Open atmosphere = rich at idle

FrmRgz2Rchz · Post by **FrmRgz2Rchz** » Thu Oct 16, 2003 6:28 am

I really like the way my BOV sounds when i run open atmosphere(OA), but my car runs like crap. I checked the 02 sensor voltages OA and closed. When running OA, I actually ran leaner at WOT, at about .82 - .83 volts, but when i let off the gas, it stayed up around .6 - .7 The car felt like it wanted to stall, but it didn't. The voltages eventually would come down near zero.

When the BOV was recirculated(closed), mixture was nearing .9 at WOT, and would immediately drop to .01 when the gas was let off.

I wish there was a way to control the fuel mixtures, so I could run OA. It seems like that is the only time my car gets attention.

vrg3 · Post by **vrg3** » Thu Oct 16, 2003 7:01 am

If you want to run a blowoff valve to the atmosphere, you should get one meant to run that way.

The stock valve is meant to be a recirculating valve. It is controlled by vacuum on its actuator. When the throttle is closed (so vacuum is high) it opens. This happens both at idle and when coasting. If you change it to dump to atmosphere instead of back into the intake, you have an intake leak whenever the throttle plate is mostly closed.

Meanwhile, the ECU is trying to do its learning thing: it watches the oxygen sensor to see if it's getting the results it wants. At idle there is a vacuum leak, so extra air gets in, making the default map too lean. When coasting after boosting, there's a boost leak, making the default map too rich. In either case, the leak disappears when the throttle is opened enough. The ECU long term fuel trims weren't meant to handle this kind of case, so you basically end up screwing up all the fuel trims.

What you want is a blowoff valve that essentially behaves as a relief valve. It dumps to atmosphere when pressure builds above a certain threshold. So, this valve will stay shut under all conditions except when you snap the throttle shut while under boost. Under that condition only, you'll have an overly rich mixture. All in all, that happens rarely enough that you probably won't have too much of a problem with your long term fuel trims.

Post by **Legacy777** » Thu Oct 16, 2003 2:12 pm

If you want a blowoff valve you need like vrg3 mentioned....one that is meant to vent to atmosphere, and you need an ECU that knows that it's doing that, and can compensate.

Buddy of mine was running an atmosphere BOV for a while, and his fuel mileage went to crap, and the car did not run as good....but it sounded cool. He ended up going back to one that vented back into the intake.

I believe there are ones that can do a partial atmosphere vent. Which would maybe give you the sound you want, but not be as bad.

IMO, I'd rather have my car run properly.......just my 2 cents.

inzomniac · Post by **inzomniac** » Wed Nov 05, 2003 6:07 am

I have to disagree on the issue of not being able to run an atmospheric dump valve.. I posted ages ago asking if it could be done.. and I was told that it couldn't without compramising performance/safety on the motor. So.. when my stock BOV decided to quit on me and start losing precious boost.. I decided that since I'm putting an EJ20 in my car soon anyway.. why not give it a shot.. what have I got to loose.. the ej22t is going for a rebuild anyway, and I can use the BOV again on the ej20...

Round One: I tried a cheap Diaphragm type dump valve bought from Demon Tweeks in the UK while I was there a few weeks ago.. I hooked this up seriously doubting if the car would work or even run with the valve on the car due to the fact that I knew it would probably open on idle... and it did. The car had irratic idle and eventually stalled every time. Not to mention the amount of un metered air entering the engine. So this one went into my friend's parts pile for Project Turbo Justy (which is almost complete.. 160 Bhp here we come)

Round Two: After I had destroyed my stock valve trying to figure out what was wrong with it (turned out to be a hairline crack around the plastic joining marks) I had to put something there. So I called around, the solution was a Turbosmart BOV which cost me somewhere in the neighbourhood of $170 CAD through a local distributor that gives the Toronto Subaru Club a discount. The valve is adjustable and allows you to put shims (washers) between the piston and the spring in order to ensure a tight seal on idle. The car idles fine and performs better than before, I have none of the previously mentioned lag after shifts.. or any sort of downside to performance or regular driving at all (including fuel mileage). If anything I've got quicker turbo spool up between shifts and the best part of all.. NO BOOST LEAK! It's not the loudest valve in the world once set up right to run in our cars (louder before you set the spacers correctly).. but it's functional.. and that's the major thing!!
Install was very easy and I can post pics for anyone who is interested, just let me know if you'd like to see them. The best setting is two out of the three shims provided.

