Pig Posted May 13, 2012 Share Posted May 13, 2012 Hi all, I have 4 days till dragonball and the car has decided to bite me in the ass. Got it back from the body shop and it was fine all the way home. Then went out for a drive, did 1 run through 2nd, 3rd & 4th WOT and then my next run I just hit boost cut (1.7bar). Stopped to check pipe and all seemed fine. I have now got home and after lots of messing possibly have put the boost pipes back on incorrectly. I had also discovered the the cable tie that was holding one of the pipes onto the lower watergate had come loose. I have since re-fitted the cable ties but it hasn't fixed it. When I blow into the pipes they are all solid apart from the one which goes directly into the intercooler pipe. Any help would be appreciated as I don't have a garage near me that could fix it and I am meant to be going away on Friday!!! Current setup is blitz boost controller with boost turned down to zero. Whifbitz twin wastegates on a T67 sized turbo. Quote Link to comment Share on other sites More sharing options...
Pig Posted May 13, 2012 Author Share Posted May 13, 2012 Here is a picture of the current pipe setup. Thanks Jon Quote Link to comment Share on other sites More sharing options...
mellonman Posted May 13, 2012 Share Posted May 13, 2012 what you could do is go back to wastegate pressure for a short term, i would expect it to be your boost controler playing up bypass the boost controler and see if it still over boosts Quote Link to comment Share on other sites More sharing options...
Pig Posted May 13, 2012 Author Share Posted May 13, 2012 How do I do that? Quote Link to comment Share on other sites More sharing options...
mellonman Posted May 13, 2012 Share Posted May 13, 2012 (edited) okay a boost controller just leaks air to the wastegate so the wastegate thinks its got less boost then what it really has so all you have to do is bypass it, find where you boost controller actuator is and there will be 2 vac pipes to it disconnect them from the the actuator and conect then together simple as . should be something like this http://www.mkivsupra.net/vbb/attachment.php?attachmentid=94491&d=1245107523 it can also be done by just fitting a vac pipe to the bottom part of the waste gate just check what you have and remember you are just bypassing the boost controler Edited May 13, 2012 by mellonman (see edit history) Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted May 13, 2012 Share Posted May 13, 2012 Turn off the boost controller would be the easiest place to start Quote Link to comment Share on other sites More sharing options...
mellonman Posted May 13, 2012 Share Posted May 13, 2012 Turn off the boost controller would be the easiest place to start haha yeah that is very true, or you could do it the hard way like i just descibed Quote Link to comment Share on other sites More sharing options...
Pig Posted May 13, 2012 Author Share Posted May 13, 2012 Ok cool, just tried that and no luck still the same symptoms... Quote Link to comment Share on other sites More sharing options...
mellonman Posted May 13, 2012 Share Posted May 13, 2012 best try my hard way then mate to take the boost controller out the equation Quote Link to comment Share on other sites More sharing options...
Pig Posted May 13, 2012 Author Share Posted May 13, 2012 Would it make a difference where which pipes are plumbed in? I assume as long a 1 loop excluding boot controllers that I am now down to seeing if one of the wastegates is staying closed for some reason? Can I bypass 1 wastegate? If it has no pipes going to it, will it just stay closed? Quote Link to comment Share on other sites More sharing options...
Pig Posted May 13, 2012 Author Share Posted May 13, 2012 best try my hard way then mate to take the boost controller out the equation That was taking it out... Quote Link to comment Share on other sites More sharing options...
Pig Posted May 13, 2012 Author Share Posted May 13, 2012 http://img.tapatalk.com/5f92e380-bd85-edcf.jpg Pic excluding boost controller. Quote Link to comment Share on other sites More sharing options...
mellonman Posted May 13, 2012 Share Posted May 13, 2012 Would it make a difference where which pipes are plumbed in? I assume as long a 1 loop excluding boot controllers that I am now down to seeing if one of the wastegates is staying closed for some reason? Can I bypass 1 wastegate? If it has no pipes going to it, will it just stay closed? have you checked all the vac pipes for damage? Quote Link to comment Share on other sites More sharing options...
Pig Posted May 13, 2012 Author Share Posted May 13, 2012 Yep, when I blow down them, they are not letting any air through. What could I do next to try and narrow down the problem? I would like to try and bypass on of the wastegates. Can I do this? Quote Link to comment Share on other sites More sharing options...
mellonman Posted May 13, 2012 Share Posted May 13, 2012 http://img.tapatalk.com/5f92e380-bd85-edcf.jpg Pic excluding boost controller. yep that should now be wastegate boost looks to be plumbed exactly the same as the pic link i put in Quote Link to comment Share on other sites More sharing options...
mellonman Posted May 13, 2012 Share Posted May 13, 2012 I would like to try and bypass on of the wastegates. Can I do this? thats the problem they are being bypassed thats why your over boosting, have you driven the car with it plumbed like that is it still the same? Quote Link to comment Share on other sites More sharing options...
Pig Posted May 13, 2012 Author Share Posted May 13, 2012 Yes, driven like that last picture and the problem is still the same. Just been to halfords and bought a load of boost pipe to change the pipes. Seems silly as the pipes are fine but I don't know what else to do Quote Link to comment Share on other sites More sharing options...
Nic Posted May 13, 2012 Share Posted May 13, 2012 Do you have a screamer pipe fitted, if so can you hear the wastegate opening as usual? Quote Link to comment Share on other sites More sharing options...
