Again, not bagging on R-techs products, but I checked their website and it shows supercharger packages ,i.e. modifications to existing motors. I'm talking about mainstream engine packages don't have Centrifugal chargers- 600SCi,700SCi, 850/1075/1200SCi, Even Teague and most others seem to go with Roots style or screw blowers, knowing they are harder on drives. Is that ALL for eye candy? Knowing they are less efficient? I was going to go with a procharger setup on my 31' Scarab because of the benefit of less load down low on the drives, I sold the boat before I got around to it.

Sorry, I do see their 800 SCi motor...Mike

It depends on the boat. Most people with the money for a 850+ HP engine is pushing a huge azz boat with it. If you are running well over 100 MPH in a heavy azz boat it is important to have a ton of power down low so you can actually get to top speed. In that case roots style is better. For a company like Merc who sells to everyone, they run roots style because you can easily run a roots blown boat in anything. A centrifugal blown boat won't work well in many cases, but where they do work they excel in many ways

In the case of a smaller boat the roots style is a total waste. Even some bigger boats it is a waste depending on weight. For example, Cig Top Gun I'd go with roots style. Cig Gladiator I'd go Centrifugal.

I realize these guys are not marine based but they make some awesome engines with centrifugal chargers.

http://www.nelsonracingengines.com/

It looks as though they might not be doing them anymore

Whipple is not roots, when you say Whipple, your refering to a screw-type supercharger, extemely more efficient. Screw type is a compressor, roots is a pump.

We made a side mount kit for awhile, but because that severly limited fitment in dual and triple applications, we stopped mfg'ing it. They worked great, excellent power, but the new stuff is better, which is mounted like a traditional supercharger, which is in the center.

Thanks,
Dustin

A centrifugal is no more efficient than a screw type. What matters is the kit, the size of the sc, rpm range, intercooler design, etc. A roots is towards the lower end of power levels, but it depends on what the mfg's are looking for. If Mercury only wants 600hp, and have a 502ci engine already, then it doesn't need to be very efficient to make 600, does it so easy. And at 4psi, it's hard to gain any advantage on blowers, because no blower is taking much power or creating much heat. Get to 10psi and above, and your talking night and day between some supercharger designs.

I'm happy to report I'm approaching 75 trouble free- HARD hours on my 496HO with a Whipple which was installed this past Memrorial Day and loving every minute .

Screw compressors like whipple/lysholm, PSI, give even more low end power than a roots, and a comparable high RPM HP as a centrifugal would.

What's a guy going to spend to put a wipple on a 454?