Why M90's are not a good idea.

[Rbsjnh]

I have seen the rise in desire-ability of the m90x superchagers. Although they are able to make more boost for k series, I really feel that you will reach the limits of them far to soon for the money invested.

I found this post on another forum, and I think it agree's with my point

Here's a dyno chart from back in July '09 when I finally got around to putting my "K23" on the dyno. I machined 4 differently sized 8-rib pulleys, but only 3 of them are on this chart. 12 psi came from running the M90 at 58% overdrive, 14 psi at 69% overdrive, and 16.5 psi at 81% overdrive. This was done more for personal data gathering than anything else, so we didn't even rev the engine to its redline which is 9,200. Basically I wanted to see what shape the torque curve would be with the little IPS supercharger cams since they're small enough to give really sweet mileage at a cruise. Its my street car so that's important, and with the gearing I'm using I'm hoping to see somewhere close to 40 MPG at an 80 mph cruise. From other S/C dyno testing I've done bigger cams would flatten the torque curve out above 6,500

to run the sc at 16.5 psi @81% overdrive is the same as running the m62 in the 11-12 psi range. realistically the heat from the sc will be extreme, again requiring cooling such as meth or aftercoolers.

and realistically where will your whp be? takes alot of hp to run an m90 at 81% efficiency. so again will this sc really be worth the investment?

opinions