Anyone who would like to argue this further should either post PERSONAL trials or come drive my car.

FrmRgz2Rchz · Post by **FrmRgz2Rchz** » Wed Nov 05, 2003 4:38 pm

When I had my stock BOV on my car, it leaked. The best time I could get with that setup was a 15.8. When the greddy was put in, I didn't leak anymore and ran a 15.3 with open atmosphere. So, yeah, you will have better performance even though it is open, but you should have issues. After a hard pull, try putting the car in neutral and coming to a stop. The car should be very rich and run like crap. If not, I would say something isn't working correctly with your BOV.

inzomniac · Post by **inzomniac** » Wed Nov 05, 2003 7:05 pm

That's just my point though... mine isn't open on idle, so I don't have any of those problems. and the valve does work propperly. Is you BOV adjustable so that you can make it close at idle?

I know when I had the diaphragm type valve in the car it would idle ok until you touched the gas, then it just got confused, started to flux between 1000 rpm and around 500.. then stall. With the Turbosmart valve I haven't had any idle problems, or after doing hard pulls in the car, it just works, period. Trust me, after all the negative feedback I've had on this site about putting an atmospheric BOV on my car I've been looking for something going wrong, and it just isn't!

FrmRgz2Rchz · Post by **FrmRgz2Rchz** » Wed Nov 05, 2003 9:34 pm

My BOV is adjustable but it's not idleing bad because air is getting in, it is idleing bad because it is so rich. After a hard pull and coming to a stop, the 02 sensor is reading about .7 volts for about 4 seconds until the ECU finally kicks in and makes it normal again.

mTk · Post by **mTk** » Wed Nov 05, 2003 9:56 pm

I ran my stock BOV open atmosphere for a short while jsut to see what it'd sound like/do. The sounds was kinda neat, but idle was terrible and the car actually died while decelerating from 60 or so mph.

I'll most likely wait till i've got an intercooler untill i get a new BOV.

MK

inzomniac · Post by **inzomniac** » Thu Nov 06, 2003 12:02 am

Andy: I don't have an air/fuel guage on my car.. so I'll have to keep an eye out for it and listen to the motor.. but as far as I can tell it's not having any problems running. well.. other than the reasons I'm putting the ej20 in

Should be happening soon.

Do It Sidewayz · Post by **Do It Sidewayz** » Thu Nov 06, 2003 5:55 am

ok. you guys are wrong (except Inzomniac)

I guess you can call me Inzomniac's Personal Mechanic about now, after numerous suspension installs, clutch install, crank pulley install, and just about everything else on his car. including his BOV.

Anyways...The first BOV he had didn't work because it was open at idle. This cause the car to suck in unmetered air. The car would suck less air from the stock air box. The computer would give the normal amount of fuel to compensate for this. BUT, the open BOV was allowing the engine to suck in unmetered air, causing the car to run super lean. As the computer is giving very little fuel, but not knowing it is receiving ALOT of air. The instant you would touch the gas, the car would become even more confused, by sucking in more unmetered air. causing the car to go super super lean, and die. NO BACKFIRES, NO UNBURNED FUEL, JUST LEAN

With the turbosmart BOV we installed later, it is closed at idle, letting the computer to get the correct idle readings, sending the correct fuel, and a good idle mixture. Meaning it doesn't run lean. it doesn't run rich it runs fine.

Now....what you are thinking is this. When you are on the boost. and let off the gas, the BOV vents the air to the atmosphere which was mettered, and the computer is still sending fuel for that air. Meaning for an instant you will be running rich. And it can lead to a backfire. However even with a re-circ BOV you will still run a little rich, as it's rerouting the air before the turbo, which is far from the Throttle body, let alone combustion chamber. Meaning the metered air still does not get to the cylinder causing a rich condition. this is GOOD for your engine. the boost pressures will elevate the piston temperatures if you do not have an intercooler. With the momentary Rich condition when you let off the gas, and the BOV vents, the engine uses the fuel to cool the tops of the piston which is a VERY Good thing. Fuel cools the tops of the pistons very well. whcih will lead to extended piston life. (trust me. in our subaru race cars we have melted numerous pistons due to high temps...and we don't run BOV's cause we are cheap)

For the longest time, gary has been telling me that the guys on this board say that a BOV won't work. and for the longest time, i've told him they are full of it.

