pleiades Posted December 6, 2003 Author Share Posted December 6, 2003 So now that I can finally find the message board again. argh I flopped ends, removed the hole (so to say) and the car peaks 12psi, drops back to 10psi and stays there. It runs smooth with no hesitations or signs of fuel cut. Tomorrow morning I will probably jack it back up just a hair. I also got my BOV installed. I'll snap pics of that tomorrow as well. Quote Link to comment Share on other sites More sharing options...
pleiades Posted December 7, 2003 Author Share Posted December 7, 2003 it seems to run best set at 10psi. (does spike 12psi at first though). Didn't get pics of the bov yet, as we just finished getting WJM's motor back in his RX. Will get pics tomorrow. Quote Link to comment Share on other sites More sharing options...
WJM Posted December 7, 2003 Share Posted December 7, 2003 Ok, I we did indeed get my RX back up and running. This time...NO LEAKS!! And...it appears as if things are pulling hard once again. no...problem. Severe boost creep past 4k at WOT....heres the thing...I cant keep it in 1st, 2nd, 3rd, or 4th for more than 4~5 seconds!! But, I did do a few long pulls in 5th, not much space around here...and it crept up to aobut 15psi...no cut, no running out of breath either....right up to 7k. Hm. So, on the last pull, notibly the most dangerous I might add, as I and the RX were doing some ungodly speed down some tar/gravel back road, looking at the boost and rpms....I pulled 15psi for about 8 seconds maybe? I know it was longer than 6!! I was counting nice and slow. And then, boost dropped suddenly to about 10psi, and I lost power, like it was bogging. No ig/fuel cut like Skipper and SubaurTex says it does, just, power loss and boost drop. OH!! 3 right over crest! CARE! TREES!! Ok, past that. Still runs like before, no issues. I should be taking it out on another run here soon....if i can get away from cleaning things up around here. :-\ Quote Link to comment Share on other sites More sharing options...
Warp3 Posted December 7, 2003 Share Posted December 7, 2003 The boost controller is now installed! Muhahaha We first swapped out the plugs (all of which had the signs of running too hot ) with new NGKs (stock spec "6" heat range). Then ran the car to make sure that install went well. (Speaking of which, the plugs are much more accessible than those on my Impreza, but WTF is up with that freaking lip around the plugs making even thin-walled sockets too thick to use! ) Anyway she was running great (and boosting to about 6.5psi), so we came back and began the MBC install. Got it installed (with the valve set to about as tight as it can be and still be "blown" open by human lungs) and made a run...dead on stock (about 6.5psi). Stopped and turned the screw 1 full turn (3/16"-24 bolt so it has very fine threads)...now the car was hitting about 8.5psi! Woohoo! Stopped again and turned the screw 1 more full turn...woohoo...10psi...hey where did the power go...oh there it is...hey where did the...oh, yeah...overboost cut...LOL :-) Quick search of the USMB forums to find which plug to pull, yank the electrical connector from the overboost solenoid and make another run...spikes to 11psi then immediately drops to 10psi and holds in each gear...sweeeet After some WOT runs (mostly uphill) with 3 people in the car, the car was running a little hotter than usual (about 2/3rds of the way up the stock gauge but still not up to the red zone) but after about a mile of "civil" driving it was back to it's normal position (about halfway up the gauge). I'm planning to leave the boost set here (10psi) until I get my intercooler/BOV setup (stock WRX parts) and 180-degree thermostat installed then it's up to about 12.5psi. Does that sound reasonable (10 psi stock, 12.5 psi with a intercooler/bov/thermostat)? I'm also planning to eliminate the cat as I imagine it's quite clogged on an 18-year-old car with 183k+ miles on it...LOL :-) Booooooost LOL Quote Link to comment Share on other sites More sharing options...
pleiades Posted December 8, 2003 Author Share Posted December 8, 2003 Whoohoo, more boost for Shane! lol.... SO are you going to drive the RX in the highlands rally Sunday? hehe.... Quote Link to comment Share on other sites More sharing options...
