02-11-2008, 11:19 PM #1
04 RXP Stage 2.5 Looking to Break 80mph!!
My ski is a 2004 rxp 109 hours and STOCK ECU.
Riva s3 sc
Piranha intercooler w/ pipes,
Piranha motor mount
4" front air intake
Riva 158°F Thermostat Kit
Thru Hull Exhaust w/ Shorty Green Box
RE Block Offs
Riva Intake Grate
Riva VTS Extension Rod
R&D Grate Girdle
Solas 15/20r Prop
Riva adj. Venturi w/ 81mm ring
Filled Ride Plate Holes / Trimmed Reverse Bucket
Perfectly Aligned Pump Shoe/Engine
I weigh 185lbs, ride sea level/salt water, and had 3-4 bars of fuel. The water temp was 42°F and the air temp was 44°F. I ran 78.7mph @ 8150 rpm’s pinned steady with a couple flashes above 79mph but too quick to read. The ski ran amazing and sounds unbelievable! The prop is unpitched & boost was between 10.5-11psi..
My ultimate goal is to break 80+ with the stock ecu and I really believe I can do this without much more work; but I need some advice. Now I know I was kind of running in abnormally cold water/air temps so the rpm's are probably way up there on the rev limiter. The machine was running excellent no calvitation or any hesitation what so ever.
Would a smaller venturi ring such as 80mm or maybe even 79mm have allowed me to break 80mph?
Does my prop need to be pitched just a bit? I'm leaning towards no esp. since Jerry already told me to leave it alone haha..
Do I absolutely need skegs or break 80mph?
Would metal pipes vs. Piranha silicon pipes make up for some lost power? I'm also planning on including a good BOV into a pipe setup. I have one pipe made in 2.5" stainless so far.
The next time I test is most likely going to be in the Ft.Lauderdale area next week so the temps are going to be much different. Most of the time around here the temps will also be much different since I normally don't ride until May at the earliest. This all needs to be taken into consideration also.
Any advice/questions/assistance would be much appreciated and I have until Friday night to make some changes before my trip to Florida; otherwise it will have to wait till May for testing I guess but no big deal..
Thanks for the help!!
02-12-2008, 12:13 AM #2
If you mean that the rpm was pinned at 8150 rpm, then yes, you were probably on the limiter and would gain a little speed with an additional +1 mm in the prop.
However, I agree with Jerry, those temps you were running won't last much longer... so your current setup will most likely be dead on.
02-12-2008, 12:44 AM #3
- Join Date
- Dec 2006
- Crest Hill, IL
80 @ stock ECU is a tough goal, lots are chasing it too...The next best option for you would be Jim's rideplate...that could push you over that threshhold...
Are you gonna tweek the prop to run a larger ring in the summer @8100, then step it down when it gets cooler?
02-12-2008, 01:27 AM #4
Yes, a Jim's rideplate, Jerry's skegs, a Rude rising rate fpr, and a Rude Charger should put you over 80 mph.
02-12-2008, 07:40 AM #5
To be honest with you,,your right there. I`d look at your intake though. What transition are you using to the charger? Check the mating of the blockoffs and the ride plate to hull. Also check you TB blade. I really think with those temps you could pull an 80 mph.
02-12-2008, 08:17 AM #6
As for the RE Plates to the hull should I just make sure that they are absolutely as smooth as possible? Right now they are siliconed but with could probably be a touch smoother?
What was your concern with the TB?
Now In the same temps would a 79-80mm ring push me over since I know I was riding the limiter pretty hardcore? And what can I expect when I ride in Florida next week are the results going to pretty different/slower?
02-12-2008, 08:19 AM #7
02-12-2008, 08:32 AM #8
[quote=kp04rxp;535902]Danny, honestly whatever I need to do I'm going to do. If leaving the prop untouched now then tweaking it for the summer is necessary then I'll pull it and tweak it! I've got larger rings and prepared to order small rings if necessary. So changing rings is not a problem either.
hmm I dunno if I'll be doing all that haha.. Maybe the rideplate if need be.
Hoss, I'm actuallly not sure what transition adapter it is. I bought the sc from Travis (nomoxp4me) and he had an aluminum transition already installed. To me it looks like a pretty nice one since all edges are flush and smooth. This would be the adapter that connects the air intake hose to the SC..Some have a aluminum or plastic ring that goes around the SC collar,and some have a 90 degree elbow that reduses from 4 inch on one side to 3 inch on the other to fit on the SC..This makes the air transition into the SC nice and smooth
As for the RE Plates to the hull should I just make sure that they are absolutely as smooth as possible?Yes you do want to make these as smooth as possible..But 98% of us are using the silicone to fill the gap..Just make it nice and smooth and youll have no problems.
Right now they are siliconed but with could probably be a touch smoother?Just smooth out the silicone and youll be fine.
What was your concern with the TB?
Check to see if your TB plate is opening all the way.
Now In the same temps would a 79-80mm ring push me over since I know I was riding the limiter pretty hardcore?They might but it will be very close..I wouldnt expect to see it consistantly if you do crack 80 And what can I expect when I ride in Florida next week are the results going to pretty different/slower?If you dont change a thing youll see your RPMs drop and your gonna see some lose in speed.
Last edited by Snoman; 02-12-2008 at 08:37 AM.
02-12-2008, 09:11 AM #9
Okay so pretty much I'm going to have to ride in some warmer weather and see how she runs then tweak from there. I do like the idea of getting dialed in with the 82mm though. That actually seems like a great.
Snoman looks like we're right in the same range with speed.. How has you luck been with breaking 80mph?
02-12-2008, 09:18 AM #10
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