A while back I was talking to you about the kit for the Ford V-10 and I thought you said something about a boost bypass that if the engine saw knocking or lower octain fuel it would actively retard the boost somehow. I am invisioning a gate of some sorts.

Question is has this been done for Marine? Could I just flick a switch or dial If I had to fill up with 87? or If the knock sensors kept going off ect... Seems to me to be a valuable option especially in a marine application to be able to dial the boost down via remote

Any ideas?

Ray,

Yes, it can be done, but it depends on the ECU controlling it and the programming. It can be very difficult and expensive.

Thanks,
Dustin

Dustin,

Dont you think this should or would be a viable option to the kits like the Popular 454 and 502 mag versions? I have 25K in each of my engines and If this option was available I seriously concider it as apposed to the unthinkable. Maybe I am paranoid but a little insurance goes a long way.

I have a Boat on an inland lake I would like to whipple but with only 89 octain fuel on the lake I dont want to be dependant on trailering it out for some 93 everytime. On a planned "hot weekend" I could trailer it out in advance for some fun running.

Maybe if "dialing it" up and down would be expensive how about a High and Low?

Using twin turbos and driver adjustable boost is the only way to go. ECU controls boost and dial to over ride is mounted right at my finger tips. Very nice option.

The problem is more complicated than just dialing up or down boost. There has to be fuel and ignition control. If normally you have 7 lbs boost and certain fuel and ignition programming and then adjust the boost to 3 lbs then the fuel will be rich and the ignition off. Rising rate fuel pressure regulators can offset this some and help. It would be relatively easy to make a second smaller bypass circuit which is selanoid controlled to bleed off some boost. The fuel curve would be rich and tougher to adjust.
Maybe a computer tile the one from FAST where you set the desired A/F ratio and the computer sets the pulse width would work.

This is exactly what the new Merc 1050 claims to do. It looks to have a whipple quad rotor on it and claims to maintain 1000hp at the prop, regardless of normal operating conditions (heat, altitude, etc).

You can also adjust for poor fuel with the timing.
MSD has units that will retard timing with boost
I think you can ajust 1, 2, or 3 degrees per pound
of boost it has a dial that you change as required

Ray,

It's a great option, but many complications, first, in the cars, were monitoring the 02 sensor so that's not real possible in the marine with any consistency at this point, then we monitor the knock system, which is far more sophistacated than the standard knock system MSD sales or is installed on the 93-2001 Merc motors. Another problem is that MEFI 1,2,3,4 do not have the capability of controlling a wastegate or bypass valve. You would need our ECU to properly do it, which we would have to program.

I don't see the fuel system as a problem, we don't open this system too atmosphere, it goes through the bypass in a circle back into the inlet of the SC. This works fine on the auto systems, both MAF and speed density systems. If the motor drops from 150Kpa to 110 Kpa because the valve opens, the system will compensate as long as the programming has been done. So it should not be richer than what's programmed. I can only see a problem if you have the Map sensor in the wrong location such as upstream, but if the Map sensor is in the manifold, and you take away manifold pressure by a bleed valve, recirculate via the bypass, or dump it via a wastegate, the Map will see a different reading. Now the motor AE will be slightly different, so the A/F should be 2-4% richer, but in a marine motor, this is very little.

The biggest problem is this, especially with the older, slower knock detecting systems, the computer is reacting to an action, an action or event of detonation, therefore the motor detonated in at least one cylinder, possibly more before the ECU reacts if it even does. So it's a reaction to the detrimental event, this is never safe, although it has the possibility of working because the motors can take some types of detonation, but continued use would lead to problems down the road in most cases. If I had a knock system that I could truly rely on, then I would feel much better about it. We've worked on some other things, such as a rotary valve which you could control the bypass valve, but this has not been tested enough to send to customers.

The computer from Fast is good, but I don't think it's fast enough to react to tuning the air fuel ratio, especially since they use a 5 wire sensor such as Motec and a few others, this is .5-1.5 of an air fuel ratio off from the actual air fuel ratio which can make it hard to count on.

To my knowledge, the 1050 Merc utilizes active boost control to maintain power, therefore the SC's are producing more air at sea level but is not being utilizied, SC's are mechanical and pump X amount of CFM at each rpm, so at higher levels of elevation or atmospheric pressure, the ECU can let more air into the engine, but if detonation comes about, the 1050 has a very sophisticated knock system and it will lower timing and or boost to be reliable. It can lower timing per cylinder with each firing, therefore power is maximized yet reliable. It's an awesome piece, there's nothing like it in the marine enviornment at this point. It uses the new Mercury 555 ECU which we have the exclusive rights to calibrate and I'll tell you first hand, it's awesome and robust. This is what were using on our new 496 kits and performance cals.

Thanks,
Dustin

Dustin,

When will the 496 kits be availabe to purchase. I have the 496 HO and am very interested in this sc. Sounds like you are going to have another great product(can't wait).

Mike

SDelim25,

Very soon, were just finalizing the computer calibration right now in a coupld of boats to make sure we release a reliable product. There will be many fail safes and will still make plenty of power! It looks similar to the new 500HP EFI setup but it's black and not as pretty since there's the coolant tank, reservior, etc. but it will do

Thanks,
Dustin