Page 1 of 2 1 2 LastLast
Results 1 to 10 of 13
  1. #1
    dv8rxp's Avatar
    Join Date
    May 2005
    Location
    detroit
    Posts
    188

    strange weekend:boost is down, speed is up

    This isnt really a question, i'm just sharing my experience this weekend.

    Since I put in the c-5 sc wheel I've been seeing and fairly solid 11.1psi @ 8100rpm, and have been getting a consistant 77.8-78 mph with a max I ever saw was 78.4mph. Yesterday I went out and my performance was all around bad. Speed was down, boost was down, and it just felt strange. I was able to get 8060rpm, but only 10.2psi and 72 mph . On my way back in I could hear some knocking and that had me worried. When I pulled it out of the water I found my riva grate hanging on by 1 bolt. Well there was my problem. The inserts are all solid, the bolt holes on the grate were gone, I've read about it so I wasnt surprized. I put my stock grate back on, and I checked for boost leaks with the air compressor just to make sure, and found none so I was thinking I'm good. Went out today with the stock grate and my boost was still low, but I was hitting the rev limiter and pulled 79.2 mph with 3/4 tank of gas. If I were to tweek my prop some more I could see 80.
    So now I have some things for me to figure out. I don't know why my boost is low when I find no leaks, and I don't know why my riva grate was scrubing so much speed and rpm. Good news is that I'm going fast, and I just thought I would share.


  2. #2

    Join Date
    Jan 2006
    Location
    Rydal, Georgia U S A
    Posts
    3,936
    +1
    14
    Fast is good

  3. #3
    Avion3333's Avatar
    Join Date
    Dec 2007
    Location
    Cayman Islands
    Posts
    686
    wow weird but at least your speed is up

  4. #4
    JPR's Avatar
    Join Date
    Mar 2007
    Location
    Down under
    Posts
    934
    +1
    53
    i had the same thing happen a while ago. soon as you look at your grate you think "f*!#$%k....... that was close" glad you sore it before it went

  5. #5
    Vern's Avatar
    Join Date
    May 2005
    Location
    Grand Haven, MI
    Posts
    3,594
    +1
    128
    Interesting ... as speeds go up the pump gets more water and more pressure. This post makes me wonder if on skis going around 80mph or more, if the Riva grate lets in more water than the stocker, and then the stock grate is actually faster? How was the handling with the stock grate?

  6. #6
    dv8rxp's Avatar
    Join Date
    May 2005
    Location
    detroit
    Posts
    188
    Quote Originally Posted by Vern View Post
    Interesting ... as speeds go up the pump gets more water and more pressure. This post makes me wonder if on skis going around 80mph or more, if the Riva grate lets in more water than the stocker, and then the stock grate is actually faster? How was the handling with the stock grate?
    I didnt feel any difference in handling with the stock grate vs the riva. I didnt have any problems with comming unhooked in the light chop and had no bounce at full speed in the smooth water, I could superman easy. In the heavier chop it's too hard to tell if one worked better than the other.
    The only thing I noticed, and this is only by the butt dyno feel of it, was that my midrange didnt seem as strong as with the riva grate. No real proof of that, and it could also be the fact that my boost is still about 1 psi lower than before.

  7. #7
    Vern's Avatar
    Join Date
    May 2005
    Location
    Grand Haven, MI
    Posts
    3,594
    +1
    128
    I don't recall anyone doing Riva vs stock grate testing back to back on a ski going close to 80 mph ... sounds like it might be an interesting experiment.

    Off topic, how do you like the C5? I have a kit, but have not installed it, been running my X charger and was debating about selling the C5 kit possibly ... was curious if you have run other SCs and how it compared?

  8. #8
    The ski's have taken a "backseat" to the Corvette DarthAWM's Avatar
    Join Date
    Nov 2007
    Location
    Odessa, TX
    Posts
    5,364
    Quote Originally Posted by Vern View Post
    I don't recall anyone doing Riva vs stock grate testing back to back on a ski going close to 80 mph ... sounds like it might be an interesting experiment.

    Off topic, how do you like the C5? I have a kit, but have not installed it, been running my X charger and was debating about selling the C5 kit possibly ... was curious if you have run other SCs and how it compared?
    I think JD1 would be the guy to ask on this. He said something a while ago about the R&D grate being faster on his 90+ RXPs than the RIVA grate(the non X skis) I did hear anything about the stock grate though.

  9. #9
    Rompe21's Avatar
    Join Date
    Jul 2006
    Location
    Tampa , Florida
    Posts
    717

    Lightbulb

    Quote Originally Posted by dv8rxp View Post
    This isnt really a question, i'm just sharing my experience this weekend.

    Since I put in the c-5 sc wheel I've been seeing and fairly solid 11.1psi @ 8100rpm, and have been getting a consistant 77.8-78 mph with a max I ever saw was 78.4mph. Yesterday I went out and my performance was all around bad. Speed was down, boost was down, and it just felt strange. I was able to get 8060rpm, but only 10.2psi and 72 mph . On my way back in I could hear some knocking and that had me worried. When I pulled it out of the water I found my riva grate hanging on by 1 bolt. Well there was my problem. The inserts are all solid, the bolt holes on the grate were gone, I've read about it so I wasnt surprized. I put my stock grate back on, and I checked for boost leaks with the air compressor just to make sure, and found none so I was thinking I'm good. Went out today with the stock grate and my boost was still low, but I was hitting the rev limiter and pulled 79.2 mph with 3/4 tank of gas. If I were to tweek my prop some more I could see 80.
    So now I have some things for me to figure out. I don't know why my boost is low when I find no leaks, and I don't know why my riva grate was scrubing so much speed and rpm. Good news is that I'm going fast, and I just thought I would share.
    You using C5 R-D wheel

  10. #10
    dv8rxp's Avatar
    Join Date
    May 2005
    Location
    detroit
    Posts
    188
    Quote Originally Posted by Vern View Post
    Off topic, how do you like the C5? I have a kit, but have not installed it, been running my X charger and was debating about selling the C5 kit possibly ... was curious if you have run other SCs and how it compared?
    So far I like the c5 for the price, if I had more money to play with I would have went with the x charger or a rude. The only other SCs I have personally used are the orriginal riva/vortec and the rr high boost sc from race tech. The hole shot and midrange with the c5 is awsome and near 80mph with more tweeking left to do, I'm sure I'll get over 80 with the stock ecu. I run the stock nozzle with the bailer tubes removed and filled, 15/22r prop pitched out to 15/23 so far, and the AAT cone.

Page 1 of 2 1 2 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. 05 RXP Strange VTS Issue - goes down but not up
    By ncdoo in forum Sea Doo Open Discussion
    Replies: 2
    Last Post: 06-03-2017, 11:43 AM
  2. Two solas impellers, one guy is down 7600 and other is up 8300
    By travis ingram in forum 4-Tec Performance
    Replies: 13
    Last Post: 09-10-2014, 12:12 PM
  3. Bogging down once warmed up good... but cause is not the VR?
    By DKFox in forum 2-Stroke Performance
    Replies: 17
    Last Post: 06-08-2011, 01:21 PM
  4. Speed Pick Up hose... here is what happened
    By rdizz81 in forum Polaris Open Discussion
    Replies: 13
    Last Post: 08-14-2010, 05:20 AM
  5. Speed is up with cooler temps
    By 1FastTrespiper in forum 4-Tec Performance
    Replies: 6
    Last Post: 10-24-2005, 07:36 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •