hey guys, I have not had my 03 wrx for long. When i first got it, it had a cheap boost guage, with basically an aquarium line running to it. It was only reading 7psi, but i assumed the guage was bad, so I took my autometer guage out of my old car and put it on the WRX, along with the hard 1/8" line out of the old car. this guage read 7 lbs as well. After a little more research, i discovered that there was no restrictor pill, and that the boost control solenoid was not hooked up at all. I ordered a restrictor pill from SOG, and put it in the line, hooking up a t to the BCS like stock. While at SOG for service, i asked them to look at boost, so they looked at my lines, hooked them up in the correct orientation on the t and placement of the restrictor pill, and told me that my guage is 7 psi off, and that the car is running 14lbs. Trusting them, i took the car home, but after thinking more about it, and noticing a lack of holding of boost, i took the guage off, hooked it up on a line with two other boost guages, and using a hand pump, built pressure and all three guages read the same. I installed the guage back in the car. The problem i am having now, is i am only seeing around 8 psi in 1-2, which i could live with i guess, but in 4th gear or so, if i floor it, boost climbs to 12 psi, then immediately drops to 8, then jumps back to 12, then back to 8, with the jump getting smaller and smaller until it balances around 8-9 psi. I dont understand what the problem could be, the car has a stock BOV and wastegate set up on it, maybe my BCS is bad. I feel like SOG did not actually diagnose the boost issue, just told me it was right, because if they took it out and drove it at any real speed (higher gear) they would have noticed the boost jumping. Anybody have any ideas, or should i take it back to SOG? thanks, mark
did they give you the right pill is your BCS connected correctly or functions See WJM oops he moved p.s. you need to provide more info on your car - mods and em
I believe boost in 1st and 2nd is correct, but you should be able to hold boost above that in all other gears.
Take it back to SOG and explain the problem. Also, dont forget to mention that you tested the boost gauge(s). There isn't an external spring attached to your wastegate is there? Just curious...
boost fluctuations occur because the setpoint and the measured is significantly different and the PID is trying to compensate. In order to resolve this is to set the target within the limits/capability of the car and all the components fully functional. Not knowing what mods and EM or what is working - all solutions is a guess. Not knowing the components is functional or not is a wild goose chase I would say test gauge, BCS, leaks, actuator, connection hoses first
Hmmm I bet there is some form of reflash on the ECU that isn't right. Best bet is to probably so to Topspeed and let them look at it.
Silver WRX w/17" silver wheels and really short tires...and some noise problems in the back? Also has 'coilovers' on stock shocks? If so, I worked on it. The ECU is seeing CORRECT boost pressures per the mods. You will need tuning in order to correct the over boosting condition (the 12psi you see it spike to on the gauge, which is actually a spike to 18~19psi). Otherwise, the boost gauge in the cockpit is off by 6~7 PSI from what the ECU is seeing.
Hey man, First of all, I am glad that you happened upon this thread. Thanks for the help. Trusting your diagnosis, I believed that the gauge was reading improperly, so i considered the possible causes for such an improper reading. The possible reasons I could think of were: 1. The gauge itself is defective 2. the line was leaking, pinched, or otherwise defective 3. The location of the tap for the gauge somehow did not work (possibly due to a large boost leak on the intake manifold, intercooler, piping, bov, etc. This is what i did in order to properly execute a process of elimination diagnosis on this problem. 1. I work at advance auto parts, so i have access to several gauges and diagnostic tools at work, as well as buddies with turbo cars, so... I borrowed another autometer from a friend, a vdo gauge from another friend, the "Faze" gauge off the shelf at work, and a vacuum/pressure pump off the shelf. I hooked up all of the gauges together with a couple of vacuum ts and line, and some clamps. I then pressurized to various pressures (5psi, 10psi, 15psi,20psi). At all pressure levels all gauges including the one on the pump read the same +-2 psi all the way across the board. This indicates to me that the gauge is not off by anywhere near 6 psi. (correct me if i am wrong) 2.I removed the T from the BOV line, disconnecting the current gauge tap, and hooked it back up like stock. I then got one long piece of 1/8" rubber line (not the hard nylon, but a real rubber vacuum line), and hooked it up to the gauge. 3.I wanted to read boost right at the turbo itself, the same boost that the BCS is seeing, so i put a t for the guage in the line going to the BCS. At this time i also verified that the restrictor pill was between the compressor outlet and the t and that one side of the t went to the wastegate actuator, and the other to the BCS, where i installed the T for the gauge. I then hooked up my gauge line straight to the gauge from this T. What I found with gauge hooked up like this. At first, i could get absolutely no reading on the gauge, it fluctuated wildly, and very quickly, unlike when a gauge is "notchy" in its movement. I thought that maybe the BCS was somehow causing this so I unplugged the electrical connector to the BCS (knowing that this would immediately throw a CEL and took it down the road, to get a consistent reading of 7psi, what i believe should be right for the BCS not connected (i.e-wastegate pressure). With my limited knowledge of subarus i see several possible causes 1. the BCS is bad, leaking, or something 2. the signal the ECU is sending the BCS is somehow wrong 3. the wastegate actuator is bad (Although i have tested it with the same hand pressure pump and it worked fine) 4. with the knowledge that you hooked it up to the computer at your work, perhaps whatever sensor tells the ECu what the boost level is is bad, causing it to get a higher reading, and decrease boost, causing the fluttering boost i am having? (help me out here). I am out of ideas. let me know what you think. Also, i did not want to come across as doubting your knowledge, it just didn't seem right to me. Thanks, Mark