Pig Posted May 13, 2012 Author Share Posted May 13, 2012 Do you have a screamer pipe fitted, if so can you hear the wastegate opening as usual? It's plumbed in. I does all sound normal as the boost starts to build though but the boost just doesn't stop climbing and very quickly hits cut. Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 13, 2012 Share Posted May 13, 2012 (edited) That looks to me like you're sending your boost pressure to the top of both (you have two, yes?) wastegates *and* the bottom of them as well, so the pressure is equal across the diapraghm no matter what the boost conditions - you'll never open the wastegate. That'd explain the overboosting. The 'bottom' feed to the wastegates should always see boost pressure, as that's what opens them. The top feed provides counter-boost to keep them shut, and that should be fed by the boost controller. The solenoid either allows boost to the top feed to keep the wastegate shut or blocks boost to allow the wastegate to open. Your initial picture looks like only one wastegate could open, as the other has the top and bottom feed coming off the same reference line. The second pic has made matters worse as both wastegates are now in this state. Bear in mind this is all from memory on how these things work and your pics My recommendation would be to unplug the hoses that feed the top of the wastegates and provide boost pressure to the bottom feeds only. That'll (hopefully!) give you wastegates working on just the spring pressure. From there we can work out how to plumb the BC back into the equation -Ian Edited May 13, 2012 by Ian C (see edit history) Quote Link to comment Share on other sites More sharing options...
Pig Posted May 13, 2012 Author Share Posted May 13, 2012 That looks to me like you're sending your boost pressure to the top of both (you have two, yes?) wastegates *and* the bottom of them as well, so the pressure is equal across the diapraghm no matter what the boost conditions - you'll never open the wastegate. That'd explain the overboosting. The 'bottom' feed to the wastegates should always see boost pressure, as that's what opens them. The top feed provides counter-boost to keep them shut, and that should be fed by the boost controller. The solenoid either allows boost to the top feed to keep the wastegate shut or blocks boost to allow the wastegate to open. Your initial picture looks like only one wastegate could open, as the other has the top and bottom feed coming off the same reference line. The second pic has made matters worse as both wastegates are now in this state. Bear in mind this is all from memory on how these things work and your pics My recommendation would be to unplug the hoses that feed the top of the wastegates and provide boost pressure to the bottom feeds only. That'll (hopefully!) give you wastegates working on just the spring pressure. From there we can work out how to plumb the BC back into the equation -Ian Hi Ian, thanks for taking the time to help with this. Since my last post, I have replaced all the boost pipes and cable tied the all on so I could ensure there are no boost leaks. I then plumbed the top of wastegate pipes into the IN section of the boost controller and the bottom pipes (including the feed from the intercooler pipe) to the OUT part of the boost controller. This now seems to be kind of working. With the boost controller on 0 - I am hitting 0.9 bar but when I start to turn up (currently 1.27) I am still hitting 1.5 bar and if I set higher than 1.27 then it climbs higher and hits boost cut at 1.7. So to confirm, my understanding from your post would be that the top of the wastegates (yes 2 btw) would go to the out section of the boost controller and the bottom (including the feed from the intercooler pipe) should go to the IN section? Or would it be easier to do as you have suggested to unplumb (liking my newly invented word there) the top feed and go from there? Pic to follow in next post, although it is difficult to see the OUT is the one closest to the IC pipe. Quote Link to comment Share on other sites More sharing options...
Pig Posted May 13, 2012 Author Share Posted May 13, 2012 http://img.tapatalk.com/5f92e380-21ed-2cc2.jpg Quote Link to comment Share on other sites More sharing options...
mellonman Posted May 14, 2012 Share Posted May 14, 2012 there are a couple of ways to plumb a external wastegate,as ian said you can just take your turbo preasure referance and T off to the bottom of the wastegates,This is how i have mine set and the boost controler set in the preasure ref,now the boost controller would have to set for that set up as the n/o and n/c come into play i cant remember what way is for what off the top of my head.its not the best way as the waste gate creaps open but it works,but dont worry about that yet got to try and get wastegate spring boost first and work from there. remember your boost control solinoid maybe faulty thats why as you turn it up you start over boosting Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 14, 2012 Share Posted May 14, 2012 Each boost controller seems to have different terminology and ways they plumb in, so I can't really say whether you should use OUT or IN or whatever. I'd just make it run off the wastegate springs first as I described earlier, and if that works OK them those lines and the wastegate are fine. Only then re-introduce the boost controller, and do that by following the BC's instructions. Post them up if you have them and we can help Having said that, I think you've got it the wrong way around - the IN on the BC valve would be for positive pressure feeding into it, and OUT would be to send that boost pressure to the top wastegate feeds as and when it felt the need. Swap the pipes over first and see what happens - if you have no joy, knock it back to wastegate spring only control and see if it all works -Ian Quote Link to comment Share on other sites More sharing options...
Pig Posted May 14, 2012 Author Share Posted May 14, 2012 Thanks Mellon and Ian. I will do as you have suggested. Yes I do have it the wrong way round according to your previous post. I can't do tonight as weather crap but will plumb with the turbo pressure linked to the bottom of the wastegates and out them to the IN on the boost controller and then the top of the wastegates to the OUT section. If that doesn't work then I will plumb the turbo feed to the bottom of the wastegates and leave the top ones off and boost controller out. Hope I have understood correctly. Want to say thank you again for taking the time to help! Jon Quote Link to comment Share on other sites More sharing options...
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