Here's an idea...why don't you guys stop conforming to what other people say, and go out there and try things. the worst that happens is it doesn't work!!!!

and consider where the advice is coming from. Some punk with a freaking N/A and FWD legacy isn't a good source of information on turbo topics. Even if he does have a turbo hood, and pink brake calipers. It doesn't mean he know's squat about a legacy turbo.

And if you question where this is coming from...i'm in the process of building a complete Turbo system for my Justy. as with all my ideas this one WILL work. trust me, it will be faster than a certain N/A FWD Legacy even if it does have a turbo hood

vrg3 · Post by **vrg3** » Thu Nov 06, 2003 6:02 am

Dude, calm down. There's no need to be adversarial.

I don't think anyone disputes that if a BOV stays closed at idle then everything will be normal except during a shift.

You're right that even a recirculating valve allows the MAF sensor to read some airflow that doesn't immediately reach the engine. However, an atmospheric valve does allow it to read much more, so the ECU will fuel much more. You can argue that this is good or that it is bad, but it's true.

FrmRgz2Rchz · Post by **FrmRgz2Rchz** » Thu Nov 06, 2003 6:38 am

Well, this looks like it just got interesting.

Redline Dreamz · Post by **Redline Dreamz** » Thu Nov 06, 2003 9:00 pm

ok. you guys are wrong (except Inzomniac)

your about to wish you never said that.

I guess you can call me Inzomniac's Personal Mechanic about now, after numerous suspension installs, clutch install, crank pulley install, and just about everything else on his car. including his BOV.

Want a cookie? Call me Andys "persoanl mechanic". Not only have i dumped more than 30 man hrs into that motor but i also spent about 5 months racing it side by side with andy at both the drag strip and SCCA OVR Solo division. There isnt much that i dont know about or cant do with that motor.

Ive been building motors probably longer than youve been gettin your self off to your dads old playboy collection. I built my first 350 with my dad when i was 11, and then managed to squeeze it into an 83 Caprice Classic when i was 12. Over the last 10 yrs ive built or worked on just about every honda motor you can think of, LD9's, L22's, 3SGTE's, 7MGE's, 4AGE's, KA24's, SR20DE(T)'s, BP6's, BP's, 4G63(T)'s, 420A's, 350's, 302's, and the newest being andys EJ22T. Your small list of tasks does not impress me in the least. If you have to do anything "numerous" times, your not doing a good job of it.

Anyways...The first BOV he had didn't work because it was open at idle. This cause the car to suck in unmetered air. The car would suck less air from the stock air box. The computer would give the normal amount of fuel to compensate for this. BUT, the open BOV was allowing the engine to suck in unmetered air, causing the car to run super lean. As the computer is giving very little fuel, but not knowing it is receiving ALOT of air. The instant you would touch the gas, the car would become even more confused, by sucking in more unmetered air. causing the car to go super super lean, and die. NO BACKFIRES, NO UNBURNED FUEL, JUST LEAN

If you had any real experience with dyno tuning or even tuning in general (which you dont seem to have) youd know that lean does not cause bogging or backfires. A lean condition will cause high idel RPM followed by immediate over heating and possible shut down. If your motor is bogging down, youve got too much fuel. If youve got rediculously snappy throttle response, your probably running a bit on the lean side.

A backfire is not caused soley on the lean condition. If you had any real racing experience (which you dont seem to have) youd know exactly when a backfire occurs. I.E. Heal toeing down into second gear for a nice hairpin and letting the tranny slow you down then getting striat back to WOT... POP... thats your backfire. Instant lean to instant rich. All that fuel just had the pleasure of expanding all that extra air that was just sitting there.

With the turbosmart BOV we installed later, it is closed at idle, letting the computer to get the correct idle readings, sending the correct fuel, and a good idle mixture. Meaning it doesn't run lean. it doesn't run rich it runs fine.

