Thanks for the info. I guess even when i put a bigger turbo on cars i never went a lot larger. Just enough to do what i wanted. I guess in a turbo specific motor things are adjusted to keep the turbo happy and being a 7-8k redline motor helps, where as the slant being na and older were never thought to be used for a turbo. Learn something every day. The 904 is happening (when i find one close). Again thanks for the info.
Look, I am no turbo expert; far from it... all I wrote is just my opinion, based on what I read.
This turbo slant six we are building is the first "turbocharged" engine I have ever worked on, so bear that in mind when you read my opinions.... I don't have a lot of experience with them.
When the factory (whichever factory it is,) turbos a car, that car must perform with excellent driveability for "madame plushbottom" and that sort of "tuning" requires a lot of engineering expertise most of us don't have... so, we do the best we can. Those factory turbo systems have the benefit of thousands of hours of research and development by bona-fide
engineers who actually know what they are doing. They,
if they err, err on the side of driveability, rather than high rpm performance, so their systems spool quickly, in cases where ours won't.
I think that is the difference; those turbos that come from the factory are borderline too small, which makes them spool readily, with less encouragement from the engine.
That makes for less turbo lag, which is important on a car that is going to be driven under all kinds of circumstances.
Our car, for example, will never see the street, so it (turbo lag) is virtually inconsequential.
Good luck with your project!!! Keep us posted!:cheers:
