I will verify the set up with an O2 in the boat under the real world load.. Its not a real bad suggestion Brad makes.

I've known him for a couple years and its actually the first time he made some sense to me. :)

Kirk, I spent some time comparing your dyno numbers to mine, although Crockett hasn't taken the time to get his fuel metering set-up working to get BSFC numbers,he does have wide band 02 sensors that read correctly. Your AFR'S are actually slightly leaner then mine,mine are closer to 11.5 under boost which makes my tune even richer then yours. I have no problem pulling past the tq peak,I highly doubt your AFR'S need to be leaner,your bsfc is a measure of how much fuel it takes to make 1 hp (overall effieciency),the numbers seem high BUT I wouldn't want to see you try to put your afr's into the 13's under high boost just to get lower bsfc's.
Dean Gellner-I have never heard of tuning a motor from the bsfc's,if a O2 sensor reads 12-1 at a given amount of boost,load and rpm and the bsfc ends up at .650 lbs per hr and you were to re-tune it to achieve let say .550 (a 18 % difference) wouldn't the afr theoretically change 18% also to 14.18-1? I agree the bsfc's seem high but they are what they are. Now maybe in your personal experience if you feel the afr's could be a little leaner,you would re-map the fuel injection map slightly until you achieved the afr reading you were looking for,lets say you went from 12-1 to 12.5-1 (4% leaner) the bsfc's would theoretically drop 4% also (.650 would now be .623),not a whole lot numerically. Just playing with the numbers.
I have been present when Crockett dynoed and tuned the last 3 motors I built and he swears a blower motor needs to be around 11.5 give or take a few tenths under hard,long sustained boost to stay together,whats your opinion on afr's under these conditions,Smitty

After getting some sleep and thinking about my conversation with kirk yesterday and after having a in-depth conversation with bob madera this morning I stand corrected on my last post. BSFC's are a measure of a engines effieciency at a certain rpm and load,PERIOD. In my last post I presented a scenario of "adjusting" the bsfc and having a resulting afr change reflected by the percentage of bsfc change,generally this can only be done on a 2 stroke engine. A 4 stroke engine has a bsfc or a certain amt of fuel its going to take to make each hp at a given load and rpm based on how effiecient the motor is. You CAN"T change the effiecieny without changing something mechanical (better scavening exhaust,less parasitic loss,better or more ideal camshaft events-ie lift/duration/timing of events,different or better flowing cyl heads). In kirks instance-you could change his air fuel ratio but why,its not pig rich by any means at 12-1 under boost. Something that isn't mentioned is his motor was dynoed with full accessorys and CMI elbow tops,they say you can't make 1000 hp with CMI elbow tops but he did. However it doesn't mean that they were ideal by any means,with his cubic inches and quad rotor whipple it is a fact that the exhaust will be backing up or be slightly in-effiecient which would give a higher bsfc number. Blower motors have inherently higher bsfc numbers due to the amt of power it takes to turn the blower (pumping losses,parasitic losses),there is also a certain amount of "blow-thru of fuel on a blower motor",fuel that does nothing other than simply pass thru the motor purging spent charge thru the combustion chamber un-swept area , kirks is no different especially at the power levels he is at,Smitty

I think you might be making a skewed comparison here without enough input calibration. BSFC's are very diificult to calculate on most dyno's , especially if the fuel flow rate sensors and such have not been exactly calibrated before the runs. When measuring fuel flow in Lbs. to calculate exact BSFC's the slight variations in fuel flow can skew the BSFC calculations quite a bit. That being said, I don't think if your wide band O2 sensors are calibrated and giving accurate readings that can be relied on that you would ever want to run a 1000Hp huffer at anything beyond 12.0 to 1 for sustained persiods in a boat. What were the EGT numbers at these readings and were they rising under a sustained pull with a slow rpm per second rate?, or did they level off at a sustainable number? Our dyno work tends to show that there obviously is a point where a fat motor will give up some power and rate of rise in power under loads, but its a pretty small percentage and the totally overfueling beyond whats needed for the blower life will definitly effect ring life and oil life.
I suspect the loss in boat performance here as it does in many boat powers is a hull, drive or prop issue.

Best Regards,
Ray @ Raylar

As I stated above I feel that the issue here is with the boat, not the motor. I looked in one of my books and here is what it says about BSFC.

"Fuel consumption over time can be used to measure efficiency as well. Fuel consumption is represented as a flow rate in pounds per hour, (i.e., mass flow per unit time). Brake Specific Fuel Consumption (BSFC)--fuel flow rate per unit power output--is the industry standard and measures how efficiently an engines uses the fuel to generate work. (HP) BSFC is another measure of how well an engine converts chemical energy into mechanical energy. It is computed as follows: BSFC=fuel flow in pounds per hour/ divided by/ brake horsepower. The BSFC will vary with rpm. A BSFC of
.50 or lower at peak torque is acceptable and considered normal. The lower the number, the more efficient the engine. A number of variables, such as frictional losses, parasitic drag, and pumping losses, will reduce overall efficiency."

After reading this article, my take is that his motor is just not that efficient, as we all know boat motors are not. He has verified that it is making the correct amount of horsepower that he paid for. I agree with Ray, the problem is probably not with the motor, but with the set-up on the boat.

Smitty

So Smitty and Ray are fixing my boat for me? Thanks guys!! When do we start?

Kirk

If I knew how to fix a hull problem I would gladly lend a hand. I am somewhat in the same position as you are. I have a ton of power but I am not as fast as I should be, and I know that someone out there is knowledgeable about setups on baja's. I just don't have the cash or time right now to dig into it.

I am sorry you are having so much of an issue. Don't for one second think that I am gloating about your issue. I would be just as frustrated as you are. I am just offering up my knowledge and think the hull is the issue here. Why don't you take it to Pantera and find out ???

Smitty

I'll stick to fix'in motors. I know just enough about hulls and drives to be dangerous!! I'll leave this type of fix'in to the real experts!

Best Regards,
Ray @ Raylar

I was just kidding Smitty!! :D

Kirk,
I know you were kidding. I just hate it when we work so hard and sometimes the $hit still doesn't work as planned !!