Jspeed:
Thanks for the encouragement and the offer, but I think if this doesn't work out, I'm going to just bite the bullet and go to fuel injection. And then an R-Tech Supercooler!
BTW: for the people who have already gone the fuel injection route: What kind of systems are you using and what did it cost you to convert? (I guess I should really run another thread on this)

Hardcore:

Nordic Heat, jspeeddemon and Turbojack all run FAST. If you decide to go this way buy the Holley EFI package without their computer. A 1000 CFM throttle body is plenty. Your engine can only displace 800 CFM X a density ratio of 1.6 = 950 HP. Should be enough?

This is what that kit looks like with a supercooler.

Tom man that intercooler looks huge! THis year Im going to go with last years setup, Too much on the plate financially. Vehicle, wedding, and so on...

I did not listen to Tomcat & went with the 2000cfm trottle body. I started out with Nordic's program & I have been having to do major changes to it to get the response right when you crack the throttle. Cost was about $5,400+. Was it worth it? Yep! Remember I had two carbs side ways mounted. As JD has said the odd side was way rich while the even side was lean.

Hi guys. Thanks for the info on the fuel injection setup. I haven't been able to find a site with any good info on a "turn-key" multi point or throttle body system which can handle 800+ hp. Tom, you might want to look at doing something there. Imagine having someone with Tom's expertise selling real bolt-on kits w/ supercharger/intercooler and fuel injection as well! Imagine just telling the man your cubes, heads and cam and he does a baseline program for his kit and all you have to do is bolt on the kit and play with a few maps on your laptop and Wallah! Instant 300+ hp bolt-on power with fuel injection reliabilty to boot. (Excuse me while I drift off to my little monster-horsepower fantasy-land!)
BTW: I have a hell of a lot more confusing data to report as I did two days of testing this weekend, but time does not permit me to elaborate thereon at this time. I will report back later with the sad details...

Hardcore:

Check out this link for plug reading info. Good pictures. As posted by rmbuilder on another thread:

http://www.maxracesoftware.com/spark_plugs.htm

Thanks Tom. From what I'm seen on my plugs - heavy black soot everywhere, I've even seen the insulator with soot on it (except the time I had the #84 jets in by accident) - I'm definitely on the rich side.
And remember, I was LUGGING with the 84's in the carb! (although that might have been at least partly the drive letting go).
It seems to me that Procharger (much like NOS with their N2O systems) like to factor in a "safety" margin for jetting. I was checking out Procharger's website yesterday and they say that the BSFC number for their setups is like .65. That seems way rich. They say that a 500 HP boosted motor needs like 325lbs per hr. of fuel based on that number. obviously, they are more concerned with warranty claims than optimum power

BTW: They have on the site a feature on the World's fastest pump gas car - a 427cid twin CARB! setup that makes 28! lbs. of boost and 1495hp!!!! If that thing can make that kind of boost AND run an 8.18 ET @ 170MPH, I MUST be able to get my little old low-boost carb setup to push my boat to 110! Interestingly enough though, all the fastest carb setups seem to use the carb hat(bonnet?) instead of the box.

Anyways, I'm now thinking - according to Alex Warlordy, two .110 needle & seats only flows about 350lbs per hour at 6-7lbs of fuel pressure. So, according to Procharger's numbers, I will probably have to go bigger on the needle and seat to be safe (If I can get the damn things to seat at boost). What do you think?

Here's what happened this past weekend:
I borrowed a Bravo XR/Imco 2" Shortie from Cayformula thinking - this should get me past the 100MPH mark easily now, carb issues or not. WRONG- The damn motor ran like a major P.O.S.! The boat couldn't get past the 80MPH mark! Ran fairly decent up to about 4500RPM and fell flat on it's face. Prop change made no difference (from 30 to 34). Ditto for plugs and jetting. Went from 99 jets to 88's on the Secondaries and no difference! WTF?
So, I'm starting to think, yep, must have really f@cked the motor this time. Compression checked out OK, though. Could it be an ignition problem?
So, I disconnected the blower bumped the timing to 34 and changed back to # 78 jetting. Back in the water, motor runs like a SOB! 88MPH & turns 5600RPM without a hitch! Definitely something is seriously amiss now with the blower setup.
This is REALLY getting to me! I'm wondering if it may be a bad coil/ignition box and it can't fire the plugs under high combustion-chamber-pressure conditions? I'm going to try a different coil (Maybe today if work permits).
I'll let you know how it goes...

