R&D tuned Sea-Doo RXP-X
The 78mph must have kit
We test exclusively the new R&D Performer kit which transforms the Sea-Doo RXP-X from a boring two-seater to an exciting muscle-craft.
Photos:www.jetskiworld.gr, Glenn Dickinson
It is well known that the watercraft manufacturers are restricting the watercraft engines and driveline in order to obey the environmental and Coast Guard rules and limitations. There are many ways to restrict a watercraft engine and the most common one is through the ECU and the fuel delivery.
R&D has recently developed a new kit for the new RXP-X 2012, a kit that transforms the lazy bone stock Sea-Doo to an interesting race weapon for the Pro Stock class. A boat that has great acceleration from very low rpm, pulls hard in mid rpm and drives you nuts at high speed, by clocking 78mph running on 91octane pump gas at 8450-8500rpm.
Behind this unique project is Bill Chapin’s ingenuity. He has worked countless hours on understanding the engine operation of the Rotax engine prior to start working on it with the scope to unleash its true potential. Initially he worked on the remapping of the Rotax ECU, by blending the right fuel delivery with the required ignition timing with the additional increase boost pressure from 7pounds (the OEM boost pressure) to 10pounds, the GPS throttle timing, the ECU’s lean fuel table and the low ceiling rev limiter functions. The Rotax engine when it operates in stock format is quite lean on idle with the AFR gauge reading 14.9 a fact that makes the engine sound a little bit peculiar. Plug in the R&D reprogrammed ECU and the engine operates healthy with the AFR showing constantly 12.5 and the rev limit is set to 8650 rpm. The R3 ECU was accompanied with R&D’s air filter plenum which breathes from right in front of the engine compartment.
We tested initially the R&D tuned RXP-X with the above engine tune up kit including the R&D intake grate, sponsons and Solas specifically pitched impeller. The result was outstanding since the craft pulled harder from low rpm with absolutely no signs of cavitation and was accelerating much faster than the stock boat. Additionally its top speed was increased a lot and actually we recorded 76.3mph.
Then Chapin modified the cooling system in order to drop the operating temperature in the intercooler. The temperature was decreased from 190F to 155-160F a fact that made huge difference to the overall performance of the craft. We went back to the water for more testing and we found out that the Sea-Doo was accelerating even faster than the previous test and also it was pulling much harder in mid rpm. The craft reached the top speed of 78mph on the GPS with the engine revving at 8400rpm, which is a remarkable result for a stock legal (Pro Stock Class) craft.
The last test was carried out on Body Beach where half of the race course was on smooth conditions and rest on heavy chop. The 78mph Pro Stock RXP-X was picking up its lean lines like a surgical knife and it was accelerating very fast and with no hesitation on every single buoy even when it was going around a hairpin. However when I rode it in the fast section the choppy conditions interfered a lot with the overall stability of the craft since the stock trim tabs had not been replaced. These sponsons limit the crafts stability on the straight line when you ride at top speed by making the craft knocking up and down, left-to-right when you ride straight towards the wave travel, or at 45 degrees or even when you chasing the waves.
When Chapin installed a set of production unit R&D trim tabs the stability of the craft was improved dramatically. The boat could be ridden safely on any direction under the choppy conditions a fact we had realized back in February when we tested exclusively those R&D trim tabs as a preproduction unit. However, when we tested the craft in the buoy course it felt just a little bit lazy going round the tight section of the course which means that I had to pick up different lines in order to keep up the speed in a good level. On the other hand I was gaining crucial time on the fast and bumpy part of the course. Those R&D trim tabs are the “Must have” R&D accessory for the Sea-Doo owners whether they use the craft for recreational use, Off-Shore Endurance racing or close course racing. Along with the R&D sponsons and Intake Grate they transform the handling of the craft from scary ride to a secure and safe missile.
R&D Performer kit parts list
R&D R3 Reprogrammed ECU
R&D Air Filter Plenum
R&D Water Pressure Valve
R&D Cooling System
R&D Intake Grate
R&D Aluminum Trim Tabs
R&D Solas Pro-pitched Impeller
Proceeding to the completion of this test Chapin suggested to swap the R&D reprogrammed ECU and test the boat only with the rest of the bolt on parts. Therefore, I took the RXP-X around the Body Beach race course for one final session. The difference in terms of acceleration was huge since the boat needed at least 4000rpm to accelerate decently and felt quite heavy and late on exiting round the buoy. On the fast buoy turns it was doing much better since the craft was already carrying some speed. Therefore, to sum it up the are three crucial parts on this kit in terms of absolute performance, the R&D Reprogrammed ECU, the R&D cooling kit and the R&D Trim Tabs. However, the rest of the parts included to this kit add small bits and pieces to the overall superb performance of this kit. This last part of the test was very important and made it much easier for me to figure out the importance and the key role of the R&D reprogrammed ECU.
Who would be interested to this?
First of all, it is worth noting that the particular R&D kit is a must have tool for the racer who competes in Pro Stock Runabout class. The unbelievable acceleration matched with the remarkable top speed, the out standing handling and the zero cavitation would be all they need to take the #1 plate. It will be a real bonus for the weekend warriors since they will be having fun outperforming their friends. Last but not least the enthusiasts will get more satisfaction out of riding their brand new toy since they will experience its true potential. Therefore, for a reasonable budget R&D managed to unleash the true performance of this craft for every kind of rider. Isn’t this a super deal or what?
Shall I buy it?
Well, simply consider that with less than $2000.00 USD you can transform your lazy RXP-X to a real Pro Stock IJSBA Legal Runabout. You will get more satisfaction out of riding it whether you out drag your friends in the lake or winning in a class of your own in the race course.
Special deal on orders with CODE: Jetskiworld.gr
R&D Racing Products USA Inc.
12983 Los Nietos Rd.
Santa Fe Springs. CA. 90670