tomcat

Dave F:

Can't wait to see that! Any thoughts about the intercooler?

Turbojack

I did not know they made a M5SC, if I had I would have bought it. Dave both Jspeed & I are/were running 12lbs in box 10 in intake, Not sure what he has now in intake. If I am not mistaken he was complaining about the air/fuel ratio from off idle to wide open (black transom).

Dave F

Tomcat,

Pro Charger has a new 648 cooler. I haven't forgot about you. When I get it together I'll give ya the measurements.

The M5 and 648 is new. I just got mine Thurs. I'll be maxing that out as well.

DAVE

Turbojack

This is my luck, I buy the best & then they come out with the BETTER. Is the setup like the M4 & dual carb box?

Dave F

Turbo,

I feel the same way. I have a stage 4 and 504 as well. When I bought it, I expected it to feed what ever motor I built. After doing the math I figured out it would only give me about 8lbs in this motor. After they did the math, they agreed with me, so, they set me up with this one.

PC's gets some bad press but they have a new guy now running the marine division. He worked with me to get this project of the ground. Things seem to be looking up for Pro Charger tech. According to the story, this guy was brought in to try to fix some of the problems that are frequently discussed on this board concerning PC tech.

This system is like the M4. It has an 8" impeller that is more aggressive than my M4's 7" impeller. It has a 12" housing like my M4 but my new M5 is the SC model. Therefore, the main bracket and crank spacers are different.
As far as the box goes, yes, you would want to use the dual carbs if you wanted to use this blowers potential. Dont use the 450's though. They don't have center hung floats and the internals are just not the way to go for this set up. They require extensive modification for proper set up. The Holley 650's are the better way for the above reasons. Thats the smallest carb Holley makes that have the "good stuff" in them.

The M4 is fine for a motor up to a 540. What size motor are you going to use it on?

Once I get this thing going I'll put my M4 up for sale. It only has one season on it.

DAVE

Turbojack

Dave- Did you have a compressor map to figure out what the blower will do. Before I did my setup when I talked to Tech they told me they had tried the 650's & could not get the same results as the 450's. Glad to hear they finally are trying to do something about their tech department. I have talked & emailed them many times & told them they needed to straight up but never saw any signs they cared.

Dave F

TJ,

No. I did not have a map. As a matter of fact after speaking with their tech and such they claim that each motor creates it's own unique map. In general I agree with that. Depending on how well the motor can move the air which translates to back pressure, it will create it's own map. But if they set up a motor as a model and give specifics on that motor, ie; cam profile, exhaust, carb flow, jet sizes, static compression, compressor speed and cubic inches etc, you can make an educated guess of what you would need for your system. That, in my opinion, is the problem. They never give specifics. Cam profile/cubic inches being one of the most important.
How I figured it out was simple deduction to be honest. I figured out how much air I was moving in my 502 considering cam profile, approx. head efficiency, exhaust, cubes and compressor rpm to what results I was seeing in my 502. Compared that to what I expect I'll need in the new motor and made an educated guess that happened to be correct.

This is where the big story/problem comes in. So, I'll try to make it as short as possible.

When I bought the M4 for the 2001 season, (Dec 2000, sold my boat June of 2002 = one season of use) the literature I read, INCLUDING WHAT IS SAYS IN THE OWNERS MANUUAL, says I can spin this thing 60,0000 rpm. So, up till about 2 months ago, I'm thinking I have plenty of room to go. I was spinning 39,000 on the 502.
I come to find out through different sources, guys were wiping these things out at 46-48,000. One guy in particular, twice! I look it up on PC's web site, the new red line is 42,000 another piece of literature said 48,000. So, needless to say I was confused. At 42k this meant I only had 3k left. I wasn't gonna be able to feed an additional 100 cubes with only 3k left on the blower.

I call PC, they admit they had bearing/transmission failure on the oil fed marine kits because of the extended high rpm.
Long story short, after long discussions, I end up with the SC and larger/more aggressive impeller. They swear to me I can spin this thing 46,000 rpm 24/7 and it wont fail. They even swore to me if it does they'll fix it. Hopefully it wont come to that. (PS. The new owners manual says 43k red line.)

As far as the 450's go. They (to my knowledge) haven't tested on any motor larger than a 540. Again, all those things I've listed above make a difference. In my opionion, you're better off going with a single 800 and have it modified then to go with the twin 450s. Again depending on how much you plan to do and according to your set up.

In my case, 600 cubes, a cam with 32* overlap and 2.25" exhaust, I think I can use the 650s.
DAVE

Turbojack

jspeeddemon- How is the FAST system working out. Since I changed heads this year I am having hell of time with jetting. Too rich @ some RPM, too lean at others.


Dave F- How is your project going?