Quote Originally Posted by SPOOLIN View Post
just a note:

A/R doesnt always affect spool. I went from a 1.0 to a 1.10 T4 large frame housing and it spooled faster. And then i moved to the 1.25 a/r and it didn't slow down at all.
as the write up says:

You can control spool on most turbochargers through the turbine housing's size, or "A/R." A smaller A/R would focus the exhaust energy more onto the turbine blades, encouraging faster spool at the expense of becoming a restriction at higher RPM's and pressure ratios. The larger A/R delays spool and allows exhaust to flow with less restriction and thus improve VE at higher RPM's. Another option is a turbocharger with an Anti-Surge compressor housing like a GT30R. This housing actually extends the compressor surge line more to the left, allowing more stable pressure at lower airflow numbers and helping make the compressor's behavior more flexible on response-based applications.

I'd refrain from the typical "This happened to me so it must be true for everyone" type of stuff without providing the physics to back it up. In your particular case there could have been hundreds of variables which played a part it what you were observing or what you thought you were observing.