ryostyle_the_¥akuza Posted September 16, 2006 Share Posted September 16, 2006 I just made a blowthru setup on my 87 RX. I've been previously venting to the atmosphere and running pig rich during shifts. Thinking back to my Eclipse I thought about how I miss my GM blow through setup. At this point I had a few mods done. Cone air filter, exhaust, top mount intercooler with custom piping, and an hks ssq bov. I liked the shock that people got when they would hear my car vent, however, I hated the fact that I was passing a couple of cops the other day doing about 25 mph and shifted and my car popped from the richness between shifts. This of course drew their attention to me, and wasted a bunch of fuel. I went home and thought to myself, this is the last time. After kicking the idea around with subarutex I decided after work today to do it. Soooo......This is what I did. The goal: Move the mas sensor after the intercooler and before the throttle body. Doing this you can vent to the atmosphere without running pig rich, due to the fact that the air is metered after the blow off valve position. (everyone knows that if you vent and the mas stays in the stock position it dumps air into the atmosphere instead of into the engine, thus making your slow compensating ecu use an improper balance of fuel/air. Too much fuel, too little air and the car bogs.) Warning, attempt this at your own risk etc etc. Mine runs perfect but, if you mix up your wires, who knows what'll happen. 1) 1 at a time, I cut my mas sensor wires and extended them 2 ft and taped them up with electrical tape. 2) then I got (2) 2 1/2"- 3" silicon couplers 3) Using a universal Mas - Air filter adapter I connected the mas to the intercooler 4) next I connected the mas to a 90 degree bend using the 2 1/2"- 3" adapter 5) connect the 90 degree bend to the throttle body using the other 2 1/2" - 3" adapter 6) Connect your cone air filter to the stock intake inlet where the stock mas used to fit (this will require a 2 1/2" opening on the Air filter connection end 7) Lastly wrap the mas extention wires in electrical tape and route them in a safe location **side Note** There are 2 white wires in the factory mas harness, cut them before the shielding (they go into a shielded black wire). Don't be dumb and mix these wires up like I did, this is why I said to extend the wires in step 1, 1 at a time. No mixup all smiles. If you mix the wires up you will get a check engine light. So do it right and don't panic. So now that the blow through setup is complete, you can vent your heart out and not pop, not bog, and not run pig rich. Also as a cool side effect, if you blow your intercooler piping off, your car will still idle perfectly. Why? Because you moved the mas to before the throttle body and the car is still getting the right a/f ratio. Now you can calmly pull to the side of the road and fix your piping instead of your car dying in the middle of the road. Pictures to Follow. The only other thing I can think of to make this setup better is, Get the lip on the universal airfilter adapter beaded so you can clamp your piping down and not blow it off. This will be your weak spot in your setup. Special thanks to SubaruTex and SubaruJunkie!! Link to comment Share on other sites More sharing options...
Phizinza Posted September 16, 2006 Share Posted September 16, 2006 Sounds interesting. But I have no idea what anyone would want a BOV over a BPV. Personally I like what a turbo does, not what sound a BOV makes. Although a truly nice sound is when the turbo spools. Just my thoughts on the matter. This is a good way to keep that ricy sound and run the right mixture though. It's amazing how many people out there don't understand BOV's stuff up mixtures. Link to comment Share on other sites More sharing options...
TheSubaruJunkie Posted September 16, 2006 Share Posted September 16, 2006 DUde i gotta see this setup! Im thinking my BPV setup is leaking, i have a ton of hoses running from my valve to the intake boot... and its getting old, so I think this will clean things up and maybe solve a couple problems im running into. I also dont care much for a BOV Sound, but there really is no difference between a BOV and BPV, so there shouldnt be much performance gain. -Brian Link to comment Share on other sites More sharing options...
