Awesome build!

 

thanks.

Hopefully some more tuning this weekend...see if I can talk the girlfriend into getting a video

 

video of the boat?? lol

 

cool thread!!!

 

only if she signs release forms.......lmao


thanks guys

 

more tuning happened this weekend...even had the girlfriend driving while I messed with the laptop..everything went well....a new serial to usb adapter cable took care of the software freezing issues I was having. (FTDI vs Prolific units.....make sure you get the FTDI unit)

Hit my self imposed current boost limit of 4 PSI and it cut spark...kinda startled me...lol...spun the A impeller 5300-5400 RPM so almost 500 HP...NOT at WOT yet...but I dont really want to spin this engine over about 5600 RPM...so more boost will probably wait for the larger jet impeller so it brings my RPM down.

Need to make a oil puke tank for this thing...the cheap craigslist engine really has some blow by under boost....at least my valvecovers wont corrode...lol

This weekend will be more tuning at my parents cabin...should be able to get some video from the dock.

 

Cool setup! I agree we need some video of that sucker stat.

Seems like you could build/setup a boost lever. That way you could bring it up to max load/rpm at low or no boost, then bump the boost up at peak RPM like an additional throttle lever. Would put much less stress/strain on the system and allow more boost with MUCH less chance of knock.

Plus... how cool would it be to have a boost lever.

 

pic from the sand bar last weekend...had a great time

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where do you have your 02 sensor installed ??

 

this weekend is going to consist of tuning the timing in the lower load areas. I will use the fuel lb/hr estimator in tunerstudio to continue to bump up timing (at a constant RPM) until the gains are minimal. Once I get above 70-80% load I will use RPM vs. MAP to continue to bump timing until the gains are minimal. I do not think I will be going above 4-5 lbs without swapping impellers.

N/A this engine wouldnt pull the impeller more than 4800-4900 RPM....so anything past that will require boost. I have a pretty conservative timing map and fuel map in it for anything above 80% load currently.

 

I have the O2 sensor installed in the right "downpipe" about 12" from the turbine outlet...its mounted in about the 9 oclock position when looking from the behind the boat. I didnt follow the 18" rule because I wanted it at least 24" from the end of the downpipe....my pipes are nominally 36" long.

 

a few pics from the weekend....took my mom for a blast through the bay....not much tuning done...just asshattery and I should have go a pic of the pipes glowing during a high speed dusk run.....this thing will be somewhat of a torture test for the ching chong GT45's as far as a consistent high EGTs....not a 1/4 mile at a time

I did take some data logs...my IAT only increased 2 deg F from at ~5 lbs of boost

The pics were shot when I was running about 4500 RPM with the diverter (adjusts the additude of the boat/roost angle) second notch from the top

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Really cool build man. I always loved seeing turbo jet boats out on the lake. Do they have gear overdrives or do they always spin at engine RPM?

 

any application that I can think of the jet (pump) is direct coupled to the engine....not reductions or overdrives

 

pretty sure our challanger is direct drive

 

Cool.. what size wastegate are you running, looking at 44s or 50mm.

 

They are direct driven from the engine. Impellers can be changed. They are like an inboard outboard setup. All is direct but you can change props. Or in jet boats, the impeller. Turbo in water is how I imagine it

 

Im running twin china 50 mm wastegates....I have the overboost safety setup in the microsquirt in case one of the wastegates seize.

 

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here is an example horsepower requirements of different impellers for Berkeley and dominator pumps. Aggressor follows a different curve per letter designation.

Example...an aggressor "b" bites like a berkeley "A/B" or "A"

 

here is a pic of the challanger we picked up a month ago

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