iNVAR Posted July 30, 2012 Share Posted July 30, 2012 Maybe the gas in his area just sucks. Where are you located? Try using the 91 ACN map instead. Link to comment Share on other sites More sharing options...
ssbtech Posted July 30, 2012 Author Share Posted July 30, 2012 Gas is fine here, top tier Shell, Chevron, etc.. Always use 91 octane and am running the COBB stage 1 91 octane map. Link to comment Share on other sites More sharing options...
bmx045 Posted July 30, 2012 Share Posted July 30, 2012 oil consumption? how much? spark plugs? Link to comment Share on other sites More sharing options...
iNVAR Posted July 30, 2012 Share Posted July 30, 2012 Two LVs today, one pre-log and one post-log. Since reinstalling the air intake resonator and removing the rattling engine cover, FBKC hasn't gone past -4 now. Time to dig deeper for a heat shield rattle, although my logs when it rattles show no FBKC. Well, here's what I see. 1) Lots of knocking. 2) You're maxing out your wastegate. See how it sits at 72.16? That's not normal. I'm inclined to say you have a boost leak. I know I said that I didn't think it was a boost leak several pages ago, but now I do. Link to comment Share on other sites More sharing options...
iNVAR Posted July 30, 2012 Share Posted July 30, 2012 For comparison: I took this log 3 years and 8 days ago when I was Cobb Stage 1, 91 octane map, bone stock everything else. You can see how the weather is based on the IAT. The logging interval is kind of big because this was before RR had fast polling, and I logged way too much stuff. Still, look at the numbers. What's the weather like where you are? And prior to your latest log, was the car heatsoaked?day 3 - stage 1 91 oct 3rd wot.csv Link to comment Share on other sites More sharing options...
ssbtech Posted July 30, 2012 Author Share Posted July 30, 2012 oil consumption? how much? spark plugs? Very little oil consumption. Going by the dipstick the oil is still just above the full mark after 4,000km. Due for an oil change in 2,000km. Spark plugs were done at 96,000km, car is at 149,900km today. I'm thinking of having the dealer do a compression or leakdown test at my 152,000km service and they can look at the plugs then. Well, here's what I see. 1) Lots of knocking. 2) You're maxing out your wastegate. See how it sits at 72.16? That's not normal. I'm inclined to say you have a boost leak. I know I said that I didn't think it was a boost leak several pages ago, but now I do. So if the wastegate opens to divert exhaust away from the turbine, the WGDC must be the percantage closed? Manifold relitave pressure is hitting 15.5 PSI, so I'm assuming that the wastegate closes up to force more exhaust over the turbine to build more pressure to achieve the target boost. I'm struggling a bit to understand how all the functions relate to one another. If there was no boost leak, would you be expecting to see a lower WGDC? What's the weather like where you are? And prior to your latest log, was the car heatsoaked? Temps have been around 70-80F for the logs. Heatsoak is doubtful as I wasn't stopped prior to the logs. Link to comment Share on other sites More sharing options...
iNVAR Posted July 30, 2012 Share Posted July 30, 2012 http://www.cobbtuning.com/Technical-Articles-s/70674.htm This will explain it all. If you're still confused after reading this, I'll explain. Link to comment Share on other sites More sharing options...
ssbtech Posted July 30, 2012 Author Share Posted July 30, 2012 Wastegate Solenoid Valve - An electromagnetic solenoid which controls the air flow from the wastegate actuator to the turbo inlet. This device is normally closed when no voltage is applied. When 12V direct current (DC) voltage is applied, by the drivers in the electronic control module (ECM), to the wastegate solenoid valve, it fully opens allowing air to pass through the device. A 0% Wastegate Duty Cycle (WGDC) setting will allow the solenoid to stay fully closed; which will force the turbo to run mechanical boost pressure. A 100% WGDC setting will force the solenoid to stay fully open; which will force the turbo to run maximum boost pressure. Thinking out loud here... Ok, so 0% WGDC means no vacuum in the wastegate actuator canister which, judging by the way the wastegate flapper moves means the wastegate is fully open. 100% WGDC means maximum vacuum at the actuator = closed flapper = all exhaust gas directed to the turbine. But looking at the pictures, when the turbo is generating pressure it would be forcing the flapper open if the WGDC is at 0%. This is worse than a brainteaser Link to comment Share on other sites More sharing options...