WRX2FFU Posted September 16, 2006 Share Posted September 16, 2006 I also dont care much for a BOV Sound, but there really is no difference between a BOV and BPV, so there shouldnt be much performance gain. -Brian I don;t like BOV's either but there is a big difference between an BOV and a BPV, not just the sound. Link to comment Share on other sites More sharing options...
Phizinza Posted September 16, 2006 Share Posted September 16, 2006 Are you talking stock BPV vs after market BOV? A BOV can be plumbed to work just like a BPV. They are essentially the same thing. Link to comment Share on other sites More sharing options...
WRX2FFU Posted September 16, 2006 Share Posted September 16, 2006 Are you talking stock BPV vs after market BOV? A BOV can be plumbed to work just like a BPV. They are essentially the same thing. Some bov's cannot be plummed back. Most of the ones that can are usually pretty expensive and don't even work as well as the stock units. But yes you are right. Theoretically any BOV that can be plummed back into the intake will be as good as the stock BPV. Personally i wuould not spend the money for a Blingy BOV just to do the same job as a stock BPV. All of this coming form someone who ran a stock BPV as long as I could. Now i have a used forge BOV that i bought for $50. My stock BPV would not hold over 20 psi without leaking. All of this is kinda OT, his Blowthru setup sounds really good. I know a couple of guys with Blow Thru setups on their STI's and they work great. Link to comment Share on other sites More sharing options...
Phizinza Posted September 16, 2006 Share Posted September 16, 2006 The only thing I can think of that you are exposing the MAF to more is heat. This isn't a problem? Man I want a SC for my Brat ! Got pics of the setup? I pretty much can imagine what it looks like, but it would be good to see it for real. Link to comment Share on other sites More sharing options...
ryostyle_the_¥akuza Posted September 16, 2006 Author Share Posted September 16, 2006 The only thing I can think of that you are exposing the MAF to more is heat. This isn't a problem? Man I want a SC for my Brat ! Got pics of the setup? I pretty much can imagine what it looks like, but it would be good to see it for real. I'll take pix later today of it. The HKS super sequential isn't a regular BOV. Its a pull type instead of spring type, because of this, it is not possible for it to leak under vacuum unlike the other bovs that leak at idle. BOV and Bypass valve same thing. Its just a matter of "Does your BOV recirculate or vent to the atmostphere" On the SSQ bov you can get a recirculating adapter.The whole point is, the choice is mine now, I'm not forced to do either one, it makes no difference now. And to answer the question, I picked up my HKS bov with my intercooler for only 75 dollars which is a steal!!! Not literally fortunately, but damn good the same. Link to comment Share on other sites More sharing options...
ryostyle_the_¥akuza Posted September 17, 2006 Author Share Posted September 17, 2006 Day 2, freeway driving and spirited cruising. Make sure your piping is beaded!!! Other than that, Everything is Excellent. I noticed the ecu during cold weather startup has the enrichment off slightly, within 1 minute its normal idle and normal operation. Running boost and venting has been perfect. No complaints, can't believe I did it sooner. I'll keep you guys posted. Link to comment Share on other sites More sharing options...
WJM Posted September 17, 2006 Share Posted September 17, 2006 hmmmm.... And I dont wet my pants....ev3r. Link to comment Share on other sites More sharing options...
JWX Posted September 17, 2006 Share Posted September 17, 2006 hmmmm.... And I dont wet my pants....ev3r. no but you wet the bed. Link to comment Share on other sites More sharing options...
WJM Posted September 17, 2006 Share Posted September 17, 2006 no but you wet the bed. The reply appropriate to this comment would not be appropriate for this thread, nor this message board. Back on topic...I've always though a blow thru maf as a bandaid over something else....but good work regardless. Link to comment Share on other sites More sharing options...
ryostyle_the_¥akuza Posted September 17, 2006 Author Share Posted September 17, 2006 The reply appropriate to this comment would not be appropriate for this thread, nor this message board. Back on topic...I've always though a blow thru maf as a bandaid over something else....but good work regardless. A bandaid? Well I tried zipties, but they just didn't seem to work in this instance so this is the best I could come up with. A blowthru setup is a blowthru setup, I didn't invent it, and I'm no innovator. Just hadn't seen it done before, and in this instance it fixed my venting based problems. Just passing what I've learned along. But I'm no Ben Franklin, if it DOA's my motor or does anything weird to my car I would tell you guys that too. I'm just basically looking at the things that worked effectively on other cars that can be applied to the RX. As far as bed wetting, ummm.....okay, I'm not going there. Link to comment Share on other sites More sharing options...
