Homer Posted November 22, 2007 Share Posted November 22, 2007 The vacuum feed should be on tapped into the compressor housing, on every installation I've seen it's been done there. I don't know why though! This feed should go to the side port on the wastegate with a tee to the In port on the BC solenoid Quote Link to comment Share on other sites More sharing options...
gsportcars Posted November 22, 2007 Author Share Posted November 22, 2007 The hole on my compressor housing is blanked off. I have taken the feed from the intercooler piping just after the turbo which is just the same and which worked fine on any other setup I have had albeit with an actuator. The other thing I thought ot is that I have T-pieced the vacuum piping right beside the controller solenoid. Is this ok? I would see how it could make much if any difference. Quote Link to comment Share on other sites More sharing options...
Chiefgroover Posted November 22, 2007 Share Posted November 22, 2007 You can park it beside mine and copy the vacuum pipes. That way you can eliminate the piping from the problem. Bring plenty of silicone hose and small cable ties. Mine uses a vacuum take off from the intercooler piping also. Quote Link to comment Share on other sites More sharing options...
gsportcars Posted November 22, 2007 Author Share Posted November 22, 2007 Ernie I might actually take you up on that offer. I am pretty sure the vacuum pipes are fine but I wouldn't mind a nosey at your motor anyway. You are somewhere in Newcastle if I remember right????? Nearly sure thats where Simon (cartoyz) told me. Quote Link to comment Share on other sites More sharing options...
Chiefgroover Posted November 22, 2007 Share Posted November 22, 2007 Yes, out the Bryansford road in the Tollymore direction. Quote Link to comment Share on other sites More sharing options...
gsportcars Posted November 22, 2007 Author Share Posted November 22, 2007 Think I still have your number here from before so I'll give you a shout if I get a chance to take a drive that way. Quote Link to comment Share on other sites More sharing options...
gsportcars Posted November 22, 2007 Author Share Posted November 22, 2007 I just drove the car home and I took it another run to see if I could shed any more light on the situation. As it stands the wastegate is plumbed in correctly and the boost controller is switched to wastegate so all should be fine but the wastegate is still fluttering open at about 0.4bar of boost. I decided to try and raise the boost via the boost controller as I figure this would allow more air pressure to hold the wastegate closed for longer and maybe it would hold long enough to reach a certain boost and stay there. What did happen was that the boost kept rising as normal past the 0.4bar mark until about 0.7-0.8bar before it would just do the same thing again. Not only this but it would then overboost again right out 1.5bar+. This has told me that the boost controller is working correctly but there is still another problem somewhere that I can't figure out. As I mentioned before it can't be a problem with the manifold as others have had because if the hole was too small, it wouldn't let enough air through to open the wastegate at it's set boost never mind having it open too early so I have completely rulled that out too. I just bought some new silicon vacuum hosing which I am going to fit to eliminate the chance of it being due to a blockage in the vacuum pipes or even a kink somewhere. But I really can't see this being the case. I am still wide open to any suggestions that anyone might have as I'm going crazy with this. Quote Link to comment Share on other sites More sharing options...
Wez Posted November 22, 2007 Share Posted November 22, 2007 If it was me working on my own car I would take the boost controller out of the equation and run on the wastegate spring to see how it goes. One pipe from a boost reference to the wastegate, thats it. Quote Link to comment Share on other sites More sharing options...
gsportcars Posted November 22, 2007 Author Share Posted November 22, 2007 Yeah mate I did that and it just acts the same as if the boost controller was set to zero. I just went and changed all the vacuum hoses for new ones and made sure that it was plumbed in the correct way again. I also made sure the centre hole on the top of the wastegate was properly sealed incase it may have been leaking and I have still had no luck with it:( This is completely baffling me as I have tried absolutely everything. The only other thing I can think of is if there is a problem with this particular type of wastegate although I can't see why. I know the wastegate itself is fine as I have tried 2 of the same wastegate with exactly the same results. Maybe this design of wastegate doesn't work well with my turbo but I always thought that all external wastegates operated in essentially the same way but with varying designs of housings and flanges etc. I am sure there are plenty of people on here who have used this wastegate succesfully???? Can anyone confirm this so I can eliminate another possibility from my very small list. Quote Link to comment Share on other sites More sharing options...
