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Where is your WB02 located? Brand/age? I wonder if this could be my issues as well. Hard to read plug fueling with E85. I rely too much on a single sensor placed 4" down stream of the turbo with an open 7" worth of dump pipe. I'll order a new sensor for kicks and see if it changes. It's past due anyway. Thanks for the update.
WB is maybe 20ish " from back of turbo in DP. It's a fairly new AEM with maybe 2500 miles on it.
As mentioned, my VE table is essentially flat. I ended up still rich on the dyno but idle cells are 40-45% (14.7) and 180kpa at 5-6.2k are low 60's (mid to low 10's)...again still really fat. Tailpipe WB from dyno was reading high 10's/low 11's and was all sooty after my 7 pulls so I have to believe my in car one is real.
Just make sure when your in car WB says anything below 11.4, that TS is actually reading this. Mine was not with the factory "AEM 42xxx" calibration. I had to put in custom values noted above to get it to read 11.4-10.8 with the WB. Below 10.8 on my in car WB and TS stays at 10.8.
That's why I also posted in the other thread about melting pistons...my car would intermittently hick-up, seemed like a plug/wire issue honestly because I have been fighting that...but it still felt "clean" at mid 9's actual AFR, just stopped gaining RPM.
Good luck and let me know what you find out please. Also please let me know if you are "including AFR" and "multiply VE". I believe you said you were but just double checking.
Man, so much intense double rainbow action in this thread...it's almost a triple.
Got my dyno sheets....comparing pull 1 & 7. PTC converter flashes to about 5200rpm btw.
Only change was ~25% removal of fuel. I wasn't sure which WB reading to believe so I stopped without cranking the boost up or adding more timing. This is the tailpipe WB btw.
Planning to buy some tires now so I can run it at the track to see what it's really putting down.
Also looking at upgrading this 79/68 turbine...I am self conscious about the size of my turbine.....it keeps me up at night.
Forced....you get a chance to try a new WB sensor?
And here is vs RPM to see the 5,500rpm "wall" I was talking about, 1st pull versus last. I am assuming most of the falling off up top is due to my turbo and not the fat AFR....but I'll let the expert turbo folks chime in on that one.
Man, so much intense double rainbow action in this thread...it's almost a triple.
Got my dyno sheets....comparing pull 1 & 7. PTC converter flashes to about 5200rpm btw.
Only change was ~25% removal of fuel. I wasn't sure which WB reading to believe so I stopped without cranking the boost up or adding more timing. This is the tailpipe WB btw.
Planning to buy some tires now so I can run it at the track to see what it's really putting down.
Also looking at upgrading this 79/68 turbine...I am self conscious about the size of my turbine.....it keeps me up at night.
Forced....you get a chance to try a new WB sensor?
It's quite apparent from that red AFR trace that something is fucked, and the problem with people using silly widebands not calibrated to a sensible range for tuning highlighted by the fact it is pegged at 10 with a total flatline. And when you then say you pulled 25%, which is absolutely huge...your AFR before was likely way down in the 8's or something, so would have been running terribly. Once tuned you should never need a wideband to read below 10....but it's always good to have it able to read down to say 9, just in case it is running very badly so it's easy for you to see it is well fucked up and how badly. But a lot using a simple analogue output for their display are often pre-set to read in the range 10-20 only...which isnt always good enough.
That sensor may be shot if its been hanging out seeing 8's AFR lol. And I always prefer digital wideband output over analog. Too much concern around differences in ground causing offset issues which throw off real AFR.
To make sure we are all on the same page. The first dyno pull off the street is the red line in both graphs....so HP, TQ, RPM & AFR. The car ran clean up top but seemed to just hang out at 5,500 and never really rev out to the limiter. Plugs looked rich but safe based on what I could find on the interweb. My WB display was kind of hidden (went for the sleeper look) and always read well within .1 AFR of TS when I compared them during normal driving and light load so I ASSumed it was correct from 10.0-20.0. Problem was, once I moved the gauge and got on a dyno where I could watch it without having to watch the road, I found that it was pegging low when I went WOT and TS only followed it down to the 11.4 range, after that, the WB kept going richer yet TS would stay at 11.4.
The hook in the red HP & TQ graph are the beginnings of the "wall" I mentioned. In my log you can actually see where RPM drops a little then picks back up the longer I stay in it. The dyno reflects that.
The green in all of the graphs is the last pull after pulling a lot of fuel out. To reiterate, the AFR you are seeing on the graph is the tailpipe sensor on the dyno, my in-car gauge displayed low 10's and TS said 11.4. I didn't pick up much HP between run 6 and 7 so I stopped there as I didn't trust any of the WB readings. I would think low 10's actual AFR would still make the car run like crap, but it doesn't.
I have since rescaled my WB so that now TS at least reads down to 10.8 when my in-car WB says 10.8, any richer and TS stays at 10.8.
