Well, did another set of datalogs in 3rd gear, tightened belt and tightened a little the Vortech BOV. Same 9.7-10psi depending if I reved 8.2k or 8.4krpms. No increase in boost basically. Now reading up a little more, apparently this is normal on AP2 like leo520 says. If I was able to rev 9k rpms boost would be 11.7-12.0 psi. I was really hoping to hit 415rwhp with this pulley, but now Im thinking it would be only around 15hp more from my last 372rwhp dyno. Will keep you updated..

 

Vortech SCi is the same blower as the Novi 1220SL (yeah, yeah, yeah call Vortech and speak to a knowledgeable tech guy if you don't believe me). I used to run a 1220SL with a 3.8" on my SOS kit and your numbers seem right. The crankshaft pulley that comes with the SOS kit is 5.45", but the Vortech I believe is 6" so that needs to be taken into account. With a ~3.0" pulley, a N1220 will only produce ~12psi/~400whp at sea level. You should something similar with the SCi. If you had an Si trim, then you would see more psi for sure.

 

U right it's same blower,but the plate design r diff from sos n vortech.
So they r different in for the pulleys.

 

There's no doubt the plates are different and have different offsets, but the compressor maps are the same. Hence, the overall performance is still inline with a N1220. The impeller speed is calculated the same way except 6" is used for Vortech for the crankshaft pulley rather than the 5.45" with the SOS.

 

U r right i get it wrong .

 

I'm not sure if v3 is different than the v2 when it comes to boost. The 4" in my ap1 made 12.5 psi. 3.8" I thought was supposed to make 12 psi in ap2.

 

I've had a similar "issue" that I've wondered about ever since I've had my SOS II. I'm making 379 rwhp on a dyno dynamics (hearbreaker) dyno on only 8.3 psi (reading from Hondata FlashPro). I am running the 4.0in pulley (one smaller than stock). I've had absolutely no problems in over 20,000 miles. In my opinion, the lower the boost, the better long term for your engine :-)

 

On my datalogs, above 7k rpms, there is a 2psi increase each 800 rpms. So an AP1 would make at least 2 psi more at 9krpms vs an AP2 at 8200rpms

 

Curious what map sensor are you running? If oem then it could be flat lining. Get a manual boost gauge or aftermarket map sensor to verify.

 

I have an SOS 4 bar Map sensor and a manual AEM boost gauge which reads 10.5 psi at max rpm (Datalog show around 10)