Phizinza Posted September 17, 2006 Share Posted September 17, 2006 Better then spending thousands on a better ECU to not have to run a MAF, surely? I think its a great idea. I wouldn't understand how people could use a BOV without a setup like this with stock ecu. I didn't mean to sound like an *** at the beginning. I just sometimes get annoyed at ricer stuff that isn't needed. I just have to keep in mind my car is SO VERY RICER. I think I've got like $1000 into things and aren't needed. So sorry if I offened anyone. What I should appritiate here is your effort in doing the mod and telling everyone how easy it is. Ok, I'll shut up now, just know that I am contridictory and talk a fair bit of ********, and that I know I do. Link to comment Share on other sites More sharing options...
WJM Posted September 17, 2006 Share Posted September 17, 2006 its not that it doesnt work...people do this on STi's with GT35R and GT42 kits since they cant afford a Hydra and/or live in a place that has OBD2 inspections....so spending the extra $200 on the blow thru setup and ~$1200 on the Cobb AP or Ecutek tuned out the door is better for them. *shrug* I just think there are better ways once you get to the level that relocating the maf makes the car work better. Its the same to me as having to mess with toe settings to make a car handle better. If you cant make the car rotate on turn in, there is a problem. Adding rear toe out is NOT the proper solution, but it does work. Link to comment Share on other sites More sharing options...
ryostyle_the_¥akuza Posted September 17, 2006 Author Share Posted September 17, 2006 No offense taken. I completely understand. I'm going to try and get some pix of it today. Link to comment Share on other sites More sharing options...
WJM Posted September 17, 2006 Share Posted September 17, 2006 awesome....i'd like to see the setup. Link to comment Share on other sites More sharing options...
daeron Posted September 18, 2006 Share Posted September 18, 2006 allright, let me see if i understand this thread entirely... I really dont know turbocharging systems in very great detail, as its all abstract theory to me never having owned a turbocharged car. A normal turbocharger has a bypass valve that vents the positive pressure coming out of the intake side of the turbo, into the exhaust system, right? and a blow off valve is a bypass valve that instead, simply vents that excess into the atmosphere then? and that is why my buddy's SRT-4 goes PSHHHHH every time he shifts under acceleration? so a BOV is simply a glorified bypass valve that typically vents to atmosphere instead of the exhaust, and makes a cool noise while doing so? and Phiz doesnt care for the sound of it, and prefers a turbosharger with the standard bypass that vents excess pressure into the exhaust. Ryostyle is talking having moved his MAF sensor (or whatever its actually technically called on the soob) up between his intercooler and his TB.. so i take it that a BOV is located then, on the intake piping somewhere? and then, that it would be electronically controlled, right? i have an auto mechanic's textbook that i would normally consult for something like this, but my buddy with the SRT-4 just borrowed it because he douesnt really know too mucha bout turbocharging systems either and he was having problems because his car was going up to 30 lbs of boost!!!!!!!! no lie, his boost gauge pegged at 26 and he was wrapping it almost around to the starting point... he discovered that the PO (cars only got like 18K!!) must have re routed some vacuum lines, and TOTALLY bypassed the wastegate actuator. Link to comment Share on other sites More sharing options...
suberdave Posted September 18, 2006 Share Posted September 18, 2006 wateing for pics... need to see pics... come on with the pics already... -=Suberdave=- http://www.suberdave.com Link to comment Share on other sites More sharing options...
