Option — Shōwa Car Tuning & Buyers Guide (2000 Edition)
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About this issue
180 available scans from Option — Shōwa Car Tuning & Buyers Guide (2000 Edition), in right-to-left reading order. Japanese OCR and English translation drafts are available throughout. Drafts have not received exhaustive image proofreading; unreadable source remains recorded in the archival data.
Page 34 — English draft translation
Larger injectors can raise boost to around 1.2 kg/cm² and target about 280 hp, but head-gasket durability becomes a concern; keep the setting near 1.0 kg/cm² for regular use. The stock airflow meter saturates at about 0.8 kg/cm². Shops differ on whether to recommend a larger airflow meter beyond that, depending on their tuning methods and philosophy, so consult your tuner.
For more power, HKS’s GT series is a common choice; the GT2540 is especially popular and can make around 330 hp at roughly 1.0 kg/cm². These bolt-on turbos are generally designed to work with a stock engine, but older PS13 models may have head-gasket durability issues. A metal gasket is recommended for safer high-power use. Intercoolers and exhaust manifolds can add power gradually. With a GT turbo and camshaft upgrade, over 350 hp is within reach. Beyond that, the pistons become the limit, so the bottom end must be built.
Captions and page details
1208085
Power-up guide
Turbo-car power
Boost increase
Replace the fuel pump, raise boost to 1.0 kg/cm², and reach about 250 hp.
A stock SR20DET runs about 0.68 kg/cm² of boost and makes roughly 200 hp. With only an air cleaner, boost is around 0.7…
…and output rises to about 220 hp. Add a boost controller and tune the ECU, and boost can be raised to around 1.0 kg/cm² for about 250 hp. At this level, install a GT-R fuel pump to maintain fuel pressure.
20DET
SR20
Replace the head gasket for peace of mind and a reliable 330 hp.
Bolt-on turbo
SR20DET bolt-on turbo setup
Approximate power
About 280 hp
1.0~
Boost pressure
S14 turbo
Specification
1.1kg/cm
+ airflow meter
+ 550 cc injectors + metal head gasket + GT2540 turbo
Approximate power
Boost pressure
Example SR20DET boost-up setup
After a boost increase, the next step is a bolt-on turbo that can use the stock exhaust manifold and piping. At this point, larger injectors—around 550 cc—help the turbo reach its potential. A fuel-pump replacement is generally essential…
About 330 hp
1.1kg/cm
1.0~
+ airflow meter
About 200 hp
About 0.6 kg/cm² / about 0.8 kg/cm²
1. Stock
Specification
+ 550 cc injectors + metal head gasket; assumes the parts required for a boost increase are installed.
About 220 hp
+ muffler
2 Air filter
…is essential.
The readily available S14 turbo needs minor modifications to fit, but the turbo itself is easy to find, so installation can be inexpensive. At 1.1 kg/cm² of boost, around 280 hp should be achievable. One step further…
About 250 hp
About 1.0 kg/cm²
2 + ECU + boost controller + fuel pump
3
About 1.2 kg/cm² · about 280 hp
3 + airflow meter
+ 550 cc injectors
HKS’s GT25 series is a representative bolt-on turbo lineup for the SR20: GT2510, GT2530, and GT2540. The higher the number, the larger the turbo. (Photo shows an S14 version.)
For an S14
32
Photo: Tetsuyuki Urabe/OPT · Report: Mamezō
When changing the turbo, the injectors should also be replaced. For a turbo swap, 550 cc injectors…
…are sufficient.