Warp3 Posted December 8, 2003 Share Posted December 8, 2003 I'm not sure yet... BTW, I'm actually hitting closer to 12psi on 4th gear runs on the interstate so I'll probably back it off a bit. This car freaking pulls like mad now! With mid-20 degree weather this morning, the engine was pulling like crazy and the tires had very little grip (plus remember I only have 1WD when I'm in FWD mode)...what a fun combo...LOL Quote Link to comment Share on other sites More sharing options...
pleiades Posted December 8, 2003 Author Share Posted December 8, 2003 lol.... You're going to get a ticket for smoking the tires, just wait! lol.... I assume you're doing the rally with coty? Quote Link to comment Share on other sites More sharing options...
Warp3 Posted December 8, 2003 Share Posted December 8, 2003 lol.... You're going to get a ticket for smoking the tires, just wait! lol.... I try not to, but it's just too tempting...LOL I assume you're doing the rally with coty? That's the plan. Not sure which vehicle we are taking yet though. Probably the Impreza, simply due to the fact that I don't know if I've owned the RX long enough to have deemed it "reliable" or not. LOL Quote Link to comment Share on other sites More sharing options...
pleiades Posted December 8, 2003 Author Share Posted December 8, 2003 Well that's how I felt when I got the RX up and running, and I decided the only way to know was just drive it! (just get AAA) lol..... Quote Link to comment Share on other sites More sharing options...
pleiades Posted December 9, 2003 Author Share Posted December 9, 2003 just more boost related info: http://usmb.ultimatesubaru.org/forum/showthread.php?s=&threadid=8523 can we make this the offical boost info thread? hehe.. Quote Link to comment Share on other sites More sharing options...
Nick Leigh mtb Posted May 19, 2004 Share Posted May 19, 2004 Hi, i have a 1989 subaru RX Turbo AWD the same as you put your boosted up turbo on. How would i come across making my own? The parts i would have to buy, etc. thanks Quote Link to comment Share on other sites More sharing options...
ThreeEyedBandit Posted May 19, 2004 Share Posted May 19, 2004 Here is a link to the one I built, very simple and only needs two seperate parts. http://www.gusmahon.org/html/boostcontrol.htm Matt Quote Link to comment Share on other sites More sharing options...
TheSubaruJunkie Posted May 19, 2004 Share Posted May 19, 2004 SWEEEEEEEEEEEEEEEET!!! Thanks 3 eyed, this is exactly what I've been looking for. -Brian Quote Link to comment Share on other sites More sharing options...
oddcomp Posted May 20, 2004 Share Posted May 20, 2004 hmm i think i will stick with my saab apc boost controller might try the manual on the wife's turbo van tho Quote Link to comment Share on other sites More sharing options...
Warp3 Posted May 20, 2004 Share Posted May 20, 2004 I went this route: http://www.geocities.com/chmwatson/FAQs/mbc.html My only notes about the above are as follows: a) Don't "buy a male coupling, hack part of it off, and tap it" as the instructions show. Instead go to the plumbing department and buy a "bushing" which is exactly what the finished product is and costs little more than the coupling does (make sure the bolt/nut you buy matches the thread pitch of the inside of the bushing, though). You can also find one of these "bushings" in a boost gauge installation kit (the one I used was from my autometer phantom boost gauge and was the perfect size). If you find that your T has a larger inside diameter than the one he shows (like mine did, though I think it may be because mine is a plumbing Tee not an air-hose Tee like he used), you will want to make some kind of sleeve for the spring so it won't bind on you. I used the gutted innards of an ink pen (which is also where I got the spring), but if I did it again, I'd probably try to find a tee with a smaller inner diameter first to make it easier overall. My MBC works perfectly (the inside thread of the bushing I used was 3/8-24 (i.e. fine thread), so I get extremely precise boost control) and has a VERY small boost spike (it only spikes to about 12.5 (maybe 13 at most) psi before settling back to a rock solid 12 psi). Note that I did not do the part with the drilling of the small hole, but have noticed no detriment from it (from the way its worded it doesn't affect anything until higher boost levels anyway, which aren't safely reachable without upgrading other parts first). Oh yeah...the whole deal cost me about $10 and you end up with enough parts that you could make a 2nd one for about $5-6 more. Recently, I bought some GM boost solenoids and am working on turning it into a 3-stage MBC now (2 user settings (controlled by 2 MBCs) + stock with a switch to select between them from the cabin). The whole 3-stage setup is only going to cost me like $60 total (for comparison, a new TurboXS MBC is $85 and their "dual-stage" MBC is $249!!!). Quote Link to comment Share on other sites More sharing options...
