Pettit Racing BPHF Hi-Flo Turbo Charger RX7 FD

Our blueprinted Hi-Flo or BPHF Turbo unit is far superior to the stock unmodified unit where mass production practices leave sharp edges directly in the exhaust path creating hot spots that can cause cracks.

With our units, turbo housings are ported and contour radiused creating a bevel on all those unfinished edges, this reduces hot spots* minimizing chances for heat cracking. 

Aside from Improving longevity this procedure also improves the flow path and efficiency of the unit.

For the compressors, we port and blend the tapered discharge outlet (snail) improving efficiency and spool up**

Then all mating flanges are machined flat and to help reduce under hood temperature a ceramic thermal barrier coating is applied to the hot section. 

All this results in a much-improved RX-7 turbo unit that has proven itself by providing both reliability and superior performance for our customers since 1994.. This same basic turbo was used in our road racing Mazda RX7 to win the 1998 GT2 Championship!

Nearly every RX7 twin turbo  we receive has cracks, we have seen many attempts to weld them but all have failed. The weld material eventually comes loose destroying the exhaust turbine wheel on its way through the turbo. 

We have found over the years that  old existing cracks*** are no longer a problem after our modifications are done and we have never seen a crack related failure of our turbo housings. This is because our procedures minimize the hot spot areas, reducing the heat loads that cause the cracks. This alone makes a huge improvement in longevity, but then we apply a Ceramic Thermal Barrier Coating to the unit further improving thermal performance. 

One of the most important things we have found is getting a proper install of the turbo unit. Using anit-seeze on all the threads and proper torque on all the fasteners is a must, then after several good heat cycles we retorque the fasteners. It is also a good practice to retorque the fasteners after track events as well as twice yearly. 

 For complete assemblies like sequential and non-sequential turbo units, the individual components are fixture assembled ensuring proper alignment.

Warranty, 12 months from purchase date, If the part fails for any reason we will replace it free, you must obtain an RA# and return the failed part to us. We only provide the replacement part; we do not pay for shipping, installation labor or anything else.  

We offer the same modification and blueprinting service for your turbo and/or manifold. Typical cost to build your turbos ranges between $1200-$1600 depending on the condition of the part. 

Each turbo unit or manifold we receive is disassembled, inspected and quoted, prior to any costs being incurred. 

FYI  Our prep and build process actually provides a part that is more stable and robust then new. All new turbo castings are “green castings' (without heat cycles) having high internal stress, a less stable part that is more prone to warping and cracking from heat load. Heat cycling from normal use together with our machine work and modifications relieve stress minimizing hot spots that promote cracking. Then to help reduce heat radiation and underhood temps, we apply a Ceramic Thermal Barrier Coating. 

* It is a fact that the OEM unmodified turbine housings as well as the new Jspec 99 style units have a design which creates an exhaust flow path that causes hot spots in several areas of the turbine housing, this leads to small cracks in the housing which will grow until finally creating exhaust leaks that make housing replacement necessary.  


**  Spool up is the time it takes for the compressor to reach set boost, our BPHF turbo units even seem to have improved spool time over the 99 J spec turbo unit with abradable compressor housing inserts. This design, where the compressor wheel is in contact with the insert is thought to be more efficient due to closer tolerances, however; this contact can generate friction and may cause slower spool times. 

*** Existing cracks in your turbo housing may be large enough to cause the part to be unusable, in this case it can be replaced, each turbo unit we receive is disassembled, inspected and quoted, prior to any costs being incurred. 

**** The same turbo unit was used on our race car but as a twin or non sequential setup


Industry Secrets they don't want you to know!

Turbo Cool Down Cycles: common sense that's not so common

 So it appears less use, (hours of operation)  means less failures, fewer repairs and your stuff lasts longer. To accomplish this just requires modifying our thinking and some changes to how we use things. 

It is common to hear I always start my car and let it run for 15 minutes before driving. Then let it run for 10 or 12 minutes to cool the turbos when I'm done. In just 1 year of daily use it can add  up to an extra 150 hours of wear and tear, unnecessary fuel consumption and as a result, the polluting emissions. That’s three strikes in my book, there has to be a better way. 

Letting engines idle to warm up dates back to the early days of automobiles and trucks, back then you had to warm them a bit just to make them go and they were so slow you didn't really need to warm the rest of the drivetrain. It's one of those handed down things my dad's dad and his dad's dad and uncle and brother that's how they did it and that's how we do it, we don't question it. 

With today's vehicles idling to warm the engine has many negative points: only the engine warms not the driveline tires brakes or suspension.  It causes unnecessary wear and tear creates unnecessary emissions and wastes fuel.  3 strikes!!

If you want your vehicles to deliver the maximum performance and longevity, with minimum expense for maintenance & repairs as well as minimize your environmental impact from emissions / pollution, there is a simple easy way. Instead of idling to warm up, just drive easy gently warming everything at once. 

A simple change to the way we do things and three strikes become three home runs. If your car is not moving, turn the engine off, no fuel is being wasted at idle, no unnecessary wear and tear on the equipment and no emissions are being generated. All those benefits from making one simple change, but with turbos everyone agrees, idling is necessary to cool down the turbos.  For countless years Idling is how turbos were cooled. it's been the only way until now.  Here’s why, idling still produces combustion feeding the turbo hot exhaust, did you ever notice even after idling for a few minutes, four or five hours later the engine is still too hot to touch. 

Endurance road racing turbocharged rotary engines is a challenge to say the least. Our turbos seemed to be holding up well as long as we serviced them every two races, polished the turbine end of the shaft and maybe changed the bearing, otherwise after two races they would fail. We theorized such a simple device a shaft with two bearings should be much more reliable. 

Then at night practice for the Daytona Rolex 24 we noticed the turbos didn't seem to be cooling down, even after 10 minutes of idling they were still glowing red hot. The instant the engine shut off the color would dull, after inspecting some failed units and doing research we were confident that heat transfer from the turbine wheel into the bearing housing was causing the thin oil film to burn forming carbon, coking up the bearings and causing the failures. 

We decided to try an idea we named “cool down cycles” and our bearing failures became a thing of the past. Now turbos lasted many races and the occasional failure was not bearing related, it was the result of other bad things we had done.

Here’s how a cool down cycle works: 

When you arrive at your destination immediately shut the engine down, then turn the key back on so only the fans run to reduce temperature of the radiator fluid, after a minute or so restart the engine for 10-15 seconds to feed the turbo’s  bearings and shaft some cool fluids. On street cars two cool down cycles usually rejects enough heat to prevent carbon and coking of the bearings. At the track after misting water on the radiator and oil coolers and performing 5-6 cool down cycles you could touch the turbos, otherwise they stay too hot to touch for several hours.  

Job security is why you never heard this before, shops want to keep cars and trucks with broken turbos lined up to be repaired and turbo builders want them piled up at their doors. 

There are exceptions; however, in extremely cold climates sometimes you have to warm it to make it go but in those environments you should have a block heater.


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