350 mag mpi upgrades?
 

Any upgrades for a 350 mag mpi that won't completely break my wallet or know where the best upgrades that are most bang for the buck. Also maybe looking to buy a used supercharger or pro charger, can't seem to find any. All help or suggestions appreciated please.

It's hard to give advice without a $$ amount attached. Everybody has a different threshold for "breaking the wallet".

what year 350 mag MPI

big difference with what you can do as far as to which ECM it is using for a stock Merc.

There isn't any thing that will make a significant gain on that engine without spending $$$. The best bang for the buck would be a Whipple. You can do the install in the boat in an afternoon. The kit comes with excellent instructions and has everything yout need. It's not exactly cheap, but in terms of hp per dollar it can't be beat.

Assuming you don't have the 555 ECM, you can do just about anything you want IF you are willing to spend the money. As Haxby said a blower is one solution, but I'd also argue by the time you did all the plumbing and configuring for a Whipple you'd be in just as deep as a full engine rebuild with good parts and a stroker motor. Either route will get you a noticeable improvement in performance. I'd plan on $8,000 +/- a couple to get what you want.

Get the serial number of your motor as BUP suggested to see where your baseline motor is. Different years used different ECM which have varying degrees of 'tune-ability.'

Good luck.

Exactly what ECM - MEFI or triple nickle or PCM 09 or PCM 09 latest version ?

If I recall correctly Whipple does not reflash MEFI but I might be wrong about that one.

I just found this thread, I also am interested in upgrades. not to hi jack, but how can I find out what ecm I have. The motor
is a 30 hour jasper marine 330 hp 350 MPI Mag engine.

On the back of the ECM is a serial/part number. From there you can determine if its MEFI 1, 2, 3 4a, 4b, 555 etc.

That and a picture and we can direct you further.

Having built a pair of 6.2s, I can reliably say there isn't a damn thing you can do "without breaking the wallet."

This isn't like modding cars where you can slap on a pair of long tube headers and pick up a noticeable amount of horsepower.

I'd echo Capt YARRRs statement but emphasize the word "noticeable". It takes a bunch of work to make any significant or 'noticeable' performance improvements.

I was looking to upgrade the exhaust this winter on mine. What are people using and any pros/cons?

Don't waste your money on aftermarket exhaust on a SBC marine motor unless you wind it north of 6000 rpm. You will see no gains with the exception of a lighter wallet.

Donzi ZX is probably big block. Maybe sbc if twin engine.
JRalston, you are best off doing a plan that does the engine and exhaust at the same time. Upgrading from OE exhaust is necessary if you improve the engine, but does nothing except look pretty if the engine stays as it was.
That said, many upgrades require better exhaust.
What is your power?

one slight advantage: You are beached on the sand bar and this cutie is bent over the side of your boat thinking "I want a ride in this!" And you are standing behind her thinking exactly the same thing... in reality the one upgrade to consider is aluminum oem exhausts. Between them and alum intakes you are taking a couple hundred pounds out of the stern. Unfortunately, the previously mentioned cutie will think "Stock exhausts? Loser!!"

twin 350 MPI's. was looking for exhaust this winter and prochargers next off season.

That is worth the money right there!!

So how much power per engine are you thinking of in the long run? And what cond are your existing exhaust in? Because this is something that can be found used with some patience...

LS3's and new manifolds to now fit the new engines...done.

Sell your existing mpi motors to all the cruisers looking to upgrade or replace.

Blowers or 454's...simple and quick. LS's will be best but will hit you for more money.

Odds are the boat is built with engines too close together to install big blocks.

sorry for the late reply. I was hoping low to mid 400hp range would be sufficient. I am told much over 80 mph and ill run out of hull on my boat. only running mid to high 60's now with 300hp per side.

I think that's a bit optimistic for a goal. On my Sunsation build with 400 hp 383s. It was reliably a high 60s boat with the 6.2s and got it to low to mid 70s.

If I wasn't forced to do a rebuild, I'd say it wasn't worth it. But since they had to be rebuilt it was a bit more fun. Opening up perfectly fine engines I probably wouldn't do.

I got 720 hours before and injector went "south" and hurt the motor. Barring that 1000 hours would have been easy.

How to Build a Supercharged Torque Monster for $3900 out of All-New Parts!

food for thought .... if only my vessel weighed about 8,000 lbs less.

Stirring the pot

2005 350 mag mpi no start no spark
 

Switched ECM from side to side swaped coils put new distrubiter module in it has the can system in it

^^^^^ HUH

HVS not phased correctly so the cam angle is off - has the HVS been moved and or pulled out and reinstalled ?? timing is non adjustable for most EFI 2001 thru current marine engines.

New cap and rotor is always needed on these apps every 1 to 4 years max.

[QUOTE=BUP;4688371]^^^^^ HUH

HVS not phased correctly so the cam angle is off - has the HVS been moved and or pulled out and reinstalled ?? timing is non adjustable for most EFI 2001 thru current marine engines.

New cap and rotor is always needed on these apps every 1 to 4 years max

[QUOTE=shimer;4688435]HVS never been removed. Got codes for Temp sensor, oils sensor, MAP sensor and TPS sensor.

I'd copy this build,Yes its a ls but get good heads and cam w/ the blower.:D
https://www.enginelabs.com/engine-te...s-new-for-2019

you realize I said its an ls,right:D Its all about air flow

Easy upgrade is what Volvo did to it. Adding about 15-25hp is using crane roller rockers 1.6:1 ratio. You can raise your limitter also. will make more power all the way around.

I just saw this. It's a few years old. My 350 mag mpi has a procharger and imco exhaust. I'm estimating around 500-550 hp. It's in a 20ft glastron gs 205 20 ft bow rider. It does a best I got of 68 mph. But I think it's at It's limit for a alpha drive. Have been chasing running issues for 3 seasons now. I'm pretty sure I have valve issues. So it's getting AFR aluminum heads soon. And possibly a nose cone and 27 prop. Maybe 600ish hp when im done. Hoping high 70s with it done.