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Old 12-24-2015, 09:08 PM   #41
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Originally Posted by aceswerling View Post
Oh, wow. Thanks for the feedback. That's sure not what I wanted to hear since I had the ECU professionally tuned to avoid this kind of trouble.

I'm confused about what you're saying because I'm not hearing any detonation at all and the car feels really strong. Also, when I look at that log, I see RPMs and boost gaining until I let off the throttle. Soon afterwards I see the boost drop first, followed quickly by RPMs. I also figure that an AFR of 12.0 is about right as well. Isn't that what I should expect?

Based on your suggestion, I'd expect to see RPMs drop before boost. No?

I know the tuner messed around with timing so that the numbers in the table are offset by an equal number of degrees in the base timing. So basically, he set the base timing offset from TDC where you'd otherwise expect and then added that offset to the timing table. Based on my own experiments, I believe his offset is about 10*. I don't fully understand his logic, but perhaps that accounts for the weird timing number?
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Oh, I see. You're talking about the bit that starts at 1919 seconds and goes to 1921. I thought you were talking about the curves that finished at 1919 seconds.

Even so, it appears to me that during those 3 seconds, I hit the gas, the boost went up, and then RPMs went up with a little lag. I'm still not seeing where RPMs were dropping where I was giving the car some gas so I'm not able to see where the detonation would be.
Check your timing with a timing light. It's easy to do and it's covered here many times. Do that, make sure the numbers match, adjust if necessary.

This is what i was referring to.



Best case scenario is a terrible misfire. But if you're running anything close to the timing your log shows, it's detonation city.
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Old 12-24-2015, 09:10 PM   #42
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That's a shitload of timing still. Basemap is like 16 degrees there
I run 20 degrees at that spot on E85 with 9:1 compression and a built motor. About 16-17 on pump gas.
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Old 12-24-2015, 09:15 PM   #43
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This is a pic of my car going from 1st through 4th. I used launch control on the start, so ignore the RPMs jumping around there as it's normal for launch control. But notice how the RPM trace is butter-smooth and only climbing up? That's how it's supposed to be.

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Old 12-25-2015, 04:08 PM   #44
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Thanks very much for taking the time to point out the problem. I wouldn't have seen that myself so I really appreciate your helping me learn.

Needless to say, this is very upsetting news since I paid a lot of money to avoid this situation. I'll share this feedback with my tuner when he's back in the shop on Monday. He's said that he's doing stuff in his tune that only makes sense if you know what's going on in his head. As an example, I put the timing light on the car at idle and was seeing the crank pulley ticks way off the TDC marks. In the Trigger Wizard, the Ignition Offset Angle is set to 6*. I had to change the offset to -4* to get the marks to line up. That's when he told me about his deliberate manipulation of those numbers in both the base timing and the timing table. So I know he's doing something but I don't understand what it is.

Regardless, I'll ask about the timing and what's up with the detonation. By itself that would tell us that the timing is incorrect even with the offset calculations, right?

If I don't get a decent answer then I'll likely tune it myself.

Last edited by aceswerling; 12-25-2015 at 04:20 PM.
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Old 12-25-2015, 04:20 PM   #45
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Based on what you just wrote, you're actually running 10* less timing that what your logs say (6 - -4 = 10). That means the "36" degrees in your log was actually 26. Less bad, but 26 is still wayyyy too much timing. I run 20 there on E85, 16-17 when on 93 Octane.

Pull the plugs and get a 10x magnification jewelers loupe and look at the porcelain of the plug. If it's detonated, you will see black specs on the white porcelain. If it's severe, you'll see little ***** of aluminum too. If you can see any of this without a 10x magnification your hammering the motor with detonation.
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Old 12-25-2015, 04:29 PM   #46
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Also as I said, the RPMs dropping in boost is one of two things, detonation, or a misfire. Either is bad, though detonation is worse as it's much more destructive. Reading the plugs will show you if the motor has detonated. If plugs are clean under 10x magnification and good lighting I'll be shocked. If it's a misfire it could be several things causing it, and it's not uncommon in the miata world as these cars have crap ignition coils from the factory.
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Old 12-25-2015, 05:00 PM   #47
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Yeah, that's what it sounds like with the timing. I asked about this, and like I said, I was told that he's doing stuff that can only make sense if I understand everything he's doing, which he didn't want to tell me.

