Joe,

I do have better answers, However this is 25 years Tom Earharts work and break throughs. Until I talk with him I'am not sure how much more to or not to say.

I have read a great deal of your post over the years and I know your no stranger to turbo's and the efforts that go into them.

So I also hope you can understand my spot on this and the repect owed to Tom aswell.

Thanks
Jon

No problem and I understand, but you know as well as I do, the moment he sells one there are no more secrets!

Have a good night, I'm still trying to catch up from 19.5" of snow last night!

I don't have pictures but I'll try to explain this a little better for you. There are many things that can be done to a turbo charged motor that make them handle throttling much better than they have in the past. Some of it has to do with newer designs and materials that allow for lighter and more efficient wheels(mainly the compressor side) as well as better performing bearings that decrease the "spool" time. Other areas, for instance, the compressor housings, are better designed to help with surging, efficiency, etc. There are other things that have been learned over the years, such as intake and camshaft design, that when utilized correctly add tremendous performance to "today's" turbos. The trick is too design an entire system that can benefit from all of this. Something we believe we doing better than anyone else.

The new plumbing you ask about has to do with the routing of the bypass valve air back though the turbo in order to spool it when closing the throttle (much like if you used a leaf blower and forced air through the turbo, it would spin) The pictures posted by cougarman are somewhat incomplete. This particular motor is in a lake boat where throttling is more or less irrelevant, and in the interest of time and money some things have not been implemented yet.

I hope this clears up some of the confusion, I would love to tell you everything that we have learned but that wouldn't be good for us would it.

And believe me that has been a subject discussed and a concern. Tom has been after this for years cause it's a passion of his and when you never let off from persistance it's amazing what is accomplished and the breakthrough's that come with that persistance.

There is a big difference in the engine builder that is passionate about what ever the choice may be VS. The builder that build's every thing and occasionally they are contracted to see if they can build a turbo engine or what ever the choice may be.

So it's been a fine line,.......do you keep it fun and keep doing as Tom has. Or does he start to offer it to the public and it turns from fun to a full time effort and all the hassel's that go with it along with letting your secretes out and fair game to all compeditors?

Hope that makes sense and not just a long ramble.

Thanks again
Jon

Granted this is un-related but may interest you as Tom is no stranger to speed and break thoughs. Also if you remember Allez Vite the 41' Apache back in the actual race days,.......Tom was the one that ended up building the engines in there for Pete Rhodes after Mercury had theres in there.

Anyway's here is the link.http://www.snowmobilehalloffame.com/earhart.htm

TOM EARHART
DATE OF INDUCTION: January 13, 1994
CAREER SPAN: 1968-1987
AGE AT INDUCTION: 51

A daring and talented snowmobile innovator, engineer and racer, Tom Earhart began his career building and racing drag and oval track sleds in Michigan as chief engineer for Rupp. His Rupp and later Speedway teams dominated Michigan racing in the early 1970's, winning three State Championships and winning again in the well-financed factory teams of the early Sno-Pro era with Earhart-designed ultra lightweight sleds.

Racing with partner Bob Gaudreau in the early 1980's, Earhart set a series of snowmobile speed records with the Mercury outboard engine-powered Budweiser Polaris, breaking the National Snowmobile Speed Record four times reroute to creating the track and suspension engineering breakthroughs that punctured the 140 MPH barrier. In his final season of speed run competition,
he posted a top speed of 177.04 MPH with the Arctic Cat Silver Bullet in 1986.

Racing against strong competition during the "big engine" days of the National Snowmobile Speed Run circuit in the 1980's, Tom proved adept at building sleds capable of record speeds and delivering the consistent piloting necessary to post records in NSSR. Tom's many technical innovation Engineering ward for his track and suspension development in 1987.

The new plumbing you ask about has to do with the routing of the bypass valve air back though the turbo in order to spool it when closing the throttle (much like if you used a leaf blower and forced air through the turbo, it would spin) The pictures posted by cougarman are somewhat incomplete. This particular motor is in a lake boat where throttling is more or less irrelevant, and in the interest of time and money some things have not been implemented yet.

Porsche has been using bypass valves on there turbo cars for over 20 years, i am glad to see though other people[like Tom] trying different ideas on turbocharger tech.

Whats a Turbo???
 

I love this thread! I love to learn, and I am learning more about turbocharging technology everyday!
I am looking in my crystal ball now and I see a turbo in the future of marine performance engines! Geez I'am getting more foresighted all the time!
Todays turbo's with VNT technology, ball bearings, electronic waste gate and boost control and electronic ECM management on the turbo engines and fuel systems, believe me when I say there is a place for properly turbocharged marine performance engines, especially when you consider the noise control issues being shoved down the industrys throats. It does not take a crystal ball to see the future of turbos in marine performance , just a little education, innovation, applications and good results, all of which is forthcomming!
As for the race between screw superchargers and turbochargers, Hell, I love a good race!! Bring it On!

Best Regards,
Ray @ Raylar

So back to the Merc thing, are they unveiling these bad boys in Miami? And anyone else hear the talk of Ilmor dropping a new motor there?

Excellent post there Ray, i still love the big supercharger but i do like seeing something new under the hatch, remember when the turbines were just hitting the poker run circuits, people were talking bad about them for slow throttle response[and they are] but we see more and more show up every year.

here a description of the bypass valve with a simple drawing of the circuit.http://en.wikipedia.org/wiki/Blowoff_valve