2009 VP 5.0 GXI - Performance Upgrades?

Afternoon,

I have a 2009 Glastron 205 GT Ski and Fish with a tower. Love the boat and don't want to change.

However, when i bought it - I was looking at economy over power and opted for the 5.0 instead of the 5.7.

I have worked with Precision Propeller and literally tried every combination we could come up with from low 17 to 22 and even shifting props.

I am a big guy... about 6'2" - 240 lbs and when 4 people or even 3 are in the boat... Slalom for me is basically out of the question or any other larger or tall adult.

Yes I can get up... but after being drug for half the lake.

What I need is more power..

I am willing to consider just about anything but I would rather not swap to a 5.7.

I have seen:
Chips but no idea if they are worth it.
Blowers. Headers etc..

What I need is someone who knows Volvo - and their stuff to tell me what I can do to maximize the power this plant can put out. The I will adjust from there and re-prop accordingly.

Can anyone give me some sound tech advice on this?

Thank you in advance

You can spend a lot of money on a blower, however a 383 stroker would be my first suggestion.

There are no "chips" that ever worked, much les one for a boat.

If you want more power, you need more motor... PERIOD.

performance exhaust wont help because you dont have enough motor for it to help. It may add 2-3 hp on your 5.0. That is it. Not worth the $1500

For $2k you can build a 383

Scott Danforth said:

You can spend a lot of money on a blower, however a 383 stroker would be my first suggestion.

There are no "chips" that ever worked, much les one for a boat.

If you want more power, you need more motor... PERIOD.

performance exhaust wont help because you dont have enough motor for it to help. It may add 2-3 hp on your 5.0. That is it. Not worth the $1500

For $2k you can build a 383

Click to expand...

Ayuh,.... Welcome Aboard,..... That's a 'puter controlled Efi motor ain't it,..??

If so, there's no power to be found without many thousands of dollars spent,....
'n then yer not talkin' Real horsepower gains,....

Yer choices are a 350, or a 383,....
Dollar for dollar, the 383 is the way to go,...
Just as you shoulda gone for the 350 in the 1st place,...
There's No replacement for displacement, when talkin' boat motors,...

Tried a four blade prop? Won't be faster top end but might get you up a little quicker.

Thank you for your replies

Yes its EFI - I figured this would be the answer - Meaning I am stuck.

Any suggestions on how or where i would go about building a 383 Stroker when I have no experience with Marine?

Will my outdrive work?

Sounds like a great idea for 2k I am interested in doing that for sure.

Would this be EFI also? or?

I am in Oregon - Any direction would be greatly appreciated!

I'm surprised your having issues. I have a 20' Reinell with 5.0 and I'm 6'2" and 210. I put smart tabs on and went to a 4 blade hustler 17 prop and its accelerates hard and yanks me instantly up to speed for wakeboarding. Both my buddies with 20' and 21' boats are amazed how quick my boat jumps on plain and accelerates. Might want to see about a 4 blade prop, that was definitely a very noticeable difference for quick starts and yanking power.

x2 on the 4 blade. I've got a 2008 21' bowrider with a VP 5.0GXi, it came with a 21 pitch 3 blade aluminum but with a light load would barely hit 52mph but was at the low side of it's max RPM range.. I switched over to a $100 Solas 21 pitch 4 blade aluminum and now it'll do 55mph at the high end of it's max RPM range, is much more maneuverable at low speed, jumps on plane quicker and at lower speed, bites better in turns, and is just overall smoother. Also, at $100 I'll just buy another if I mangle a blade.

To build a 383, you buy a scat 3.75" stroke kit and take the 350 block to a machine shop. The machine shop takes it from there. To get a block, any post 1996 350 block and heads will work

Then you swap longblocks with the 5.0 and remap your efi

Scott -

I follow what you are saying completely.

I have a 2009 5.0 GXI

With that said - I have a concern about the remapping.

I contacted a company in California called ODB Diagnostics regarding the remapping that was suggested to me/

He indicated that my ECM i- nobody is remappable them.

1) Do you have a place I can contact with build numbers etc and verify this ECM is remappable before I take this on?

2) If I get a solid 383 will my current out drive handle the 400hp I would like to have in a 383?

Your 383 will have a solid 330hp at prop, or about 390 at crank unless you go nuts with cam and custom exhaust. If you cant remap your existing ECU, get one you can.

I've had the 5.0L on two significant boats (5000 pound and 6000 pound), and neither had issues with jumping on plane. Granted, I had the DP drives, but the point is if the prop system can get the power to the water - that 5.0L is no whimp. My current boat has the 5.0L GXI, and it will drag my beamy 3-tonner up to 43MPH.

Just food for thought.