Silent dump valve

Discussion in 'Mechanical - Engine, Gearbox, Exhaust etc' started by Steve Rawlinson, Nov 27, 2018.

  1. I've bought a R26 which the dealer assures me is totally standard.

    I can hear the dump valve. It's not loud but I can hear it, and seeing as I'm not 16 I don't think an audible dump valve on a 2 litre 230bhp engine is rad or sick or whatever other adjective they've come up with recently.

    Is it possible to replace it with a silent one?
     
  2. Have you checked to see if it is an oem one fitted?
     
  3. I haven't. I would not know what to look for or where.
     
  4. Is it running a standard air box? If not, then you will be able to hear the standard dump valve. If it is a standard air box, then the most common place for an aftermarket dump valve would be cut into the main boost hose that runs along the top of the rad.

    Post a pic up of your engine bay and someone will soon tell you!


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  5. Would that not be a good place to start......
     
  6. Here you go. The non-standard air box sounds likely.
     

    Attached Files:

  7. You've got a forge dump valve fitted to the car, on the black Silicone "T" pipe that says Forge on it
     
  8. That was quick! Thanks.

    So is it just a question of getting that replaced with something less noisy? The OEM unit perhaps?
     
  9. Gets a bit complicated if the previous owner fitted a blanking plate onto the turbo (to replace the OEM recirc valve) as to get totally back to standard you'd need to refit one (ball ache of a job). You could just replace the T piece silicone hose with a straight connector hose, but you'd also have to plug the small hose that connects to the top of the silver valve or you'll get no boost (I may get corrected on that though). You would then replace the tisssshh noise with a turbo flutter noise instead so still not silent!
     
  10. OK, I've had a word with two techs in Dartford and they're happy to put it back to standard or (which is easier) fit a quieter one I supply.

    So: any recommendations for a silent dump valve?

    Thanks to everyone for their help, much appreciated.
     
  11. You will need to fit a standard air box and get that k&n filter off it or you will always hear a noise from it plus that type of filter will lose power as i found out a long time ago.
     
  12. Yes, a oem one....
     
  13. You’re looking for a recirculating dump valve (as per OEM). This pushes the pressurised air from between throttle butterfly and turbo outlet back into the inlet side of the turbo.

    What you have is an atmospheric one, so the pressurised air is just vented into the engine bay, hence the noise you get.


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  14. Apparently you can't buy the OEM ones separately from the turbo (according to Renault Enfield).

    There's a forge direct replacement which presumably will do the trick.
     
  15. Yep that will do the job, just make sure you fit the correct spring - too strong and it won’t open and you’ll end up with turbo flutter, which will be equally noisy through an open cone filter!


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  16. Dont waste your money on a Forge unit, buy Propefekt, A bit confused why you can not source a 2nd oem one, but still
     
  17. I have a OEM one if you want it
     
  18. Well, a couple of things have happened today. The first is that two techs tell me that I only need to replace the pipe because the original valve is very likely still to be there.

    The other thing that happened is that the clutch broke while I was on the north circular road, the car is no longer driveable, and the dump valve is a bit secondary.
     
  19. Hmm, what kind of dealer did you buy it from? They told you it was completely standard, which it clearly isn't (dump valve and cone filter at least), they're saying the original recirc valve is probably still fitted, which if it is means neither valve will be working correctly, and now the clutch has failed. Depending on the deal you got I'd be tempted to hand it back..
     
    Mikeyjp likes this.
  20. Depending on what the clutch issue actually is, and how they react to it, I might well send it back. It's supposed to be a new clutch and a fully rebuilt engine. The warranty does not cover the clutch and I'm certainly not paying for it.
     
  21. Is there any paperwork to back up that the engine has been rebuilt and has a new clutch?
     
  22. Yes, there's receipts, but it's from the dealer I bought it from who also carried out the rebuild. I have it booked in for a full inspection to get this independently verified next Wednesday but it didn't make it that far.
     
  23. I really don’t want to piss on your chips and sound like a know-all, but in your position I would hand it back, get a refund, and look to buy one from a reputable source / forum owner etc.

    If this really was a standard car, I’d question why it needed an engine rebuild - these are not motors that are prone to failures! I just get the feeling that either someone has unloved it, or there is some history to the car that either the garage aren’t aware of (unlikely if they’ve carried out the work) or are failing to tell you.

    If you got it very cheap, then maybe it is worth sticking with, but as soon as you’ve authorised a repair, you’re pretty much sealing the fate of your ownership. It might just be bad timing with the clutch, but then what else could go wrong next? You’re more likely to see things go wrong if they’ve just been tampered with in my opinion.


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  24. What he said ^^

    Can of worms by the sound of it.

    Clearly don't know the cars if he thinks it's standard even though there is bloody big dump valve right in front of you...

    Not called stealers for nothing!
     
