I agree with Tim..
Engine building 101..

 

I can't see what Tim writes cause he is blocked.

 

+1..

 

I would unblock Tim. He isn't afraid of speaking his mind but he's a wealth of
solid info and a damn decent guy when you get to know him a lil better.

I got a fully built 3.8 litr, alpha 3073s with a slap bang up aftermarket engine
management and e85 and I run 2 bar on occasion. At 2 bar this thing runs like
a bat out of hell.

It is, as it's been mentioned, all relative to the particular application. If your
mechanical stuff and fuel are commensurate, have at it! If they're not......
you'll know pretty quick.

 

Man this is worse than waiting for the next episode of Dexter.

Are they close to finishing your car?

 

think of boost as a measure of restriction rather then a measure of horsepower. an example : (theoretical numbers)

say to make 700hp it takes 1200cfm of air moving into the cylinder with the proper fuel.

okay now to achieve that 1200cfm turbo A needs 2.0 bar to do that but it spools very quickly.

turbo B is much larger and can produce 1200cfm at .7bar of boost but takes longer to spool.

boost is not important unless your familar with the rest of the car.

boost doesn't have any effect that is worth noting on valve springs or lifters.

high rpm, oil starvation, big cams, all these things will affect your valvetrain.

a lot of boost and timing will increase the cylinder pressures to the point at which will push the head right off the block, which then the boost has to go somewhere either in between the cylinders and straight outside. or as said earlier pressure goes into the coolant passages and cause havoc in there over time.

but the worst part of all of this is every time the head lifts that fire and combination of antifreeze pushes out at high pressure velocity and heat it eats away at the surfaces. Like water carving through the land.

i bought a mkIII supra once that the rear cylinder gasket has disentigrated so bad we had to deck the block .050 and the head .035 and run a thicker head gasket to get back to OEM compression ratios.

so assuming were talking about this car, normal turbos for this application say tial 30's and 2.0 bar of boost. tuning is definately gonna come into play on what you can run everyday on the fuel you choose, not to mention the havoc your drivetrain will take up against that horsepower. the weakest link will fail not if its when.