Getting the most horse power

[Galvez83]

Hi folks, i im looking to get some feedback in regards to getting the max hp out of a 5.7 vortec. Long story short 2000 four winns 238 vista had a bad 305 tbi vortec that i am swapping for a 350 tbi vortec. I sent the computer in to get re programmed. My outdrive is a dp-sm. Any ideas reagarding any to raise the horsepowers without going to a 383?

 

[Scott Danforth]

Hi folks, i im looking to get some feedback in regards to getting the max hp out of a 5.7 vortec. Long story short 2000 four winns 238 vista had a bad 305 tbi vortec that i am swapping for a 350 tbi vortec. I sent the computer in to get re programmed. My outdrive is a dp-sm. Any ideas reagarding any to raise the horsepowers without going to a 383?

go big block?

seriously, ditch the TBI, go either MPI or carb, go with a better cam and go with a stroker

with a good cam and a good 4-barrel carb or MPI, you can get about 300hp at the props with the stock 350

with the same good cam, better pistons, some head work and you can get about 320hp at the prop

with a 383, you can get about 340-350 at the prop. to go more, you need expensive exhaust.

with TBI, stock cam, stock pistons, etc. you can get about 260hp maybe 270hp at the prop

 

[Bondo]

Hi folks, i im looking to get some feedback in regards to getting the max hp out of a 5.7 vortec. Long story short 2000 four winns 238 vista had a bad 305 tbi vortec that i am swapping for a 350 tbi vortec. I sent the computer in to get re programmed. My outdrive is a dp-sm. Any ideas reagarding any to raise the horsepowers without going to a 383?

Ayuh,..... If the "Tune" is a good one, you'll be gettin' the most outa the hardware ya got,......
Yer eliminating the one thing that'll Really make a difference,.....

 

[Galvez83]

What cam and pistons should i be looking at for the stock TBI to see some gains?

 

[Bondo]

What cam and pistons should i be looking at for the stock TBI to see some gains?

Ayuh,...... Ya got the cart before the horse don't ya,..??

Ya gotta build the long block, Before any computer tunes,.....
Are ya plannin' a full on reman on this 350,..??
I s'pose ya could swap a cam, but swappin' pistons usually requires machine work,....

 

[Scott Danforth]

If you are going to swap in different pistons, you may as well do a complete stroked rotating assembly as its the same amount of work

If you are going to stick with the electric toilet, stick with a stock mtor

 

[QBhoy]

I think the main issue is that you have tbi controlled by an ecu (I think). If you went mpi you’ll either need to spend a fortune on the top end injection system and ecu. Probably about as much as making it worth while to get a stroker or an mpi whole engine used.
I’m in a similar situation where my mpi had a cam fitted when new as part of a performance package. There was however no thinking around the ecu and it giving normal fuelling conditions. The result is a powerful engine near the top end…but over fuelling issues and laziness down low

 

[Galvez83]

Yeah its a reman 350. My current 305 that came with the boat its crappers.

 

[tpenfield]

Be mindful of the cam shaft in that you cannot get too aggressive with it, else you run the risk of hydro-locking the engine at idle speeds.

Good marine cams are really boring . . . lots of lobe separation and little overlap.