boosted 5.3 airboat
#22
only issue so far is the wg stuck closed once. went from 10psi at 5000rpm to 30psi at 6500rpm. didn't blow up. we think the dump tube is too short and it is warping the valve. we are extending the dump tube.
the boat is much faster now. changed the angle of the blade to the boat and added a 4th blade. the boat leans a lot less. no he has never maxed it out, it just keeps pulling. we need to get a gps on there and get an idea of how fast it is really going.
we are going to set up a 2 stage boost controler on it. lower the 1st stage to 5psi or so and up the 2nd stage to 15psi or so. less when he doesn't need it and more when he wants it. seems like a good idea.
#25
he is now running a 2 stage boost controller and stepped up to a 5 blade prop. it sure feels fast. we are going to gps it tomorrow and see how fast it is really going. i dont see maxing it out since it never seems to stop pulling. no one wants to die.
i am not sweating the 30psi thing. we took a 6.0 powered mustang up to 25+psi many times on purpose and for full 1/4mile runs. this was only a quick flash to 30psi and it had plenty of fuel and no timing.
i am not sweating the 30psi thing. we took a 6.0 powered mustang up to 25+psi many times on purpose and for full 1/4mile runs. this was only a quick flash to 30psi and it had plenty of fuel and no timing.
#28
sure. after tieing the wg into the down pipe there have been no more stuck waste gate issues. the boat has been running 15psi for awhile now and ripping up and down the river all summer long. very few issues and this thing sees a lot of run time.
one issue we have not figured out...
when the boat is under a significant load for an extended period of time the ecm will shut down. there has been 2 times when the owner was towing another boat and had a full load of people. he was running 5psi at over 4000rpm for more than 15minutes and the thing just shut down.
i wonder if it is injector related. the injectors are high z but not 12ohms, i think maybe only 9 ohms. run those at a high duty cycle for long enough and maybe the current draw is causing something to trip out. the ecm will not do anything, not even cycle the fuel pump. unhook it for a few minutes and it fires right back up.
one issue we have not figured out...
when the boat is under a significant load for an extended period of time the ecm will shut down. there has been 2 times when the owner was towing another boat and had a full load of people. he was running 5psi at over 4000rpm for more than 15minutes and the thing just shut down.
i wonder if it is injector related. the injectors are high z but not 12ohms, i think maybe only 9 ohms. run those at a high duty cycle for long enough and maybe the current draw is causing something to trip out. the ecm will not do anything, not even cycle the fuel pump. unhook it for a few minutes and it fires right back up.
#31
TECH Junkie
iTrader: (50)
one issue we have not figured out...
when the boat is under a significant load for an extended period of time the ecm will shut down. there has been 2 times when the owner was towing another boat and had a full load of people. he was running 5psi at over 4000rpm for more than 15minutes and the thing just shut down.
i wonder if it is injector related. the injectors are high z but not 12ohms, i think maybe only 9 ohms. run those at a high duty cycle for long enough and maybe the current draw is causing something to trip out. the ecm will not do anything, not even cycle the fuel pump. unhook it for a few minutes and it fires right back up.
#32
stock ecm. 114lb high z injectors. fuel pump is ecm controlled.
the ecm is completely shutting down. no hptuners connection. no fuel pump turn on. no injector prime. we tried hot wiring the fuel pump and it still did nothing.
the ecm is completely shutting down. no hptuners connection. no fuel pump turn on. no injector prime. we tried hot wiring the fuel pump and it still did nothing.
Last edited by parish8; 01-06-2013 at 05:21 PM.
#34
Does the boat start to get unstable at 50? You're probably right, a john boat with a high center of mass + blinding speed isn't probably the best idea...
....but it sure as **** is cool!!
....but it sure as **** is cool!!
#35
i am still thinking it could be the high z injectors. they likely draw more current that the stock ones and are creating a lot of heat when at a higher duty cycle for extended period of times.
#36
the owner is going to get some rods, pistons, ls9 head gaskets, better valvess and head studs and we are going to turn it up. likely max out that turbo.