at high revs, high cilinder pressure produces torque. And power is calculated from torque multiplied by 2 multiplied with revs in Hertz and pi. P=T*2*pi*n.

If you use lets say 2,5Bar of boost, something like 840+hp should be attainable. And some guys in rally cross and pike's peak/ hill climb events utilise these high power level four or six banger engines. Tune high normally aspirated and then add boost, a lot of boost...

If you retune your supercharged engine to 120hp normally aspirated and then boost the sucker to 1Bar. You should get at least 240hp if optimally designed.

So in that case I consider 140hp at the wheels (drive train loss is really small, not that percentage crap everyone uses) is a low figure. There are technical reasons why a manufacturer gets such a low output. 1. most consumer cant drive for shit and are impressed by everything over 200Nm. And you have all the practical stuff like bad fuel in parts of the world.

And in the real world you're held back by design features like small port cylinder heads, bad head design, emission optimized injector positioning and last but not least budget. Not to forget available transmission ratios and number of gears.

But to answer your question about which header and exhaust package your would benefit from. Probably the R1 + 2,5 competition exhaust. You will not suffer from any Helmholtz pulse issues due to the supercharger in the intake tract.