Everybody else, thanks a lot for the help, Here is some background information about my cars mods. It has a full invidia turbo back, with a bellmouth downpipe. It has a mesh filter (like the K &N filter kit, but not, just an adapter and large mouth opening filter clamped onto MAF. and however irrelevant, it does have some stupid skunk 2 coil overs, that WJM mentioned that suck. thanks, mark
Reading the boost at the boost control lines on a bleed type setup, I have always seen large variations in boost...as you are seeing the air thru the restrictor, and then the boost as the BCS bleeds off the boost in order to run higher boost. What you need to do it hook the gauge up directly to a manifold vac. source...not tee'd in with a BOV, FPR, MAPS, or anything else. I have found that the factory boost gauge setup has a VERY SUPER SMALL restrictor in it at the tee connector on the BOV line. This works fine for the stock gauge...but any aftermarket gauge on the factory line setup will read VERY incorrectly (My autometer was reading 5psi off of full boost, and would only read 8~10 inHG when its really pulling 18 inHG)...once the restrictor is removed from that line at the tee connector in the BOV line...I have found that any average aftermarket gauge as long as it starts off acurate...is always within 1 psi of what the ECU is seeing. My setup uses the factory line w/out the restrictor....as the car originally had the Performance Gauge Pack in it. I have since replaced it and I am now using an autometer boost gauge (25inHG to 25 PSI boost is its range). It reads within 1 psi of the ECU when its in boost...and is nearly dead on when under vac. conditions. I'd still find a dedicated source just to make sure....then hook it back into the BOV line w/out the restrictor (if there's one in the line) and compare the readings. If its still off...well, take it to TS for verification...Doug and SS will be able to tell really quick if the ECU is lying. I did not see any odd data. I did several pulls under street condtions (stop-1-2-3 gears. Roll in 1-2-3) and several highway pulls (2-3-4 rolls) and it did exactly as I expected it to with the mods it has.
I found that I had to play with the diameter of the tubing going to my Autometer gauge to get it to read what the ecu was seeing. I ended up having to go with a larger diameter tubing that what came with the gauge.. Solved the problem for me.
I use the manifold pressure I T off the brass elbow at the front center of the manifold (near the alternator) I dont use any restrictor nor oversize line - a restrictor will delay the true reading if the line is long and an oversize line will be ok but not necessary - i would think an oversize line will reduce jitter but not as jumpy. If you can log then you can truly see what the ECU sees and how it compensates to keep you in target. If the dial gauge is not accurate then throw it away, rather than reporting wrong info. Your car seem to have a few issues and until you confirm one at a time you wont be able to solve it THE BCS system is not a complex one
Okay, update I removed the t i had in the wastegate/bcs line, and hooked up it up just like stock. I also made sure that the BOV line was hooked up like stock as well. I t'd the gauge into the small vacuum port on the intake near the alternator. The readings here are relatively consistent with in other places. at idle, it pulls around 17 in hg with the ac off, and 15 with the ac on, it pulls around 23 in hg under decel in the midrange. It was reading boost, peaking around 14psi on the gauge, but still jumping around. In order to isolate the problem further from a wastegate spring issue, or leak, or something else, i left the line to the BCS open (A common dsm/honda turbo trick to increase boost, same as the stock bcs function, bleeding boost off so the wastegate does not see it until a higher level). I then very carefully drove it, feathering the gas to keep the boost under 15. If i held it correctly, it would hold at any level i made it, from 7 on to 15 psi. Should i try replacing the BCS?, or getting it tuned, or both? I would like to get a tune somewhere along the lines of a Cobb "stage 2" but open source tuned perhaps, if this will fix my problem, 2 birds with one stone. I have not had a chance yet to hook it back into the BOV T to check for consistency between several ports, but i believe i am getting a good reading now, just either the BCS or tune will not bleed boost consistently to run 14 psi. thanks, mark
It needs to be tuned. On my WRX: Ported stock manifold Random Tech Uppipe BPM Crossover pipe Titek 3in catted DP HKS Hi-power 3in catback Agency Power inlet pipe The boost would over shoot to 18~19 then fall on its face to 10 during initial spool. After that it would take most of the pull in the gear (3-4-5) to let the ECU sort it out(going from 10 to 17, then 11 to 16...12 to 14...13~14). It never sorted it in 1st or 2nd. Most of the time it just kept oscillating from 18 to 10/10 to 18. It took me about 30 mins with ecuflash to fix it. Now it holds a steady 13.93 psi (stock boost target, which makes it SCCA-STX legal) in the areas that the map targets 13.93 psi. Cliff notes: Get it tuned.
