Jetting/tuning For Procharger setup
 

I am giving serious thought to buying an intercooled M-3 Procharger for my TCM/Merlin 509.
I don't want to have the added expense of a custom calibrated carb (like Nickerson's) unless it's absolutely necessary.
My motor came complete with a "Hardcore" (Heh! Heh!) 870cfm carb (by World/Bill Mitchell) and according to the dyno sheet, it has in #74' main jets all around. That sounds lean to me so I'm thinking Bill Mitchell must have done something to the Power Valve circuit. If this is so, I may be able to jet the carb up to get decent performance. Any ideas on this? Has anyone had any experience with a similar setup? I don't mind spending time fine-tuning the jetting but I would like to get a safe ballpark number for the main jets to start with.
Also, what about plugs and timing?
I'm thinking about 30 deg. total on the timing, but don't know about the plugs. My motor has the big valve (2.30" int.) iron Merlin VR heads and I believe 9:1 compression.
Any ideas would be greatly appreciated.

It's necessary!
Think about how much you have into your motor. For a few hundred dollars, it's worth it to have Dean do your carb.

DAVE

You will never get any other answer here. Apparently Dean is the only man in the world capable of tuning a carb for a procharger,,,hope we don't lose him. Procharger says go about 10-12 jets up and work down. I don't have a lot of faith in them but I'm gonna try it and do like you're talking about,keep the timing down and watch plugs,EGT etc. I got tired of hearing just let Dean do it. I can rebuild my motor for the cost of his carb. I guess when you have a monopoly you can make a nice income. Nothing against him, I have no doubt he's the best it's just that I'm here for tech help. I don't see advice to "just send your motor to X or your drives to Z" but nobody want's to touch a carb (or even guess as to what he does)???WOW . I'll let you know after I blow mine up,hee,hee

Pro-Charger
 

I have had experience with a Pro-Charger-mostly bad. With the carb set up it is very important that your fuel is boost referenced properly. For every pound of boost you have to have one pound of fuel pressure. I set mine at 8lbs with no boost. Pro-Charger did not really work until I changed pulley to get 7lbs of boost. At wide open throttle fuel pressure was 15lbs. 502 c.i. motor ran 103 in 25 Eliminator Daytona. Note: Pro-Charger blower belt must be very tight or it will slip.

How do you tell if it's slipping? I have 5# pullies and am considering going to 7 after I get the bugs out. Are you saying it was easier to tune when you went to 7#'s?
I am using a Holley 750 DP with 72 and 86 jets and plan to go up to 84 and 98 when the boost is running,does this sound about right? I have an Aeromotive boost ref. reg.(ref off the blower box) and thought 7# base was about max,,how much will the Holley take before starting to bleed thru,,guess I could figure that out by watching the sight plug huh? Any place other than Procharger to buy pullies?Anybody wanting to sell 2-7# pullies(12 rib) Thanks

Hardcore:

There is a lot of expertise on this board regarding blowthrough supercharging. Dave F is right. You can't simply jet the carb richer. You need to modify the power valve circuit to get some semblance of fuel metering in response to changes in air density. This is beyond the ability of most mechanics. You do need a carb specialist who has proven he knows how to do it. Nickerson and a very few others have done it. I recommend Nickerson because I have done two dyno tests and one in water test with his stuff and it works. When you are done you will have $6-7K in your supercharging setup; the cost of having your new carb modified may be 5% of the total, but it can mean the difference between a rocket and a bomb.

Your 509 is a great base for blowthrough supercharging. We have seen 800 HP. There is more to this story, but to save typing I refer you to our website.

www.rtechperformance.com

Tom

My Pro-Charger was set up at 84 and 98 on jets. Nickerson did the carb. Most Holley carbs will take up to 9lbs of fuel pressure at idle before bleeding fuel off. When I first got the carb back from Nickerson the motor ran fat. I dialed the carb jets to 82 and 96 and it was still fat. I changed pulley to run 7lbs of boost and everything came together. I was one of the first ones Nickerson did a Pro-Charger carb for. It was 4 years ago so the way he does them has probably changed. I had problems with the motor running irradical. One pass would be good and the next bad. Belt was slipping on the big end. Tightened it up like a rubber band and ran consistant after that. I didn't like the looks and squeeling sound the Pro-Charger made so I broomed the Pro-Charger and switched to a 8-71 Littlefield. Ran PFM Gorilla fuel injection system and intercooler. It was sweeeet until computer problems drove me crazy.

so it squeels when it slips,plain enough I guess. Does belt dressing give a better bite? Do you have a measurement for deflection or just make it real tight?Thanks

I tightened it big time. No measurement.

Thanks Steve,I need the help