iNVAR Posted July 30, 2012 Share Posted July 30, 2012 Key thing to remember: when the wastegate flapper is shut, EG goes through your turbine, which produces more boost. At 100% WGDC, your flapper is supposed to be shut tight, which means you're attempting to produce boost.it's not vacuum that controls the WG. it's BOOST that controls it, which I'll explain below. As for the rest, you really have to understand the plumbing of the turbo. In a stock setup, there is a line that comes from the compressor of the turbo. That line is split in two; one split goes to the solenoid (BCS) and the other goes to the wastegate actuator. The wastegate actuator is attached to the flapper, and the actuator is spring loaded SHUT. On the stock setup, I believe the spring is about 12 lbs, but I'm not sure. This means that the actuator will stay shut until about 12 lbs of pressure pushes on it. There is exhaust gas that pressures against the flapper. When your car is idling, this EG pressure is pretty low and the wastegate will stay shut. When your BCS WGDC is 0%, this means that the solenoid valve is *shut* and when it's at 100% WGDC, it means that the solenoid valve is open. When your turbo spools up and starts producing boost, when your BCS is at 0% WGDC, the valve is shut and therefore all the boost pressure that the turbo is produced is in that line coming from the compressor (the one with the T in it) and all the boost pressure from the compressor goes to your WG actuator and pushes against that 10-12 lb spring. However, when the WGDC is at 100%, the solenoid is energized and therefore the valve in it is open all the way and is bleeding the pressure from that line. The BCS sends that air back into the intake track. Meanwhile, your WG flapper is being held shut by the spring on the actuator and the only pressure that 10-12 lbs spring is fighting against is the EG pressure. If you're with me so far, at this point you should start realizing on your own that in order for the WG flapper to even be opened, you actually have to be producing boost first to push the arm open. The amount of boost necessary to crack open the flapper is called "wastegate pressure" which you hear a lot of people refer to. A stock VF40's wastegate pressure is somewhere between 7-9 lbs depending on the engine load you're seeing. It's less than 10-12 lbs on the spring because the pressure required is that spring's 10-12 lbs minus the EG pressure behind the flapper. When your ECU goes into limp mode, you'll run WG pressure, which means the solenoid is shut off, and therefore the pressure on that line will be pushing against the WG actuator, which will open the WG flapper. The more boost the turbo produces, the more it'll open that flapper, which means more EG will bypass the turbine, and prevent the turbo from producing more boost. Link to comment Share on other sites More sharing options...
ssbtech Posted July 30, 2012 Author Share Posted July 30, 2012 So is the wastegate solenoid either open or closed, or is it vairable from 0-100? Is the WGDC value recorded in the log referring to the wastegate solenoid valve or the wastegate position itself? And what about the 72% WGDC in my logs suggests a boost leak? I'm assuming this number should be 100% instead of 72, and that the boost leak is preventing enough pressure to build in order to achieve 100% WGDC? Link to comment Share on other sites More sharing options...
bmx045 Posted July 30, 2012 Share Posted July 30, 2012 72 is YOUR cap Link to comment Share on other sites More sharing options...
iNVAR Posted July 31, 2012 Share Posted July 31, 2012 So is the wastegate solenoid either open or closed, or is it vairable from 0-100?Technically, the solenoid is either on or off, but the higher the duty cycle, the more frequently it's on so it has the effect of being variable then. Is the WGDC value recorded in the log referring to the wastegate solenoid valve or the wastegate position itself? The value recorded is the DUTY CYCLE (hence the DC) of the solenoid. http://en.wikipedia.org/wiki/Duty_cycle And what about the 72% WGDC in my logs suggests a boost leak? I'm assuming this number should be 100% instead of 72, and that the boost leak is preventing enough pressure to build in order to achieve 100% WGDC?No, it shouldn't be 100%. You're still not getting it. There are certain tables that cap your WGDC. Your cap at that particular area is 72%. The point is that you shouldn't be hitting that cap and STAYING at it for that long, because it means your ECU is unable to add more WGDC to shut the WG flapper more to produce more boost and that's why you're underboosting. If a car (mine) produces 14-15 lbs of boost at 69-70% WGDC and it's known to be good, and now you're running the exact same setup and you're hitting the cap at 72% and STILL aren't able to hit your targets... it raises questions. Let me ask you... That last log you pulled, were you on a straight and LEVEL road? Because that matters, a lot. Temperature matters too. If it's really hot, or you were on a downhill slope when you did the pull, that'll throw things off big time. Link to comment Share on other sites More sharing options...
