maybemark Posted February 17, 2009 Share Posted February 17, 2009 Hi everyone I have an 82 280zx, with megasquirt. I decided to go with a hy-35 turbo. The hy35 has the smaller exhaust housing. We put on an external wastegate can from a Volvo. I'm not sure, but I think it's set for about 8 or 10 lbs. Well, the can opens the wastegate just fine, but I still build up over 20lbs of pressure on my boost gauge. I have no idea why it's not staying at the 8 or 10 lbs. When I had the stock turbo, I ran it at about 15 lbs using a valve. Without the valve, it only gave me 7 lbs of boost. Now, with no valve it just spikes. I have 3" pipe coming off the exhaust side of the turbo, all the way back to the rear of the car. Has anyone had this problem? Does anyone have any sugggestions for me? thanks Mark Quote Link to comment Share on other sites More sharing options...
S130Z Posted February 17, 2009 Share Posted February 17, 2009 How old is the waste gate? It might be leaking. Is it an internal wastegate? When you say "can" are you talking about the piece that attaches to the rod of the wastegate? Quote Link to comment Share on other sites More sharing options...
big-phil Posted February 17, 2009 Share Posted February 17, 2009 Sounds to me that the waste gate is not opening. You say it opens fine, how do you know? Are you revving the piss out of it and watching? Either that or the waste gate hole is not big enough to let enough exhaust bypass the turbo. Quote Link to comment Share on other sites More sharing options...
maybemark Posted February 17, 2009 Author Share Posted February 17, 2009 Thanks for the thoughts. Yes, when I say can. it's the rod that goes to the wastegate on the turbo. Phil, you ask, How do I know that the gate opens all the way? Tonight, we went ahead and put compressed air to the can, got the gate open, pinched down the rod with a small vice grips, just kept it open, and ran it, 2nd gear, it spiked, 3rd gear, it spiked, 4th, it spiked, had to stop for a red light at that point. Quote Link to comment Share on other sites More sharing options...
big-phil Posted February 17, 2009 Share Posted February 17, 2009 Thanks for the thoughts.Yes, when I say can. it's the rod that goes to the wastegate on the turbo. Phil, you ask, How do I know that the gate opens all the way? Tonight, we went ahead and put compressed air to the can, got the gate open, pinched down the rod with a small vice grips, just kept it open, and ran it, 2nd gear, it spiked, 3rd gear, it spiked, 4th, it spiked, had to stop for a red light at that point. the hole has got to be too small. I ported mine out as far as I could get it to control spike. Quote Link to comment Share on other sites More sharing options...
maybemark Posted February 18, 2009 Author Share Posted February 18, 2009 Has anyone else put in an hy35, and had the same problem? Quote Link to comment Share on other sites More sharing options...
S130Z Posted February 18, 2009 Share Posted February 18, 2009 Big Phil has and his problem was the whole being too small. Watch his video and try grinding it out. Pull the turbo out and see what you can mustard up. Quote Link to comment Share on other sites More sharing options...
maybemark Posted February 18, 2009 Author Share Posted February 18, 2009 Anyone other than big phill, has anyone else had this problem? Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted February 18, 2009 Share Posted February 18, 2009 Yeah, I did. With my t3/t04 e. The hole wasnt big enough to let enough exhaust pressure bypass. Quote Link to comment Share on other sites More sharing options...
tech9 Posted February 20, 2009 Share Posted February 20, 2009 That turbo is made for HIGH boost, you need to port the wastegate for your "tiny" engine to be able to handle it. If I remember, you have to port it almost the full size of the puck to get manageable boost. Sounds like he don't trust bigphil Quote Link to comment Share on other sites More sharing options...
TimZ Posted February 20, 2009 Share Posted February 20, 2009 Sounds like he don't trust bigphil Then maybe he should try searching - it's not like this has never been discussed, and it's not like nobody has ever had boost control problems with too small a wastegate. Quote Link to comment Share on other sites More sharing options...
maybemark Posted February 20, 2009 Author Share Posted February 20, 2009 Sounds like he don't trust bigphil This is not true, as soon as I heard what Big Phil had to say, I pulled the turbo out, and ported the wastegate Then maybe he should try searching - it's not like this has never been discussed, and it's not like nobody has ever had boost control problems with too small a wastegate. I did do reserch on it, and i didn't find anyone telling, you have to port the wategate, that's why I put this post on. In the meantime, since I last posted. I had a great telephone conversation with Big Phil, he's a great guy, and I have to say, his videos helped me alot, on what i wanted to do with my 280zx. I went ahead and pulled the turbo out, I ported the wategate area, until the puck hardly covered the hole. I turned the housing over, and ported out alot of extra metal in the way of the air flow. I worked on it for over 3 1/2 hours. I got the turbo in last night, and took it for a short test drive. Well, it certainly helped. I didn't spike to 20+ lbs when i stepped all the way down on the accelerator. But it didn't help totally, cause it did creep up to 15 lbs, in 2nd gear, when the actuator I think is somewhere in between 8-10 lbs, it's from a volvo. At this point, I'm not sure if I want to pull the turbo out again (I might) or just live with these numbers. I am hoping to be able to run 17 or 18 lbs, but controlled by a boost controling valve. I do appreciate the help that people give me from this forum, and I want to thank the ones that give me good advice. Mark Quote Link to comment Share on other sites More sharing options...
S130Z Posted February 20, 2009 Share Posted February 20, 2009 If worst comes to worst you can weld up the puck and attach an external wastegate for more control. Sorry your still getting boost creep, I hope you get things squared out. Quote Link to comment Share on other sites More sharing options...
tech9 Posted February 21, 2009 Share Posted February 21, 2009 Well, theres some threads that i'm GLAD that I havn't trusted the poster Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted February 21, 2009 Share Posted February 21, 2009 I've done the same thing and ended up with a bit of creep as well. I wouldn't worry about it as long as it's at a manageable pump gas level. Quote Link to comment Share on other sites More sharing options...
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