GrayZee Posted July 26, 2005 Share Posted July 26, 2005 I borrowed a boost controller off of my buddy (BernardD) and decided to make my own "copy" of it. So I bought $10 worth of parts from the hardware store. Well the first run I tried it out and the boost spiked up to 20+ psi before I even knew what hit me! I was only for a split second but it really freaked me out! Right afterwards it was running terribile, I thought it might stall out, idle was poor, hesitant throttle response.. very bad sounding in general.. A few minutes later it was fine. I had to mess around with the spring several times as the boost kept spiking up to 15 or so. I didn't want any more than 10 or so as I have no intercooler or water injection. Finally I got it so that it runs around 10-11 and man what a difference!!! The car is pulling harder than it ever has and seems to be ok with the higher boost, no pinging, although it was quite a cool day. I'll have to keep an eye on it till I can look at the ecu tuning. Quite a close call on the engine though, I doubt it would have taken that for very long at all!! Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 26, 2005 Share Posted July 26, 2005 I've pegged boost like that a couple times like once when the hose to the WG actuator blew off... as long as you let off right away you should be fine, especially considering the 280zxt and Z31 turbo EFI's tendency to run REALLY rich when boost first hits especially at a lower RPM. Chances are it probably didn't ping at all for that split second... though I wonder what would have caused the car to run crappy for a bit after that? Anyways with the Z31 ECU and those big injectors 20 psi probably wouldn't even be a problem... well of course there's the lack of the I/C Quote Link to comment Share on other sites More sharing options...
GrayZee Posted July 26, 2005 Author Share Posted July 26, 2005 Actually I don't have those big injectors in my car anymore. I put them in my Pathfinder and went back to the stock injectors along with a un-tuned 84zxt ecu. I was thinking more on why it ran so poorly afterwards. I can't see it being anything to do with the engine, just a shot in the dark but perhaps the injectors took a workout trying to feed enough fuel for 20psi and got hot? I can't imagine anything else... Quote Link to comment Share on other sites More sharing options...
racerx260 Posted July 28, 2005 Share Posted July 28, 2005 When You Spiked To 20lbs Of Boost The Computer Dumped Maximum Fuel In There And You Cut Off The Air When You Chopped The Throttle.this Flooded The Cylinder And Wet The Plugs And It Took A Little Running To Clear Up The Over Rich Condition. Just A Guess.i Was Thinking Of Making One Too. What Did You Use And Is It A Air Bleeder Type Or One With A Needle Valve, Or Other? My 260 Has A Stock 83 Turbo In It . I Was Going To Start With A Boost Controler To 10lbs And Modify My Pop Off With Washers To Raise The Boost Level. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 31, 2005 Share Posted July 31, 2005 I know the question wasn't directed at me but I thought I'd pitch in I'm using the 'Grainger valve' style homemade boost controller. Total cost of parts is about $10, and the finished product is a nice small part, unlike some of the other MBC's I've seen 'recipes' for floating around on the net which end up being pretty bulky and ugly. This is a ball and spring type valve, it's not a bleed valve, no air is getting let out of the system. It works great, the only downside is that it does spike a bit, 1-2psi before settling to it's set level, in my case, 13psi. Otherwise it's a great solution considering it's very low price, it responds very quickly, much less lag. You can get the parts from Grainger or Mcmaster-Carr, unfortunately I lost the link with the part #'s but maybe someone else has them? Quote Link to comment Share on other sites More sharing options...
Metro Posted August 1, 2005 Share Posted August 1, 2005 Part no #48935K25 and here's a guide http://www.xmission.com/~dempsey/perform/grainger.htm Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted August 1, 2005 Share Posted August 1, 2005 Part no #48935K25 and here's a guide [url']http://www.xmission.com/~dempsey/perform/grainger.htm[/url] yeah that's the main part... that's the harder way to do it though, there are actually two more part numbers you can also get from Mcmaster-Carr that take care of the ends instead of having to epoxy in those plastic ones. Then you also just need to drill a .020" hole in one of the ends for the pressure bleed. I'm gonna look for my reciept for the parts... I usualy keep reciepts for just about everything so I probably have it. you can go here to see a pic of how the finished product looks using the other two parts vs. those plastic ends: http://www.dawesdevices.com/boost.html You know, it might actually be worth it to just buy it from them, they've dropped the price on the basic unit finally... used to be $50, now it's only $25. I guess they have the $50 one too, which is the same thing with some 'exclusive' materials that supposedly make it perform better? Quote Link to comment Share on other sites More sharing options...
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