"Free" may have been alittle broad, but even Ford admits the blower on the KR500 motor in the Mustang uses 150hp at full boost, that's more than an exhaust restriction.
Each have their pros and cons. To me, it seems turbos are more "tweaky" , but I like the sound! we will see

On my old setup in my 30' Checkmate, we had 25 lbs of boost and 25 lbs of exhaust back pressure. So back pressure doesn't always exceed boost pressure.

A good race twin turbo set up with headers and you will never look back!! Had one in a raysoncraft 21 v-drive was pretty bad ass.

The simplicity of the roots is hard to ignore but say you get the the point where you are transfering 150 hp from the face of the crank to the top of the engine into something has some very measurable inertia , you will probably have to start losing some forward passenger space too . And your long haired blond friends in the boat may be reduced to only sitting in the front seat(s) unless they tuck thier hair into tight fitting hats...or you have a big boat where the engine sits deep

good examples of how BSFC numbers can change, based on the type of forced induction, and should not be considered a fuel mixture tuning number.

Exactly. We ran at a 10.9 AFR under boost as that was what the engine wanted.

I like the "WOW" effect of turbo. My setup is old as $h!t, but when people hear that I have twin turbos, they are impressed. My original set up is a 1980 Mercruiser 475 HP twin turbo/ SSM II. Is has RayJay turbo, a PFM intercooler and wastegates. The exhaust risers say Gale Banks on them. I run about 10 lbs of boost. I know that I can easily overpower the TRS drives with the set up. TurboJack gave me some good tips on my set up. I cruise at 3800 at 2 " of vacuum at 40 mph. I can increase the throttles one click and Im making 4 psi of boost and running at 60. Its fun to her the turbo whine. I haven't had mine out in rough stuff (haven't had it running long enough, plagued by engine problems and drive problems) but the turbos are so small that I boost is instant after 3900 rpm.

[ATTACH=CONFIG]542715[/ATTACH][ATTACH=CONFIG]542716[/ATTACH]

A bit OT, but if you like turbo whine go to 3.30 in the vid.

3 x 57 liter W18 diesels, 5000 hp

https://www.youtube.com/watch?v=LXqCzD38zX0

I run an M3SC Procharged with a COG drive on my 540. Made my own main bracket which sets it off to the side of my exh manifold, down low. It's got a shift wine to it at RPM, enough to kno it's there but not annoying. Most get a smile out of it. I'm pullied for about 8 psi at 6300rpm. If I'm anything over 3000 rpm it'll make boost instantly if I open the throttle because the blower is spinning. If I'm light on it just cruising I'll even show engine vacuum. In bigger water I can close the blades, the BOV will dump the excess boost, hammer open and instant boost again. I love it. Very well mannered at the dock, for a cam with 250@50... Being no boost. Easier on drives while getting in plane. Plenty of torque with a 9.2-1 540 and easy on the motor because I only have the boost when I'm in the throttle. It runs way cool and has been very reliable.

Compound turbos in my 6.4L Power Stroke diesel. 700 HP 1300 FT LBs. Live turbos to. If you want no lag, then go smaller chargers. Then you lack the air flow in the top.

Roots take more power to turn, make more heat, boost off idle, look and sound neat.

Different strokes for different folks.

^^^ good info.

One thing i have noticed during some testing. I had always been told roots blowers make tons of heat. I think that can be misleading somewhat.

On icdedppls non intercooled 10-71s on his 540s, making 7ish lbs of boost, intake temps are around 130-140, as long as you hold it wot. Intercooled setup like that around 115*. Now, thats on a blower that isnt spinning to the moon. Ive heard of procharged aetups running similar temps intercooled. Not sure on turbos?