Theoretical idea regarding compression ratios and boost

[Guest]

You don't need a 2.5l. 2l go very nice when built right. Best thing you could do is talk to the right people. You don't necessarily need huge cams either. I'll be running 260 intake with avcs and 9.8mm lift and 270 exhaust with 10.8mm lift. The whole idea that I've learnt is to scavenge all your exhaust gasses as fast as possible. That's how you get the best response. And once you have done that, any turbo you get you will make good power

[boon]

My 2c, having played with some of this myself...

"Lag" and fast response are not the be-all and end-all, maybe if you're doing autocross or something, on a fast road car a big ****-off turbo is way more fun and delivers the power in a much more exciting way. Let's be honest, in a road car you're either puttering around like a nana, in which case a huge turbine housing makes the off-boost response a whole lot better because the engine isn't exhaling through a straw (or a P18 turbine housing), or you're giving it arseholes in which case the fact that you don't really get much boost until 4000rpm doesn't matter because you're up in the 5-7k area anyway, and your big honking turbo is on boost regardless.

Originally I built my car to be super responsive/spooly, this meant I had meaningful boost before 3000rpm, but it also meant that it fell on it's face as soon as the real fun began.

IMO turbos put a smile on your face through the old-school savage power delivery when they come on boost, not through their ability to make your 1.3L eco-sewing-machine behave like it's actually a 2.8L V6.