turrrboze...?

[Len]

Directed more at Big Grizzly, Forrest and Allan Brown and the rest of the High Perf people with an upbringing in extreme hi-po (eg. 427 side oilers/H&M) ...why is it that we don't see more TURBO's on boats that are so Torque hungry with their outdrives and the water? Does it cause a lot of trouble in the exhaust ...cams? ...reversion? ...or just placement? ...real estate?...Seems to me that a Gale Banks or like could be fitted easily (instead of a B&M or Procharger) for less and provide significant gains. I am NOT an engine man and have little insight to the pro's and cons here so don't throw tomatoes at the stage... http://www.donzi.net/ubb/confused.gif (oh, and by the way,...If I missed any incredibly talented engine-meister,..I am sorry...I know you are out there...many times over...You too Geoo...Paulo,...Ralph,...Emmo,...Craig,......Owen, ..., Mad Poodle (Scott),..the OTHER ONE AS WELL. http://www.donzi.net/ubb/eek.gif Thanks to you all...



[This message has been edited by Len (edited 12-10-2000).]

[Forrest]

In a nutshell Len, since they are exhaust driven, turbos generate a lot of heat. Heat is tough to deal with on a boat with a closed engine compartment. Turbochargers do aid in overall engine efficency since they recover a portion of wasted fuel energy (exhaust heat) and converts it to mechanical energy that turns an air compressor - which makes additional heat! I remember in the past, there were some turbos for marine use that had water jacketed housings in an attempt to keep them cool, but the simplisty of the of the less-efficent belt-driven supercharger had too many advantages over turbo charging, and for that reason, you just don't see too many turbocharged gasoline engines in boats these days.

Marine diesel and turborcharging is another story though.

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Forrest

[BigGrizzly]

The turbo has durability problems. I won't get techee on you. Like the guys said excess heat builds up then that heat builds, etc. get the picture. Then under a closed deck gas oil fumes oh my. One more thing its not as drivable as a supercharger. When you pull the throttlel back the turbo keeps going at 60,000rpms and no cool air. How many Indy's were lost because of a bearing failure!

[This message has been edited by BigGrizzly (edited 12-10-2000).]

[Edward Donnelly]

Hate to be the devils advocate but,I ran a twin turbo in my 16'for 10 yrs. My Criterion had a twin turbo. I ran the 350 in my 16' at 18 to 28 lbs boost (waste gates). I ran 12 to 18 lbs in the Criterion. Cooling is not a problem when you use a scoop pick up. Heat is not a problem when you use water cooled manifolds, and a water collar around the turbos.(pics of the 16' with turbos in photo contest) ( pic of Criterion with turbos in registry under Donnelly Edward) Why did I take them out? Too fast and I wanted to toy with a tunnel ram fuel injection system. I don't recommend turbos with electronic fuel injection. Now I am looking for a 4 lb. procharger system. Complete Gale Banks twin turbo for sale $5,000 Canadian

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[rayjay]

Hey BigG, oh boy here it starts...

Ed, Why would you not recommend using E.F.I. with a turbo?

rayjay

[BigGrizzly]

Well Rayjay, Here we go again, just one more time and I'll stop all this foolishness. Any info on your project? Hope you get it together.
Hey Ed get the rest of your boat in the registry, I see gayl banks I see them all. Get that beautiful boat in there in all its glory. We don't care about no stinking huffer!!! Get that boat picture in, so the rest of us can enjoy it too. That is a one of a kind.
Randy

[This message has been edited by BigGrizzly (edited 12-11-2000).]

[avk]

Turbocharging and Donzi boating should get along very well. Most boat operation is done at more or less a steady throttle compared to an automobile and also done at higher engine loads. At my shop we do a lot of service work on turbo cars and they really do not have some of the problems that people think they have. Yes the turbo unit gets very hot but there are very good water cooled jobs to keep the heat down. Most turbos are oil cooled. The operating confines of cars is much more demanding than a boat where there is more room around the turbo unit.
With that said you need to engineer the motor to accept the turbo to realize full gains. If you have 10:1 CR motor and to paste a turbo giving you 7 lbs of boost, what you really have is a 15:1 CR motor and all its problems with preignition etc. All of this can be overcome by computer controlled ignition, cams etc. The twin turbos cars we work on run 10.5:1 Cr and 12 lbs of boost but it takes a computer to control the timing and fuel mix to keep it happy on pump gas. I cannot imagine running a turbo motor without FI controlled with an ECU.
There are several ECU's now on the market that do all of these things and are programmable via a laptop computer. The one we use the most is made by Haltech and the average cost of the ECU is about $700. They make one that plugs directly into a 350 EFI Mercruiser and you can custom program it to your needs.