Recently, Jerry Gaddis from GreenHulk.net made a wonderful comparison of all the available aftermarket intakes grates for the Yamaha GP1800 and VXR. These intake grates, which will bolt up to all current GP1800’s and 2015 and newer VXR’s, are offered by WORX, R&D, and RIVA Racing.
For anybody considering performance enhancements and upgrades to the stock intake grate for these skis, this is an excellent test and data analysis of each available grate and we recommend that you review these results. Before we get to results though, let’s take a look at the conditions and ski setup that Jerry was using.
The test was being performed on a GP1800 with the Green Hulk Stage 3 kit with an additional “ultimate air intake kit” both of which you can find at the links embedded here. For those of you not familiar with the Stage 3 kit, it consists of the RIVA MaptunerX bundle package, a Solas 13/18R impeller, RIVA intake manifold upgrade kit, Fizzle Y1000 Yamaha intercooler with all necessary hardware and TiAL blow off valve.
The kit also includes the RIVA engine cooling upgrade kit, RIVA titanium valve retainer upgrade kit, RIVA F2 supercharger impeller, RIVA 1000cc high impedance pro series fuel injector kit, and the RIVA billet fuel rail. The same Stage 3 kit comes with the WORX intake grate which is being tested along with the other two.
The testing conditions were performed on the same waterway with all runs conducted within forty minutes or less of one another and in the same direction for maximum consistency in wind and water current conditions. The tests were performed on the above mentioned GP1800 at 9000 RPM with a half tank of fuel and an air temperature of 77 degrees Fahrenheit. The tests are mainly looking at acceleration and top speed comparisons.
As Jerry points out in the forum discussion, the acceleration data begins at 10 mph since the ski can not sit stationary in the water. All data begins at 10 mph for a consistent starting point. But enough about the experimental conditions in this process. I’m sure you came here to find out about the independent variable or in other words, which intake grate do I buy?
Well if we look at the numbers alone and as Jerry points out, the RIVA intake grate is the clear winner in both acceleration and top speed. All units showed a top speed in the low to mid 87 mph range. While top speed numbers were very similar for all three intake grates being only fractions of a second apart, the acceleration data definitely shows clear gains from the RIVA unit.
There are however some differences in the pump sealing when comparing the three intake grates as discussed in the test results. It is clear that the RIVA unit has a better inherent design to the pump seal, which consequently could be the factor that gives it the edge in this test.
This fact is also discussed heavily between members of the forum in this particular post. Additionally, the RIVA unit being made of solid stainless steel, could be a better choice from a strength standpoint.
Whatever the conclusion may be, it is definitely clear that any of the aftermarket intake grates will give significant gains in acceleration, hookup, and overall performance of your Yamaha GP1800 or VXR WaveRunner. Special thanks to Jerry Gaddis for making this test. For full details, be sure to check out the forum link above and the YouTube video here.
