twin turbos on a 350 - input?

[thehawk109]

I am trying to decide if it would be worth it to put twin turbos on a chevy 350 in a diamond race boat...Any input on power increase? Would it be worth it? Any input would be greatly appreciated

 

[kev_79]

Re: twin turbos on a 350 - input?

Are the turbos made for boating use, or automotive? If the exhaust doesn't have to be cooled, like on most inboards, it should work. As far as automotive, I think the expected power increase for one good turbo is about 33 percent, but due to law of diminishing marginal return, you might expect 50 from 2. Twin turbos are an effective setup done right, but you might want to consider recamming, port and polish, and bigger carb with one turbo. You might save some money, and get more power. As with anything though, power and reliability don't go well together. Good luck, and definately check out the carb, cam, 1 turbo combo to see what's up. I think it will do better.

 

[thehawk109]

Re: twin turbos on a 350 - input?

its for boating..I know the water goes through the exhaust manifold, but does this process act to cool the exhaust or heat the water? Is there an easy way to fit turbos around that?

 

[Dhadley]

Re: twin turbos on a 350 - input?

It will work just fine. The problem with turbo's in not making power -- they will make plenty -- it's keeping the power in check. You don't just add turbo's to an engine, it should be built for them from the ground up. <br /><br />For the best in depth info on torbocharging call Tom at Flagship Marine Engine Co. 800-282-2840.<br /><br />They are some of the best in the country at all kinds of boost producing packages. <br /><br />Good luck!

 

[kev_79]

Re: twin turbos on a 350 - input?

The water in the exhaust acts to cool the exhaust so the heat doesn't melt any rubber hoses on the exhaust system. I have yet to hear of a turbo on that type of setup. Most full race boats are built with exhuast coming out of the top with no worry of melting anything. Good luck, let us know what you find.

 

[Dhadley]

Re: twin turbos on a 350 - input?

Hey Hawk - I just read an interesting article about Fred Inman (owner of Imco) and his new 36 Eliminator Daytona. It's powered by 3 small blocks. Each one has a Quad Rotor Whipplecharger (2 superchargers per engine). Each one is 775 hp on 92 octane at only 7 lbs boost at 6000 - 6200 rpms.<br /><br />It's amazing what can be done. Most everybody has gotten away from turbos for numerous reasons (turbo lag being one) and gone to some type of supercharging. Very neat stuff. <br /><br />Let us know how you make out. Good luck!

 

[thehawk109]

Re: twin turbos on a 350 - input?

that is just freakin amazing...I wish i had the money to do stuff like that. I'm not sure whether to go with a souped up 350 or just go ahead and stick a 454 in it...both have their ups and downs. the good thing about a 350 is that there are parts EVERYWHERE for them. Another Q...would a supercharger generally wear out quicker than say turbo?? seems like the high rpm's would would wreak havic on a supercharger. I know next to nothing about boats but i am working on that..thx for replys

 

[Dhadley]

Re: twin turbos on a 350 - input?

You wouldn't have to turn the rpm that Fred is. There are plenty of packages that will achieve the output you are looking for at 4400 to 4600 rpm. Like I say, give Tom a call. They can supply you with a big block if that's the route you decide to go. <br /><br />Keep us informed. Good luck!