Drift Tengoku — September 2004 · Page 38
Page 38 — English translation
The GT2540 is the best way to build on the RB25's strengths! Focus on response and pickup. The recommendation here is a GT2540 targeting roughly 380 PS.
Don't dismiss it because it falls short of 400: torque is the RB25's great attraction. Nemoto at Symex believes chasing extreme output misses the point. A GT2540 strengthens its torque rich character while retaining enjoyable top end.
Boost arrives around 3,000 rpm, making it fun on the street and small circuits. A larger turbo, such as a GT2835 series unit, can exceed 400 PS, but choosing one solely for that figure can leave the engine in an awkward middle ground, with neither strong bottom end nor exceptional top end. The GT2540 also needs only a fuel pump upgrade, adding value.
Pair it with a front mount intercooler and suitable exhaust with a catalyst. The article quotes ¥222,100 for the turbo kit, implying a total under ¥300,000 including tuning. At 400 PS, the airflow meter, injectors and gasket also need replacement, sharply increasing cost.
For a similar reason...
...the A'PEXi AX53B70 is recommended too. For further improvement, add a larger intake plenum while continuing to prioritize response and pickup. Trying to get everything can leave the engine difficult to use.
If you insist on more power and an external wastegate sound, aim decisively beyond 500 PS instead of making an unsatisfying compromise. Symex recommends the RX-6, one of A'PEXi's largest turbos, with Poncam camshafts and a Trust intake plenum. This produces more than 500 PS, although boost does not arrive until roughly 5,000 rpm.
It suits drivers who enjoy revving hard. Fuel pump, injector, airflow meter and head gasket upgrades are essential...
Captions and page details
Power upgrade guide
A fine build from Symex
Nakamura's Skyline: RX-6 specification
This Skyline demonstrates the high rpm focused setup described in the article: an RX-6 turbo, Tomei Poncams and a Trust intake plenum. The fuel system is fully upgraded and the metal head gasket is 1.2 mm thick. A custom exhaust manifold replaces the kit's supplied item to achieve the desired appearance and sound.
RB25
Edition
for
The RB25 is often compared with the 1JZ...
...the approach to increasing power is quite different.
A larger turbo increases peak power, but on an RB25...
Enjoy its strong torque without sacrificing it.
Against its 1JZ rival, aim to win on corner exits...
...rather than on the straights.
Symex's
A radiator and oil cooler are essential!
Pay close attention to the spark plugs
Top recommended turbo
...manage them carefully!
Spark plugs
Don't underestimate this!
GT2540
HKS
For ECR33 / ER34: ¥212,100
The GT2540 is the largest GT25 sports turbo kit. Its compressor housing is larger than the GT2530 series', enabling output approaching 400 PS. Its ball bearing core also provides good pickup.
Once a front mount intercooler is fitted, an RB25 can struggle with coolant and oil temperatures even at the boost upgrade stage. A three row radiator and 13 row oil cooler are essential. Fit them alongside the turbo if the cooling system is still standard.
NGK racing plugs are strongly recommended. Use heat range 8 mainly for street driving, or 9 for frequent hard use. Symex customers reportedly use 8 on the street and switch to 9 for circuit outings.
Get even better pickup with a larger intake plenum!
Symex uses Total Quartz 9000 engine oil, described as fully synthetic with performance comparable to the special oil Total supplies for Formula One. Nemoto says the exact brand is not mandatory, but continuing to use the same oil used when the engine was tuned is a basic principle.
A larger intake plenum can further improve response from low rpm. Set the car up for response rather than chasing peak output. The Trust plenum fitted here is for ECR33 and costs ¥89,250.
9000
quartz
36
Photography: Hiroki Iwashima
TOTAL
About this issue
ドリフト天国 (Drift Tengoku), September 2004, is a Japanese drifting magazine. This archive preserves 316 scanned pages in their original right-to-left reading order, including the covers.
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