Recently a customer brought us a damaged K04 turbocharger for service. The turbo was burning oil and exhibited excessive shaft play. Upon removal of the compressor housing, it was evident the turbocharger sucked in debris in its life and the leading edges of the compressor wheel blades were damaged.

The following tasks were performed to ensure this turbocharger will keep service its owner:

• This turbocharger was part of the APR upgrade for the 2.0TSI and 2.0TFSI VW engine family. The turbo was disassembled, all components inspected and cleaned. The turbine shaft was checked for straightness, masked off for media blasting of the blades, inspected for stress fractures, and finally, polished. After that, turbine shaft size was measured with a micrometer to ensure it was still within specification.
• Compressor wheel had to be replaced and we found an exact copy of the original 6/6 wheel that was in that turbo.
• All housings were media blasted and cleaned.
• A rebuild kit was used consisting of a new journal bearing, oil seals, O-rings, thrust components, and most importantly, a true 360-degree thrust bearing. The OEM thrust bearing found in the Borg Warner turbos uses five small pads to support the thrust loads. We have a custom thrust bearing made with full 360-degree support. Just think about walking on thin ice and crawling across it.
• Turbocharger rotating parts were component balanced and then as an assembly to ensure trouble-free operation in a performance application.

We offer complete K03 and K04 rebuilding and upgrading service to suit your needs. We also offer individual parts for sale such as turbine shafts, billet compressor wheels, rebuild kits, 360-degree thrust bearings, and heat-treated tool steel oil seals.

Enjoy a few picture of the finished product!

Front view of the finished and rebuilt APR K04 turbocharger

Rear view of the turbo assembly

Comparison of the OEM thrust bearing, on the left, and the upgraded PRE 306-degree thrust bearing, on the right

Finished cartridge with a new billet compressor wheel.

Finished cartridge and the turbine shaft of this K04 turbo.

Cartridge installed in the media blasted turbine housing manifold assembly.

This is another testing session of the PRE 11 blade billet compressor wheel on a Subaru. This time the candidate is a 2008 STI with the EJ257 engine equipped with dual AVCS. This car belongs to the tuner we use for all our ECU calibration needs. This car suffered a rod bearing failure at 125,000 miles. Upon engine inspection, the failure was directly caused by a stuck relief valve in the oil pump. Needless to say, the engine required a rebuild. Instead of going all-out crazy build, the tuner wanted a car that would be as comfortable as stock with a bit more go. the goal was to use basic, readily available parts to show that you can build a reliable, quick, and fun STI at a reasonable price. I will not go into intricate details of the engine rebuild. Rather, I will list parts replaced and machining service performed. Nothing “trick” to say the least.

Block rebuild parts and services:

• CP forged pistons with coatings on skirts and crowns, OEM 8.2 compression, 99.5mm bore; PN: SC7420
• OEM STI connecting rods; inspected and honed on the bearing end to recondition them
• ACL Race series connecting rod bearings
• King XPG main bearings
• ARP head stud kit, 11mm standard kit; PN: 260-4701
• New OEM STI heat treated crankshaft, 79mm stroke; PN: 12200AA330
• New OEM 12mm oil pump; PN: 15010AA310
• New OEM engine gasket kit
• New OEM thermostat
• New OEM water pump
• New OEM STI oil pan
• Killer B EJ25 Ultimate oil pickup
• Cylinders honed as an assembly with two torque plates
• Block cylinder head gasket surfaces machined
• Main bearing housings line honed
• Bearing clearances and ring gaps checked and adjusted to PRE spec

Cylinder head parts and services:

• Cylinder heads disassembled, plugs removed and heads thoroughly flushed after bearing failure
• AVCS sprockets disassembled, inspected, and cleaned
• Supertech standard size, 36mm, stainless steel intake valves
• Supertech standard size, 32mm, Inconel exhaust valves
• Supertech dual valve spring kit with titanium retainers
• Both cylinder head gasket surfaces machined
• Radius valve job on the intake and exhaust seats
• Valve clearance checked and set to PRE spec

Accessories and bolt-on parts:

