Thread: GTX SC insane rpms
06-29-2006, 05:38 PM #1
GTX SC insane rpms
Finally got the GTX together the night before the AWA DC freedom ride, which was pretty damn cool by the way, and i couldn't have done it without Shibby. Only trouble i had was a loose exhaust clamp and the fact that i can only use 1/2-2/3 throttle even in the chop. I installed a trued stock RXT prop that Steve lent me and i'm turning almost 7,800 RPMS and not even at full throttle. WOT sees numbers well past the 7,700 mark on chop and glass. The only mods i have done are freeflow exhaust, nopas, and a half stock intake. At best i'm seeing 62mph and thats just depressing. Steve and i were talking about maybe using a 14/17 or 14/19. Anyone have any suggestions?
06-29-2006, 06:23 PM #2
I was also thinking about running a 2 degree wedge to try for some gains.
06-29-2006, 06:26 PM #3
07-06-2006, 11:21 AM #4
Ok...Im posting on behalf of 01xDime....
He installed his 14/17...this reduced his rpms about 100 to about 7660 to 7700..He is aware this is still kind of high...He got a GPS reading of 63.8 and was porpoising very badly on calm water.
He has the custom intake, riva grate, nopas, and Stock RXT driveshaft...
Can you all give some opinions on what he should do to get his rpms down ( prop suggestion maybe with some more speed ). Also, any suggestions on the porpoising?
Thanks guys in advance....
07-06-2006, 11:28 AM #5
add a little pitch to the trailing edge... there's no out of the box prop that's gonna put him where he needs to be. the 14/17 isn't enough for most any modded ski, and the 14/19 is too much for an RXT unless u got plenty under the seat.
either bend it himself or send it out for a repitch...
porpoising... see if it goes away when he removes the pump wedge... sponsons will help take away some of the bounce, and the skegs will also help reduce it when they are available.
07-06-2006, 11:31 AM #6
He ordered the 2deg wedge and hasnt received it yet.. so he he is porpoising without the wedge and is afraid to even put it on now...
07-06-2006, 04:28 PM #7
What ECU is he running?? The rpm`s don`t seem that high unless its still running the 03 ecu with the 7650 limiter. Forget the wedge unless you only run on glass and are only looking for top speed.
07-06-2006, 04:41 PM #8
Stock ECU if om not mistaken...He WAS hitting 7800 RPMS with it until the prop change...
07-06-2006, 05:18 PM #9
Thats correct Brian, i'm running the stock 03 GTX ecu and if the limiter is at 7,650, then mine is broke! Yesterday i was turning a constant 7650+ and touching 7,700 at times. On the DC freedom ride and on tuesday i was turning 7,750+ in the chop with the stock RXT prop. I'd be half tempted to see if anyone has a RXP/RXT ecu for sale. I dunno if i need to upgrade to an RXP fuel pressure regulator. I am afraid that i just wasted $120 on a 2 degree wedge since porposing is so bad. I can sit upright all the way forward on the seat and still experience mild porposing. In the superman position porposing is so bad you can't maintain that position for long. This is frustrating since the numbers just don't add up. I'm running 63.8 mph at 7,600+ rpms with more than a Riva stage one kit (minus the 2 degree wedge) which claims 67mph. I think the next thing is to ditch the Riva BOV thinking that it's possibly causing a boost leak but if that was the case i would only increase my rpms. So i'm left wondering where the answer lies and what would push me over 65mph. I figured if anything that 14/17 would knock my rpms too low. I think i might give bending my prop a lil bit a try myself. In the mean time i'll just pull my hair out.
07-06-2006, 05:31 PM #10
You would have to upgrade to the rxp fuel reg as well if you changed the ecu.The limiter uses whats called a soft limit initially untill your revs go really high then it goes to a hard limit which is very easy to hear and feel.You may be getting onto your soft limit without realising it which would explain your lack of speed.If your going to stick with the stock ecu you need to get your revs down to 7600 so a 14/19 may be just the thing.
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By Tampa Florida in forum 4-Tec PerformanceReplies: 0Last Post: 05-11-2009, 01:29 AM
By xBigDaddyx117 in forum 4-Tec PerformanceReplies: 72Last Post: 01-29-2009, 10:31 PM
By TampaGTXSC in forum 4-Tec PerformanceReplies: 23Last Post: 01-26-2008, 08:32 AM
By lextoy in forum 4-Tec PerformanceReplies: 4Last Post: 09-04-2007, 09:01 PM
By ajGTXSC in forum Sea Doo Open DiscussionReplies: 6Last Post: 07-10-2007, 12:14 PM