Josh LaFountain

Im a new member to OSO. I recently bought a 2000 PQ 280 silencer. 502mag MPI. CMI headers and the rest is stock. Im looking in to Force induction of some sort??? It runs between 65 and 68 rt now, Wanting to run 80+ mph. Any advice?

Uncle Dave

Yes

Build or buy an entire 2nd engine from the ground up and pull the one you have and put it on the shelf when you go to sell or screw up the high HP one you'll have a marketable boat.

Between the 2 go with the whipple.
You will spend an eternity chasing a procharged boat all over the place getting it to run right. The threads here on this site are an indicator.

Note: I have neither and no dog in this fight Im a fan of high HP NA/injected boats. My engine advice would be to build an injected 540-632 BBC and be done with it.

dont forget about steering.....and headers/ high end manifolds.

Uncle Dave

pqjack

if you want to go the forced induction way,i have one of each (whipple and procharger),both for 454/502 mpi for sale...i respect everybody's opinion,but its no more problem than running after parts that dont come in,machine shops with extended delays,and yes,im a blower fanatic
jmo...

Josh LaFountain

My engine already has CMI Headers so i would need to get external Steering possibly? Im not looking to go crazy with it. Just around 5lbs of boost should keep it reliable and jump the top speed up 10+ MPH from the research ive done. And PQJack whats the story on what you have for sale?

Uncle Dave

I wouldnt have my heart set on 10MPH.

Rule of thumb is 1 MPH for 20HP added and I dont see 200 more HP from 5lbs + bolting blowers on factory engines is a recipe for 20 hours of life.

Steering is a really good idea above 80- your gimble will wear prematurely without it and its a good idea to check it now.

Go grab the skeg and lift up as hard as you can and tell us how much play is in it.

UD

Josh LaFountain

1/8 to 1/4 inch of play in the gimble. the boat just turned 300hrs on the meter. it has 40+ lbs of oil pressure and dosent use a drop. And as far as how much speed im wanting to gain? Thats My decision. I want a good reliable boat to party on that will run "GOOD" And not get me killed. Im not looking for a 100mph boat and im not doing to spend $30,000 on a 900SC. So the 200 hp i would gain from the 5lb of boost is what im looking for.

verbi69

What I think Uncle Dave is trying to say that a 502 on 5 pounds of boost won't give you the 700hp you will need to get the 280 over 80 mph.
My 2003 280 is now running a consistent 80 mph with 700hp....is there more left in it...probably, but that takes a whole lot of tweaking and patience.
Take care and have fun!

offshorexcursion

iTrader: (5)

I love my procharger and would rec to anyone! The smartest and most cost effective way to gain more speed is to buy a different boat. But if you love your boat get the procharger, external steering, a new prop, upgraded outdrive, and you will gain 10 mph. Prob not worth the money though.

Doing it again I would keep my boat stock and save for a new boat. Boating often in a reliable boat is more fun then broke down at the dock.

I could not give up the speed though so instead I bought a reliable cruiser to use when I break my imco sc outdrives! (Currently saving for surface drives of some sort)

pqjack

agreed...on a 502/415hp,aiming for 625-650hp would be more realistic...

Uncle Dave

1/4 inch of play is in the verge of needing replacement- put another 100HP against it and you risk breakage, external steering will extend the life of the gimble dramatically.

As far as your engine not using a drop of oil - thats good, but at 300 hours I'd leak it down to see what its holding or you could end up blowing oil right out the disptick and through the breathers first time out.

At the same time your stock engine wont be able to cool your oil without an external cooler and you'll find during a hammer down run that the oil temps will skyrocket and then back at idle your pressure will drop to almost zilch.


If I sound like I am discouraging you from bolting a blower onto your stock engine its because I've been there and done that several times and it ended badly each time, or if it didnt end badly- it ended quickly - like a season.

You seem to have your mind made up (as I did) so I'll stop chiming in going forward and watch and see.

Uncle Dave