We all love a tidy retro-fit and this KE30 Corolla is exactly that! Since the dawn of SR20’s we here in Australia have been swapping the tired 3k and 4k Toyota engines with the far greater potentiality of the Nissan SR20. Here at Powertune we have been tuning and modifying SR20’s for well over 10 years, and with that over the years we have developed a range of SR engine packages to suit all our enthusiasts needs. When HYROLA rolled in through the doors well over 3 years ago he was already fitted with the SR20. It was a completely stock SR20 with an unknown turbo setup, and of course our primary focus was to make sure it the package was functioning safely. After a once over inspection, a Haltech Sport 1000 ECU was installed in combination with a Flex Tune sensor, and dialed it in to 260kw on our Dyno. For over three years it was happily running with 260kw at the wheels, until the head gasket decided it had enough and let go not too long ago. It was time to go bigger and better!
We sat down with the owner and decided to go with our Stage-1 High Power engine build, a daily 500hp at the wheels being our goal. This package entails a complete engine rebuild from the block up, with upgraded aftermarket parts replacing some OEM components. We begin by completely stripping the engine down to the block. We then chemically clean, deck, bore, and hone the block. Now that the block is super clean we can give it an in-depth inspection by carrying out a crack test to insure the block’s integrity. In this case the SR block was rock solid, off we went.
Internals & Bottom end :
JE Pistons 86.5mm 8.5:1
Upgraded 9310 Wrist Pins
Nitto H-Beam SR20 Conrods with ARP2000 bolts
Crank was ground 0.25mm for that perfect finish
Tunnel bore block
Clevite race engine bearings
Nissan SR20 rear main crank seal
ARP Main stud kit
Top end :
New OEM timing chain kit
ARP Head stud kit
Tomei Head gasket
Powertune Special Head
SR20 BC Spring & Titanium retainer kit
Nissan SR20 Intake manifold
Fuel System :
Twin Bosch 044 fuel pumps
Bosch 1250cc injectors
BPP Fuel Rail
Turbosmart fuel regulator
Turbo System :
Garret gtx3076r @ 29psi
Tial rear housing
CRG high mount steam pipe manifold
Custom Powertune hot side cooler pipe
Turbosmart external waste-gate
Custom Powertune dump pipe plumb back to the screamer
Custom Powertune 3.5″ stainless steel exhaust
Helping HYROLA put the power down to the bitumen is an custom in-house RB25 gearbox conversion. Always a better option to over engineer components when ever possible, a Toyota Hilux diff takes care of the enormous torque that this package will produce. We are sticking with the Haltech Sport 1000 ECU, with added engine protection sensors. Allowing us to log and monitor at any desired point. This is instrumental when it comes to tuning the package correctly.
After a week or so of running in the freshly built SR20, HYROLA was back for the final tune of the Haltech Sport 1000. Tuning the package is a balance between power and response. Unfortunately when using heavier valve springs on SR20 engines, Nissan’s VCT or variable cam timing unit does not seem to handle the task well. It will always suffers from a premature failure and is a $700.00 fix every time. We decided to not use it, instead we have chosen to use a vernier/adjustable cam gear for the intake cam. Not the most ideal way we know that.
When tuning the power band, we need to choose the RPM band that will be used the most. In this case due to this being a street car, which isn’t exactly driven to pick up the ‘bread and milk’. More like weekend thrashings! We sacrificed some low end torque for more top end power. To achieve this we give the cams a wider separation angle or less intake cam advance. Finally producing 375kw @ 6100rpm on 29psi.
Now can we tune the ENGINE MANAGEMENT SYSTEM. Fuel tuning is as per normal. This is the case for all gasoline internal combustion engines . Ignition curve is tuned knowing each individual internal component inside the engine, and keeping to the limit of all the parts used.
Head gaskets, head studs, con-rod bolts all have a limitation. Knowing how much cylinder pressure/ torque can be pushed depends on the components used internal to the engine. Knowing how much RPM the components can withstand reliably comes only with experience.
KNOWING THE LIMITS. Since we built this setup from the ground up it gives us more comfort knowing where we can, and can not push this engine setup safely. These are the biggest added bonuses when we are able to manage the entire project for our customers.
When we are tuning an engine that we have built block up, we can push it to the limit and STILL feel comfortable. Even still due to our over-engineering we are delivering the owner’s request of 500bhp at only 80% of the package potential. Keeping well within the safe limits for a long and safe life with the Powertune philosophy “use the smallest turbo to reach the target horsepower”