blake culp Posted May 14, 2006 Share Posted May 14, 2006 I am running a tial extrenal wastegate, and because i have a small exhaust leak around the flange on the pipe side of the wastegate i can hear when it opens. I have the 12 psi spring in it, yet it startes to vent as early as 5-6 psi. Since im not really excited about spending 250$ on an electronic boost controler that will pressure the atmosphere side of the wastegate till the set boost pressure is reached i think i found another solution. Tell me what you think First the only parts i think ill need is the current ball and spring manual boost controller i have on hand, but not using. An adjustable pressure switch, like the ones people use for the 7th cold start injector mod. And then a dual stage boost control solenoid like the ones sold on dawes devices, now three bar racing. I actually have all the parts laying around from previous setup's. So here is the idea, set the adjustable pressure switch to activate at 10psi then run vacume lines from the manifold to the three port solenoid and to the pressure switch. From the three port solenoid to the wastegate atmosphere side and finally the wastegate pressure side. When the pressure is below 10psi the solenoid will send pressure to the atmosphere side of the wastegate holding it completly shut, after 10psi the pressure switch will activate and "switch" the solenoid to release the pressure on the atmosphere side and then apply the pressure to the pressure side of the wastegate, thus venting the excess exhaust and stabalizing the boost at 12psi. I think this could really help by shaving off some turbo lag and increasing low end torque, all for less than 75$. If you wanted to raise boost more put the manual boost controller in and set it to 14psi and the pressure switch to 12psi for example. Think it would work?? Quote Link to comment Share on other sites More sharing options...
alexideways Posted May 14, 2006 Share Posted May 14, 2006 WOW!, can't really help there, this is allready way more than I know about electronic boost controlers but, keep us posted on your progress, souds very interesting and feasable. Quote Link to comment Share on other sites More sharing options...
TimZ Posted May 14, 2006 Share Posted May 14, 2006 Yes that will work, but you should be aware that the failure modes of this are pretty severe. If the switch doesn't get tripped for any reason (hose falls off, wire comes loose, fuse blows - pretty much anything), your wastegate will never open and you will have uncontrolled boost and broken stuff (most likely ring lands) shortly thereafter. It would be a good idea to put some thought into how to get around this. Maybe reverse the logic so that you have to power the solenoid to block the signal to the wastegate. That strategy is a little better - at least for most of the failures, you'll just get stock boost. Quote Link to comment Share on other sites More sharing options...
BLOZ UP Posted May 14, 2006 Share Posted May 14, 2006 You'll probably have boost spikes, and boost creep, but it might work. I got a cheap Profec B Spec I off ebay, I'll never go back to non electric boost controllers now. Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted May 14, 2006 Share Posted May 14, 2006 It will probably spike BAD. Guess we won't know till you try it, but there is significant lag for the wastegate flapper to open since it won't be seeing boost at all due to the solenoid. All of the EBC (I think) use PWM with the solenoid so that it doesn't seem fully closed all the time. For overboost protection, just use a pop-off valve. Mario Quote Link to comment Share on other sites More sharing options...
blake culp Posted May 16, 2006 Author Share Posted May 16, 2006 I was also thinking i might get spikes, boost creep shouldnt be a problem because i have absolutely 0 creep right now, and once the solenoid trips and is applying pressure to the presure side of the tial it will allow the same volume of exhaust to bypass the turbo as before the mod, thus no creep. Bloz up- how much is cheap for a profec b spec? does it also have a line to go to the atmosphere side of the wastegate? I guess the reason i cant justify spending so much on an electric boost controller is because my manual one works fine without spiking, just the wastegate in my opinion opens too early which i think adds to the lag. What is really so good about an electronic boost controler, and im not asking to be a dick, i really want to know. I wouldnt mind spending 100-150ish for a electronic boost controler, but all the ones i saw on ebay seemed to be around 250. Quote Link to comment Share on other sites More sharing options...
Hugh Posted May 17, 2006 Share Posted May 17, 2006 THe electronic boost controller has a duty cycle, using PWM as mentioned above, which opens and closes the valve very quickly. Going from manual to electronic makes the turbo spool faster, spike less, and hold on to boost in high RPM longer. A great EBC like the AVC-R will allow you to adjust duty cycle per RPM, and it even self-learns to fine tune the duty cycle for you. (if you so desire) I've found MBC's lead to slow spool, spikes, and either rising or falling boost in the high RPM. I like your idea. It sounds cool to me. It would be nice to activate the MBC at a lower boost than its needed to avoid the spike. Activate the MBC at 10psi, and have it regulate 12psi... or something like that. This should keep it from spiking crazy like. Personally, I think you should build this thing if you have the parts to do it. It will be a fun Mr. Wizard style project, and makes for great conversation. If its gonna cost you much money out-of-pocket, then forget that. Just save some pennies for a decent EBC. I've had my AVC-R for 6 years now, and I've changed everything else on the car, including the car... but the AVC-R is still in there and working great. Quote Link to comment Share on other sites More sharing options...
Guest 2004 srt4 Posted May 18, 2006 Share Posted May 18, 2006 emginerunup has something like that. you can either switch from low to high boost w/ a button or it activates when the water injection turns on. Quote Link to comment Share on other sites More sharing options...
Guest 2004 srt4 Posted May 18, 2006 Share Posted May 18, 2006 http://www.enginerunup.com/parts/electric-boost-controller-failsafe-feature-/prod_46.php i'm sure you can use your pressure switch instead of their nozzle switch. Quote Link to comment Share on other sites More sharing options...
zguy36 Posted May 22, 2006 Share Posted May 22, 2006 Your electronic setup will have no advantage over a normal manual setup. Stick with the simple ball and spring until you can afford a real electronic setup. Quote Link to comment Share on other sites More sharing options...
alexideways Posted May 27, 2006 Share Posted May 27, 2006 Your electronic setup will have no advantage over a normal manual setup. Stick with the simple ball and spring until you can afford a real electronic setup. Would you minde explaning a liitle further, reasons, facts, I'm on a steep learning curve right now and ask and read any info available, then I confirm or infirm by comparing with other sources, any info on what you just said would be helpfull. thanks Quote Link to comment Share on other sites More sharing options...
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