1) Your impressions on valve springs/retainers for high boost set-ups? I usually (okay, always) defer to Larry's word in situations regarding Honda D and B series motors and supercharging.. but I have a couple alternate reliable sources contradicting his words... To get my head built
correctly this time around for running some boost, I know my stock valve springs don't retain their correct damping rates under boost.
Larry's word: "If an engine's to see boost that's under 12-13 psi, stock springs can work fine, however, they must be shimmed to achieve their optimal pressure. Any head that's had a valve job MUST have the springs shimmed to restore the stock spring height dimensions."
"The other guy" says that I will need some titanium springs and retainers to reliably run the boost levels Larry refers to above.
I Keep trying to find some info on this, but my usual sources are coming up a little dry. I guess I should see if the Hostboard crowd will throw me a bone...
2) I thought quite a while back about using an M90 over my M62 for my boosting "needs," as even though the larger dispalcement will bleed more torque off my engine, the larger unit also makes much more efficient power, naturally putting out more airflow with fewer rotations.. and I've ever read data suggesting that at the same rpms as an M62, the M90 will lose much less power to friction (just as the M62 loses much less power to friction than the M45).
Well, to make a long story short (too late...) a source informed me that a couple of companies (that you and I both know) are using a blower
even larger than an M90 on an H22A.. and it is making field-leading power levels. Is this just import market bullshit propaganda, or more mad scientist creations that seem too extreme to believe but actually hold true (like the first time I read about the Endyn SC - you may remember my reaction in that SHO post
)?