need more horsepower out of STOCK 454MPI

[96donzi]

I Need Ideas On How To Squeez More Horse's Out Of My Stock 1996 454 Mpi With Out Spending A Fortune Im New To The Io Motors Any Little Secrets Or Computer Chips Somebody Mentioned K And N Flame Arrestor I Have Silent Choice Thur Hull Exuast Any Ideas Would Help My 1996 22 Ft Donzi Classic Be More Peppy. Does Anybody Now The Average Stock Speed 4 This Boat Im Going About 68 To 70 Mph Cannt Get Over 4300 Rpms

[BoostDaddy871]

Your engine RPM seems a little low to to me. You should be able to safely spin to 5300 RPM. I would think a prop change is in order. Something that takes a smaller bite would lighten the load on the engine allowing it to screw itself farther through the water for more boat speed. Consult a prop guru!
As for changes to improve engine performance, please remember that the fuel map in the ECU will have to redone. Some times this is a long trial & error process. The model of ECU will determine who can do it.
Hope this helps.

[Beer-30]

There are several things you can do. Unfortunately, they are all fairly pricey. A "top end" kit is the best thing for your situation, as you have a decent bottom end and just need better breathing. Head work and valvetrain are the biggies here and will wake your motor up. AZS&M has a reworked MPI manifold for your application that would go along with reworked heads and a better cam. This is all in the thousands when all is said and done.
Exhaust is one of the first steps you could take - if you are going to keep the boat. Don't go spending $3K on exhaust if you have any notion of getting rid of the boat in the next decade or so. Better flowing exhaust would set you up for whatever you end up doing to the motor. It would be an immediate 30-40hp increase.
Smaller things you could do are roller rockers. Even roller TIP rockers are a legitimate 20 hp or so. First of all for the fact that they do not flex like stock stamped rockers - losing valuable valve lift. Second, they are generally 1.72 ratio instead of 1.7 (or less), so you gain a bit of cam just from that. Thirdly, they free up lost hp that is used up by the rocker sliding against the valve tip. The roller tip is the main help in this situation.
AZS&M and Teague also have an "MPI wake-up kit" that has a K&N filter, an MSD spark box and an adjustable fuel pressure regulator. All is supposed to be good for a few 10s of hp or more for less than a grand.
A guy here HAD a 27' Advantage with your motor. I now have his 22P B-1 prop that he could not swing. He ended up with a 3-blade 23P.
Here is the AZS&M Super TuneUp Kit: http://www.azspeed.com/pepa.html

[96donzi]

thanks for the advice guys im going to look into those mpi intakes and play with prop sizes thanks again

[NdaWind]

I have same motor in a 22' advantage so far the best prop is a 23 4 blade gets me right about 5100rpm. Your probably much lighter than I as i only get about 55mph on a very good day.

[96donzi]

im about 3700 pounds but im getting about 65 mph with a 3 blade 25 pitch mirrage and 385 horse. what boat weight and horse are u running ?

[Beer-30]

I am about 6000 lbs, 425hp, 24P 4-blade B-1, 5000 rpm.