• OEM STI TMIC
• Go Fast Bits blow off valve(BOV)
• OEM 2008 STI cat back exhaust
• OEM headers and cross pipe
• PRE 11 blade IHI VF48 turbocharger
• Ceramic coated turbine housing
• GrimmSpeed up pipe with Tial 38mm wastegate provision
• Tial 38mm MVS external wastegate
• 4 port boost solenoid
• Invidia bellmouth downpipe
• GrimmSpeed 3in downpipe to OEM exhaust adapter
• APS hard turbo inlet
• Injector Dynamics ID1000 injectors
• TGV delete
• Cobb Accessport V3 controller
• Cobb flex fuel kit with differential fuel pressure sensor

First phone call I received from the tuner and he asked me “What the f$#% did you do with that turbo?!?!?” I was a bit worried but it turned out the spool of the car was so fast it required some trick tuning. The tuner commented that the car spooled so fast and air flow readings were so high for the given throttle input that the car was going into open loop operating. Using Cobb software, the ECU was calibrated to run conventional “pump gas” and E85 fuels. The tune was so good, the car would start, run, and idle on E85 in 20-degree weather without the typical gimmicks associated with E85 fuel and cold starts. The car is a blast to drive with loads of torque and any damp or wet conditions render first and second gear utterly useless with respect to traction.

Below is a dyno graph of this car comparing logs in 3rd and 4th gears. Note the car reaches 20psi boost in 4th gear by 3000RPM. The tuner commented he can be a bit more aggressive with boost solenoid and AVCS control to reduce spool by another 100-150RPM. Keep in mind, this is still a journal bearing turbocharger. Logs were done using E60-E70 fuel according to Cobb Accessport V3. Tuning can be even more aggressive with higher ethanol content fuel, which is unfortunately not available in Illinois during winter months when this testing was performed.

This second graph shows just a third gear log of this same setup.

You may purchase this billet compressor wheel from our eBay store: PRE IHI VF48 11 blade compressor wheel

What is new at PRE? Recently released and selling all over United Stated and even internationally. We are talking about the head stud kit for the Nissan QR25DE engine. We worked with ARP to make this kit available. No more using factory inferior torque to yield bolts.

PRE FASTENER ADVANTAGE:
PRE head stud kit is made to order by ARP and includes 10 head studs, 10 specialty nuts, 10 parallel ground washers, 1/2 oz. pack of ARP Ultra-Torque fastener assembly lubricant, and installation instructions. All Pro Series studs are centerless ground, heat treated prior to thread rolling and machining, and are nominally rated at 220,000 psi. These fasteners deliver a 50% increase in tensile strength over the OEM head bolts.

 

ADVANTAGE: HEAD STUD VERSUS HEAD BOLT:
-More accurate torque preload of the fastener. PRE studs, unlike bolts, do not twist during torque process, thus giving you a more accurate reading than traditional bolts that twist.
-Elimination of cylinder head lift. Cylinder head lift occurs when extremely high combustion pressure loads force cylinder head separation from the gasket interface, lifting it off the block mating surface, and blowing the head gasket.
-Reduction of head gasket fretting. Head gasket fretting is micro-motion between cylinder head, head gasket, and block interface resulting in the material loss at the joint. 
-More consistent alignment of cylinder heads. PRE studs installed prior to head gasket and cylinder head help with alignment and seating.
-Faster and more accurate engine assembly and disassembly

KIT CONTENT:
-10 head studs
-10 nuts
-10 washers
-assembly lubricant
-installation instructions

APPLICATIONS:

• Nissan Altima
• Nissan Sentra
• Nissan Frontier
• Nissan Murano (Japanese market)
• Nissan Rogue
• Suzuki Equator

Price: $170 shipped in the USA. International shipping available.

BACKGROUND

We were contacted by a team competing in the Pirelli World Challenge with an Aston Martin Vantage V8. The team was supplied a prepared race car with a stock engine which is not suitable for endurance racing. We designed and supplied forged pistons, forged connecting rods by Carrillo, PRE head stud kit, PRE main stud kit by ARP, Race Series main and rod bearings by ACL. All parts were specifically designed to be lightweight and sustain high engine speeds. Pistons designed with a strutted forging for strength and short 2.000in tool steel pins for strength and reduced bending. Pistons machined with lateral gas ports for top compression ring. Carrillo connecting rods designed for specific engine speed and take all component weight into account for inertial load analysis. Based on piston and connecting rod weights and engine speed the rod bolt loads were calculated and Carrillo CARR selected. Connecting rods designed with an H-beam profile. ACL Race series main and rod bearings were supplied for this engine; an exclusive from PRE.