Homer Posted November 22, 2007 Share Posted November 22, 2007 I don't think it's that, I had the same setup on mine but with a larger T67dbb turbo, it works perfectly. Not sure what else to suggest. Quote Link to comment Share on other sites More sharing options...
gsportcars Posted November 22, 2007 Author Share Posted November 22, 2007 Tell me about it.... I have completely run out of ideas. I've never been this stuck with any problem of any sort before!!! Quote Link to comment Share on other sites More sharing options...
Soonto_HAS_soop Posted November 22, 2007 Share Posted November 22, 2007 Haven't bothered reading the entire thread, but have you tried changing the wastegate spring, the standard spring in the XS wastegates are crap and don't hold the power. Grab a cheap upgraded spring off ebay and swap it out and retry. Had a similar problem on a friends car and it was the wastegate getting overwhelmed with the crap spring. Quote Link to comment Share on other sites More sharing options...
gsportcars Posted November 22, 2007 Author Share Posted November 22, 2007 Do you mean, get a heavier spring for higher boost or just a "better quality" spring with the same tension. Also would I not need to buy a spring that is made specifically for these wastegates and therefore it would just be the same spring or are there springs from other makes of wastegate that would or possibly fit fine. Quote Link to comment Share on other sites More sharing options...
Ryan.G Posted November 22, 2007 Share Posted November 22, 2007 I would recommend pressure testing the system to make sure 100% there are no leaks in piping as is sounding like its either a nackered wastegate spring or boose leak. If you say you have tried 2 wastegates then i would not rule out a boost leak as cant see 2 springs being duff. Ryan Quote Link to comment Share on other sites More sharing options...
gsportcars Posted November 22, 2007 Author Share Posted November 22, 2007 This is the only suitable spring I could see but it seems to be the exact same spring that comes supplied with the wastegate. http://cgi.ebay.com/ebaymotors/Turbo-Wastegate-Spring-15-Psi-Replacement-WG-Spring_W0QQcmdZViewItemQQcategoryZ33742QQihZ004QQitemZ140181195407QQrdZ1QQsspagenameZWD2V I also don't know for certain what spring is in my wastegate at the minute but I assume it is a 1bar spring. I know the original one was a one bar spring so I could try that spring in and see. But as I said it was the same with the old wastegate. Another comlpete long shot is that maybe my boost controller is taking a positive electrical feed from a weak source and having problems operating the solenoids under boost. I don't know if the soleniods would use that much power at all though??? Quote Link to comment Share on other sites More sharing options...
gsportcars Posted November 22, 2007 Author Share Posted November 22, 2007 Ryan what I don't understand is how a possible boost leak in the intercooler piping could cause the wastegate to shutter open and closed under boost. I have never heard of a knackered wastegate spring. Does this just mean that it doesn't have the strength to keep the valve closed? If so then surely it would then in essence just become a weaker spring and cause the wastegate to open at a lower boost, but it should still operate as normal? Quote Link to comment Share on other sites More sharing options...
rpslaughter1982 Posted November 22, 2007 Share Posted November 22, 2007 I would definately check that all the intercooler pipes/ intake manifold are leak free. I'm sure I'll be corrected if wrong but my take on the above is as follows: The wastegate takes pressure from the compressed air after the turbo. If there is a leak it will cause the pressure going to the wastegate to fluctuate. The pressure will rise then fall as the air escapes. As the air escapes the wastegate will think the turbo’s boosting less so will close again, the pressure will rise and could cause some over boost at this point because the turbo will be working even harder to make the same pressure. This is how my mind sees it anyhow Quote Link to comment Share on other sites More sharing options...