  25. Feel for you Steve :cry:
    They are great cars when good. If you are still within 30 day I think the law allows you to return the car for a full refund. Especially as clutches aren’t included in the warranty!
    Sorry for your woes and I wish you the best of luck going forward........
     
  26. It turns out that a hose came loose. My local garage reattached the hose and it came off again (while they were testing it). They've ordered a new hose & clip. If that doesn't work it's a new slave cylinder.

    The dealer I bought it from is paying for all this but he says if it needs the new cylinder he wants it back to fit it himself. It'll cost £250 to recover it back to him to fit a £100 part so that's not going to happen. If he insists on having it back it'll be for a refund.

    Assuming the clutch issue is resolved it's going into a renaultsport specialist for a full inspection next wednesday. Depending on the outcome of that I'll decide whether to keep it or not.
     
  27. Good luck with it all.
    I had similar niggles with mine initially, got them sorted in the end with polite, but firm negotiation and the odd but of humour. :wink:
     
  28. On with the saga...

    The dealer paid for the clutch repair and also for the dump valve removal. Exactly as predicted by Two Techs, the renaultsport specialists in Dartford I had it booked in for a checkup with, the recirc valve was still in place.

    The checkup went well, nothing serious wrong, so for the moment I'm going to hang on to it. I'm still only 8 days into the 30 during which I can return it.

    So - back to the original issue of the silly noises. As predicted by somebody up thread who clearly knew what they were talking about, removing the dump valve has not suppressed the noise of the turbo I can hear. If anything it's a bit louder. The sound comes from the passenger side exactly where the air filter is. Do I need to put the OEM airbox back on to get rid of it?
     
  29. yes, induction kits are more noisy, thats why people buy them.
     
  30. Oh ok, I was under the impression that people bought them because they conferred a performance advantage somehow.
     
  31. Ultimately, performance is gained from the turbo inlet side of things by having as minimal resistance to air flow as possible. This is why drag racers tend to not run any filter or pipe work to their turbo, they just leave it open to the air.

    However, in a road car, there is obviously a need for an air filter. On a standard car, it’ll tend to be a flat panel mounted inside a box - to keep noise down. People opt to fit an open cone (induction kit) style filter to either increase the noise or for a performance gain. An air filter’s performance is a function of size (area available for air flow) and pressure drop (how hard it is for the air to pass through the material - paper / cotton / mesh etc). In an ideal world, you want as big a filter as you can fit, and with a low pressure drop material. The downside to a low pressure drop is that the quality of filtration isn’t as good. It is a trade off between performance and size.

    Assuming similar filter material between a panel filter and an open cone, if the overall area of the cone is smaller than the panel, then you will be losing power. I’ve seen a lot of cars running really diddy cone filters, and I’m sure they would be suffering from this. The extra noise of an open cone often gives the placebo effect of an increase in power!


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  32. The increase in induction noise I can live with, but I hate hearing the turbo whoosh when I lift off the accelerator. It makes me wince with embarrassment. I'm in my late 40s, not my late teens.

    I now have a standard recirculation valve only (forge dump valve is now sitting in a box on the floor) and I am still hearing it. Grr.
     
    Pondman likes this.
  33. Unfortunately you can’t have induction noise and no turbo whoosh (you’re hearing the excess pressure being dumped into the pipe work with the filter on the end). I run a standard air box on mine, and even that has more induction and turbo spool sound than any standard car I’ve owned before. Having watched videos on YouTube of people running cones, there’s no way I could put up with it, but appreciate everyone has their own preference.

    By the sounds of what you’ve described, I’m sure you’d be happy with the noise from a standard filter and air box. If you want more noise from it, you can open up the air inlet hole in it, which is common for people to do for a bit extra audible pleasure.


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  34. Yep, standard airbox seems to be the way forward.
     
  35. Right.

    Standard airbox fitted. Noise finally gone. Thanks very much for all the advice.

    Oil change & brake fluid flushed just in case. New 2DIN stereo fitted (discovered front speakers blown, replaced). K-Tec short shift fitted. Tracked at Bedford. Collapsed Engine mount replaced. Decals removed.

    Case closed.

    whiteR26.jpg
     
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  36. Hi Steve,

    Glad you managed to get the car in your frame of preference.

    I don't know if it's just the angle or shadows etc of that last pic you posted, but the color of the door looks quite off compared to the from fender/wing and the rear of the car. It's almost greyish?

    Does the door feel normal to operate? Alm the hinges there as per factory? A friend of mine only realised later on his door hinge was welded on after something happened to the door, probably sidd impact.
     
  37. AB007C7C-3425-4B0A-AA7A-65AE6E7C5406.jpeg 512DA6C1-4AF0-480A-AA17-39DB97114422.jpeg
    I think it always looked that way from some angles from what I remember. I found these pics of when i owned it.
     
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  38. Yeah I think it's a trick of the light. It looks absolutely identical colour in the flesh.
     
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