I think you're a lil bit mixed up mate. NO BOV is naturally open (impossible due to their design), just some (most back in the day before cars ran AFMs so needed them to be shut) have springs weak enough that they stay open thanks to the vacumn sucking them open even at idle. All Jap ones and most modern twin piston ones are made with strong ass springs so they only open during the time where there's the biggest pressure differential on both sides, ie for the second or two after the throttle is lifted from full boost, where there's BIG vacumn showing in the vac side of the BOV, and boost pushing on the other side still. But either way, no BOV is best, as any at all removed some of the air that should be used to make the ALS work.
I was under the impression that with a bypass valve ALS, the engine would still have vacuum, since air doesn't go through the engine though a partly open throttle, but via the bypass valve. I'm thinking that's the reason why the bov is going off. Am i right? Probably not. What i was thinking is that the bypass valve setup is set at a certain threshold/boost level. As the throttle is closed, boost pressure goes through the bypass valve feeding air to the exhaust manifold at its set threshold, while simultaneously... any excess boost pressure gets vented out the bov with the engine under vacuum. But yeah, correct me, I'm here to learn.
Yes, you're sorta right, that's something I mentioned in the first reply. IF the car has EGR anti-lag (ie not bypassing the throttle, like most do) but going direct to the exhaust manifold or turbo, then yeah, there would be, at least sometimes, enough vac post throttle to open a BOV. The thing is, I'd be surprised if that car ran that, as to be honest very few do run that setup. Either way, there'd be no need/use for the BOV, how severe the ALS is is almost solely controlled by the amount of airflow bypassed, no need to vent it via a BOV.
Im not talking about egr anti lag... Im sure those extremely gay regulator valves are mounted after the throttle body, on one of the intake runners. I didn't know you could use egr for an anti lag feed... I find that funny. Those crappy emission bs, power-robbing-after-120,000-on-the-clock exhaust-fart-into-intake engine de-tuners are the first thing i delete/block from the intake system. Ftr i'm talking about Mitsubishi evolution 4 upwards type of anti lag - with the bypass valve before the throttle body. Not to be confused with EGR valves. Im sure you know what setup Mitsubishi uses, I've seen the pics of the bypass valves in your fc3s build thread. (awesome btw)
EGR anti-lag IS what Evo's use. EGR anti-lag gets it's name from the fact that most of them use either a modified EGR valve (there is no exhaust recycling happening in EGR ALS), or in Mitsubishi's case, something that IS just an EGR valve with the addition of a 1way valve so no air reversal can happen (ie no exhaust gas can actually be recycled). If that's what that car is using, ie a valve to let air go from the boost pipes directly into the exhaust manifold or turbo without going thru the engine, then a BOV could still operate, but all it'd do was make the ALS not work as well as it could.
can you call it the sas valve like mitsubishi originally intended.. or just bypass valve? i dont like the word egr..... reminds me of check engine lights on hondas and the pain of messing around with emission gayness.
Just bypass makes me think of a blowoff valve. Only call it EGR as it's the most common name for it, SAS valve is deffo better, and makes more sense.
Wouldn't the EGR system be a lot nicer to use, seeing as you still have vacuum and thus it's easier to maintain brake booster and whatnot? why is it more comon to see throttle bypass? as for me ( I have no experience with ALS) it would seem a bit easier even, to operate an EGR ALS system
Brake booster is no issue, just run an electronic pump for the vac- Cosworths run electronic brake boosters as standard. The reason throttle bypass ALS is more popular is it needs less changes to make it work, and all else being equal it's the most effective/brutal, hence it's use in Rallycross. WRC and Circuit cars use EGR/SAS systems most commonly these days, as they tend to be a bit less harsh on components.