PRE head studs start out as tool steel rod, that is CNC lathe machined, threads rolled, and heat treated. PRE main stud kit consists of M10 primary main studs, M8 secondary main bolts, and M8 perimeter bolts.

Pistons: Standard bore forged pistons designed with maximum allowed compression ratio by sanctioning organization. Pistons sent out for coating service. Polymer skirt coating reduces friction and prevents piston and cylinder wear while ceramic crown coating reflect combustion heat and prevents piston overheating and aluminum fatigue. Tool steel piston pins and gas nitrided piston rings selected for this application. Forged pistons weight was same as factory cast piston

Connecting rods: Carrillo forged connecting rods with H-beam profile designed for this engine. Carrillo multi-phase CARR bolts selected based on component weights, engine stroke, and engine speed requirements. Connecting rod weight reduced significantly from stock rod.

Bearings: ACL Race main and rod bearings used in this engine. ACL Race bearings are of tri-metal construction and connecting rod bearings made using heat treated steel backing.

Fasteners: Bespoke head studs designed for this application. ARP supplied main stud kit.

 

Below is a dyno graph and engine and vehicle preparation summary of a 2002 Subaru Impreza WRX wagon we tested recently. Testing was performed with a target boost of 21psi and still a very conservative ECU calibration. Peak boost is 21psi and tapers down to 17psi at redline.

Engine short block build details listed below:

• OEM EJ205 block (bored 92.5mm, honed with PRE torque plates, deck milled, align honed)
• New EJ257 heat treated crankshaft; PN: 12200AA330 (rebalanced)
• King XPG main bearings; PN: MB5382XPG
• ACL Race connecting rod bearings; PN: 4B8296H
• Manley forged stroker pistons; PN: 620005C-4 (weight matched as a set and coated skirts and crowns)
• Manley H-beam forged connecting rods; PN: 14024-4 (weight matched as a set)
• ARP2000 head studs; PN: 260-4701
• New OEM STI 11mm oil pump; PN: 15010AA360 (deburred and blueprinted)
• New OEM gasket kit
• Gates Racing timing belt kit; PN: TCK328RB
• New OEM water pump
• OEM STI baffled oil pan
• Killer B EJ25 oil strainer

Cylinder head build details listed below:

• EJ205 cylinder head castings
• 3 angle valve job
• deck mill heads
• measure and adjust valve spring pressures
• measure and adjust camshaft follower clearance
• Supertech stainless steel intake and exhaust valves; standard size
• Supertech dual valve spring kit
• OEM valve stem seals
• GSC S1 camshafts

Fuel/Ignition/Misc system:

• Injector Dynamics ID1000 injectors with PNP harnesses; originally car fitted with FID(Fuel Injector Development) 1000cc injectors; FID injectors made for terrible tip-in, idle, and part throttle driving was horrendous! ID1000 without retune made considerable improvement. After retune, drivability is delightful).
• Walbro 255 fuel pump
• New OEM ignition coils
• New OEM IAC(idle air control) valve
• Autometer gauge pod replacement bezel
• Stack oil pressure gauge
• Stack boost gauge

Exhaust/Turbo/Intercooling:

• Borla header; already on the car and had to be repaired due to warped header flanges
• Borla catback exhaust
• Full Race up-pipe
• Full Race Borg Warner EFR7163 turbocharger with internal wastegate, recirculating valve, and T25 flange
• Full Race V-band down pipe
• Up-pipe, turbine housing, and downpipe ceramic coated by Full Race
• Mishimoto TMIC kit
• PRE TGV delete service

Drivetrain:

• Spec stage 2 clutch (surprisingly very good feel and street drivability characteristics)
• 2006 STI 6 speed transmission swap

Finally, the dyno graph! 398WHP using Dynojet calibration! Click to enlarge.

Due to popular demand we are now offering Subaru ignition coil connectors to the public.

