Upgrading my 300xs

[merctech5591]

Well its time to drop in the hydro tech tuner.. i will pull it apart tonight and put it in. After searching for a stock 300xs tuner i finaly found one.. if the after market stuff does not work it will be going back to stock.

[Maritime_Eng]

Well its time to drop in the hydro tech tuner.. i will pull it apart tonight and put it in. After searching for a stock 300xs tuner i finaly found one.. if the after market stuff does not work it will be going back to stock.

Yeah I am very curious to see how the tuner performers. Keep us up to date on this project! Good luck!

[merctech5591]

just finished installing the tuner.. nice when everything comes apart with no problem!just need to connect thermostat hoses and pans and im ready to go.

[merctech5591]

just finished installing the tuner.. nice when everything comes apart with no problem!just need to connect thermostat hoses and pans and im ready to go.

[DRHOBACK]

are you going to get it wet tomorrow

[merctech5591]

on the water as I'm typing. This motor is a train. No more off idle hesitation pulls hard out of the hole, mid range pull is way up. Top end is sweet. I'm running a 5 blade hill 30p. Use to pull 6100 at max, now it will spin it wright to the 6800 limit. Same set up nothing has changed 1/2 tank of fuel. Next I will install the str throttle body. I would of put it. On but merc put a safety Torx screw that I did not have. All I can say is Yeah!!!

[Maritime_Eng]

Wow that is awsome results! Keep us posted!

[Liberator*21]

Ya gotta love it when everything works out for the better..............sounds like your on the right path to more power.....

[merctech5591]

once i get the motor dialed in i will start messing with fuel/air psi.restricting the air dump line will allow to increase a/f psi without messing with spring tension. going to try a fuel pressure regulator with a vacume line to the intake manifold to get a/f pressure back to stock at idle. then inscrease a few pound's when vacume drops.. sounds good in theory.. well see if it works..

[jpf091959]

Wow, that is the kind of news I was waiting for. Hey once you get it dialed in, post what worked and what didn't.

[merctech5591]

Wow, that is the kind of news I was waiting for. Hey once you get it dialed in, post what worked and what didn't.

well as of now the only thing i was not happy with was the cut tuner. the hydro tech tuner is the way to go.. also the water dump is going to be a little more work keeping the mid shiny. i will be out sunday morning with the gps and a couple of prop i use to run when the motor was stock. i have before speeds so i have something to compare too.

[bravo 1]

how much louder was it with the hydro tec tuner VS stock sure like how quiet the xs is

[merctech5591]

how much louder was it with the hydro tec tuner VS stock sure like how quiet the xs is

the tuner added a little depth to the sound but is a little louder.. at wot u still have to turn your head to hear the motor. mid range is up a few db's but no were near as loud as a 280ss.

[sammythebull]

do you have to use the poppet kit to run the tuner? what do you gain by running the poppet kit?

[merctech5591]

do you have to use the poppet kit to run the tuner? what do you gain by running the poppet kit?

the tuner has no passages for water other than the water tube.. the 300xs adaptor plate is semi dry and dumps loads of water thru the rear grommet. simmon recomended the poppet kit so i went for it. it does take the shine away from the mid because of the extra heat but if it works out the way i hope it will i can deal with a little wax. going to work on the boat this afternoon, need to change the livorsi gps antenna and do a few odd and ends on the boat.. sunday am is d day.. i will have videos and pics for thos who have asked..