Science Abuse Posted March 2, 2007 Author Report Share Posted March 2, 2007 On a stock case you'll will make good gains down to around a 3.10" pulley, after which you enter into diminishing returns unless you have the case S-ported to reduce heat generation. The M90 turns into a heat pump under 3.10" unless said porting is performed. Hmm, instructions? Just to make sure I'm measuring right, what is the diameter you guys are quoting for "X.xx pulley"? This is important. I'm wondering if it isn't already at its peak. How much power to GTPeople generally get out of M90s? Quote Link to comment Share on other sites More sharing options...
excell Posted March 2, 2007 Report Share Posted March 2, 2007 You need a CNC to do the S-porting. Don't cheap out on it. I have a source you can send the blower to who does great work and very reasonably priced. x.xx" pulley = x.xx" in diameter measured at the rubs. Dummy. It heavily depends on the engine setup. But the BEST has been around the 450WHP area, which is full cam and heads, etc. and a 2.50”. You simply cannot compare the 3800 engine to yours, it’s completely different and they make power completely different. Quote Link to comment Share on other sites More sharing options...
excell Posted March 2, 2007 Report Share Posted March 2, 2007 P.S. When I say don't port it yourself, I mean it. You can seriously fuck up the performance of the supercharger to the point where you lose massive power if you don't have the proper equipment. Quote Link to comment Share on other sites More sharing options...
Science Abuse Posted March 2, 2007 Author Report Share Posted March 2, 2007 x.xx" pulley = x.xx" in diameter measured at the rubs. Dummy. Ouch, good thing I've been measuring from there. Seems I've got more maths to do, like measuring my crank pulley. I was hoping for a raw CFM rate, any idea where I can get a CFM@RPM map for these? What it will probably come down to is guessing by percent diameter decreased. If what you say is true, then I already have the smallest pulley I'm going to find....unless there's OD pulleys for the M62 and they fit. Quote Link to comment Share on other sites More sharing options...
excell Posted March 2, 2007 Report Share Posted March 2, 2007 Ouch, good thing I've been measuring from there. Seems I've got more maths to do, like measuring my crank pulley. I was hoping for a raw CFM rate, any idea where I can get a CFM@RPM map for these? What it will probably come down to is guessing by percent diameter decreased. If what you say is true, then I already have the smallest pulley I'm going to find....unless there's OD pulleys for the M62 and they fit. The 3800 crank pulley is 6.9". The map in that link I posted is the closest I have. I know I've got a CFM@RPM graph somewhere, but I'll have to find it. What size pulley is on it now? Quote Link to comment Share on other sites More sharing options...
Science Abuse Posted March 2, 2007 Author Report Share Posted March 2, 2007 The OE pulley measures between 2.5 adn 2.75 across the ribs, probably closer to 2.75. Its difficult to get my calipers where they need to be. Quote Link to comment Share on other sites More sharing options...
excell Posted March 2, 2007 Report Share Posted March 2, 2007 I'd be interested to see the size of your crank pulley. Another note to consider, the smaller pulley you run on the supercharger, the less belt surface it has. I can tell you with certainty you'll run into belt tractions issues if you go much smaller on the supercharger. I would start looking at the possibility of increasing the size of your crank pulley. Quote Link to comment Share on other sites More sharing options...
Science Abuse Posted March 2, 2007 Author Report Share Posted March 2, 2007 Another note to consider, the smaller pulley you run on the supercharger, the less belt surface it has. I can tell you with certainty you'll run into belt tractions issues if you go much smaller on the supercharger. Indeed. Luckily, the reason measuring was so hard for me, the belt covers about 200deg of pulley surface. I can't run out to measure it right now, plus it's damned tight down there. The best I've got right now is this picture. http://i11.ebayimg.com/04/i/07/38/bd/68_1.JPG Quote Link to comment Share on other sites More sharing options...
Buck531 Posted March 2, 2007 Report Share Posted March 2, 2007 Eric.. Your inners of your M90 should be comparable to mine. Stocker is on the left, ported is on the right. This was done by my friend in Minnesota. http://bucky.kicks-ass.net/car/blower/compare.jpg Comparison of the inlet http://bucky.kicks-ass.net/car/blower/inletcompare.jpg Some other pics. http://bucky.kicks-ass.net/car/blower/ Quote Link to comment Share on other sites More sharing options...
excell Posted March 2, 2007 Report Share Posted March 2, 2007 Love you Buck, but Eric, I cannot recommend the work that Buck had done. There are too many of these home porting self-proclaimed "professionals" fucking up people’s car parts for half the price of the real shops. This work is best done by a professional who has experience and proper tooling. Quote Link to comment Share on other sites More sharing options...
Science Abuse Posted March 2, 2007 Author Report Share Posted March 2, 2007 Wouldn't have been Steigmeier, would it? Quote Link to comment Share on other sites More sharing options...
Buck531 Posted March 2, 2007 Report Share Posted March 2, 2007 Love you Buck, but Eric, I cannot recommend the work that Buck had done. There are too many of these home porting self-proclaimed "professionals" fucking up people’s car parts for half the price of the real shops. This work is best done by a professional who has experience and proper tooling. To each to his own. At least mine doesn't look like an Intense Gen V blower. . Mine looks almost exactly like ZZP's and/or W-body stores outlets. Yes, there are some people who can fuck stuff up. I dropped a solid .3 tenths with mine along with a N* Tb. Kinda hard to beat that for the price I paid to have it done. Mine wasn't done with a dremel either. Quote Link to comment Share on other sites More sharing options...
excell Posted March 2, 2007 Report Share Posted March 2, 2007 No blower, not even a Gen V, will net you 30HP by itself. His blowers certainly aren't the worst, but it's a far stretch to say it looks "exactly like" ZZP's porting. I can see quite clearly the quality of the work in the pictures you posted. Imagine what I'd see in person. Quote Link to comment Share on other sites More sharing options...
Buck531 Posted March 3, 2007 Report Share Posted March 3, 2007 Do you know who did it? . I didn't say I gained 30 HP by just the blower... there's just no way. I also added the N*.. I also dropped .1 in the pulley. Probably those 3 combined helped gain it all. I got the blower done last year so I can prepare for a possible i/c this year. We'll see though. Depends on a lot of things. ya.. I can imagine what you've seen in person . Quote Link to comment Share on other sites More sharing options...
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