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Autocross Build GSX AutoX Street Mod

Rating:
5/5,
Year:
1997
Model/Trim:
Mitsubishi Eclipse GSX
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  1. silvreclips

    silvreclips Proven Member

    1,115
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    Joined Jul 19, 2005
    Greenville, South Carolina
    @miguelmcv yea you are correct. I was just throwing out the idea, I didn't think it through. But either way yea a larger pulley should help out. I run an under drive pulley on the crank and my PS still works fine at idle.

    I'll go out and measure how much the diameter changed just to give you an idea.

    You may be able to just make a spacer for that line instead of making a whole new one. Does anyone make a larger pulley or does it have to be custom?
     

    Autocross Build 365  1

    1998 Mitsubishi Eclipse N/T
    fwd · manual · 2G DSM
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  2. ec17pse

    ec17pse Freelancer

    3,732
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    Joined Nov 1, 2008
    London, Europe
    what you could do is take out your spring and install a slightly stiffer spring in its place,

    a bigger pully would work and a bigger crank dampner would also help this but not as much as the pully on the ps pump itself.

    another thing to look at is the evospec pully kit they make, its over sized for the waterpump so slows down the pump and also will slow down the powersteering pump also

    https://www.dsmtuners.com/threads/new-billet-underdrive-water-pump-pulley.524417/

    http://evospecperformance.com/
     

    Road Race Build 10K  10  55

    1997 Mitsubishi Eclipse GST
    175 whp · 180.1 lb/ft · 2G DSM
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  3. silvreclips

    silvreclips Proven Member

    1,115
    299
    Joined Jul 19, 2005
    Greenville, South Carolina
    @96dsmftw just fyi. My stock crank pulley was 6 1/4 in diameter and my under drive pulley is 5 in diameter.
     

    Autocross Build 365  1

    1998 Mitsubishi Eclipse N/T
    fwd · manual · 2G DSM
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  4. silvreclips

    silvreclips Proven Member

    1,115
    299
    Joined Jul 19, 2005
    Greenville, South Carolina
    Also, when I modded my PS pump, which is a bit different then the 4g pump, I wasn't able to shim the spring, I drilled out the holes some that restrict fluid flow at high rpm. Maybe that would help eliminate the high rpm cutout.
     

    Autocross Build 365  1

    1998 Mitsubishi Eclipse N/T
    fwd · manual · 2G DSM
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  5. ec17pse

    ec17pse Freelancer

    3,732
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    Joined Nov 1, 2008
    London, Europe
    I asked evospec and the normal version is $125 and if you want it anodized its 160 they do 3 version but V1 is there unit with the PS pully attached
     

    Road Race Build 10K  10  55

    1997 Mitsubishi Eclipse GST
    175 whp · 180.1 lb/ft · 2G DSM
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  6. 96dsmftw

    96dsmftw Supporting Member

    188
    110
    Joined Jun 23, 2011
    Richmond, Kentucky
    I was thinking of staying away from changing the crank pulley size. I was thinking of it as I need my waterpump to spin quickly because Running the car hard at slow speeds heats it up quickly. I'll look at the slower water pump. It just seems weird to me. Changing that spring is also an interesting idea.
     

    Autocross Build 5K  15

    1997 Mitsubishi Eclipse GSX
    12.166 @ 117.000 · 2G DSM
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  7. ec17pse

    ec17pse Freelancer

    3,732
    1,638
    Joined Nov 1, 2008
    London, Europe
    The idea of over spinning the pump is not as you think, the faster you spin it the more bubbled you create and its not good for cooling. You might find slowing down the pump will work better for you as thats what alot of people try and do. Its why im looking to go EWP because i can control the speeds and it wont over spin the pump to levels it cannot control temps well
     

    Road Race Build 10K  10  55

    1997 Mitsubishi Eclipse GST
    175 whp · 180.1 lb/ft · 2G DSM
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  8. silvreclips

    silvreclips Proven Member

    1,115
    299
    Joined Jul 19, 2005
    Greenville, South Carolina
    Bobby, your talking about cavitation, it's a possibility if the impeller does spin to fast, but I would expect to see impeller damage and possible pump failure if that was the case. Are there other ways to tell if that's happening?
     

    Autocross Build 365  1

    1998 Mitsubishi Eclipse N/T
    fwd · manual · 2G DSM
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  9. ec17pse

    ec17pse Freelancer

    3,732
    1,638
    Joined Nov 1, 2008
    London, Europe
    Thats the word, i forgot it as i was tryping LOL, I dont know how to check for it or if its happening. Other cars get around this by modifying the fans in the housing but if that would work on ours i dont know. The easiest way to solve most of the issues is the pully to slow it down, it still works but up top it does not over spin causing issues
     

    Road Race Build 10K  10  55

    1997 Mitsubishi Eclipse GST
    175 whp · 180.1 lb/ft · 2G DSM
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  10. silvreclips

    silvreclips Proven Member

    1,115
    299
    Joined Jul 19, 2005
    Greenville, South Carolina
    Maybe you need to eliminate the spring completely and find something rigid that is the same size so the restrictor valve can not engage ever.
     