Homer Posted November 22, 2007 Share Posted November 22, 2007 I would definately check that all the intercooler pipes/ intake manifold are leak free. I'm sure I'll be corrected if wrong but my take on the above is as follows: The wastegate takes pressure from the compressed air after the turbo. If there is a leak it will cause the pressure going to the wastegate to fluctuate. The pressure will rise then fall as the air escapes. As the air escapes the wastegate will think the turbo’s boosting less so will close again, the pressure will rise and could cause some over boost at this point because the turbo will be working even harder to make the same pressure. This is how my mind sees it anyhow Makes sense to me In case you don't know it, there's a simple way to pressure test the IC pipework. Get a motcycle inner tube, cut it, seal one end to the pipe just off turbo, the other end to the pipe into the manifold, attach a foot pump and pump it up to 25-30 psi. Listen for the leaks.. Quote Link to comment Share on other sites More sharing options...
UltraFlynn Posted November 22, 2007 Share Posted November 22, 2007 In case you don't know it, there's a simple way to pressure test the IC pipework. Get a motcycle inner tube, cut it, seal one end to the pipe just off turbo, the other end to the pipe into the manifold, attach a foot pump and pump it up to 25-30 psi. Listen for the leaks.. I just thought through that idea and it's brilliant. Rubber seals easily and you have a valve to attach the pump to. Awesome tip. Quote Link to comment Share on other sites More sharing options...
gsportcars Posted November 22, 2007 Author Share Posted November 22, 2007 Indeed that is a nice idea. I see now what you mean about the boost leak causing the problem. Has this been known to happen before? And that process that you described above rpslaughter.... I assume this all happens in very quick time in order to give very rapid shuttering of the wastegate? Looks like I'm buying a motorbike tube tomorrow then LOL. Quote Link to comment Share on other sites More sharing options...
gsportcars Posted November 22, 2007 Author Share Posted November 22, 2007 Sorry for all the double posts but just as you have described this to me I have thought of something else. When this shuttering occurs my HKS analogue boost gauge needle shutters at the same time. I had orginally put this down to the diaphram in the wastegate moving in and out and causing the boost to shutter back through to the intercooler piping and therefore giving an unsteady boost reading on the guage. I know this is still very much a possibility of what is happening but the above explanation of the boost leak does seem more likely to be the cause of a shakey boost gauge needle. Like I said before guys... all help is much appreciated so thanks for the advice so far, it's been a big help in eliminating possible causes!! Quote Link to comment Share on other sites More sharing options...
Homer Posted November 22, 2007 Share Posted November 22, 2007 It's all a question of elimination, you'll get there soon Just another thought - what afr's are you seeing when this occurs? Typically when a boost leak occurs the car runs very rich. In your case it might only be for a short period but I'd have thought you'd see something odd appear on the afr gauge.... Quote Link to comment Share on other sites More sharing options...
gsportcars Posted November 22, 2007 Author Share Posted November 22, 2007 I don't know what the exact figures where as Jonny was doing the mapping in the passenger seat but he did say that they stayed constant. The fuelling certainly didn't drop as I asked him could it have been down to a faulty injector and he said the fuelling stayed as is so it was highly doubtful. I am well used to the process of elimination with this car lol. I am just running out of things to eliminate!!!! Quote Link to comment Share on other sites More sharing options...
Homer Posted November 22, 2007 Share Posted November 22, 2007 I'd recommend getting an AFR gauge asap, they're an absolutely essential gauge for single turbo supras. Quote Link to comment Share on other sites More sharing options...
UltraFlynn Posted November 22, 2007 Share Posted November 22, 2007 I am well used to the process of elimination with this car lol. I am just running out of things to eliminate!!!! Keep the faith. There is a problem there and with perseverance you will find it. Just keep eliminating things that could be wrong. Quote Link to comment Share on other sites More sharing options...
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