Of course it runs fine... beacuse its so tightly closed its functioning like its not even there. This is why the venting is not loud, its barely opening. If you knew how to use a BOV properly (which it doesnt seem you do) youd know that you need to let it be just loose enough at idel to be on the verge of venting while running an internaly wastegated turbo. If you tighten it to hard, it wont open and your going to get your self some backspin. Then you can say bye bye to your turbo. The real reasoning for having a BOV is jsut to have a safe guard against wastegate failure. If your vacuum hose pops off your wastegate, your BOV needs to be loose enough to keep you from over spooling. Thats whats its there for. Making a cool sound just happend to be one of the side effects.

Now....what you are thinking is this. When you are on the boost. and let off the gas, the BOV vents the air to the atmosphere which was mettered, and the computer is still sending fuel for that air. Meaning for an instant you will be running rich. And it can lead to a backfire. However even with a re-circ BOV you will still run a little rich, as it's rerouting the air before the turbo, which is far from the Throttle body, let alone combustion chamber. Meaning the metered air still does not get to the cylinder causing a rich condition. this is GOOD for your engine. the boost pressures will elevate the piston temperatures if you do not have an intercooler. With the momentary Rich condition when you let off the gas, and the BOV vents, the engine uses the fuel to cool the tops of the piston which is a VERY Good thing. Fuel cools the tops of the pistons very well. whcih will lead to extended piston life. (trust me. in our subaru race cars we have melted numerous pistons due to high temps...and we don't run BOV's cause we are cheap)

If youve ever messed with fuel maps (which its appearent you havent) youd know that a fuel map has 3 inputs, not 2. Your MAF, O2 readout, and TPS all control your fuel map. Your computer reacts almost instantly with your TPS so your little theory about the computer still dumping fuel in after the TB is closed, is completly, and totaly WRONG.

Theres no such thing as a "re-circulating" BOV, its called a BPV or By Pass Valve.

It does have an intercooler. I piped it in myself just after i did the IHI TD05H swap.

If youve ever done any intake design and testing (money says you havent) youd know that @ 6000rpm that EJ22T is pumping air into the TB at about 32m/s... so even if the air had to be pushed through 34in ( 1 meter) of pipe, it would still only take .03125 seconds for it to reach the TB... hardly "far" IMO.

Rich is NOT good, nor is a lean state. Rich is safer than lean all up untill the point of hyrdalock but BOTH ARE BAD. Any real turner knows this.

Piston top temps are the least of your problems. The Cylinder walls are the issue. Every moving part in your motor is lubricated and COOLED BY OIL, NOT FUEL. Your block and head casting are cooled by your water system.

For the longest time, gary has been telling me that the guys on this board say that a BOV won't work. and for the longest time, i've told him they are full of it. Here's an idea...why don't you guys stop conforming to what other people say, and go out there and try things. the worst that happens is it doesn't work!!!!

Guess what bonehead, thats what we did. We tried it, and guess what, it DOES NOT WORK PROPERLY WHEN SET UP PROPERLY. If we wanted it to work properly, the motor wouldnt last without a full intake rebuild, which i might add im designing and fabricating myself. If you want video, find me someone to host it and you got it. Watch the video confirm everything said and then tell Andy or myself that we are "full of it". I dare you. You know, i once drove 861 miles to race someone because they were running there mouth about how thier car was faster than mine in a chat room. Needless to say, i won, and taught many people real quick that i wasnt just some guy who watches Fast and the Furious movies and memorizes SuperStreet, Import Tuner, and Sport Compact Car articals... I AM THE REAL DEAL.

and consider where the advice is coming from. Some punk with a freaking N/A and FWD legacy isn't a good source of information on turbo topics.

You make me laugh. I drive an NA LD9 powered cavalier, but ill put the PEPSI CHALLENGE up that says i can school your ass on a turbo setup of any kind on anymotor.

And if you question where this is coming from...i'm in the process of building a complete Turbo system for my Justy. as with all my ideas this one WILL work. trust me, it will be faster than a certain N/A FWD Legacy even if it does have a turbo hood

I know where its coming from, and so does everyone else whos read this crap. Who cares if you build a turbo setup and its faster than a freakin NA FWD legacy. ITS NOT SUPPOSED TO BE FAST! Youd have to run a nothing more than 16.5 to beat that NA.

Im sorry Inzomniac, but i think you need to find yourself a new mechanic becuase this guy is gonna help you do nothing but blow your shit up.