    Autocross Build 365  1

    1998 Mitsubishi Eclipse N/T
    fwd · manual · 2G DSM
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  11. Black95TSIawd

    Black95TSIawd Proven Member

    1,701
    317
    Joined Jan 28, 2003
    Dirty, New Jersey
    You might be onto something.

    Bobby could make it.
     

    5K  8

    1998 Eagle Talon TSi AWD
    184.4 whp · 251.0 lb/ft · 2G DSM
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    96dsmftw likes this.
  12. 96dsmftw

    96dsmftw Supporting Member

    188
    110
    Joined Jun 23, 2011
    Richmond, Kentucky
    I have a spare P/S pump I can take apart and see. However I believe the reason it is in there is so the pump doesn't over pressurize and blow the seals on the rack. It might work for a stock rev limit because the pump is spinning within stock limits. I am going to try a 8k rev limit this year. With the pressure increasing as the rpm increases, over stock rev limit could cause a pressure problem. I might look at removing the spring and making it fixed, like you suggested, and then having an inline pressure relief valve. The relief valve would still keep a limit on pressure but not impede flow rate to nothing like the stock valve does.
     

    Autocross Build 5K  15

    1997 Mitsubishi Eclipse GSX
    12.166 @ 117.000 · 2G DSM
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  13. silvreclips

    silvreclips Proven Member

    1,115
    299
    Joined Jul 19, 2005
    Greenville, South Carolina
    Without a pressure sensor on the high pressure line we will never know. When I modded mine (420a) I drilled out the holes essentially making the spring regulator useless. I have had no issues with my 7.5k rev limit currently. I also am running an under drive crank pulley so the pump does turn slower then stock.

    Good luck with whatever you decide to do.
     

    Autocross Build 365  1

    1998 Mitsubishi Eclipse N/T
    fwd · manual · 2G DSM
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  14. ec17pse

    ec17pse Freelancer

    3,732
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    Joined Nov 1, 2008
    London, Europe
    I have my old pump i had to replace so i could look at it and see how that would work, not sure if its got a built in bypass for lower revs or some safety thing
     

    Road Race Build 10K  10  55

    1997 Mitsubishi Eclipse GST
    175 whp · 180.1 lb/ft · 2G DSM
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    Black95TSIawd likes this.
  15. ec17pse

    ec17pse Freelancer

    3,732
    1,638
    Joined Nov 1, 2008
    London, Europe
    Got pics of your process? Im thinking the passsge ways could be larger reducing the pressure, as a guess. I would really have to play around with it more and see
     

    Road Race Build 10K  10  55

    1997 Mitsubishi Eclipse GST
    175 whp · 180.1 lb/ft · 2G DSM
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  16. silvreclips

    silvreclips Proven Member

    1,115
    299
    Joined Jul 19, 2005
    Greenville, South Carolina

    Autocross Build 365  1

    1998 Mitsubishi Eclipse N/T
    fwd · manual · 2G DSM
    Loading...
    RWD4G63 and ec17pse like this.
  17. ec17pse

    ec17pse Freelancer

    3,732
    1,638
    Joined Nov 1, 2008
    London, Europe
    So when i rebuilt my spare pump ages ago and installed a few weeks back i stretched the spring out because this ruins the preset tension but it helps keep it further up. Its not the most well engineered way of doing it but it will work. Just dont over do it though or you will cause more issues then fixing. I did mine about 7-10mm.

    Im still looking into it to see if there is a much better solution thats drop in
     

    Road Race Build 10K  10  55

    1997 Mitsubishi Eclipse GST
    175 whp · 180.1 lb/ft · 2G DSM
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  18. 96dsmftw

    96dsmftw Supporting Member

    188
    110
    Joined Jun 23, 2011
    Richmond, Kentucky
    I'm going to look at making a different sized P/S pump pulley on the water pump. I noticed the pulley on the pump doesn't look like it comes off easily. There are a few ways to get it done. Thanks for the ideas.

    I also have a question about my next mod. I am in the process of building a 2.3 6 bolt. I will be using a 2g head. I have been thinking about break in. Its not as easy using the same tune because even though all of the parts are the same at first, I have 0.3L more displacement. I am on speed density, is that going to be enough to do a quick 15 min break in? I will probably add a bit more fuel globally to help and will watch the AFR doing my pulls.
     

    Autocross Build 5K  15

    1997 Mitsubishi Eclipse GSX
    12.166 @ 117.000 · 2G DSM
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    BLACK'98DSM likes this.
  19. midwestmopar

    midwestmopar Proven Member

    47
    52
    Joined Feb 14, 2020
    Commiskey, Indiana
    Screenshot_20200312-094631.png
    congratulations on the cover shot of then KY event! I hope to see you there.
     

    Autocross Build 207  3

    1996 Mitsubishi Eclipse Spyder GST
    fwd · manual · 2G DSM
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