1991 Nissan 240SX LE

Installation And Tuning
Stephen Rhim Of G-Dimension
Facility And Dynamometer
Provided By Ultimate Tuning

Then, after a good deal came up on a blacktop SR20, he assured us that if he did have to swap out the 240's tired (Read: perfectly fine) ka, any SR replacing it was going to stay stock, damn it! Once that day came, he even went so far as to retain the factory side-mount intercooler, exhaust and keep boost limited to the factory 7psi setting. In his defense, we think he had genuine intentions of keeping his word. That is, until the suggestion was made of using his car as a Power Pages test vehicle. "I guess we could try it," he conceded after approximately 1.3 seconds of inner struggle, "but I probably won't keep the parts on afterward-I want to keep this car stock..."

But after feeling the pull of an additional 30 horses unleashed by an A'PEXi downpipe, cat-back exhaust and grounding kit, all bets were off. The mods stayed on and the search for more power began.

A month later we found ourselves on the quest to extract more power from the grocery getter, but not for any personal satisfaction-no; we wanted to prove once and for all, just how much power the SR could churn out with its original T25 turbo, 370cc injectors and factory-tuned ecu. And possibly settle some lingering disputes about modding a boosted car in general.

With the conclusion of last month's testing, Carter's SR-powered 240 was able to transfer 180.7 whp and 164.0 lb-ft of torque at peak output, with the help of a tubular turbo manifold and A'PEXi intake, and the other afore-mentioned goodies. The factory side-mount intercooler and piping were retained, along with the stock Turbo outlet pipe, catalytic converter and all belt-driven accessories. While the peak output seemed a tad on the low side, mid-range power was plentiful, the car handled a daily commute with ease and tested even compression across the board-a veritable "go ahead" for further modifications.

Our first step was to see what gains could be found by replacing the SR's only remaining exhaust restriction (other than the catalytic converter): Its turbo outlet pipe. A side-by-side comparison between the SR's factory unit and a cast replacement given to us by Phase 2 Motortrend will show the aftermarket elbow's larger inside diameter, especially where the factory unit tapers inward sharply in front of the internal wastegate. Phase 2's elbow also features a flange that isolates the wastegate as it opens, protecting it from the chaotic exhaust flow leaving the turbine that may otherwise impede its performance. Although the elbow's most noticeable benefit seems to be the five-to seven whp top-end, pay close attention to the 10 lb-ft spike in torque production just after 3,000 rpm-proof of the Phase 2 unit's design improvements over the stocker.