windsurfnut

Don't Flame, I know its a SBC TBI motor..but I'm looking on some ideas to step it up.

As posted, I have a 5.7 EFI / Alpha set up on a Stingray 220SX. Reasonably light and efficient hull for its style.

What can I do to add some power to the motor?
Firstly, I'd like to keep the EFI - its TBI and I realize I may be limited to what can be done here. If there is gains in going with a better intake manifold and carb, I'm good with ditching the EFI and going that route.

Secondly,
I have thru hull exhaust now. They exit under the waterline with exhaust tips that have internal "crossbracing" in them that I assume is a muffler. I'd like to change these out to a more flow thru style.

Any reasonable investment builds will get me to the 300-320 pshp goal? Anything more I'm sure the Alpha will dislike.

3pointstar

Winsurfnut

I'm not a motor expert by any stretch. However, I have read a number of posts over the years at this site asking pretty much the same types of questions -- squeezing more power out of engine. For all practical purposes I think just basic stuffs might add a few more hp - but to be honest the 5.7 motor is pretty limited without spending mega bucks- and then at the end of the day you still have approximately the same engine with all types of modifications that will cost more to repair.

If it was me I would stick to the basics as much as you can - keep it tuned up, good wires, rotor, cap, plugs, filters - air and fuel. Keep the prop in good repair - no dings and the hull clean. it is amazing how much these do improve the overall performance.

When all is said and done you are going to start looking for a little larger boat with a bigger engine-- speed does some pretty crazy things to people -- I know it bit me. Hang in there

3pointstar

phragle

iTrader: (3)

build it to 383 cam,heads intake, exhaust...450+ hp if done right. Its just a matter of what you really want and what you want to spend.

SB

iTrader: (1)

Making that hp with a 350 is easy. Your boat will respond well.

However, only tough part maybe the EFI chosen - either you or a trusted tuner that will tune your boat 'live' is what is required.

Your Alfalfa drive will be fine.

This is a perfomance boat site, so:

3pointstar is just being a buzzkill. LOL.

Stock sucks unless Merc Racing engines.

GB

Humble opinion...Keep it stock and enjoy. When the time comes to upgrade to a different boat, you're ahead of the game.

My two centavos

lsc86

Lots of ways to skin this cat, all depends on what your all in budget is and time frame. Definitely helpful if you list your boating area in your signature, finding local help and advice much easier that way.

Myself, I typically lean to selling what I have and taking the performance upgrade budget $$$ + time invest + loss of aggravation to get into another toy- at least as I get older.

I'm no outdrive expert, but with increased torque and abuse, I'd be hesitant with adding too much snot to that Alpha, at least for my own personal comfort and you're talking about a much bigger/expensive project to get into a Bravo setup. Which brings me back to my initial thoughts of selling and moving on.

If you're still wanting to tweak your existing mill, the sky is the limit with a SBC. Cam and heads are the key parts, plus ditching the TBI for a regular carb setup. 355-383 cid, quality heads/porting/valve train, intake/carb, plus a decent cam grind to tie it all together and you're into the 400 hp range on pump fuel. The individual parts aren't as critical the how they all work together - that's what differentiates builders in my world.

In the end you'll have to decide what direction to go. It could be a very fun build as those Stingray hulls are quite efficient, but if you shell out 'X' dollars + time on this project, don't expect to get much if any of it back when you do go to sell.

Dave M

^^^ This.

BTW, where do you use the boat?

SB

iTrader: (1)

Is this no longer a performance site ?

Jeez, people used to get the cold shoulder in the tech section with stock black motors.

Stingray's respond well to power increases, just saying.

I'm kinda beside myself right now, depressing this is, but I'm just another guy with an opinion.

Wobble

you've been known to get exited about 5.7 tbi motors

SB

iTrader: (1)

Truth....nope. Just something we had to deal with for many years as they needed serious help in the power department.

Wish we had the LS trucks back then, other then them corroding so damn fast.

I like my carburetors - but like everything else, they aren't for everyone.