Guest the_dj Posted June 6, 2003 Share Posted June 6, 2003 How can I make the actuator on my '82 zxt more sensitive...to open the wastegate at say 2-3psi. I want to be able to turn my boost down as close to 0 as possible, and then use a valve to control the actuator. That way it's fully adjustable from no boost to full boost. I need to keep the boost loooow (2 psi or lower) until I can get new injectors. The ones I have are maxed out, but I have some time now to install the turbos and want to get them in and running. Thanks, Sam Quote Link to comment Share on other sites More sharing options...
yo2001 Posted June 7, 2003 Share Posted June 7, 2003 Probably not, since if you got a actualtor that loose, it'll leak under boost (creep) Quote Link to comment Share on other sites More sharing options...
fl327 Posted June 7, 2003 Share Posted June 7, 2003 whats wrong with your injectors? as for low boost, just drive slow, and you should be ok, right? Quote Link to comment Share on other sites More sharing options...
Guest the_dj Posted June 7, 2003 Share Posted June 7, 2003 I only have 24lb injectors, and with my work on the heads, my cam, and intake, they are sitting at 90+ duty cycle naturally aspirated. Since I'm using twins, I want a way to actuate the stock wastegates, and make sure they both open at the same pressure guaranteed (to make sure neither turbo overspools to compensate for early opening on the other one). The only way I can think to do this is regulate them lower, and use a bleeder valve to send pressure to both at the same time at the set pressure. Am I going about this the wrong way? Quote Link to comment Share on other sites More sharing options...
fl327 Posted June 7, 2003 Share Posted June 7, 2003 i thought this was for a stock zxt? Quote Link to comment Share on other sites More sharing options...
Guest the_dj Posted June 7, 2003 Share Posted June 7, 2003 i thought this was for a stock zxt? The turbos are from a stock zxt. They are going on my not-so-stock (Chevy 350) '78 Z. Quote Link to comment Share on other sites More sharing options...
fl327 Posted June 8, 2003 Share Posted June 8, 2003 it would be just as expensive to get them to run lower boost than it woudl be to just fork out for injectors, i believe. 7psi on each is the lowest with the stock actuators. Quote Link to comment Share on other sites More sharing options...
Guest the_dj Posted June 8, 2003 Share Posted June 8, 2003 it would be just as expensive to get them to run lower boost than it woudl be to just fork out for injectors, i believe. 7psi on each is the lowest with the stock actuators. Is there some way to be assured that both actuators open at exactly the same time? I can keep my foot off the gas to keep the boost down, but I don't want to be over spinning one turbo just because the actuators aren't the same. Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted June 8, 2003 Share Posted June 8, 2003 Just unhook the swing valve from the actuator and let the wastegate sit wide open. This will limit your boost to a couple pounds. I did this when tuning my EFI first time running. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted June 8, 2003 Share Posted June 8, 2003 it would be just as expensive to get them to run lower boost than it woudl be to just fork out for injectors' date=' i believe. 7psi on each is the lowest with the stock actuators.[/quote'] Is there some way to be assured that both actuators open at exactly the same time? I can keep my foot off the gas to keep the boost down, but I don't want to be over spinning one turbo just because the actuators aren't the same. For twin turbos, I believe balance is achieved with an exhaust balance tube connecting each turbine inlet. It will assure you have equal exhaust pressure behind each turbine. Then the compressor outlets are joined after the intercooler. There should then not be enough of a difference in actuators to create any serious flow imbalance. Quote Link to comment Share on other sites More sharing options...
Guest the_dj Posted June 9, 2003 Share Posted June 9, 2003 I like the idea of leaving the wastegates unhooked for now. Maybe I'll leave them like that until I can afford a pair of aftermarket gates. There is no way to run a balance pipe between them. No room. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted June 9, 2003 Share Posted June 9, 2003 Even with aftermarket gate, the lowest springs are 6-7[si. I guess you could cut it or something Quote Link to comment Share on other sites More sharing options...