I took some timing out and ran the car on the street without meth/water injection and I am nearly as lean on the VE as I was with the injection. This makes sense with the small amount I am spraying.Warning, my VE table is a mess…I know…but the idle cells, cruise & light load are all right where I want them. It’s hard to do any tuning in the other areas with a 5200 stall and quick spooling turbo. The circled part is the only area I leaned out on the dyno. If my WB is correct, they actually need to be lower…which will make my VE table essentially flat, not the typical looking table I see in other tunes.This also had me worried to go any further on the dyno as it doesn’t make sense.Through my searching, the only things I found that could contribute would be that I am “including AFR” so the VE table is multiplied by target AFR/Stoich AFR, which would lower my actual VE number.I am also running a 1:1 fuel pressure regulator and FAST 85lb Ls2 injectors…which are really just stock, de-capped Ls2 injectors.Some on the megasquirt forums said de-capped high impedance injectors sometimes do weird things at the higher dwell and flow increases significantly.This would also lower my VE more than usual. Hope that novel clears things up.
EDIT, not sure what's up with the bold or lack of spacing and grammar lol
ddnspider, thanks for the response. I will be getting another sensor to try as well. I have not searched it, so forgive me, but how do I switch to digital input for the MS3 with this AEM WB, or can I? I guess I have to setup the CAN interface?
Ah crap, my bad. I forgot you were on MS3, I don't know that system. I use EFI Live with stock PCM and just plug right in with a digital input. Your novel is interesting. I would also be careful about tailpipe readings as I've seen them off by a point (reads lean) compared to up at the header. It sounds odd that it "runs well" with such a rich AFR, which is why it sounds like something maybe be fooling you to think it wants to run that rich, but it really doesnt. Low 10's, and pulling 25% of fuel, and I'm surprised you weren't getting rich knock.
I haven't had a chance to play with car yet. New LSU 4.9 sensor is here though. ( I run a PLX devices WB02 on the Rx-7) Is your WG recirculated? Leaks in the exhaust system? Either of those will cause the tail pipe sensor to read lean. The bigger the leak, the leaner the reading. My DP is super short and at idle/cruise with the dump open/closed the AFR will swing quite a bit... I always assumed this was just "free air" getting in there. But at WOT it's always been stable. I assumed this was because free air could not reach it then. Can't see it, but the sensor is about 6" down form the 90* bend.
The WB02 calibration thing seems off to me. It should be linear curve on that sensor. 1-5 v 10:1 to 20:1 I run the same AEM setup in the mustang. Anything richer than 10.0 wont' display, but as mentioned you won't ever be there with a decent tune anyway. If you don't have the sensor calibrated that way, I'd say you have some kind of weird voltage offset going on. Where do you pick up your 5v source? Have you logged that sources voltage at RPM by chance? Should always be pretty rock steady at 5v.
Last edited by Forcefed86; 07-26-2018 at 12:55 PM.
Thanks for the response. WG is dumped, not recirculated. The shop owner said he typically sees ~.5 AFR ratio leaner at tailpipe....my car was a little more but I did not do a thorough job of welding up things after the mufflers...so I am sure I am getting some air in there. Nonetheless I would have kept going until the tailpipe read 11.4-5 and still would have been safe, but the look of my VE table and not knowing true AFR without the meth kept me from going farther on the dyno. I now know that meth was not the issue.
As far as the calibration, I have logged WB voltage and the lowest it ever got was around .68v...never 0v...so you may be on to something with the voltage offset. Right now my calibration is the same at 20v as the manual says but I believe it's ~9.2 AFR for 0v. Both TS and my WB agree everywhere except below 10.8. According to the megasquirt forums, this is a common problem with the AEM and TS not agreeing with the factory calibration settings. My voltage findings matched the post numbers to use within a tenth or so.
Right now I have the AEM powered by the same 12v source as my goldbox. I didn't think the AEM gauge would work if I gave it 5v from TPSref, nor would the current capacity be enough to power the sensor. All grounds for goldbox and the sensor are at the same spot on the back of the DS head. As far as I know, the AEM doesn't have a way to power the controller with 12v and the 0-5v signal with the TPSref but I would love to be wrong.
I believe the WB is accurate at idle & cruise as I can tell by the way the car runs when I swing the WB lean or rich with my tune. When I was messing with the calibration, I was forcing a 10.5 AFR at part throttle and could smell the fuel and tell the car was loading up.
I am sure you found a good price on the sensor, would you mind PM'ing me your source?
You are right, I had a brain fart. Been working with pressure sensors lately and I tap the 5v ref for them. I believe the WB02 controller in the gauge regulates voltage for the sensor. Which is why the output is 0-5v. So the voltage regulator in built into your gauge and likely just fine. Even with a varying bat 12-14v supply. You’d have to check voltage at the sensor plug to verify.