Hardcore:

You will get to the bottom of this. A BSFC of 0.6 - 0.7 is often recommended for supercharged engines, and we have seen these numbers on Nickerson's dyno on engines making great power. If you can do 88 mph with 500 HP, you are going to be well over 100 with 700+ HP.

Heavy black soot everywhere is way rich. The normally aspirated baseline was a good idea. But if you were running 78 jets and 80 PVCRs, man that's a lot of fuel. Unless Bill Mitchell has also opened up the air bleeds, I would be expecting to see black smoke? Maybe you should call them and tell them what you're doing. Are we missing something about the carb modifications they do that could explain things?

A stock 850 Holley comes with 80 jets all round and two power valves like yours, but much smaller PVCRs. I got the figure of 40 PVCRs from the Holley book I mentioned above. They put small PVCRs in these carbs because the main jets are so big, they only needed to add an addtional 25% fuel. Your PVCRs are adding 100% more fuel! Compared to a stock 850 you should have been way rich on your normally aspirated test. But the engine still ran great...did you happen to look at the plugs after that test?

I have to start somewhere so I took the stock Holley as the normally aspirated baseline, and did the calculation for a supercharged engine with 1.5 density ratio.

Stock 850 - total metering area = 0.02516 in2
X 1.5 D. R. - total metering area = 0.03774 in2
- 80 PVCRs - total metering area = 0.02012 in2
Requ'd jets - total metering area = 0.01762 in2

4 @ 75 jets - total metering area = 0.01767 in2!!!

I hate to say this but the jetting you used for the normally aspirated test looks like it is in the ballpark for the supercharged test! That's why you did no damage with the 84s. So why did the engine run so well normally aspirated? The only explanation I can think of is that your ignition system can still fire the way rich mixture normally aspirated, but can't cope under boost.

If you used 88 jets all round for the supercharged test, your total metering area was 0.04444 in2. That's 18% more than required by the calculation.

I am assuming that your tests both involved going right to WOT from a cruising RPM. At WOT throttle all fuel metering area is available. Normally aspirated you used a smaller pitch prop and the engine took the rich mixture. Supercharged you used a larger pitch prop and the engine took the even richer mixture decently, but stopped accelerating at 4500 RPM. I don't know how much boost you saw when you first jammed the throttles open but the larger pitch is an extra load. And if you're way too rich, you can't make the power to spin that large pitch any faster. How much boost were you seeing at 4500 RPM?

How did the engine respond when you backed out of the throttle during these lugging periods. Did it seem to get more power? If you back off and the engine springs to life there is too much fuel being dumped in all at once. If your main jets were the same 88 for both primary and secondary, then richness didn't change with throttle opening due to a richer secondary. But the power valve is an on/off switch, and your PVCRs carry a lot of fuel. This would be another clue that the engine was too rich.

I know my heart would be pounding, but if your plugs say "too rich" you need to go into your Holley jet box again.