Guest the_dj Posted June 9, 2003 Share Posted June 9, 2003 Hm. This is definately something I need to figure out. If you wanted to run 5psi from a twin turbo setup, how would you accomplish it? Whatever method that is, is what I'll use. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted June 9, 2003 Share Posted June 9, 2003 Suppose, you can restrict the compressor side with a restrictor. I don't know, I've never actually seen one done like that. Quote Link to comment Share on other sites More sharing options...
1FASTKINGCAB Posted June 9, 2003 Share Posted June 9, 2003 Just unhook the swing valve from the actuator and let the wastegate sit wide open. This will limit your boost to a couple pounds. I did this when tuning my EFI first time running. what he said, only I would try to hook up a bike style brake/ shifter cable to the flappers that way you could manualy controll boost. I hope that made sense. lol Quote Link to comment Share on other sites More sharing options...
Guest the_dj Posted June 9, 2003 Share Posted June 9, 2003 Just unhook the swing valve from the actuator and let the wastegate sit wide open. This will limit your boost to a couple pounds. I did this when tuning my EFI first time running. what he said' date=' only I would try to hook up a bike style brake/ shifter cable to the flappers that way you could manualy controll boost. I hope that made sense. lol [/quote'] NOW we're talking!! Massive space and budget savings, and with a proper strength cable and some locknuts I can hold them to exactly the same measured distance open. Can anyone see this causing any problems? I understand lag will be more of an issue, but this seems to be an ideal solution until I can afford a set of aftermarket wastegates and an intercooler that allows 6-9psi of boost. Quote Link to comment Share on other sites More sharing options...
1FASTKINGCAB Posted June 9, 2003 Share Posted June 9, 2003 I was thinking if you ran a cable from one W/G to the other and the off of one ran another cable to a nice place under the dash a mounted an old style bike shifter. you would then have a full manual boost controler for less than $20 The ONLY problem I see (And this is why I haven't done this) if that you could very easily crank the boost to a an insane level and blow all kinds of $hit up. But I would think if you had enough self controll (I don't) it could help alot. just replace your 5" tach with a 7" boost gauge Quote Link to comment Share on other sites More sharing options...
Guest the_dj Posted June 9, 2003 Share Posted June 9, 2003 I was thinking if you ran a cable from one W/G to the other and the off of one ran another cable to a nice place under the dash a mounted an old style bike shifter. you would then have a full manual boost controler for less than $20 The ONLY problem I see (And this is why I haven't done this) if that you could very easily crank the boost to a an insane level and blow all kinds of $hit up. But I would think if you had enough self controll (I don't) it could help alot. just replace your 5" tach with a 7" boost gauge Hobbs style pressure switch at 5psi to turn on an overboost LED in the car + a 6psi pop off valve is wonderful insurance at all times. If the light comes on, you're boosting too much. Also, adjusters placed in the engine bay help to remove temptation Quote Link to comment Share on other sites More sharing options...
Guest the_dj Posted June 9, 2003 Share Posted June 9, 2003 I came up with a quick idea for a wastegate control: It's a powerpoint presentation because that was easy to make diagrams in. It's just a sketch, but I believe with some testing it has a lot of potential. The diagrams are spread out to multiple pages, but in practice the entire unit and all systems could be contained in a small box with many placement options. http://66.100.35.107/actuator.ppt Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted June 9, 2003 Share Posted June 9, 2003 I was thinking if you ran a cable from one W/G to the other and the off of one ran another cable to a nice place under the dash a mounted an old style bike shifter. you would then have a full manual boost controler for less than $20 The ONLY problem I see (And this is why I haven't done this) if that you could very easily crank the boost to a an insane level and blow all kinds of $hit up. But I would think if you had enough self controll (I don't) it could help alot. just replace your 5" tach with a 7" boost gauge The only problem with this "controller" is it's not a true controller. The boost will not come up quickly and it will vary with load and RPM. The nice thing about a closed loop around the wastegate is you get ideal control - boost comes up as fast as possible, and it is limited to a set level across the rpm/load band. Holding the wastegate open will get old fast when you see how slowly boost builds, Quote Link to comment Share on other sites More sharing options...
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