adding performance to a stock 454 Mag EFI??
 

I have a 1995 advantage with a 454 Mag efi, 150hrs, thru hull exhaust, this thing is bone stock. I have had thoughts about a procharger, but dont really know what I can do to make reliable horsepower. Should I start adding other items like ignition, exhaust, ect, before I even think about adding a supercharger? I dont know what is avalible, or what direction I should head in.

The problem is once you start tinkering with it, the reliability goes down and maintenance goes up. If you are mechnically inclined and can do all the maintenance/fixing issues and don't mind doing it, then I have a list of goodies for you. The only other option is if you have tons of money and have a trustworthy mechanic.

Remember most any upgrades (that make any real power) are gonna require a reflash of your EFI. Please don't think you can get away without this.... many people try it and eventually have it tuned correctly.

Now supercharger will give you the biggest bang for your buck.... but how much bang will be determined by your exhaust, fuel system, and tune.

You can do headers and the simply bolt on stuff, but gains will only be minimal, until you get in to the motor. If your serious and want the power and reliability, then you owe it to yourself to call Eddie with Youngs performance.

I am a mechanic, and understand that high performace usually means added maitnace. I just dont know what is avalible to ad some ponies in the marine market. Like I said I have thought of a supercharger, but I dont know what it takes to make it reliable on a stock 454 Mag/Bravo1. (ie Exhaust, ignition, ecu flash, fuel, outdrive??) What I have in mind may not be possible while keeping the reliability!

All of the above are needed to keep it reliable. Also you will need hydraulic steering for speeds abouve 70mph to keep it safe.

About every 15hp increase will equal 1mph on the top end.

Since you are a mechanic, here's what to do.

Take the heads off and get a single angle valve job done with PC seals. Polish the combustion chambers in the heads to make the chamber smooth to avoid hot spots. reinstall the heads using studs and good head gaskets. Call Dustin Whipple and order up a Whipplecharger kit and install it. Install a separate water supply to feed the intercooler.

Now you will have a boat that is very reliable and should run about 15 mph faster than stock. I did this same conversion yrs ago and it now has over 400 trouble free hrs on it.

Ill sell you my 415 hp stock 502 Multiport injected motor ready to drop in !! Very reliable, cheaper than procharger!!!

How fast do you want to go and how much money do you have to spend? Once you get the speed bug there is no turning back and you will never be satisfied. I have had the bug for years now and just can't kick it. Your first upgrade should be the exhaust with long risers, it will only get you 1.5 to 2 MPH. You will need the exhaust upgrade for the performance cam. Next call RMbuilder and get one of his custom cams. Have your computer flashed to the new components. Try a few props and pick the best one and have it lab finished. This will be a good start.

give me the details Dookie, I have a friend that may be interested. Where are you located?

What speeds and props are you runing now? I have the same boat as you with 454 and procharger. I get 70mph with 26p with light load and 65 loaded. Thanks, Matt

Yesterday I hit 63MPH @ 4850RPMs with a 23 4 blade. I think I had a plug laying out, heard a small miss underload.