Noddle Posted March 17, 2009 Share Posted March 17, 2009 Hi, I'm have problems with over boosting, so I put my 7psi actuator on today because my other one was a 10psi with a external spring to help reduce the psi, hoping to stop it over boosting (12psi), but it didn't make any difference. So in my testing I left the waste gate open (unconnected from the flapper arm), PSI started to build a 4k, at 5k it hit 10psi, I lifted my foot when it hit 12psi, so to me this means the waste gate is not letting enough exhaust out through the wategate., So I believe I need to open the hole (in the wastegate), but what I need to know is how much meat the little flapper needs to seal, and for it no to burn through. Note: wategate is in the turbo if I didn't make it clear. Nigel Quote Link to comment Share on other sites More sharing options...
boardkid280z Posted March 18, 2009 Share Posted March 18, 2009 Try googling for some pics of ported wastegates and see what others have done. Try to look for the more professional sources. Just cause someone posted a pic on the internet of their "Ultimate Flow Port Job", doesn't necessarily mean they know what they're doing. I have seen many pics of ported wastegates and it seems like some get close to 1/8th overlap or less even. I think since the flapper is closed it is still bypassing most of the exhaust gas to the turbine, so even with minimal overlap, there shouldn't be a noticeable performance loss. Quote Link to comment Share on other sites More sharing options...
Noddle Posted March 21, 2009 Author Share Posted March 21, 2009 Hi, I did some work on my wastegate this afternoon, but it looks like there just not enough material to remove to fix the issue.. 7psi up to 5K, 12 psi by 5.5-6K Nigel Quote Link to comment Share on other sites More sharing options...
jc052685 Posted March 22, 2009 Share Posted March 22, 2009 yep, know the feeling. Going with external wastegate now. Quote Link to comment Share on other sites More sharing options...
boardkid280z Posted March 26, 2009 Share Posted March 26, 2009 7psi up to 5K, 12 psi by 5.5-6K Nigel So you put it back on and were still having the same issue? Was it any better? I was talking to hughdogz, and he mentioned that jgkurz ported his hole and took too much out, so there wasn't enough material for the puck to seal. So now he can't build boost. Not sure about the details, so you might get in touch with him if you're still trying to make this work. Keep us up to date on what you do. Quote Link to comment Share on other sites More sharing options...
hughdogz Posted March 26, 2009 Share Posted March 26, 2009 ...I was talking to hughdogz, and he mentioned that jgkurz ported his hole and took too much out, so there wasn't enough material for the puck to seal. So now he can't build boost.... If I remember right, that was before he went with his divorced wastegate setup. Yeah, let us know how this turns out... Quote Link to comment Share on other sites More sharing options...
Noddle Posted March 26, 2009 Author Share Posted March 26, 2009 So you put it back on and were still having the same issue? Was it any better? yes it was better, before PSI started to build at 4k, at 5k it hit 10psi, I lifted my foot when it hit 12psi, (with out actuator connected) from memory with the actuator connected, it was about 5psi at about 3.5 -4 k after 7 psi up to 5K, 12 psi by 5.5-6K so up to 5K the waste gate is working as it should (I have a 7psi actuator now) after that it starts to over boost. I have two ways to go, I could add to the flapper to make it larger (maybe a thick washer, slightly larger, spin the centre out so it fits over the original flapper, and weld then together, then make the hole larger, (this may not be to hard to do) or what's I'm going to do over Easter, fit my intercooler, and run 12psi, and tune Megasquirt to run rich at 5+ k Nigel Quote Link to comment Share on other sites More sharing options...
zguy36 Posted March 26, 2009 Share Posted March 26, 2009 The easiest way to fix the problem, just run 12psi of boost! Quote Link to comment Share on other sites More sharing options...
jgkurz Posted March 27, 2009 Share Posted March 27, 2009 The easiest way to fix the problem, just run 12psi of boost! Simple but not far from the truth. I'm short on time right now so I have to be brief. My problem was not that I could not seal the ported wastegate hole but that the larger hole created a larger puck surface for boost pressure to push open the wastegate. Typically a small wastegate port will cause boost creep at higher RPM's. I had the opposite in that my boost would bleed off at higher RPMs. All that is behind me now that I have a external Tial wastegate. I suggest you not port your internal wastegate. It will just cause you more headaches. If you are running higher pressures with a T3 or T3/4 you will probably not need to bleed off as much pressure meaning a larger wastegate port will not necessarily be helpful. Remember, a large wastegate (as sized for your application) will bleed off boost great if you want to run low pressure boost. However, it will do a poor job of regulating boost at high boost pressure since more flow is going through the turbine and not through the wastegate. Hope that helps. Quote Link to comment Share on other sites More sharing options...
hughdogz Posted March 27, 2009 Share Posted March 27, 2009 That makes complete sense John. Since pressure = Force / Area, a larger opening (area) would need a larger force from the actuator to hold the puck shut at the same pressure. Thank you for the correction. [Edit: another good tidbit of info I got from John was sizing the proper wastegate actuator. If the wastegate is sized for say 7psi (stock) it can work well at twice that operating boost pressure (~14 psi). More than that and you may be asking too much of it...I want to get an adj one soon where you can swap out the springs] Quote Link to comment Share on other sites More sharing options...
rossman Posted April 5, 2009 Share Posted April 5, 2009 Curious, what size is your wastegate port before and after? Also keep in mind that the wastegate housing also affects amount of flow that is bypassing the turbine. You could make the hole 2" but if the housing is too restrictive it won't do much good. If you want to keep the internal wastegate you might consider a larger more tapered exhaust collector. I have an ATP "Ultimate" Internal Wastegate. It's not running yet but hopefully it and the slightly over 1" wastegate port will flow enough to prevent boost creep. Quote Link to comment Share on other sites More sharing options...
Noddle Posted April 6, 2009 Author Share Posted April 6, 2009 Curious, what size is your wastegate port before and after? Also keep in mind that the wastegate housing also affects amount of flow that is bypassing the turbine. You could make the hole 2" but if the housing is too restrictive it won't do much good. If you want to keep the internal wastegate you might consider a larger more tapered exhaust collector. I have an ATP "Ultimate" Internal Wastegate. It's not running yet but hopefully it and the slightly over 1" wastegate port will flow enough to prevent boost creep. Hi, The original hole was 20mm, I open it up to about 24mm as for the housings, the first picture ( above ) shows the type of housing it is, it's about 1 inch deep At the moment, I'm fitting my intercooler, I will run the 10psi actuator, and see how it goes. Nigel Quote Link to comment Share on other sites More sharing options...
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