265 Dump valve boost leak?

Discussion in 'Mechanical - Engine, Gearbox, Exhaust etc' started by Ben_r1, May 18, 2014.

  1. Got a Forge DV on the car with whatever spring is supplied with it, all worked fine and dandy.

    Remapped car today with RSTuner now it seems there is absolutely no torque whatsoever for 80% of the pedal travel and as soon as you floor it the car goes off like a steam train. Does seem to be making a lot more turbo whistle.

    Is my DV spring too weak and allowing the boost to bypass? If so why does not leak at full throttle? I would have presumed it would leak at high boost instead of intermediate boost levels.
     
  2. Never had any experience of this but have you tried it on different throttle maps?

    Also you should be able to monitor throttle position using the rstuner software if I remember correctly.

    You could also do a performance analysis using rstuner and see what the graph looks like.

    May also be worth monitoring the boost levels through the rs monitor or rstuner to see what they're doing.

    Hope this helps.
    Ash
     
  3. Cheers mate, having a quick read up online it seems the spring within the DV holds the boost on partial throttle so I'm guessing it's too weak and at full throttle the boost then holds its shut. I'm going to fit the blue rated spring and see how that works for me :smile:
     
  4. Ah I see, hopefully that solves your problem then! I always find the rstuner is a great tool to use when fault finding
     
  5. How many more times can you say rstuner
     
  6. Oh piss off dan :tongueout:
     
  7. Fitted blue spring in place of yellow and it's solved the problem, it's an absolute animal mid range now! But on the negative doesn't dump as much on partial throttle and not as loud at full boost.

    It was a most strange feeling though, almost like a turbo'd VTEC, nothing nothing nothing and then the whole world set alight!
     
  8. You swapped from bluefin to rst ben?
     
  9. Couldn't you have used the original spring with some shims so that it still holds boost but dumps more?
     
  10. Yes mate all these lean running problems got me concerned so I got rid of the bluefin and was going to keep it standard but then someone got me an RSTuner as a gift so be silly not to use it!

    Yeah could have but over the noise of the turbo sucking in and the Scorpion it's difficult to hear if the DVs leaking at all so played it safe and went for the stiffer spring, I may have a little play another time.
     
  11. So rst over the bluefin all day right? Just thinking if i fancy it down the road
     
  12. All these plug and play maps are a heap of headache imo. There's always some sort of issue with them no matter what one you get. Just pay the money and get a custom map, then you have piece of mind that it's right.
     
  13. Fastchips RS Tuner I now have installed seems fine, smoother delivery of power than the bluefin as well.
     
  14. Would be good to see the difference on the rollers Ben?
     
  15. Absolutely, unfortunately though once you use the RS Tuner it locks the ECU out to any other remote box :worried: From drivability alone I can feel more mid range and a smoother power delivery.
     
  16. Even if you remove the RS Tuner map from the ECU first?
     
  17. My R26 has had a loud whistle on boost since I got it in Jan and I reckon I'm having the same problem you did ... but mines the standard dv :/
     
  18. Nice it was the spring, if u map ure car and got oem dv then yes u got a dv leak problem, get a forge dv.

    To check if u got a leak u could presurize the system, for that u need this materials.
    a3uqazar.jpg
    With a compresor u just presure to 1 bar and with some soap check for any bubble
     
  19. A weak spring will only cause leak during part throttle when the pressure between either side of the throttle valve are different, once on full throttle the higher pressure in the intake manifold should supply the top of the DV with enough force to hold it down.

    I'd suggest you check your recirc valve ( or standard DV as you've put it ) for a split diaphragm as I think this can happen.
     
  20. wrong reply ..
     

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