You can upload your changes on the fly and watch how the engine responds.

how do you do that with mefi burn?

On the dyno you could stab the gas off idle and it lit right up. After I get the blown tune where I want it I'm going to switch back to my N/A set-up for a couple of rides and go thru and fine tune that,Smitty

Most dynos will not load a engine with alot of power off idle like that. We have control over the water in and out of our break, from years of on water testing we know what kind of load is needed and our break can reproduce it. You could have tuned with your 2bar map on your n/a set up, call me and I will tell you how we do it. to much typing for me and if spell a word wrong or have bad gramer some keyboard comando will jump me. Remember I am from Louisiana lucky I can type at all. You did a great job with your set up keep at it you will be happy when your done.

Mark

Keep the Tunerpro and MEFIburn screens up at the same time. As you make changes in the bin in Tunerpro and save them, you can do uploads to the controller of that saved bin with MEFIburn. It takes about 10 to 15 seconds to do the upload with a MEFI 4.

can you do that with the eng running?

Yes!

I'm digging this mefiburn program,I'm going to go out fri again and run my next smaller blower pulley and a 32 pitch prop. If the part throttle cruising afr's change much from where they are at I'm going to save a copy of the tune I have with my 4.0 pulley and the 30" prop and make the neccesary changes and create a second tune file that I can switch to with the laptop when I want to run that set-up. You could never do this with a set program without the ability to program your own tunes and upload/download them so I think thats cool. I'm going to work on the off idle too, thanks everyone,Smitty

We haven't uploaded any changes on the fly yet ,so far we been cruising anywhere from idle to 5200 while watching the 02 meter and what map setting we were at then writing it down in 200 rpm increments then stopping and tweaking the bpw accordingly. We did data log some of the faster runs then played them back. Its definately a challenge to drive and watch the 02 meter at higher speeds,my son watches the computer screen and writes down the map setting and calls off each rpm band,it would be near impossible to do by yourself. My boat is a real handful once you go above 5200 and go over 70 mph,near impossible to drive and even watch the afr meter, we made a few short burst full throttle runs and luckily the afr's are close to mid 11's in higher boost settings so tyler did a pretty good job on the dyno and I'm not trying to retune them much. I ran this a year before even putting the 02 meter on it and its never melted down at wot. When this motor made less hp 3 years ago (945 on the dyno) Tyler tuned it on the water and the afr's under boost were farther off so we had to make wot runs one after anotherafter another. That day of testing was grueling,ran 90 gallons of gas thru it,finished off a set of lower unit gears and stood the boat up on end a couple times over ship wakes at 90 mph while getting afr readings in the upper rpm bands. Motor makes another 100-150 more hp now and runs 8-10 mph faster so I'm glad the wot tune is fairly close. Like I said before,I can't see someone trying to program a boat from scratch that runs extreme power and speeds without getting it part way there on the dyno,thanks for your input,Smitty

This is very interesting and while I have learned a few things reading this it is still way over my head.

Interesting that there are programs out there like these but I for one simply to not have the time, enough knowledge or the desire to risk my motors while experimenting.

I for one think that putting the motors on a dyno with a proven builder like Mark or Tyler that have years of real world experience is the smart way to go. Then you simply go boating and enjoy!

You would be surprised how different an engine can run from being on a dyno to the final installation in the boat. I've seen some that came off the dyno and the tune is near perfect in the boat. Others you look at the tune in the boat and you wonder if it is the same engine you ran on the dyno just days before. Exhaust, fueling, cooling, accessories, and environment all play into it.

Ultimately what really matters is how it is tuned and runs in the final installation. In my opinion you are experimenting more by taking a engine straight from the dyno and running it and not tuning it in the boat or car. The real world conditions can sometimes be a very harsh critic.

Bob

That really depends on who is dyno'ing and how it's been dyno'd. I know Mark and I can get it basically 99% done on the dyno, we know what makes the motors rich/lean, what type of load and acceleration/decelerations to use that simulates the boat. In the boat, you can actually only get about 75% of the cal done, because you simply can't get all the load points, although you can get all the main points that your running with that prop/boost/trim/etc.

Artic is doing right with different pulley's and props, that is key to making it right for all future envoirments. We go a step further, were lucky, we have our local lake at 800feet, then we go up to 6000 feet within 1 hour, but we only do this on new cals, get our multiplier tables right, make a few changes to the base table that we know won't effect much at sea level and then we go back to 800 feet, finish it off. From there, we now have a predictable cal for almost all envoirments. You also need to get up super early and finish the "cold start" area's, which I believe are some of the hardest to do. This is one major advantage to the dyno, you can turn that AC on and use water through the engine to get it cold, but once you start it at the lake, you only had that 1 shot.

Dustin