We are proud to offer brand new, OEM ignition coil connectors for all Subaru engines equipped with individual cylinder ignition coils. Subaru engine bays reach very high temperatures causing plastic connector heat cycling and leading to brittle tabs which eventually break off. Engine vibration causes loose coil connection and leads to misfires and in worst scenarios engine damage. Subaru dealer will not sell you individual connectors. They will only offer you a complete, new harness for ~$300. This is an economic repair option for your Subaru. These connectors compatible with all USDM, JDM, and worldwide market Subaru’s using coil-on-plug ignition system. We have large supply of black connectors and limited supply of white connectors. Please email for availability and ordering. 

Compatible engines and vehicles:

• EJ205 USDM 02-05 WRX
• EJ257 USDM 04-07 Impreza STI, single AVCS
• EJ257B USDM 08-14 Impreza STI, dual AVCS
• EJ255 USDM 04-08 Forester XT, Legacy GT, Outback XT
• EJ255 USDM 06-14 Impreza WRX
• EJ207 JDM Impreza STI
• EZ30D
• EZ36D

Content: one ignition coil connector 

Notes: Rubber insulating grommets, metal terminals, and yellow lock wedges available separately. Please inquire about pricing.

Connector cost is $5USD each and shipping is flat rate $7USD, whether you buy 1 connector or 50. International shipping also available.

Look at our other available Subaru parts and service!

You may purchase these connectors from our eBay store:

Black ignition coil connector

White ignition coil connector

4 piece connector set; 2 black and 2 white

6 piece connector set; 3 black and 3 white

Pavel’s Racing Engines is pleased to offer parts to rebuild your damaged or worn out IHI VF34 ball bearing turbocharger. This turbo typically found in Subaru Impreza STI vehicles with an EJ207 engine.

DIMENSIONS:

• Inducer: 48.00mm
• Exducer: 53.00mm
• Exducer tip height: 9.20mm

You may purchase this turbine shaft from our eBay store: IHI VF34 turbine shaft

We also offer billet compressor wheel upgrade for the IHI VF34 turbocharger. Compressor wheel description link found here: PRE billet compressor wheel comparison

You may also purchase this billet compressor wheel from our eBay store: PRE VF34 11 blade billet compressor wheel

Pavel’s Racing Engines is extremely excited to offer this product to the public. We have been testing these compressor wheels in various turbocharger models and engine combinations. Every time this product proves to make more power than its cast aluminum counterpart!

We tested these compressor wheels on the dyno with a consistent 25-30WHP gain at same boost level as stock cast wheel. Torque increase was moderate as well in the mid-range engine RPM. All testing performed on same vehicles within a narrow installation time window to reduce erroneous data.

This particular post focuses on billet compressor wheels for IHI VF-series turbocharger found on JDM, USDM, and UKDM Subaru Impreza WRX and STI vehicles.

COMPATIBLE TURBOCHARGERS:

• VF30 (JDM V5 STI)
• VF34 (ball bearing turbo)
• VF37 (twin scroll turbo, JDM V7/8 STI)
• VF39 (USDM 04-06 STI)
• VF43 (USDM 07 STI)
• VF48 (USDM 08-15 STI)
• VF52 (USDM 09-14 WRX, upgrade for 2008 WRX and 05-09 Legacy GT, originally VF40 or VF46)

PRE BILLET WHEEL FEATURES AND ADVANTAGE:

• 11 blade design: Conventional design is 6 tall and 6 short blades. Garrett has proven higher flow potential of the 11 blade design and it has been adopted to this compressor wheel for IHI application. 
• Extended tip design: Conventional compressor wheel tips perpendicular to the exducer diameter. Extended tip technology originally developed as “cheater” compressor wheels for racing use. Standard exducer diameter is 60mm, while extended tip compressor wheels had 63mm exducer diameter for total blade area increase of 6%. This of it like a larger area of an airplane wing allowing for increased lift. The larger surface area allows for increased flow volume at same turbo speed. 
• Slim blade design: Performance feature designed to increase air flow. Slim blades have a smaller cross-section allowing more area between blades for air. Flow is increased at same turbo speed. Thinner blades also weigh less for reduced moment of inertia and faster spool.
• Slim hub design: Another feature designed to increase air flow. Slim hub increased air volume with each rotation. Flow is increased at same turbo shaft speed. Smaller cross-section hub weighs less for a reduced moment of inertia and faster spool.
• Material selection: Conventional compressor wheels made by casting aluminum alloy. PRE compressor wheels machined from billet aluminum alloy block. Billet blocks are forged. This compacting of molecules increases material density and strength. Increased strength of billet material allows for reduced blade and hub cross-section and weight reduction without increasing internal stresses. 
• Balancing: PRE compressor wheels inspected and computer balanced to less than 0.5g-cm^2. This does not mean compressor wheel should be swapped as-is. Stack-up dis-balance is always a factor and compressor wheel balancing should always be performed by a professional using entire rotating assembly. 

