Why M90's are not a good idea.

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

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Originally Posted by Joe McCarthy

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

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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

I'm new to the rotrex world, as I'm a turbo guy. But I love that more info is coming out for these and more people are running them. In for info.

An m90 is not a Rotrex its a roots style blower similar to a Jackson racing

I've been watching the supercharger upgrade talks on crsx and the lysholm was on my list. My buddy just did his swap and it's awesome. But now I see them messing with the whipple supercharger and it's gotten crazy!!! but in my opinion if you got the m90x to lets say 450whp and grabbed traction you would walk a 500+ turbo RSX until they finally caught up. The instant power and torque would be amazing

I dont disagree, I think lynsholm's and whipples are way to go

Im more surprised these havent caught on

http://i259.photobucket.com/albums/h...AxMzcuanBn.jpg
http://i259.photobucket.com/albums/h...AxMzMuanBn.jpg

4 blade eaton's aka TVS superchargers.

instant boost of a roots but buries m62 and m90's as far as efficiency goes

Dam that looks fun Rich s/c are a blast I had a s/c gsr in an ek hatch that thing was so much fun .I cant imagine how much fun a k series hatch with one of these sittin on top of would be but I'd love to try it ! s/c sure do have the fun / holy shit factor goin for em

There's no way that's gonna be a functional twin-sc setup on an Si, just a comparo shot?

Quote:

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Originally Posted by Rbsjnh

An m90 is not a Rotrex its a roots style blower similar to a Jackson racing

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Whoops :shrug: Shows how much I know :biggrin:

Quote:

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Originally Posted by Si Speed 317

There's no way that's gonna be a functional twin-sc setup on an Si, just a comparo shot?

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no thats really going on there no doubt. I was set up alittle while ago to add that to my motor, but hate the design of the cte and jr manifolds/

so I am going custom

that is the only thing delaying using that blower on a k series

^yeah the JR manifold is a HORRIBLE design with restrictions everywhere.... even the inlet neck is a killer... let alone the rest of the ENTIRE kit