Originally dyno tuning the DOC Race Supra with our GT40R setup, we sat just above 500whp on pumpgas. This is a relatively low output from the sought after 2JZ engine, but a joy to drive with this powerband. With this graph before our intake manifold, you can see the drops after peak-power is reached just under 90mph and beyond in 4th gear…
We used our car as a comparison to show the Intake Manifold improvements on a smaller scale of measurement.
The test cars specs is as follows:
-Completely Stock JDM 2JZGTE
–DOC Race Open T4 Turbo Manifold
-“Modified Factory Upper Plenum”
-Garrett GT40R turbocharger
-Tial MVR wastegate
-AEM Series II EMS
-Dual Denso intank fuel pumps
-91 Octane Pumpgas
Pictured below is the “modified factory upper plenum” used in the BEFORE test; this is a popular modification for gains…
Here’s a picture of the New Intake Manifold installed with the RMR 90mm throttle body. We adapted the Ross Machine throttle body with the same size 3″ tubing and a reducer..
These are the side-by-side results with no tuning adjustments:
The mid-range gains shown after the intake manifold are noticeable when boost is ramping up. The transient throttle difference is huge; you feel a lot more boost response when re-applying the throttle in and out of load.
The largest and most noticeable change is the top-end; even though this car still has the low profile factory JDM camshafts, the top-end of this power band has been completely revamped by adding the intake manifold. The maximum power output may have only increased 3whp but the noticeable change is at high RPMS, you can see up-to a 70whp difference and a smoothed peak-graph. This has tremendously changed the way this car drives, it can now “carry-gear” without choking power and also places the engine in a much more desirable/usable RPM upon gear change.
We have made great improvments by adding our Billet Intake Manifold, anyone looking to push beyond the 600whp mark this is a must-have piece. We are currently building the cylinder head and adding Stage II BC camshafts for further improvements to the power-graph.
For an extreme look here is the Hyperspeed 3.2 liter Stroker, Precision 8285 car running the DOC Race Twinscroll Manifold and DOC Race Intake Manifold. This is 38psi no additional fueling making 1176whp: