Shannon's SR20DE+T

I keep hearing about how good this combination is. And now I'm a believer!

Shannon practices what is becoming a lost art - performance on a budget. His SR is in a well used KE70 'rolla. He simply fitted the SR20DE and bolted on the turbo bits. This included ECU, injectors, AFM, wiring loom, igniter, coils and a GT2530 turbo. With the mandatory FMIC + 3" exhaust.

The first dyno session was done at minimum boost just to make sure everything was OK. Boost curve was very lazy, starting around 6psi and slowly rising to 8psi. The standard DET maps actually weren't a bad match, although I did tame the IGN timing down a bit. This netted an impressive result, although both injectors and AFM didn't have a lot left.


Results of tuning ECU with standard turbo/inj/AFM	Mixtures	Log showing RPM, airflow and injector duty cycle

Next session 480cc injectors from an S15 were fitted and boost was increased using a Turbotech valve. We meant to run 12psi but the end result was actually closer to 11psi. After some initial runs at 11psi it was clear that it was leaning out above 6000rpm. We checked fuel pressure (VL turbo pump) and all was good. Turns out that the AFM was topped out! We quickly fitted an RB25 unit and away we went again. Managed to get mixtures where we wanted them and then played with IGN timing. The power was just falling out of it! Even with a decent IGN timing safety factor and very safe mixtures it still made well over 180rwkw on 11psi!


Comparison of 8psi and 11psi	Log showing RPM and airflow for std AFM	Log showing RPM and airflow for RB25 AFM

Note that at 182rwkw the RB25 AFM still has a bit of headroom. But not a lot. S15 injectors are fine though.

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