YOU JUST GOT OWNED

vrg3 · Post by **vrg3** » Thu Nov 06, 2003 9:21 pm

Guys, seriously, knock off the ad hominem arguments and personal attacks. The writer's experience in somewhat-related work is only one of many axes along which a post's value can be judged.

Perhaps we need a clearer explanation of how the TurboSmart valve works. Is it still diaphragm-based, opening when manifold vacuum is high? If so, then you could potentially set it to open at around -20inHg. That would keep it shut when idling but open when the throttle is closed at high engine speed. It may not stay open as long as would be ideal, though.

From what I can tell from hacking at the ECU, fuel maps in our stock ECUs are 2-dimensional. The axes are load and engine speed. Readings from the throttle position sensor and oxygen sensor are incorporated into the programming as correction factors but aren't in the maps.

Even if the TPS indicates that the throttle is closed, the ECU will still provide an amount of fuel more or less proportional to measured airflow.

Redline Dreamz · Post by **Redline Dreamz** » Thu Nov 06, 2003 10:26 pm

vrg3 wrote:Guys, seriously, knock off the ad hominem arguments and personal attacks. The writer's experience in somewhat-related work is only one of many axes along which a post's value can be judged.

Perhaps we need a clearer explanation of how the TurboSmart valve works. Is it still diaphragm-based, opening when manifold vacuum is high? If so, then you could potentially set it to open at around -20inHg. That would keep it shut when idling but open when the throttle is closed at high engine speed. It may not stay open as long as would be ideal, though.

From what I can tell from hacking at the ECU, fuel maps in our stock ECUs are 2-dimensional. The axes are load and engine speed. Readings from the throttle position sensor and oxygen sensor are incorporated into the programming as correction factors but aren't in the maps.

Even if the TPS indicates that the throttle is closed, the ECU will still provide an amount of fuel more or less proportional to measured airflow.

Well i sat back and watched all of your posts. After reading them all i felt like i was playing a part in Billy Madison. You know the part where he talks about the industrial revolution and it makes absolutly no sence??? Thats waht i was thinking about everyhting i read. I can see most of you guys have a very good understanding of how this stuff all works but what i saw WAY TOO MUCH OF, was people jumping to conclusions and giving thier opinions based on those conclusions.

i.e. perhaps before you make a comment like "If you want to run a blowoff valve to the atmosphere, you should get one meant to run that way.", you should ask what type of valve hes running. The answer to that BTW is a Greddy Type-S.

Or even better, your whole fuel map theory... is just that, a theory. If your hacking at an ECU and its telling you RPM and "load" has anyhting to do with your fuel... your reading it wrong or you have one messed up ECU. The only thing that RPM has to do with it is your airflow @ that RPM which is read by... the MAF sensor. Your O2 is like a very crude EGTS and your TPS controls the flow pressure and duty cycle of your injectors. I too had a hard time understanding it, but thats how it works.

The point is this. Ive been on here a while and notice noone really flames on anyone else... which is really cool but sometimes it has to be done to keep people from giving out incorrect information and leading to the spread of a butt load of misconseptions and blown up motors. Do i enjoy flaming on people who couldnt buy a clue about motors... absolutly, do i like doing it... no. Everyone just needs to be a bit more careful about the things they type and commit opinions to, including myself. I do think my last post was a bit overboard but i dont appreciate by any means anyone telling me or Andy that we are "full of it" or setting something up incorrectly especially when the people doing so havent a clue in the slightest.

inzomniac · Post by **inzomniac** » Fri Nov 07, 2003 12:03 am

Redline:

Anwyay.. before you start yipping at me. You assume to know alot about the guy (Chris) who you so eagerly started ripping into... you don't, so calm down. I don't see anywhere in there that he directed anything towards you, rather than acting like a two year old back, you claim to be older and more mature.. so show it.

As for the valve, I know my engine is going down anyway, so I thought I'd try out a BOV, the one I've got seems to work, and that's what I've posted. I've got NO problems, and find my car drives better than stock configuration.. that was all I was trying to say, and I belive I did. If I end up screwing something up that I find to be a result of putting on my BOV, then I'll let you guys know. But for the time being it works.