That car used to be my friend's, then another friend bought it a made it 2jz s13.4 running als aswell. I had a thread about it: http://www.driftworks.com/forum/dri...2822-nissan-200sx-s13-4-2jz-drifting-als.html
facebrick.... people calling it egr als now STOP. This is an evo 4 engine bay, all oem excecpt for the factory intake pipe thats polished up and a few blue hoses. That black rubber hose just before the throttle body, going to some valve thingy, is the sas valve/bypass valve/anti lag valve. Sits there on all evo oem 4/5/6/7/8/9's... and de-activated by factory. Installed purely for rally homologation. Opens up to divert intake air to the exhaust manifold, then bang bang.. anti lag. The SAS valve/bypass valve/anti lag valve Broken SAS valve with intake pipe. (connects to the throttlebody) The outlet on the right is for the BOV Link: What's This That's Broken? - lancerregister.com Stop calling it an egr valve, because its not an egr valve. Ok get it? Proper anti lag... no egr, ok? ok... Everything under the double dotted line is EGR EMISSIONS CRAP. ================================================================================== How-To: EGR Removal VIII/IX (and charcoal/EVAP canister) - evolutionm.net "The EGR recirculates EGR gas from your exhaust into the intake to reduce the formulation of Nitrogen Oxides." It also "injects soot filled gases into your clean intake manifold getting it dirty and VERY hot" EGR bullshit... the red arrow is where EXHAUST GAS ENTERS your intake EGR valve... wheres the so called air feed from the intake pipe? and where does it go to the exhaust manifold? Red arrow shows where this piece of shit egr valve sits. Take note that this is after the throttle. This is where Exhaust gas enters the intake when the egr valve opens.... Ok, so lets do some modifications for anti lag, and reverse this setup. The pic below would be your air feed, from the intake, to the exhaust manifold... You reckon this little hole is enough for an airfeed if you actually wanted to incorporate EGR antilag? "Nah yeah it' be sweet as..." Yeah right... More EGR gayness... mmm fapfapfapfap... oh wait im not gay. Call it the anti lag valve. Please... A lot of cars have these egr things for emissions purposes. We need to stop confusing the two, cause in the future it will save heaps of poor chaps that would go and do a google search for anti lag, see all this egr bullshit in this anti lag thread, then brag to their mates that their car has anti lag. "Yeah bro my ek9 type r has antilag... look its got the wastegate valve on the intake runner" Genius.jpg
For fucks sake, lol. I already SAID it's often called EGR anti-lag as you OFTEN use an EGR valve. Even WRC cars did. Escort Cosworth WRC car ran a modified Supra EGR valve if I remember correctly as it's 'SAS' valve. I first ran anti-lag on a car over a decade ago, when Evo's were way too new for anyone to be stealing SAS valves off them etc. Everyone used the term EGR anti-lag due to the use of an EGR valve to run it (needs a big one, most are too small). If they were just called anti-lag valves everyone would mix them up with normal throttle bypass anti-lag valves... Fuck, there's a guy on here with a C20LET running anti-lag using an EGR valve. Even in the pics you posted you show it's almost the same, they have the exact same function barring Evo SAS valves have a 1way valve in them which is handy. I own about 10 of them, lol. Calling them an anti-lag valve is a bit basic as they are totally different to throttle bypass anti-lag valves. Try and use a throttle bypass valve to run the 'other' type of ALS and you'll end up with a melted pool of plastic and aluminium. And seing as 99% of throttle bypass anti-lag valves are just ISCV (some completely unmodified, ie the Bosch one like Silviafan above run on his ALS setup) your last point about Civics thinking they have ALS just because they have an EGR valve is retarded, as in that case every fucking car with an ISCV would think they have an ALS valve, lol. So yeah, www.genius.com/bollocks/pointlessargument/gay
nah yeah starvos i know haha.. i knew that would wind you up. #itsnotcalledanegrvalvecausethatstandsforextremelygayrecirculator.
Now that is cool as FUCK. And you can see that setup is more than just noise as loads of flames are coming out the screamer pipe, and as wastegates are only open at full boost, it's staying at full boost even off throttle, which is nice.
Its called a "fresh air system" in the industry for obvious reasons and we don't run it is because it is illegal. Trust me, I would love to as it is magical. It gives you all of the benefits of usual "Air Bypass ALS" but doesn't give you the negative effects such as poor "throttle" to "power" control. Anyway, lets call it the "Fresh Air Valve" hahahaha
