I have a 350 Mag MPI in my 1998 22 Scarab. I would like to get some more power out of it. Anyone know of any good cam upgrades for this package? Thanks

How much more power are you looking for. That will determined how extensive the mods are. There are several good cams from Comp Cams, Crower etc that will work with a roller motor like yours. To optimize you should get the ECM tuned as well.

I guess I should start by asking how much horsepower the MPI manifold will support? I would like to get it up over 400 if possible. I am planning on upgrading to CMI E-Top headers as well. Thanks again.

it's my understanding that that stock manifold and fuel injection setup is going to keep you right about where you are headers will do nothing unless you change that or Pro chargeI personally would not procharge that engine with stock pistons

I'm interested as well.

A comp cam xm 276 would be as hot as one would want to go with wet exhasut a xm270 would be quite nice.You will notice it reqire's some modification's..and ground on a 112 lsa

http://www.carcraft.com/techarticles...pring_upgrade/

http://www.pacificp.com/forum/viewto...d21288c9eebedd

Page 2 is where the meat of the conversion come's to light

The below should be part of the thought process

http://www.perfprotech.com/blog/unca...d-and-checking

http://www.michel-christen.com/ExhaustElbows.pdf

Thanks for the info Pliant. I was planning on upgrading to Imco exhaust, so that should take care of water ingestion issues. I like the Beehive springs too. :-D

I have twin 6.s MPIs in my boat. When I first got it I thought that there might be some easy horsepower left on the table. There isn't. The pro builders chimed in as well as many other experienced boaters. You have to do a complete package: heads, cam, intake, computer retune, and headers are over 2k. If I want to go faster I will buy a faster "stock" boat. You will spend a lot of money (don't forget a new prop) for 5-6 m.p.h. and probably not recoup your investment when you sell. JMO.

these marine mpi's don't have any real upgradability. they are good on fuel and dependable. but they are what they are for the most part. you want more power, go carb. alum heads-exh-intake. then keep the stock stuff to reinstall when you sell it...a large part of the speed increase is the 150 lbs you took outta the back of the boat with the lighter parts.

I was worried the intake might not support much more horse power. I will still probably upgrade to Imco Powerflow exhaust to give it a little better sound and shave some weight. Thanks for all the info guys.