ssbtech Posted July 31, 2012 Author Share Posted July 31, 2012 No, I know I'm not getting it. I don't know what my target boost is supposed to be or how you know it's not reaching that. The last log wasn't on a level road, it was an incline. It wasn't too hot either, 70-80F as mentioned above. Link to comment Share on other sites More sharing options...
ssbtech Posted July 31, 2012 Author Share Posted July 31, 2012 Duh... Target boost = boost error-actual boost. Link to comment Share on other sites More sharing options...
bmx045 Posted July 31, 2012 Share Posted July 31, 2012 You can log target boost you know... Link to comment Share on other sites More sharing options...
ssbtech Posted July 31, 2012 Author Share Posted July 31, 2012 Ok, I think I'm getting it now... Boost pressure forces the wastegate open, the wastegate solenoid valve operates to reduce pressure in the line keeping the wastegate open thus closing the wastegate and allowing the intake pressure to build. The wastegate solenoid is essentially acting as a valve that in my case is 72% open. Link to comment Share on other sites More sharing options...
iNVAR Posted July 31, 2012 Share Posted July 31, 2012 Yes, but it's actually the other way around. The solenoid activates to *increase* pressure in the line. At 0% WGDC, all the pressure stays in the line which forces the WG door to open. At 100%, all the pressure (or as much of it as the setup allows) is bled away. This is where the difference between a 2 port and 3 port is. 2 port setup (which is what OEM is) bleeds pressure away. 3 port setup actually blocks off pressure completely. Link to comment Share on other sites More sharing options...
ssbtech Posted July 31, 2012 Author Share Posted July 31, 2012 Ok, phew. Now that that's out of the way, back to why my car stinks of sulphur and is knocking Link to comment Share on other sites More sharing options...
bmx045 Posted July 31, 2012 Share Posted July 31, 2012 Clogged cat? Link to comment Share on other sites More sharing options...
iNVAR Posted July 31, 2012 Share Posted July 31, 2012 ^-- That's a possibility too I suppose. Either way, your boost isn't developing properly. You were going uphill. That should allow you to build up boost quicker and harder. You should need LESS WGDC as a result. Link to comment Share on other sites More sharing options...
DocHolladay23 Posted July 31, 2012 Share Posted July 31, 2012 iNVAR and bmx, without thanking all of your recent posts I just want to say thanks for the information. You're a great help to tuning n00bs like myself. Now if you (bmx) would just stop getting yourself banned we'd be in an even better position! [sIGPIC][/sIGPIC] You want stickers? Hit me up here!!! You want a shirt? Hit me up here!!! Link to comment Share on other sites More sharing options...
iNVAR Posted July 31, 2012 Share Posted July 31, 2012 Ok, I think I'm getting it now... Boost pressure forces the wastegate open, the wastegate solenoid valve operates to reduce pressure in the line keeping the wastegate open thus closing the wastegate and allowing the intake pressure to build. The wastegate solenoid is essentially acting as a valve that in my case is 72% open.Just read this again. Yeah, pay attention to my post right after yours. You have things backwards here. You can think of the 72% as how *shut* your WG door is. At 100%, your WG door should basically be shut completely, therefore producing maximum boost. iNVAR and bmx, without thanking all of your recent posts I just want to say thanks for the information. You're a great help to tuning n00bs like myself. Now if you (bmx) would just stop getting yourself banned we'd be in an even better position! Meh, no big deal. I try to pass on what I learned from reading and from other people helping me out too. Link to comment Share on other sites More sharing options...