Redline Dreamz · Post by **Redline Dreamz** » Fri Nov 07, 2003 12:28 am

inzomniac wrote:Redline:

Anwyay.. before you start yipping at me, you assume to know alot about the guy who you so eagerly started ripping into... you don't, so calm down.

As for the valve, I know my engine is going down anyway, so I thought I'd try out a BOV, the one I've got seems to work, and that's what I've posted. I've got NO problems, and find my car drives better than stock configuration.. that was all I was trying to say, and I belive I did. If I end up screwing something up that I find to be a result of putting on my BOV, then I'll let you guys know. But for the time being it works.

The whole picture thing is way played out... nice effort though. Anyway, if what you have works for you for the time being, all the power to ya. My angle is that to make it work properly you have to set it up improperly, which you may or may not have done... i couldnt be sure without seeing/hearing or even driving it for that matter.

You also need to remeber that if your running the stock turbo and boost, which i ass-u-me you are since you didnt mention any of that prior, the effects will be a lot less damaging. On a TD05 running 1-1.5 bar... things start to get pretty hairy if you arent extremely careful about the way you install and set things up.

Somehting ive learned is that every motor is different and reacts differently to everything. Your motor may not give two shits about your setup with a BOV and that may be a bad thing. If your motor isnt sensitive to its setup, it may be difficult to troubleshoot your problems (if any) before its too late.

I just give a strong word of advice... be extremely careful when doing anything to a motor that makes it other than stock. Ive seen the worst that can happen from that and that motor put a connecting rod through someones calf muscle. I dont think thats something that anyone really wants.

inzomniac · Post by **inzomniac** » Fri Nov 07, 2003 12:48 am

Trust me man.. as Chris will tell you, I'm about the most cautious person in the world when it comes to doing shit to my car... (I also work in Performance parts, so I do tons of reserach while I'm bored at work, so everything on this car has been reserached through and through, it's not the best, but for what I can afford it is) I'm running the thing stock boost due to the fact that the car is dying and I don't really feel like putting out for a new motor until I have the cash in my hand. Like I say.. I'm happy to guini pig this out until something happens to my motor.. I'm also (once I have cash in my hand) see how much the stock motor will take sans I/C... I know it's a great motor, but I don't have the $$$ to re-build it propperly and I've got a guy that'll throw in an EJ20G cheaper than it costs me to fix my engine.. and use my engine even blown, as payment.

Do It Sidewayz · Post by **Do It Sidewayz** » Fri Nov 07, 2003 1:13 am

Gary probably is the most cautious person i've ever met.

Heck he wouldn't even let me put in his boost gauge until he went to the bathroom and i already had it almost completely finished.

Anyways. i was prolly a little overboard as well. I'm just not a fan of people telling you it won't work, when they haven't tried anything.

I respect that you've done a pile of research and work on a pile of engines, and it's from people like you, that people learn a thing or two.

You ideas on what's happening make some sense...however i'm positive that this is not what we were seeing on Gary's car when we were playing around with the BOV. i'm positive that this thing was running way lean at idle, and dieing because it was getting absolutely no fuel. It's running at a real low idle, and the minute more air is introduced it'll kill itself. The reason why it wasn't getting itself way hot, and melting stuff it because it was only running for a few seconds. On the rich front, i agree with you, it's not the best and makes crappy power, but you would have to basically be getting no spark for it to hydraloc itself. Plus when you are talking about running rich it's maybe for a second.

The reason i say running rich for that second is a good thing is because, on our race cars (old subaru turbos) we have been melting pistons for years because of running higher boost levels. We found (and were told) that the only way we could keep pistons in them, was to raise the fuel pressure to a level that the car was running rich, and when off the throttle the raw fuel was used to cool the tops of the pistons. I'm not saying that the pistons are solely cooled by the fuel, because that is obvious. We just found that the extra little bit of fuel helps lower the temps.

Anyways. gary is running a stock turbo, stock boost (for now) and no intercooler.

As far as racing and dyno experience. i've got some.
I've been racing karts for 6 years, and last year i won the Canadian National Karting Championships.
I've also been racing cars for 3 years and won my class every year i raced, also winning the Overall Championship once.
Dynoing..i've had more than a few hours on the dyno tuning my kart, playing with jets, needles, carbs and so on.

