Page 1 of 2 1 2 LastLast
Results 1 to 10 of 18
  1. #1
    West Texas RXP skoepp's Avatar
    Join Date
    Oct 2007
    Location
    west texas
    Posts
    12,019
    +1
    149

    GTX Mods with Cast Pistons

    Ok, I read every thread (all the way back to 2005)that dealt with GTX Mods by search. To be honest the older threads are very interesting.

    I want to update the charger to 06 spec and put green charger. I would also like to add the XS intercooler.

    I am not very interested in updating the ECU unless I sometime decide to update my rxp ECU.

    How reliable will the green wheel and XS IC be with stock pistons.
    Will I need to change out the fuel reg to 58 or leave stock?

    Any comments appreciated.

    Just out of curiouisty what is the cost to change to to forged pistons.
    that being all parts and labor.


  2. #2
    jpeconsult's Avatar
    Join Date
    Jul 2007
    Location
    Pineville, LA
    Posts
    5,448
    +1
    1
    skoepp,

    It seems like you and I are trying to accomplish the same thing...maximize the GTX SC. I think you are a bit ahead of me on mods. I would also like to know the above mentioned info. Is it as simple as changing the pistons? I thought there was more differences in the 185 -vs- the 215, besides the IC. I understood we are limited to the mods we can have because of the pistons. Is that it? Just the pistons and make mods in appropriate order? --Jeremy

  3. #3
    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 jpeconsult View Post
    skoepp,

    It seems like you and I are trying to accomplish the same thing...maximize the GTX SC. I think you are a bit ahead of me on mods. I would also like to know the above mentioned info. Is it as simple as changing the pistons? I thought there was more differences in the 185 -vs- the 215, besides the IC. I understood we are limited to the mods we can have because of the pistons. Is that it? Just the pistons and make mods in appropriate order? --Jeremy
    The three major differences in the motors is ECU: 7600 vs 8100 max rpms, the sc Drive gear: Lower gear ratio, and cast pitsons: weaker and slightly higher compression than the forged ones.

  4. #4
    West Texas RXP skoepp's Avatar
    Join Date
    Oct 2007
    Location
    west texas
    Posts
    12,019
    +1
    149
    Quote Originally Posted by DarthAWM View Post
    The three major differences in the motors is ECU: 7600 vs 8100 max rpms, the sc Drive gear: Lower gear ratio, and cast pitsons: weaker and slightly higher compression than the forged ones.
    Ya, I read all that till my eyes hurt this afternoon. I realize the differences I just want to know my limits with what I got. I ran search on GTX Mods and read every thread that dealt with gtx mods. It was very interesting to see all the comments back in 05 and all the changes to now.

    I feel preety safe installing the Green wheel and the IC could do nothing but help the motor, but I saw were some guys were changing the fuel reg from stock 44 psi to 58 psi?

    I also plan to change the pump out, but know is giving me no problems.

  5. #5
    jpeconsult's Avatar
    Join Date
    Jul 2007
    Location
    Pineville, LA
    Posts
    5,448
    +1
    1
    So if we change ECU, gears, pistons and compression...Can we play?

    Serious, making those mods...will they allow us to start looking at more serious mods.

    As if gears and pistons were not serious. --Jeremy

  6. #6
    Quote Originally Posted by DarthAWM View Post
    The three major differences in the motors is ECU: 7600 vs 8100 max rpms, the sc Drive gear: Lower gear ratio, and cast pitsons: weaker and slightly higher compression than the forged ones.
    The compression is lower 8.1-1 RXP is 8.4-1.

    I have a freind that has the fan with no intercooler and it was ok but we are putting in the pistions before we go any farther with his mods.I would say if you do the ECU you need to do the fuel pump and regulator from a RXP.

    If you do the pistons than put a RXP gear on the supercharger and put in the flywheel gear we did this to his already.We also did the ECU and fuel pump assembly.I would stay away from intercooler and only do a supercharger fan not a real big supercharger unless you do the pistons.

  7. #7
    West Texas RXP skoepp's Avatar
    Join Date
    Oct 2007
    Location
    west texas
    Posts
    12,019
    +1
    149
    Quote Originally Posted by jpeconsult View Post
    So if we change ECU, gears, pistons and compression...Can we play?

    Serious, making those mods...will they allow us to start looking at more serious mods.

    As if gears and pistons were not serious. --Jeremy

    I'm no expert, but I believe that if change some internals of the motor you can have the same reliabilty of the 215hp, and once you have done that, yes you can start the mod feast. But in the end I would think you would have spent more to accomplish that goal than just starting with 215 and then moding. It all depends on what you are trying to accomplish.

    If you are looking to run 75 or better I would think it would be cheaper to start with a 215hp and then mod.

