MC Express Turbo vs Mr Turbo (long post)

OB_gsxr1300

Registered
Just got back from Motorheads shop, and seen his MC Express Turbo..
If you are in the market for a turbo, you should REALLY take a serious look at this unit. Although it is pricey, in this case you do get what you pay for!
Some observations, the Turbo is a heavily modified Mitsubishi G13 (off of the 3000GT's), this Turbo is a "Hybrid". If your familiar with Garrett turbos, "Hybrids" are turbos that incorporate the best features of several models into one.The exhaust housings are heavily modified, allowing the use of a larger compressor wheel, increased bypass valve volume etc. This turbo also utilizes water cooling, the centersection of the Turbo is cooled by a radiator bypass hose, removing heat from the center section of the Turbo increases the bearing life.
Comparing MC Express Turbo to the Mr Turbo turbo...The Mr Turbo uses a RayJay F40 (F40 is the compressor wheel), this Turbo is a larger unit (overall demension), plain bearing. The large surface area is used for cooling. Rebuilding a Rayjay is a piece of cake, almost any turbo shop in the country has the parts to repair it. The biggest difference between the MC Express and the Mr Turbo turbochargers is the compressor wheel effienceies. One rating a Turbo is given is the "efficiency rating", this is a simple 1-100% scale. In a perfect world, we could design a Turbo that builds boost without generating heat. BUT, unfortunetly, heat is generated when we build boost (compress the air). So the higher the "efficiency rating" the LESS heat that is generated at a set boost level. Inotherwords, the MC Express Turbo has rating of 78% and the Mr Turbo has a rating of 69%. The MC Express Turbo will produce 9% more HP.
This is were the Intercooler is used. To reduce cost, the Mr Turbo system does not use an intercooler. THe MC Express does, BUT, you have to make the intercooler large enough with a large internal airflow that is not restrictive. Most bike intercoolers are to small, bikes just don't have the frontal area to install one. This is another area that MC Express has done there design homework, they incorporated a large curved intercooler that utilizes the factory RAM air holes. Reduced intake air temperature, increases the O2 level and reduces the killer of turbo bikes, detonation.
Fuel delivery:
Mr Turbo takes advantage of the factory EFI system to it's fullest. They increase fuel pressure to compensate for increased boost level. This is why the MR Turbo system is limited to 7psi of boost or 240hp, the factory EFI system's fuel delivery is max'd out.
MC Express incorporates 4 addtional fuel injectors. These injectors (to my surprise) have the lastest technology, "quadhedrial cone" spray patterns. A fancy term for 4 fine spray mists vs 1 large cone pattern. The advantage is finer spray patterns, better fuel atomization. The injectors are built into the intake manifold, pointing down the into throttle bodies.
MC Express incorporates a pressure activated switch to turn on the secondary (or staged) injectors. A VERY antiquated (old??) way of doing it, but very simple and cost effective.
The manifolds are very well done, although both need more intake pleneum volume. The exhaust manifolds, both could use longer primary tubes, but space on the 'Busa is limited.
Insummary:
The MC Express is a real quality unit, almost a custom made look. The pieces are really heavily constructed, almost overkill.
The Mr Turbo is a simplier unit, tried and true turbo. Least expensive of the bunch.
Biggest problem with both of these systems, you are EXTREMELY limited in the power delivery control. What I'm refering to is controlling the boost and fuel level deliveries. Both of these systems NEED programable EFI, think of a PC II on steriods. Like how about a PC IV!!
I have programmable EFI on my turbobike, I have progressive boost control based on gear and RPM, digital water/methonal injection (reduces detonation), traction and wheelie control, two-step, anti-turbolag, autoshift control, Wide band Lambda closed loop and If I want progressive NO2.
Welcome to the digital age......
 
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