I do agree with you that every motor is different. and every computer is different. sometimes some motors are just better than others, and no one really knows why. I have a motor for my kart that is half a second faster a lap than than another one. Everything is the same, just one is plain faster.

and the numerious times thing...thats the suspension. Gary keeps jumping his 3000+lb car and wonders why he blows struts. But that's also the beauty of the KYB lifetime warranty. Everything else...we've only done once...except for maybe brakes....that's cause it's a 3000 lbs car, and he uses the brakes to much.

Anyways...i agree it's prolly not best to argue on here. just sometimes i find it as part of the joy of message boards.

btw. i give you guys lots of credit, you've tried lots of stuff, and if it did or didn't work that's cool. I didn't mean to pick on you guys specifically.

vrg3 · Post by **vrg3** » Fri Nov 07, 2003 1:16 am

See, Redline, the problem I have with the way you flame is that it seems to carry an arrogance -- you make the assumption that what you say is gospel and that others are completely wrong. I'm not saying you actually believe that; it's just how it comes out to the rest of us.

You recognize that you're not infallible, right? You say things that are wrong, just like the rest of us. You don't understand everything perfectly.

Why not try to be constructive about correcting what you perceive to be errors?

So let me offer this: I know for a fact that the ECU maps are two-dimensional. I have begun to disassemble the ECU's code as well as examine its data. Further, it's almost universal to have a map indexed by load and engine speed and then add on power enrichment and closed loop corrections.

Take a look at any aftermarket ECU mapping and you will find that RPM is universally one of the axes. The other axis is usually some kind of computed load value, measured manifold pressure, or (rarely on the street) throttle position.

Especially since our cars do not have calibrated throttle position sensors, fueling based on throttle position would be impractially imprecise. Also, the TPS does not control fuel pressure; fuel pressure is controlled by the fuel pressure regulator which is referenced against manifold pressure. On turbocharged cars, manifold pressure can vary widely with respect to throttle position.

All reliable information I have read in service manuals and from WRX tuners supports what I've written here. If you have some good sources of more information I'd be very interested in them, since it is one of my goals to fully understand my car's engine management.

Do It Sidewayz - I'm curious -- do you know for sure that the blowoff valve is venting enough to prevent compressor surge and to keep the turbo spinning?

Do It Sidewayz · Post by **Do It Sidewayz** » Fri Nov 07, 2003 1:49 am

to be honest. i'm not completely sure to answer your question.

We had just got the Turbosmart BOV on his car when i received a phone call which i had to attent to immediately.

I told Gary to adjust as he saw fit, but i'm not sure it was completely nessesary.

With no shims in the BOV you could hear it "clicking" (opening just the slightest bit and closing again very quickly at idle). Gary wanted to add an extra shim (actually he added 2) so he did. Now thinking about this more since the fact, i'm not sure this was the right decision. I think it was actually better in concept to have it just on the verge of opening is the best way, as it will open easier and more. which in turn vents more pressure, and does help keep the turbo spooled and prevent compressor surge.

the reason i think this. is because when there were no shims the BOV was much louder, meaning it was venting alot more air.

Redline Dreamz · Post by **Redline Dreamz** » Fri Nov 07, 2003 2:27 am

vrg3 wrote:See, Redline, the problem I have with the way you flame is that it seems to carry an arrogance -- you make the assumption that what you say is gospel and that others are completely wrong. I'm not saying you actually believe that; it's just how it comes out to the rest of us.

You recognize that you're not infallible, right? You say things that are wrong, just like the rest of us. You don't understand everything perfectly.

Why not try to be constructive about correcting what you perceive to be errors?

So let me offer this: I know for a fact that the ECU maps are two-dimensional. I have begun to disassemble the ECU's code as well as examine its data. Further, it's almost universal to have a map indexed by load and engine speed and then add on power enrichment and closed loop corrections.

Take a look at any aftermarket ECU mapping and you will find that RPM is universally one of the axes. The other axis is usually some kind of computed load value, measured manifold pressure, or (rarely on the street) throttle position.

Especially since our cars do not have calibrated throttle position sensors, fueling based on throttle position would be impractially imprecise. Also, the TPS does not control fuel pressure; fuel pressure is controlled by the fuel pressure regulator which is referenced against manifold pressure. On turbocharged cars, manifold pressure can vary widely with respect to throttle position.

