Page 1 of 3 1 2 3 LastLast
Results 1 to 10 of 22
  1. #1
    formerly Gold06RXP Turbo Nick's Avatar
    Join Date
    May 2007
    Location
    Dayton, OH
    Posts
    2,095
    +1
    97

    Was I expecting to much on Riva rear air?

    I just installed the Riva rear air kit. I am a stage one plus the xs IC. Last week befor installing rear air kit I was seeing 8160 to 8180 max rpm. The temp was 72-73 and the water temp was 75. I was seeing 7.9-8.0 psi on my digital boost gauge. Today I went out after installing the rear air kit and was seeing 8100-8120 max rpm. Water temp was 78 and air temp was 88-89. Max boost was 7.5 psi. I was expecting to see 8200 rpm and was dissapointed. I know the air temp was way higher and the water has warmed as well. I have the stock SC and stock exhaust still. Would this be a normal result for my mods. Do you have to Have SC mods and exhaust mods to get the full effect of the 4 in. rear air intake? I already checked for boost leaks and found none. And I checked the slip moment on the SC and its at 80 in/lbs. So as far as I know everything is set up properly. I know ill probably get to 8200 in cooler waether but just wanted to know if this seems normal for my mods or if I need to check something out? Thanks for responses.


  2. #2
    JFizzleJR's Avatar
    Join Date
    Aug 2005
    Location
    FL
    Posts
    8,628
    +1
    808
    If you don't ride in the ocean then I suggest cutting holes in your rear grab handle for 2 to 4 flo-rites. If you place them right you can get 4 on. I noticed a HUGE difference by doing this (I only managed to get 2 on).

  3. #3
    formerly Gold06RXP Turbo Nick's Avatar
    Join Date
    May 2007
    Location
    Dayton, OH
    Posts
    2,095
    +1
    97
    I did install the two flow rites that came w/ the kit in the grab handle right above the red intake cloth

  4. #4
    JFizzleJR's Avatar
    Join Date
    Aug 2005
    Location
    FL
    Posts
    8,628
    +1
    808
    hmmm
    i guess it's got to be the RAD and water/air temps then..

  5. #5
    Quote Originally Posted by GOLD06RXP View Post
    I just installed the Riva rear air kit. I am a stage one plus the xs IC. Last week befor installing rear air kit I was seeing 8160 to 8180 max rpm. The temp was 72-73 and the water temp was 75. I was seeing 7.9-8.0 psi on my digital boost gauge. Today I went out after installing the rear air kit and was seeing 8100-8120 max rpm. Water temp was 78 and air temp was 88-89. Max boost was 7.5 psi. I was expecting to see 8200 rpm and was dissapointed. I know the air temp was way higher and the water has warmed as well. I have the stock SC and stock exhaust still. Would this be a normal result for my mods. Do you have to Have SC mods and exhaust mods to get the full effect of the 4 in. rear air intake? I already checked for boost leaks and found none. And I checked the slip moment on the SC and its at 80 in/lbs. So as far as I know everything is set up properly. I know ill probably get to 8200 in cooler waether but just wanted to know if this seems normal for my mods or if I need to check something out? Thanks for responses.
    Not a true test. The RAD was most likely the cause of your loss of RPM, it's not just an air and water temp game. However, I am willing to be that if you were to have ridden that day with the regular intake your RPM and boost would be much lower. Did you get any speeds?

  6. #6
    Quote Originally Posted by JFizzleJR View Post
    hmmm
    i guess it's got to be the RAD and water/air temps then..
    bingo. RAD will play a bigger role the more you start modding.

  7. #7
    formerly Gold06RXP Turbo Nick's Avatar
    Join Date
    May 2007
    Location
    Dayton, OH
    Posts
    2,095
    +1
    97
    KID I was still able to pull a 72.8-72.9 and even a 73. When you guys say RAD to you mean temp? I am going out again on Wed. Its suppose to be much cooler. Like highs in the low 70s. Will be interesting to see what happens

  8. #8
    Hydrotoys's Avatar
    Join Date
    Jul 2005
    Location
    Mesa, AZ
    Posts
    16,712
    +1
    85
    Fill in the top part and calculate. This is a quick way to determine your Relative Air Density. I prefer the Density Altitude reading myself. But if you want to compare back/back mods, you have to do this, or you are just guessing in the dark.

    http://www.hydrotoys.com/wavs/pda-de...a-denscalc.htm

  9. #9
    Quote Originally Posted by GOLD06RXP View Post
    KID I was still able to pull a 72.8-72.9 and even a 73. When you guys say RAD to you mean temp? I am going out again on Wed. Its suppose to be much cooler. Like highs in the low 70s. Will be interesting to see what happens
    RAD is your adjusted elevation. You know how we have talked about how the higher you go above sea level, the more RPM and speed you will lose? Well RAD is your calculated elevation. Say you are running at 1000ft. above sea level. You plug in your actual elevation, air temperature, altimeter setting, and dew point to find your adjusted elevation. Say it gives you a figure of 2000ft. So even though you are running at 1000 ft above sea level, your engine is going to perform as if it were at 2000 ft. above sea level.

    I use weather.com to fill out these to calculators.

    http://wahiduddin.net/calc/calc_da.htm

    http://www.anycalculator.com/enginehorsepower.htm


    I then save the information in a spreadsheet so I can compare conditions and setups as such. I know I'm probably overdoing it, but I'm just looking for a pattern to emerge after enough data logs. See what affects us the most.
    Last edited by RXP-REX; 03-26-2010 at 11:33 AM.

  10. #10
    Quote Originally Posted by Hydrotoys View Post
    But if you want to compare back/back mods, you have to do this, or you are just guessing in the dark.
    True story.

Page 1 of 3 1 2 3 LastLast

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. There’s Still Time To Act on RIVA’s 4th of July Sale Now!
    By Rustymuscle in forum The Watercraft Journal
    Replies: 0
    Last Post: 07-02-2015, 12:00 PM
  2. Riva Rear air set up on 08 set ups ????
    By mrbtd in forum 4-Tec Performance
    Replies: 6
    Last Post: 08-19-2010, 06:44 PM
  3. replacing filter on riva rear air intake
    By axl86 in forum 4-Tec Performance
    Replies: 6
    Last Post: 05-15-2009, 11:16 AM
  4. Extra Outerwears Material on Riva Rear intake ideas??!??
    By NoMo-xp4me in forum 4-Tec Performance
    Replies: 7
    Last Post: 08-30-2007, 09:52 AM
  5. Riva Rear Air on stock exhaust pics
    By badams7 in forum 4-Tec Performance
    Replies: 9
    Last Post: 04-18-2007, 10:43 AM

Posting Permissions

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