okay, if i intend to either put an aftermarket uppipe or gut mine, should i get it tuned after i do that? presumably if an uppipe and air filter effect it that much, an aftermarket up pipe would make a huge problem. What kind of tuning would you recommend? I have tuned several cars a/f using afcs, a maf-t, and briefly on an aem ems. if nothing else, should i take it to topspeed? how much approximately will that run me? I would like somewhere around a stage 2 tune, with 15 psi which should be safe on stock fuel right? thanks, mark
if you change any pipes you need to tune stg2 you can go to 16-17psi safely with 93oct i know of many running higher than that psi since you have knowledge of tuning you may want to try Opensource (not recommending just a suggestion)
i am currently reading up on opensource tuning. I would love to find some quick and easy complete "Stage 2" maps, and bam-upload and get 16-17 psi and good fuel/timing curves, something tells me i cant find ideal maps out there though. so i should probably wait to do upipe etc if i am going to get it tuned, but if i go opensource, i could tune it now, then reflash later when i do more mods, that is a big advantage. im not sure what to do
Update WJM-i finally figured out why the boost gauge was giving problems despite being tested against other gauges. Inside of the T they had the line ran with was a tiny restrictor, killing the reading. Now, with it Teed into the bov with a new T and line, i am having boost jumping from 14-10-14-10-14-10 infinitely. so, i concur that i need a tune. Let me know what you think about the tune, where to take it, what to do prior to a stage 2 and 16-17 lbs.
Top Speed...AFTER you install an uppipe...either gutted stock unit, or ebay special/random tech/turbo xs/etc. Basically, do all your mods before you tune. SAFC's do nothing for the 1999+ SUBARUs. The ECUs learn around it in no time. I told you something was screwy with the 'boost gauge'... that restrictor does the trick everytime.
okay, i want to put an up pipe on it, but what other mods should i do along the same lines before a tune? Budget minded, i mean, you know along the same lines as i/h/e for any other car. I've read that, just to clarify, i wasn't suggesting using one on it, just previous experience. Yeah, i need to have more faith in my mod friendly SOG. I have heard so much about dealerships telling people boost problems are normal, i didn't give you the benefit of the doubt. My bad. On a side note, when you had my car, and i said it was making a clicking noise, im not sure you heard what i am hearing. It is a rotational click, (goes up and down with vehicle speed). IT doesnt matter if it isin or out of gear, or if the engine is running or not, and the application of brakes doesn't make a difference. IT sounds like it is in the front, like a rock stuck in the tire, but not. I put it up in the air and let it idle in first gear spinning all wheels, and it didnt do it, only on the ground. It is worse when it is cold in the morning, and i hear it rolling through a parking lot basically. IS this normal subie driveline noise or should i be worried? thanks, mark
Up-pipe, AND put your STOCK intake system back on. The stock airbox, stock in-fender snokrus, and the duct that goes from the snorkus to the radiator support on top-behind the grille. It makes a huge difference in every day driving-driveability. It allows cooler air into the engine more consistently. Also the design of the box creates a nice smooth laminar air flow across the MAF....which is HUGELY important. Well, dont expect that kind of work from SOG anymore. I'm the only person that would actually get the SSM3 AND my laptop out to data log the car and find out what the real problem is(exception, SS when he worked there). Asides from that, no other person at that dealership (again, except SS when he worked there) understands how everything really works with the ECU/boost/other engine control attributes...much less have their own laptop to begin with or how to work the SSM3 to log what needs to be logged. Indeed, most dealers are only interested in making quick money off of services: 15k, 30k, 60k, 90k, timing belt jobs, rotate/balance...etc. Those are the gravy jobs that pay nice and can be done fast. So when you give an average tech a modified turbo car...unless they have experience with the problem at hand and/or comprehend the exact operational functions of everything on the car...they usually try to blow it off as 'normal for the mods' or something else...and never fix the REAL problem. However, there are times that you come across someone who really knows whats what (if the dealer has a performance department, ppl like SS, myself, Jose at Koby, the people at Mastro in Tampa FL) and the problem is found and solved quickly. Your average aftermarket performance shop isnt going to know about SUBARU's either....unless they have a few years experience with working on them