thank You for the info about theese turbochargers, it seems that they used traditionally designed turbo setup. This means that engine is comparably strong through wide range of rpm's. Big turbo idea leaves engine nearly stock up till the powerband and then 300rpm's step and You are in another world... I mean that You have 80HP's at 4000 and You have above 300 at 4500rpm's... /for example/
I like my idea far more -> Look it this way:
We understand HP's by torque multiplied by rpm's and something else. this means, that You double the power by doubling the torque /which generally affects piston pressure/ or doubling the engine speed /which is not safe because it would be too high reving for the inside parts.
But: look what will happen when we would put highest torque present in stock engine for example 2000 rpm's higher...
with stock setup and internals we would make much more power not affecting internals at all /I mean that we wouldn't put any more piston pressure but we would be able to get MUCH more HP's.../
Generally it is quite achievable when You put big turbo into this setup:
look what happens:
at stock peak torque turbine is not producing boost, so we have "stock" engine curves.
above stock peak torque our big turbo starts producing boost, what affects torque and risens it up. But in stock engine the torque was falling down, so we want to raise it just to the "stock engine peak torque" level...
And going up with rpm's, we keep the pressure regulator to give us "just" the amount of air needed to keep the torque at this level up to the red line...
Look at the torque/power graph for the M42 engine. I don't see it now, but generally the peak torque is 175Nm at 4300. At peak power we have just about 110Nm but at 6000 and this gives us 136 HP's. If we could raise the torque at this moment to the 175Nm level, the power output would raise about 1,59 times which gives us 216 Hp's... Still having completely stock pressure, torque or any inside strenghts. Of corse rpm's raise, engine wear is bigger, but the inside strenghts are nearly on the same level - not affecting internals more than while reving 4300 under full load.
Immagine 30% safe area. This means that stock engine can keep up to 130% of stock peak torque /175Nm*1,3=227,5Nm /, and this gives us 280Hp's at 6000rpm's
Heh we have just 30% more torque... It's not a black magic for a turbocharger ;-) But it has to be done near the red line...
Generally we've just build 280Hp's M42 with stock internals and it is still quite safe for them. Isn't it what You wanted to achieve oldboy? And the taste is that below the powerband You still have stock 1,8 ltr engine burning about 8-9 ltr per 100km !!!!!
BUT EVERYONE : I'm not the expert, this is my idea of building turboed M42 which will be done next winter ;-) I'm still collecting info and money for the project...
