MAGNUM Dyno-Boost Boat Performance Chip

[Damon]

Anybody ever heard of this outfit?

https://www.magnumtuning.com/en/detail/dyno-boost-boat-performance-chip/mercruiser/383-mag-stroker-6-3l-350hp

They apparently sell a chip that they claim can improve the performance of my Mercruiser 383 MAG Stroker MPI by 15% (HP and Torque) and fuel economy by 6%. They also claim that "This popular remapper chip remaps the lean factory fuel curve settings restrictions implemented due to requirements which manufacturers have to comply with." Do the factory guys really set this restriction? If so, why?

To be honest, I've been somewhat disappointed with the performance of this engine due to the poorer fuel economy than I got with the 351W carbed motor, and falling a little shy of my recommended RPM range with the same prop I had on my 351W. If this is a legitimate product, I'd be willing to give is a shot. I always thought the advertised 390 max ft lbs seemed low for any 383. If I can unleash the potential performance with this motor, I'd be stoked!

[Damon]

I've already put over 1200 hours on this motor over the last 4 years. Unless I can get better performance with it, I will likely go with a custom built carbed 350 or 383 for my next repower. I've been checking out some of dyno tests on YouTube and I'm seeing some very impressive numbers for both of these motors. I'm liking the Comp Cams Xtreme Energy camshafts! At this point, I'd probably go with the XR258HR-10 (206/212 @ 0.05 with LSA 110). Decent idle slowing trolling live bait at 600 RPMs is a must!

[Quik Fix]

Damon, I have the Comp Cams Extreme Marine XR264 HR in my stroker.

[Damon]

The 264 cam is very nice! But I would need a smaller version of what you have solely for better idling manners for slow trolling.

The marine versions do not include 206/212 grind, which is why I’d opt for the non-marine version for my purposes. If I was not so hung up on the slow trolling thing, I’d go the next step up like you did. I did notice that the Marine versions have the 112-degree LSA versus the 110 on the non-marine ones for some reason.

BTW, how are things going with your 383? IIRC, you were working some bugs out on your accessories.

[Quik Fix]

Got it all done. Very happy with the engine. Fuel burn is not as good as I would like but I'm still almost 2MPG. Tops out at 30 MPH and without the tower I'm sure I could get more. Also I still have the 16 x 17 prop. Performer manifold and Etec 170 heads seem to be a good choice. Overall, I'm happy. And it looks cool. Y'all know how important that is with me..

[Ship]

I once told somebody that I would rather a running pile than a backed up pretty turd. I still think that way! To get both a moving and pretty turd is heaven.

[Damon]

I once told somebody that I would rather a running pile than a backed up pretty turd. I still think that way! To get both a moving and pretty turd is heaven.

A well balanced movement! It took me a moment to process your statement, LOL.

[Ship]

Yep! You are right on. But it does have other applications>

[Damon]

Jerry, how’s your idle @ 600 RPMs (give or take)? Do you think it would do okay at 600 RPMS in gear?

[tuner]

Damon, I would keep your existing cam, it is very good. GM used the "marine" cam in the Ramjet 350 engines which produce 350hp and 400ft/lb.

If you choose the XR258 cam, custom order it from Comp Cams with a 112 or 114 LSA. The cost is the same. The greater LSA reduces overlap and will allow the engine to perform better at slow idle. Advancing the cam 2* will also improve low speed power and idle quality.

[Damon]

Don’t get me wrong, I like the way my motor performs between 3000-4000 RPMs a lot. Just wish it got about .20 - .25 nautical mile per gallon better fuel economy, plus about an additional 250 RPMs on top end. To get there now, I would need to go with a prop smaller than what I had on my 351W.

This is what interested me in the Magnum tuner/chip in my initial post above. If it could muster the additional RPMs on top end, plus any improvement in fuel economy, I’d be as happy as a clam!

I may just pay the $380 to give it a try.

[Damon]

Never mind! Read reviews and other information about this and other outfits like them. It seems like a snake oil type product.

I’ll continue to enjoy what I have and bring the extra gas for the longer trips!