iluvdrt Posted May 20, 2004 Share Posted May 20, 2004 when you are running that much boost dont you need at least a recircualting valve? how is the lag without one? are you intercooled? i have been thinking about this for a while. i am concerned about the dependability issue though. Quote Link to comment Share on other sites More sharing options...
iluvdrt Posted May 20, 2004 Share Posted May 20, 2004 Here is a link to the one I built, very simple and only needs two seperate parts. http://www.gusmahon.org/html/boostcontrol.htm Matt that site doesnt tell you what sizes everything is. i feel i am honestly to dumb for this application. i work on the most expensive aircraft in the marine corps, but yet i cannot build a mbc.:-\ Quote Link to comment Share on other sites More sharing options...
calebz Posted May 20, 2004 Share Posted May 20, 2004 Try this one instead.. I believe all the sizes and such are there. http://www.geocities.com/chmwatson/FAQs/mbc.html Read the post a couple responses up about peculiarities and issues with building this one. Quote Link to comment Share on other sites More sharing options...
iluvdrt Posted May 20, 2004 Share Posted May 20, 2004 Try this one instead.. I believe all the sizes and such are there. http://www.geocities.com/chmwatson/FAQs/mbc.html Read the post a couple responses up about peculiarities and issues with building this one. the geosites link hasnt been working for me. i did find this one: http://www.c-speedracing.com/howto/mbc/mbc.php i read about the fuel cut, and that will be a problem as i think i am hitting now with stock boost sometimes at ony 4500. it is very harsh too. it feels like the darn car shuts off for a second, then it goes again. Quote Link to comment Share on other sites More sharing options...
calebz Posted May 21, 2004 Share Posted May 21, 2004 I just checked the Geocities link and its working at the moment. Personally, I haven't run into the fuel cut yet.. Even at 12psi Quote Link to comment Share on other sites More sharing options...
Hondasucks Posted May 21, 2004 Share Posted May 21, 2004 Man, I wanna crank mine up now! I have mine at like, 9 PSI or so.. I just poked a few holes in my wastegate line, although hopefully soon I will be getting an MBC and an AFC in trade for some parts :-) Quote Link to comment Share on other sites More sharing options...
Warp3 Posted May 21, 2004 Share Posted May 21, 2004 when you are running that much boost dont you need at least a recircualting valve? how is the lag without one? are you intercooled? i have been thinking about this for a while. i am concerned about the dependability issue though. I'm working on it...hehe I have a stock WRX intercooler/bypass valve combo that I'm planning to install as soon as I figure this freaky hesitation thing out (which I thought my new O2 sensor had fixed, but apparently not ). There is lag, but not really more than at stock boost levels. From what I've read on this board these engines have a valve in the throttle body to prevent it from just slamming shut when coming off the gas anyway (though I kinda wonder at what psi point is that setup no longer sufficient). Quote Link to comment Share on other sites More sharing options...
rallyruss Posted May 21, 2004 Share Posted May 21, 2004 The dash pot on the throttle return will not be sufficient for increased boost. mine dont work at all any way. go with a bypass set up. bosh type works well. if you use a wrx IC the factory one is really good. Quote Link to comment Share on other sites More sharing options...
WJM Posted May 21, 2004 Share Posted May 21, 2004 Shane, bring the RX to the meet tomorrow, and I'll fix the hesitation. Quote Link to comment Share on other sites More sharing options...
oddcomp Posted May 22, 2004 Share Posted May 22, 2004 according to my pilfered dodge shadow boost gauge i am at 10-11 psi and have never hit fuel cut yet... but then again in about a week or less that will never be a issue again Quote Link to comment Share on other sites More sharing options...
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