Keep in mind the ecoboost lineup as well as mercs 1350's & 1650's have significantly lower compression ratios and let the turbo do the work in the form of boost.

Dustin's motors are low compression also, most forced induction motors are. The 1350 is 7.8:1 and Dustin's are 8.2:1. Both pretty low.

I think the motors Dustin just built would cost around $70-80k depending on exhaust and options.

Really a great value when you consider cost of rebuilds and maintenance and $ per HP.

MP

Ecoboost doesn't have low compression, it's 10:1. Mercury racing is 7.8:1 vs the 1075's being 8:1. Certainly not much of a change.

Dustin, you are correct, I was mistaken on the ecoboost.

Wow that does not happen very often on OSO. LOL :-)

Just when I start to think everyone on OSO acts like children someone finally acts like an adult. I love learning and debating and its nice to see someone can still do it with class.

MP

Dustin , do you know how much boost a Merc 1350 has at WOT ?
I,m trying to understand why the Merc 1350 has 28 psi boost during accelerating,and one would think the turbo,s are VGT style ..or the turbo,s are relativaly small to spool up fast ,and run high in boost quickly ,but to have high backpressure exhaust side while keep pressing boost.
I see on some pics the turbo,s have electrical operated waste gates ,so I can understand how they control boost thru the powerband .

The varible turbine turbos I mentioned before had the ability change thier "size" by manipulating vanes inside the housing and use of waistgate and vanes controllerl intagrated into an EFI system, bosst could be controled through out the RPM range.

turbo2256b: Input from someone with your resume is really appreciated. Like the old days on OSO!

What do you think about the new BorgWarner EFR series? It looks like the compressor map is wide enough and the turbine is efficient enough to support low flow/high boost without twin scroll or variable. Their approach seems to be mixed flow turbine, giving up some peak efficiency for a wider range of operation.

Ok i,ll bite here and jump off the nice nice bit i go to a poker run to see big blowers vibrating the dock and blower rolling now its called old school but thats what i want to see and hear we walk right by the shiny, looks like it belongs under the hood of a toyota, purring while idling mercs as they make martinis in cockpits so big a leather couch for a back seat might be more approiate! i want to see the ratty old V bottom with big cube,s with massive blowers and carbs big enough to run an aircraft carrier! anyone here remember the engines in sorcerior? or the echo of inxs as it went by? any one here ever play reggies 177 speed run thru a big sound system? i want the hair on the neck to stand up! I don,t want civil in a bad ass boat i want to always know were playing with fire! Old school maybe but rat rods are the rage these days. Now for a bit of fun if Duck dynasity goes poker running what boat can you picture Si in?

It varies depending on the baro and temp but 18-20psi of boost at high rpm. The turbos are realitively small. The 1650 has much larger turbos and significantly more boost.