Extended tip technology comparison: black dotted line is conventional design and the red dotted line is our billet wheel design.

Recently we dyno tested a couple of Subaru cars and recorded data logs. To keep this an apples-to-apples comparison we tried keeping the variable to a minimum. This comparison shows a 42WHP gain at 1.5psi LESS boost than stock turbo.

Car 1 (Red Line) 2007 Subaru Impreza STI

• Stage 1 rebuilt short block with 8.8 compression forged pistons
• stock rebuilt cylinder heads
• stock fuel injectors (maxed out at 21.5psi)
• stock fuel pump
• larger intercooler
• Perrin inlet pipe
• OEM rebuild VF48 turbo with cast compressor wheel (6/6 blade design)
• ECU tuned by 555 Motorsports

Cars 2 (Blue Line) 2010 Subaru Impreza WRX sedan, 5-speed manual transmission

• Stage 1 rebuilt short block with 8.6 compression Wiseco forged pistons
• stock rebuild cylinder heads
• stock fuel injectors (maxed out at 19psi due to higher flowing compressor wheel)
• stock fuel pump
• larger intercooler
• Perrin inlet pipe
• OEM VF52 turbo rebuilt with PRE billet compressor wheel (11 blade design) VF52 same size turbo as VF48. The only difference is compressor housing outlet orientation. All other internal parts same.
• ECU tuned by 555 Motorsports

Clink image to enlarge

 

You may purchase these billet compressor wheels from our eBay store:

PRE VF30 billet compressor wheel

PRE VF34 billet compressor wheel

PRE VF35 billet compressor wheel

PRE VF37 billet compressor wheel

PRE VF39 billet compressor wheel

PRE VF48 billet compressor wheel

PRE VF52 billet compressor wheel

Pavel’s Racing Engines is pleased to offer high performance connecting rod bearings for the Subaru FA20 and Toyota/Scion FRS 4UGSE engine. This bearing kit made by King Bearings and meant for high performance street and race engine use.

AVAILABLE GRADES:

• H-STD (standard)
• HX-STD (extra clearance by 0.0010 inch)
• H-STD 0.025 (less clearance by 0.0010 inch)
• H-0.25 (undersize 0.25mm/0.0100 inch, repair size #1)
• H-0.50 (undersize 0.50/0.0200 inch, repair size #2)

KIT CONTENT: 8 high performance tri-metal connecting rod bearing shells

KING XPG BEARING ADVANATGE:

The unique combination of design, metallurgy and engineering come together to deliver what drivers expect from high performance tri-metal engine bearings.

• Designed to withstand higher RPM conditions, King XPG Race Series engine bearings are available for many of the popular 4, 6 & 8 cylinder applications and feature: 
• pMax Black high strength overlay plate with reduced thickness for improved fatigue properties 
• Hardened steel backs on all rod bearings to improve the support of the bearing lining and assist with bearing retention in the housing 
• Increased crush for improved bearing retention 
• Elimination of flash plating on the back of the bearings to improve heat transfer through the bearing sand to maximize the grip between the bearings and its housing 
• Increased eccentricity to compensate for bore distortion at high rpm and to assist in the formation of hydrodynamic oil films 
• Bulls Eye Tolerance- tight consistent wall tolerances to help you maintain consistent clearances 
• Enlarged ID chamfers on bearing edges where required to accommodate large fillet radius on performance crankshafts

COST: $130 shipped in USA and Puerto Rico. Email us for specific grade availability.