Prospeed Toyota Tundra Race Intake and RCF Throttle Body Kit

We would like to share with you some dyno numbers and data for the new products we have been developing on the Toyota 5.7 platform. Please keep in mind we use a hub dyno which removes the inertial losses from the tires. This can account for a few % higher #s than what you may see on a dynojet due to the size tires a lot of Tundra guys run. It's not a drastic difference but we want to be sure and put that out front! The majority of the gains were at higher RPM as these mods affect the total airflow capacity of the system.

As you will see in the data provided most of the restriction doesn’t start to show up until 3500RPM and higher. Our test vehicle was a 2018 Tundra with Magnuson supercharger, Griptec 2.30 upper pulley, Prospeed catch can system, Prospeed full fuel system complete (with our drop-in injectors, TI Auto fuel pump, billet fuel rails, and lines), American Racing off-road headers, and Corsa exhaust system, tuning with HPtuners, 93 octane, and logging via our Motec C187 logger.


The above graph shows 3 different configurations that we tested. We made sure on final runs to do 2 back to back pulls (2 runs for each config shown in graph) just to ensure consistency in the dyno readings. This allows us to be sure there are no anomalous high reading runs.


Now to the meat and potatoes!

Red/Yellow Run

These runs are with the stock throttle body and the Magnuson intake piping/airbox. 580HP/523TQ

Looking at the data here (Screen 0) you can see that in this configuration that the blower inlet pressure had dropped to around -1.44psi, and the pre throttle inlet pressure is at a -.91psi deficit. This is obviously not optimal and restricts the blowers final boost capacity to 8 psi with this header/pulley combination. At this point, the factory mass air meter was also at the end of its usable range hitting the upper voltage limit. When upgrading to the larger intake we will be increasing the tube diameter which will effectively increase the upper range limit of the stock mass airflow meter.

Pink/Light Purple Runs

After fitting the Prospeed 4.50” Race Intake System the engine power increased to a peak of 630HP/540TQ. 


Looking at the data in (Screen 1) you can see the intake system reduced the pre throttle inlet pressure restriction down to a final value of .06psi (resting pressure is .34). This in return also reduced the pre blower inlet restriction to a value of -.63. This doesn’t seem like much but it was worth a final gain of 2psi of boost, 50HP and around 15TQ as most of the restriction/gain is at higher RPM.

Maroon/Dark Purple Runs

Our final mod was the Prospeed RCF Throttle Body Adapter Kit, which netted us 570TQ ( a gain of 30 ). The peak HP number did not increase as due to some sort of airflow/tq limiter (ignition based) was engaging on these runs (as seen in the graph) and causing power to taper off hard before hitting the main fuel cut. But once we sort out the 2018 ECU side of things based on the current trajectory, we are estimating 650-660 by red line.

Looking at the data on these run (Screen 2) we have a final blower inlet pressure of -.45 and the reduction in restriction happened early in the run (approx. 3600RPM) which you can see correlates nicely to the gains on the dyno graphs

Final Run

The final screenshot (Screen 3) shows the total improvement in restriction and boost from baseline to the fully modded runs.

The power numbers are with a very rich mixture of 10.1:1 AFR, as the factory Toyota ring gaps are extremely tight. Running these trucks leaner under long hard loaded pulls ( full out 1-5 freeway pull ) can cause the piston to grow enough to butt the ring gaps which is what we believe to be the cause of all the broken ring lands these engines are known for. So by running it very rich we keep the cylinder temps down as much a possible to try and reduce the possibility of this happening. I think the misconception is that knock is what’s killing these engines, but the Toyota factory knock control is very aggressive and does an excellent job of preventing repeated knock events, so we feel in our opinion this is not likely the cause for the majority of damage a lot of people see with the supercharged trucks. This is why we highly recommend upgrading the fuel system as we’ve shown in previous data that even with factory TRD SC components once you optimize the cam angles and put a high flowing exhaust system on these trucks there are major restrictions in the fuel system that cause the passenger side to run significantly leaner than the driver side.