Korean R34 GTR vs S15 GTX35 30psi

Posted by in Brewed News, Brew Crew, Tech, Brewed Projects on August 30, 2015 . 0 Comments.

Nismo RB26 GT-R and GTX35 S15 Tuning Trip in Seoul

South Korea is a very interesting place with a booming “pop culture” and a young population that loves to express itself through a variety of styles, hobbies, sports, arts, etc. For some this may come as a bit of a surprise but among these social clicks lies a diehard group of gear heads and motorsports fanatics that build and modify USDM, JDM, EUDM and of course KDM vehicles alike. 

While living in Seoul back in 2010-11 I met a Mr. Kim (owner Pro-Concept Korea) through snowboarding of all things. We got to talking and long story short I quickly learned his power FC had been tuned poorly and his S15 not running well. I have had a lot of experience on the old PFC boxes and Mr. Kim was happy to have someone who knew what they were doing available to properly tune the ECU. Before the re tune Mr. Kim ordered up a few special parts from our location in the USA that we I installed at his SUPER clean work shop in Incheon (suburb of Seoul). This first build was your basic GT2871r, tubular manifold, 80mm turbo back, 550cc injectors, 255 walbro, front mount, EBC and the power FC (z32 MAF). S15 street car build Seoul 2010/11 GT2871R SR20det Brewedtuned 

S15 Forged Bottom end and GTX35 VE turbo kit

velocity element Vband Sr20 turbo manifold

A few years go by and Mr. Kim continues to request parts from Brewed Motors US for his customers and always keeps us up to date on his personal S15. In the summer of 2015 Mr. Kim decided his S15 was ready for a makeover. After wide body, wheels and paint he sent me an email requesting: pistons, rods, GTX35, VE turbo manifold and a nitrous kit. We quickly got all the parts shipped out and he assembled his new forged internal SR20 in preparation for the new turbo kit and Nitrous. Once the engine was complete we scheduled the dates I would travel to Seoul to handle the final set up and tuning.  

Velocity Element Vband turbo manifold SR20

By the 1st of July I was in Seoul wrapping up the custom down pipe, wastegate re-circ tube and plumbing for the new s15 build. To help ensure the trip would be cost effective Mr.Kim had also lined up a second Nissan for tuning, one of his customers with a R34 Skyline running Nismo twins and an HKS Fcon Vpro ems. July 9th both the S15 and R34 were boost leak tested and ready for tuning. After an hour with each car tuning on the street we headed to dyno. Thanks to my time with the cars tuning on the street at the dyno things progressed quickly and each car only required ~45 min tuning on the dyno to complete.

gtr brewed dyno tune

First up was the RB26 powered R34 running HKS Fcon, nismo twin turbos, 555cc injectors and pump gas. Although the r34 owner could not verify this, based on how the car "tuned out" and the power it made I suspect the RB26 had 272* or 280* cams which are a good match for the larger Nismo Twin turbos. On the street I was able to dial in the “economy” section of the tune to net 24-27mpg (as long as the driver stays out of boost) and on the dyno the car put down 447whp at only 1.25 bar of boost. Unfortunately at this point the little 555cc injectors were maxed out preventing me from tuning for more boost. With a set of Injector Dynamics 1000cc injectors 500whp would have been no problem at about 1.6-1.7 bar boost on pump gas.

gtr-rb26-dyno-tune-17psi

As the S15 was being strapped down to the dyno Mr. Kim came to me and said he really wanted to “push” the engine for max power. I let him know I always tune for the best power with the most reliability and that the limiting factor for his car would be the small 264 cams and the ~91-93 oct pump gas. After 5 pulls in “low boost” 1.5 bar the car was making 411whp (through a z33 trans and big heavy 19” wheels). At 1.5 bar the engine was still VERY happy with a good amount of ignition timing and with no knock I started turning up the boost. 15 minutes later the car was at 1.9 bar (~29psi) and putting down 451whp still with no knock. With this much boost from the GTX3582R the cams, intake manifold and stock head ports really start hold back the power as they simply cannot keep up with the GTX35’s air flow. Once the low and high boost was dialed in we could move on to the Nitrous. Using a Zex wet nitrous kit (triggered at WOT) with a 25 shot jet the car put down 483WHP with a HUGE increase in the midrange power. Even with 29psi and a 25 shot there was no knock, smooth power delivery and extremely low EGT’s. (The low egt’s I must credit to the VE turbo manifold, Tial Vband turbine housing and MVR 44mm waste gate. These parts allow the exhaust to flow almost unrestricted which keeps lowers EGT’s and helps prevent knock aka detonation in the engine. OF COURSE tune also plays a HUGE role in the EGT’s and knock.

high boost tuning 2 bar pump gas

After the Dyno session we headed out for a quick cruise to give the owners a chance to enjoy their properly tuned cars. A few short minutes later I was greeted with ear to ear grins and “komsomneda’s” (thank you) from 2 very happy Nissan owners. After a few laughs about just how much better both cars drove compared to before they were “Brewedtuned” we headed off to our top secret Korean Fried Chicken and beer spot to discuss the next tuning trip to Seoul.

  • Power FC speed density tuned with Datalogit
  • stock bore CP pistons (stock compression)
  • manley H beam rods
  • ACL bearing WPC coated
  • 264 cams (need to be changed to 272 or 280* easily another 50 HP)
  • Velocity Element Vband manifold with Tial MVR
  • GTX3582R .63ar turbine (small for this size turbine wheel)
  • stock intake manifold (30-40 HP available with Velocity Element intake manifold)

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