Phizinza Posted September 18, 2006 Share Posted September 18, 2006 allright, let me see if i understand this thread entirely... I really dont know turbocharging systems in very great detail, as its all abstract theory to me never having owned a turbocharged car. A normal turbocharger has a bypass valve that vents the positive pressure coming out of the intake side of the turbo, into the exhaust system, right? and a blow off valve is a bypass valve that instead, simply vents that excess into the atmosphere then? and that is why my buddy's SRT-4 goes PSHHHHH every time he shifts under acceleration? so a BOV is simply a glorified bypass valve that typically vents to atmosphere instead of the exhaust, and makes a cool noise while doing so? and Phiz doesnt care for the sound of it, and prefers a turbosharger with the standard bypass that vents excess pressure into the exhaust. Pretty much all right execpt not the exhaust... It vents from one side of the turbo to the other basiclly. So with a normal setup it would take air from just after the turbo and vent it to just before the turbo (well thats how the MX-6 does anyhow) Doing this will stop the pressure in the intake and thous letting you slow down. A BOV takes the air from just after the turbo (keeping in mind this is messured air, so if you lose any of it the computer will go mad) and vents it to atmosphere. With moving your MAF (or what ever) to between the turbo and intake (well, between the point where you put the BOV and intake) you can vent this air before it is messured. I don't care for the noise as it doesn't do anything for performance. And on most setups it makes the car run rich like ryostyle was explaining. I prefer the spool sound of the turbo.. Which either means its bearing are screwed or its on big turbo pushing alot of air Link to comment Share on other sites More sharing options...
ryostyle_the_¥akuza Posted September 18, 2006 Author Share Posted September 18, 2006 Heres the Pix Boys, finally found some batteries. Link to comment Share on other sites More sharing options...
mikeshoup Posted September 18, 2006 Share Posted September 18, 2006 Can't quite tell how your PCV system is routed. Only real problem I could forsee is if the PCV system is routed in before the MAF, oil could condensate on the MAF wires. Link to comment Share on other sites More sharing options...
ryostyle_the_¥akuza Posted September 18, 2006 Author Share Posted September 18, 2006 Good point. I'll have to figure something out to address that. Thanks for bringing it up. Maybe I'll get a catch can for that. Link to comment Share on other sites More sharing options...
daeron Posted September 18, 2006 Share Posted September 18, 2006 Phiz: thank you. once you explained it, it became utterly clear.. i just needed someone to spell it out for me so I knew i was right. i understood the relocation of the MAF and why it helped, i just never REALLY had equated or understood the difference between BOV and BPV before. as for the exhaust, i must have been thinking the wastegate.. thats what vents excess exhaust flow thru the impeller and back into the exhaust, right? ive handled over a dozen turbos, we have a small collection up at the shop from someone elses parts gallery... so since the wastegate is tied in with the turbo, and often built internally, i suppose thats what i must have mistaken for the bypass valve you folks is talkin about. I thought somehow the BO and BP valves were related to that circuit. oops! going from abstract to real knowledge is hard for me without concrete examples. hence, why i have no REAL grasp of spark timing, came profiles, or much suspension yet... since i havent had any breakdowns in those areas, nor have i done much pre-emptive work. but all these things are falling into place the more i do. I cant wait to build a head for my Zcar; there are like eight different head castings to choose from, a couple different valve options, and once i get down to bottom end, so many piston/CR options it could make a soob engine builder sick. BTW that IS a real nice setup, good fab work. dont forget that until any catch can may be installed, your intercooler is serving as one, so you are liable to get buildup in there before you soil your MAF. Link to comment Share on other sites More sharing options...
Phizinza Posted September 18, 2006 Share Posted September 18, 2006 You can use a fuel filter in the PCV line to stop the oil. It's a bandaid, but works fine for some. Just another filter to change regulary Link to comment Share on other sites More sharing options...
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