regularly. Places like BG, TS, Perrin, Cobb, (usually big name places) and others. But the local around the corner go fast shop is going to cause more harm than good. No dealership is 'mod friendly'...so to speak. SOA has guidelines and recommendations on how to deal with modified cars...however, each dealer is independently owned and has their own set of rules. Most dealers will not even work on a car if its modified. Otherwise, Steven (kingwrex) over at Classic would be my first choice to recommend people to if they wanted a SUBARU dealership in the ATL area to take their WRX/STi/RS/Legacy/Forester/etc to. I did notice that the transmission is making a lot of different noises...I never heard a clicking noise, but that doesnt mean its not there and i just didnt hear it over everything else. The level of noise from your transmission is concerning...however, since it shifted fine and otherwise felt smooth...the noise was not 'excessive' compared to the average noise level for mod'ed WRXs, alltho it is on the upper end of the tolerance. I'd be on the look out for a spare low mileage unit out of a stock car. Preferably from an early 04. The later 04's and up have different axles. The 06~07 has a different clutch setup and final drive ratio...the cost of that swap is considerably more than an early 04 trans.
thanks man, since i don't have the stock parts and would have to go buy them, wouldn't i be better off either plumbing cold air into that filter or running a cold air intake, or is the stock airbox not a power restriction at all. Okay, well im assuming (maybe wrongly) that if i have put 4500-5k on the car with the click that it is nothing major? maybe i will change the fluid, and run the old through a magnetized net and see if there is any metal in it. Also, 1 more question for you. a buddy jacked up my car on the rear diff the other day, and i feel like the back suspension is squeaking more now, did he do any damage? thanks for all the help, mark
Do some reading and tune it yourself...what you are describing to me sounds like your wastegate duty cycles are just too high or the turbo dynamics numbers are off. One thing that can make this happen is rapid changes in temperature outside...lately it has been swinging from 80+ during the day to 40-50 at night. This can play hell with the computer.
by the way guys, anyone who has been following this thread, I posted pics of said 03 with boost issues. lol http://www.wrxatlanta.com/forums/showthread.php?p=208180#post208180
I jack subarus by the rear diff all the time. no issues. Dont modify the dynamics tables if you do tune yourself...you'll need to turn the wastegate duty down a good bit for it to reach its stock targets. Or, just increase the target levels, tho I do NOT recommend that w/out having a wideband and EGT installed and capable of logging those along with logging the info found in the ecu. You can usually find said intake pieces for cheap or free from someone who has non-stock intake pieces.
WGDC - BOOST - PID - RPM - TPS they all go together you cannot just tweak one and not tweak the others. EQ. your map can say i want 20 psi at 3000 RPM your ecu will try to hit that number maxing your WGDC plus the PID but still not hitting but when 20 psi is hit but now its 4000 RPM you have another WGDC# and PSI and it will try to chase it again and its all over the place. What im trying to say is that there are more than just numbers on the map. you cannot just use target values and not know what are your limitations and capability of your vehicle. If you do not understand and realize its more than just one table and 3d maps then its better to get it tuned by a professional that does this for a living, than screw it all up and "kaboom" Personally i thnk your car has a few mods but the ECU is not tuned for the mods.
I haven't read the whole post, but make sure it's a WRX 1.30mm restrictor, *NOT* an STi 1.00mm restrictor. Siegel
Exactly. Alltho if all you want to do is make the car hit stock boost levels...then the wastegate duty table is all you need. More boost=fuel/timing/target/WGDC...and more. That makes a HUGE difference. However, his car has a stock size pill...its not all over the place like others with the sti pill untuned that i've seen. It'll hit its target after a few (2~4) oscillations. Edit: importracer689, you should double check the pill JUST to be sure...
thanks man, i guess its just my shitty blown stock struts with those springs/perches i believe im going to get it tuned, just a stage 2, then later when i mod it more (starting with a new shortblock), i will get into some custom tuning. thanks
okay, i will get the part number when i get home and post it yeah, see i want a tiny more boost than stock, like an average "stage 2" map, around 15psi, and a tune to compensate. at this juncture i do not want to deal with tuning it myself, but later, when 1. it is 100% paid for, and 2. i dont rely on it for 400 or so miles a week.