Hey Tomcat. I agree with you on the jetting. I couldn't believe the PVCR's were so big the first time I saw them myself. The dyno sheet that came with the motor indicated that the motor was jetted with #74's but the carb actually had in #78's. I can tell you that the plugs have always looked rich before I put the blower on and I would have jetted it down if my jet kits had come before I got the blower.
(BTW:The Dyno sheet said the motor made 574 hp @ 5600 and 631 ft/lbs @ 4200, if memory serves)
I'm not sure about the air-bleeds, they don't look too big (.030" ish) but I'm not sure what they would be stock anyhow and from what I understand they really make the booster signal sensitive so if they are larger than a regular 850, then that could account for the big PVCR's, because the more emulsion, the lesser the signal and,consequently, the bigger the necessary total metering area, right?
I was thinking of buying a Proform 750 main body and billet base-plate (89.99 and $129.99 respectively from Summit) and put them together with my metering blocks/ float bowls and try that. But, if I'm already way rich with a 850 throttle body, I would have to jet down a whole lot for the 750 setup. BTW: Procharger actually recommends a 750 carb for up to 900HP. I might just plug the secondary P/V and just try staggering the jetting by 6-8 #'s to compensate. The 2nd P/V does allow for the carb to be jetted leaner for high speed (3/4 throttle) cruise but I don't mind being a bit rich there anyhow,as long as I can get the WOT metering optimum. Most regular mech. secondary Holleys don't have a 2nd P/V, from what I've seen. (Only the models that have 4-corner idle seem to have them).
Alternatively, I'm thinking of buying a 750cfm Mighty Demon which doesn't have a secondary power valve and start all over with the jetting.
Something I forgot to add was that the fuel pressure was fluctuating slightly (1-2psi) at W.O.T and spiked by about 2-3 psi above max when I chopped the throttle. I think this is at least partly due to the boost spike in the box when I closed the throttle though.
Also, The boat didn't run any faster at WOT than at say 3/4 throttle. In fact, once it was at like 4500RPM w/ like 2/3 throttle and I pushed the throttle WOT it felt like it wanted to slow down! The more I think about it, the more I think you're right Tom. The jetting is probably nearly right (for WOT) at 2/3 - 3/4 throttle before the 2nd P/V comes in and when it does it just floods the engine.
The reason I feel that it might be an ignition issue thrown into the mix is that I've already run 100MPH (albeit briefly) w/ a 34 B-1 on one occasion and 99MPH on another w/ a 29 Houston Accelerator prop, both times with #90 jets and 6.5inHG. P/V's. That was with the motor relatively cold, though. Once it warms up, it's a dog.

Yeah, if you were at 2/3 throttle, the secondaries probably weren't even open. Then bam...a cloudburst of fuel. It sounds like your fuel pressure regulator is tracking box boost pressure well. It doesn't sound like the problem to me.

I think the reason that many double pumpers don't have secondary power valves is there's no point. Once the secondaries open, vacuum is low enough that the power valve is always open. You could play with this to have another "stage" for steady state cruising at a higher RPM, but for sudden transitions to WOT it isn't necessary. If you can get the WOT right, and know the total metering area that worked, then you can play around distributing that fuel between primary and secondary, jets and PVCRs.

We have experienced this lugging with Nickerson (750) carbs, but just in the last little bit of throttle. He does not use the secondary power valve. I don't know what size primary PVCR but with 78 jets in the primaries and 94 jets in the secondaries we got this "lugging" sometimes. I never thought of it but it could be that it was worse when the engine was warmed up. Anyway, when we called Dean guess what he told us to do? "Take out some secondary jetting, like to 92 or 90". There we were looking at these bone white insulators, shaking our heads!

These jet sizes don't transfer to the 850 as you know, but I think if you plugged the secondary power valve and played with the jets you would make progress. The fact that you got to 100 with such a rich mixture just because the engine was cold is amazing and promising.

Because the secondary PVCR is so big, the 6-8 jet sizes rule of thumb doesn't work, but you don't want to replace all the lost fuel with bigger secondaries anyway, so 6-8 sizes is probably good enough. I worked this out just for the hell of it.

Primary 88s ----- 0.01216 in2
Prim PVCRs 80 -- 0.01005 in2
Secondary 96 -- 0.01448 in2
Grand total ---- 0.03669 in2

This grand total is close to what I calculated above for a 1.5 density ratio, and remember that the venturis do compensate for density somewhat anyway. I think your on the right track.