Really didn’t find a great deal but PLX devices has the 4.9 LSU for $60 now.
That sensor may be shot if its been hanging out seeing 8's AFR lol. And I always prefer digital wideband output over analog. Too much concern around differences in ground causing offset issues which throw off real AFR.
he isnt seeing 8's..it's flatlined at 10 dead...so it could be 8...9...7..6...etc He can never know without a proper reading
Thanks for the response. WG is dumped, not recirculated. The shop owner said he typically sees ~.5 AFR ratio leaner at tailpipe....my car was a little more but I did not do a thorough job of welding up things after the mufflers...so I am sure I am getting some air in there. Nonetheless I would have kept going until the tailpipe read 11.4-5 and still would have been safe, but the look of my VE table and not knowing true AFR without the meth kept me from going farther on the dyno. I now know that meth was not the issue.
As far as the calibration, I have logged WB voltage and the lowest it ever got was around .68v...never 0v...so you may be on to something with the voltage offset. Right now my calibration is the same at 20v as the manual says but I believe it's ~9.2 AFR for 0v. Both TS and my WB agree everywhere except below 10.8. According to the megasquirt forums, this is a common problem with the AEM and TS not agreeing with the factory calibration settings. My voltage findings matched the post numbers to use within a tenth or so.
Right now I have the AEM powered by the same 12v source as my goldbox. I didn't think the AEM gauge would work if I gave it 5v from TPSref, nor would the current capacity be enough to power the sensor. All grounds for goldbox and the sensor are at the same spot on the back of the DS head. As far as I know, the AEM doesn't have a way to power the controller with 12v and the 0-5v signal with the TPSref but I would love to be wrong.
I believe the WB is accurate at idle & cruise as I can tell by the way the car runs when I swing the WB lean or rich with my tune. When I was messing with the calibration, I was forcing a 10.5 AFR at part throttle and could smell the fuel and tell the car was loading up.
I am sure you found a good price on the sensor, would you mind PM'ing me your source?
You're making little sense. Whether front of car or tailpipe makes no difference...the exhaust composition doesnt magically change over that relatively short distance. Readings should be the same ( although yes if there are air leaks that will **** up the readings at the tailpipe. Simple solution...dont have air leaks and if there are, do not use the tailpipe )
And in no way whatsoever should you be trying to feed 5v from anywhere into a wideband controller. Instructions will be clear, they are all powered from an ign 12v source. The only interconnection with an ecu/logger etc should be the analogue 0-5v out from controller to ecu ( and sometimes they'll offer a ground to go with that which you'd share with the ecu sensor ground )
Or of course if there is a serial/digital/CAN comms option.
With analogues, these should always be manually verified that what the display is telling you...is matched on the external device.
And what are you saying has the same calibration at 20v ? Nothing on the car/wideband or whatever should ever be reading 20v.
To be clear, my AFR was something <10....it is not anymore and I believe my AEM is giving me a reading fairly close to what it actually is (still going to try another sensor for an additional data point), my issue was was just what TS was seeing below 11.4. When I first wired the car up and it was NA, I ensured that the WB and TS were reading the same, and they were, but being NA, the AFR never got richer than 12.5. My fault for assuming that they would match the entire range of 10.1 to 20.1.
The 20v comment was a typo, I meant to say my calibration is 0v=9.29AFR and 5v=20AFR...with the later being what the default is, just the low side was tweaked.
I only made the comment/question about the 5v to the WB because I did this with a speed sensor that was "12v" and it works great....however a speed sensor is vastly different than a WB...so I was thinking someone had figured out how to disassemble the gauge and separate the two internal power sources or the like.
I paid for an hour on the dyno with me doing the tuning. The shop owner asked me if I wanted the tailpipe WB...since it didn't cost me any extra, I said sure....more data the better. I understand the chemical composition of the exhaust does not change but I would say the probability of leaks and air contamination would get higher, the farther you go with your exhaust (more welded joints, more chances for leaks). The only "free time" I get to work on the car is between the hours of 10p & 5am...I will not be burning midnight hours to de-sloppy my catback. Pre-turbo to turbo to DP to 6' after the WB is leak-free for sure and has been verified, the catback was just quickly/crudely added to knock the noise down.
It's a freaken miracle that the car even moves under it's own power given my schedule.
To bring this full circle, my AEM WB after the turbo read 10.2-10.4 and the tailpipe sensor after 12' of exhaust and most definite air leaks was 10.9-11.0...I have come to the conclusion that my actual AFR is somewhere in that range, most likely low-mid 10's. My hope is that Forcefed will find something with his tune related to the WB as I seem to have had the same issue as him....the hanging rpm/wall. My converter and valve springs were not the issue, nor was the Goldbox.
07-11-2018, 01:06 PM