    I bought both of my skis last spring for very good prices, but I also searched for 3 months for them and had to go out of state for both of them. The 2004 had only 19 hours and the 2003 had 33 hours and the sale prices were to good to reveal. Now, my approach to moding my skis has been different per ski. To this point I do not have alot in the gtx and as we speak it is getting donnor rxp exhaust parts now.

    It all depends on your goals and pockets.

  8. #8
    Red Devil's Avatar
    Join Date
    Apr 2005
    Location
    Chesterfield/Richmond, VA
    Posts
    1,809
    Take it from someone who has been where you are. I spent a ton of cash just converting my 185 hp 04 GTX to just equal a 215 hp. There is a lot more involved than ya think. If you are really going to be modding your GTX, now would be the time to consider getting rid of it and starting with a 215 platform. You not only have the cost of the parts, but labor as well. ECU, Pistons, new fuel pump assembly, fuel regulator, overdrive gear, intercooler, drive shaft, wear ring, and a few other expensive goodies I am probably forgetting. Looking back on it now, I would have gone another route. One other thing to remember is if those cast pistons let go, your GTX will be toast anyway. Just some food for thought.
    Last edited by Red Devil; 01-25-2008 at 05:23 PM.

  9. #9
    West Texas RXP skoepp's Avatar
    Join Date
    Oct 2007
    Location
    west texas
    Posts
    12,019
    +1
    149
    Quote Originally Posted by Red Devil View Post
    Take it from someone who has been where you are. I spent a ton of cash just converting my 185 hp 04 GTX to just equal a 215 hp. There is a lot more involved than ya think. If you are really going to be modding your GTX, now would be the time to consider getting rid of it and starting with a 215 platform. You not only have the cost of the parts, but labor as well. ECU, Pistons, new fuel pump assembly, fuel regulator, overdrive gear, intercooler, drive shaft, wear ring, and a few other expensive goodies I am probably forgetting. Looking back on it now, I would have gone another route. One other thing to remember is if those cast pistons let go, your GTX will be toast anyway. Just some food for thought.

    Thanks for the reply,


    I read alot of your threads from 2005.

    One question. If I put xs ic and green wheel do i need to do anything eles or will it be safe???????????

  10. #10
    Keep this in mind: although there are affordable add-ons, you would have to decide what is best based on your ability to install/mod your ski.
    You can easily spend 1500-5000 on mods and still not out-perform the 215 RXT.
    I personnaly had my boat at a best of 69.2-69.8 even included the kitchen sink.
    There are many ways to go about getting decent results and inginuity goes along way.

    there are quite a few IC set-ups that members have built upon and designed there own plumbing and bracketry. maybe for some it is best to just purchase an IC kit with everything you need being the easiest solution bc all the thought is already done.

    common GTX SC mods:
    SC updated shaft kit, steel washers, choice of sc wheel, (must match what your add-ons)
    IC kit (Riva, Piranha, XS)
    air filter kit (Riva, R&D, Home made)
    some form of exhaust mod, resonator delete, thru hull, custom.
    if your going to up the boost, it`s best to add the Rotax 58psi fuel pressure reg.
    seperate cooling for the IC, add a strainer is a must!
    catch can
    and imho iridium plugs.

    there is also speed and handling in the hull:
    wedge, nozzle, rings...
    sponsons and grate.
    RE block-offs or Riva block-offs.

    the cast pistons can handle alot of the mods with the stock and the 215 hp ecu. keep the rev limit below 8200.
    keep it simple by building to retain the stock injectors.
    remember, you install one mod, then you`ll be installing another to support the one you just installed. (in most cases...)

    Make a plan, have a goal and follow thru. realistically if money is a great concern modding the 185hp GTX`s to achieve a realistic performance goal, then maybe you should consider trading up to the RXT...

    In my personal experience, I had a blast tweeking the GTX.
    I will always remember that ski!...PR...
    Last edited by Pale Rider; 01-25-2008 at 05:32 PM.

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. need a 03 GTX-SC with a bad piston
    By Obergie in forum Texas
    Replies: 0
    Last Post: 06-25-2015, 10:06 PM
  2. 96 GTX with melted piston
    By Comp in forum Sea Doo Open Discussion
    Replies: 0
    Last Post: 06-26-2011, 08:40 AM
  3. 4-tec GTX 185hp with over bore and RXP pistons?
    By swedaniel in forum 4-Tec Performance
    Replies: 22
    Last Post: 11-22-2010, 09:05 AM
  4. Replies: 6
    Last Post: 01-23-2008, 04:13 PM
  5. 2004 GTX SC with plastic pump?
    By Green Hulk in forum 4-Tec Performance
    Replies: 17
    Last Post: 08-15-2005, 09:26 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
  •