I want the boat to be faster and I need 260+ hp, low weight for good balance and low consumption on cruise and low speed. I suspect the hp is down somewhat compared to new. What can I do to make this engine more powerful and sound better? The carb engine has no 'cassette' inside the mid section so it has that mean Merc 2,5 EFI like sound on idle and really fun to run. Fuel has become crazy expencive and it charges the battery way too weak. It has 31 boat races and over 1600 houres now. I really like that engine and it has never been apart except heads off for inspection and new gaskets + powerhead off to paint the engine and to replace the bottom seal and gasket. It was estimated that it delivered around 260 hp. My boat and 225 2,6 liter carb engine has run since 1987 and still runs fine. So, the limiter shouldn't be an issue until you get to those speeds. The reference to the 93 wasn't an insult.sorry if you took it that way.it's the speed that the Tuff ran with the 300hpdi which obviously had the stock box on it. If you want to build a motor that is more extreme than what is currently available than yes FM won't only be a huge benefit but a necessity.for a stock motor with heads and BB throttles I don't see there being a benefit. There is only power above the limiter if its ported.and even with porting I ran my best speed at 6100. The fuel curve is NOT the rev limiter.you asked about fuel. My motor is NOT crazy.don't get me started on HT.my point was that it is easier to have your motor built to the 345hp spec than it is to try an mess with the fuel curves in the box. Rick if there's more HP above the Rev limiter then why not run a smaller pitch and tap into it? your like a Broken Record.lol yours is CRAAZY. its about making your motor better and if that ='s a mph then cool.Īnd Rick we know my motor isnt ported. it not about all of the sudden being in the 90's. That being said you could just have it ported and pump the compression (the next phase.22?) and add more power for less money.then start thinking about fuel curves, timing, and rev limiters. Just remember.Lean is mean.and that motor is expensive to tune by plug chops and EGTs. If you're talking about adding a HP here or there buy finitely tweaking the fuel curve to run on premium.than yes there are probably some maginal gains to be had BUT given how HT operates and the HPDI system is an open loop I would say that there is enough fuel there to make whatever they can make with the phase III.or 4 or 5 whatever they call the ported/high compression version of your motor. Hydro-tec has made more power out of the HPDI than you have in your motor.with the stock box.which tells us it's not starving for fuel until it gets to wherever they got to with the motor.

It absolutely could.but you'll have to add something to the equation (more than you have now) whether it be compression, porting, magic.to see APPRECIABLE gains. I think fuel management will make power with out any porting.

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