All reliable information I have read in service manuals and from WRX tuners supports what I've written here. If you have some good sources of more information I'd be very interested in them, since it is one of my goals to fully understand my car's engine management.

Do It Sidewayz - I'm curious -- do you know for sure that the blowoff valve is venting enough to prevent compressor surge and to keep the turbo spinning?

I agree with all that was said. Perhaps i was a bti hasty to ass-u-me with the subaru fuel map setup. However, on every GM, Toyota, and Mazda map ive looked at, its inputs has been MAF/MAP, TPS, and O2. Pehaps its different because the subarus are a hot-wire system that i dont yet fully understand.

I do know that the way i say things carries arrogance... its because i mean it to do so. Maybe its because im tired if internet idoicy, or maybe i just like making other people look like retards... whatever the reason is, i will respect the places it comes from and no where else. As some of my friends and I say, "we take care of our own".

vrg3 · Post by **vrg3** » Fri Nov 07, 2003 3:33 am

Redline Dreamz wrote:However, on every GM, Toyota, and Mazda map ive looked at, its inputs has been MAF/MAP, TPS, and O2. Pehaps its different because the subarus are a hot-wire system that i dont yet fully understand.

All GM, Toyota, and Mazda maps you've looked at are 3 dimensional? Can you show me where I can read more about this? It seems like it would be hell to tune.

The engine management systems I'm familiar with do take input from all sensors. Most of them are just used to modify the value read from the map. For example, the colder the coolant is, the more each injector pulse is lengthened. And when the throttle snaps open, the injector pulse is lengthened. And when the oxygen sensor reads rich during closed loop, the injector pulse is shortened. But these actions are all accomplished with simple code and maybe one or two parameters, not with a map.

I do know that the way i say things carries arrogance... its because i mean it to do so.

Well, that's not nice! :P

Maybe its because im tired if internet idoicy, or maybe i just like making other people look like retards... whatever the reason is, i will respect the places it comes from and no where else. As some of my friends and Isay, "we take care of our own".

The places it comes from? I don't follow. What's the antecedent to "it?"

I don't think any of us here think the people you mock look like retards. And of all automotive forums I've been on, I'd have to say this is the one with the least idiocy.

vrg3 · Post by **vrg3** » Fri Nov 07, 2003 3:37 am

Sorry, I forgot to address the on-topic part:

Do It Sidewayz wrote:I think it was actually better in concept to have it just on the verge of opening is the best way, as it will open easier and more. which in turn vents more pressure, and does help keep the turbo spooled and prevent compressor surge.

the reason i think this. is because when there were no shims the BOV was much louder, meaning it was venting alot more air.

Yeah, I think right now the valve probably isn't venting as much as it ideally should. It's probably enough to protect the turbo from killing itself, but ... well, it's all a compromise. The bottom line is that there's no way to completely satisfy all the issues of an atmospheric blowoff valve when you have to keep fighting the ECU.

Redline Dreamz · Post by **Redline Dreamz** » Fri Nov 07, 2003 6:14 am

All GM, Toyota, and Mazda maps you've looked at are 3 dimensional? Can you show me where I can read more about this? It seems like it would be hell to tune.

Just read a Apexi SAFC II tuning guide. Im sure you could do a search for it on google or yahoo and find it. It is extremely difficult to tune. Thats what makes the SAFC I and II so popular over stand alone units. Most people dont know where to start with a stand alone unit. The SAFC I and II do all the rough calculations for you and just display all the inputs you can imagine. To do it with a stand alone unit you need a couple things. EGT guage, voltmeter(s). The EGT guage just tells you that your A/F ratio is off, not rich or lean, just off. The voltage for the TPS lets you know what percentage your throttle is open and the voltage for the O2 tells its input from the ECU. If the ECU is higher than a unique voltage then its running lean, lower, its running rich. THIS ONLY WORKS WITH O2 SENSORS WITH 3 OR MORE WIRES. You go thru and fix these fuel points from 50% - 100% going every 1%. It takes quite a bit of time but when your done, youve never seen a powerband so smooth or a torque band so solid. Its a beautiful thing when its done right.

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Open atmosphere = rich at idle

Open atmosphere = rich at idle