ssbtech Posted July 31, 2012 Author Share Posted July 31, 2012 Well it's a lot to get your head around, that's for sure I do appreciate the information, I hate being such an info-leech As for the sulphur smell - clogged cat? really? I know that sulphur is a by-product of the catalyst process, I don't see how a clogged cat would still allow enough exhaust past to (nearly) hit target boost yet cause a leak pre-cat that's getting picked up and sucked in by the cabin air intake. One mechanic at the dealer said sulphur smell is normal - to a degree he's right, but I've had the car for 8 years and I know how much smell is normal for that car. It's significantly worse than it ever was, even on the same hilly highway that I've driven well over 1,000 times. All I can think of is unburned fuel making it to the cat. That would have been explained by the fouled injector (too lean, not combusting, passing onto and being burned in the cat) but now that the injector is good, that makes no sense. No other misfires being detected on the roughness monitor that I can see, at least on idle anyway. I should log that a few more times. Link to comment Share on other sites More sharing options...
fahr_side Posted July 31, 2012 Share Posted July 31, 2012 You're over-thinking this issue with the pre-turbo cat. There are a number of reasons it could be blocked. Fact is that healthy or not it slows spool and costs you power and efficiency. They do sometimes fail dramatically and destroy a turbo with shrapnel. Just get rid of it already. iNVAR is probably correct and you have a leak somewhere. If you're pegged at your maximum WGDC and still falling short of your boost targets you can look for the following problems: 1. Exhaust leak pre-turbo. You fail to build enough pressure in the exhaust manifold to drive the turbine to create the boost you're targeting and could hit before. 2. Air leak post-turbo. You're spinning the turbo hard enough but the air bleeds out of the intake system and doesn't pressurize the intake manifold. The boost control system sees the problem but doesn't understand the cause. The turbo gets pushed to limits set by the boost control system (maximum WGDC) to try and hit the target and still fails. As a side-effect the air that's been drawn through the MAF sensor is still being fueled for, even the air is leaking out before it reaches the cylinders. Now you're spraying fuel to burn air that isn't there, so you run rich. Of course without a WBO2 sensor you can't see this because the dumb OE O2 sensor in the exhaust manifold is basically blind under boost. 3. Your pre-turbo cat is so clogged that it's drastically reducing exhaust flow to the turbo. This causes late spool (see how your boost error does not drop below 1psi until 3,426rpm? On a stock turbo car you should see peak boost by 2k0rpm!). It also causes the boost control system to wastegate much less, in order to try to reach target, meaning WGDC climbs to compensate for the lack of exhaust flow / energy. A clogged cat can also prevent all of your exhaust gas escaping from the cylinders, which dilutes the incoming mixture and increases exhaust gas temperature. That in turn can cause knock, even though your AFR is correct (any leaks notwithstanding). Do a leak test on the intake system to cross #2 off your list. I'm recommending you just ditch the pre-turbo cat because it will save you headache down the road if it disintegrates, it will fix issue #3 if clogged, and swapping it / replacing the gaskets assures you on issue #1. It is possible that your clogged cat is causing a leak at say the manifold / up-pipe joint. It doesn't have to leak much to smell it in the cabin and a small leak will delay spool badly but still allow you somewhere close to target boost at higher revs. I've seen this many times. In your position I'd get a proper intake leak test done first. If that comes up healthy replace the up-pipe and downpipe at the same time. Catted or uncatted DP is your choice. Then get a pro tune for stage 2. If you're in a full-on smog nazi state and afraid of the man, or don't want to change parts / bribe people for inspection, then either gut your up-pipe (difficult) or get an oem catless one. Then go get a pro tune for stage 1. Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs. Link to comment Share on other sites More sharing options...
ssbtech Posted July 31, 2012 Author Share Posted July 31, 2012 Thanks, that makes sense now. I'm not going stage 2, I can't afford a clutch that will hold it at nor do I have tuners around here. Cobb stage 1 is what I have to work with. I'll see about having the dealer stick in an OEM catless up-pipe when I take it in. Link to comment Share on other sites More sharing options...
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