But it sounds like the 10* offset might have been calculated incorrectly. If the timing is supposed to be 16* and we're seeing 36* in the log then perhaps he put a 20* offset in the ignition map instead of the 10* it should have been. Am I thinking about this right?

I just went outside and checked the #1 and #2 plugs. Both of them looked perfect, which is a relief. I'm running the FAB9 CoPs and we had some trouble with misfires that I thought had been fixed by switching to sequential ignition. I guess not, which means we've still got some work there. As you said, that's better than detonation, and we still appear to have a timing issue to fix.
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Old 12-25-2015, 05:15 PM   #48
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If you didn't use a 10x magnification and good lighting then you need to. Wrote all that out for a reason.
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Old 12-25-2015, 05:17 PM   #49
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Yes, I looked at them with a 10X magnifying glass in daylight. Thanks for making sure though.
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Old 12-26-2015, 03:27 AM   #50
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Pat has a true crank sensor, and you (likely) read off the timing belt still.

So, take what pat says about the smoothness of the RPM plot with a massive grain of salt.

Your tuner still sucks massive peen though, if he didn't set the trigger wheel he missed step 1. Whatever is going on in his head is irrelevant, it's built on bullshit. He likely won't admit it, he either doesn't know or doesn't care.
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Old 12-26-2015, 04:11 AM   #51
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Pat has a true crank sensor, and you (likely) read off the timing belt still.

So, take what pat says about the smoothness of the RPM plot with a massive grain of salt.
Your RPMs don't jump around like that from a cam angle sensor driven by a timing belt. If that sensor's RPM jumped around THAT Much on its own (sensor or timing belt inaccuracy), it wouldn't be accurate enough to predict timing of the crankshaft to within a degree or two.
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Old 12-26-2015, 04:20 AM   #52
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Mine do, my car does not detonate or misfire in boost. There's a reason I want a crank trigger wheel.

I also run 26degrees around 4k and 4psi, but I don't often see that cell and I'm on e85...
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Old 12-26-2015, 03:04 PM   #53
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Thanks for the input, guys. Yes, I'm running all the timing off the CAS and don't have a crank trigger wheel so I'm grateful for another explanation. For the record, my tuner warned about problems running timing off the CAS as opposed to the crank. You may recall from another thread that we determined the CAS was surely less accurate than the crank, but should be sufficient since many NAs run that way.

I'm not in a position to refute Deezum's opinion on my tuner since I'm not sure what he's doing. He's been working on my car for several months and I'm still seeing issues. That's sure not good. This thread has been very useful in helping me understand what might be going on. I'll bounce this off him and see what I make of his responses. Then I'll decide how to proceed.

In the meantime, can you guys think of why TunerStudio would be reporting AFRs .3 higher than the gauge is saying? Recall that if the gauge is showing 14.7 then TS is typically showing 15.0. I checked the calibration in TS and it appears most O2 sensors use the same voltages to correspond to AFRs so it seems like there shouldn't be much need for fiddling here.
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Old 12-26-2015, 03:18 PM   #54
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Quote:
Originally Posted by aceswerling View Post
Thanks for the input, guys. Yes, I'm running all the timing off the CAS and don't have a crank trigger wheel so I'm grateful for another explanation. For the record, my tuner warned about problems running timing off the CAS as opposed to the crank. You may recall from another thread that we determined the CAS was surely less accurate than the crank, but should be sufficient since many NAs run that way.

I'm not in a position to refute Deezum's opinion on my tuner since I'm not sure what he's doing. He's been working on my car for several months and I'm still seeing issues. That's sure not good. This thread has been very useful in helping me understand what might be going on. I'll bounce this off him and see what I make of his responses. Then I'll decide how to proceed.

In the meantime, can you guys think of why TunerStudio would be reporting AFRs .3 higher than the gauge is saying? Recall that if the gauge is showing 14.7 then TS is typically showing 15.0. I checked the calibration in TS and it appears most O2 sensors use the same voltages to correspond to AFRs so it seems like there shouldn't be much need for fiddling here.
It's not your CAS, it's impossible for your RPMs to drop by 100 RPMs WHILE ACCELERATING when under load due to belt stretch/CAS sensor inaccuracy, but at the same time the CAS be accurate enough to predict ignition timing withing a degree or two.

Fab9 coils are pretty but a terrible weak setup. Those coils are designed to be driven by a CDI (400+ Volts to coils) but are instead driven by an ignitior (12V to coils), that's your misfire problem. Stock coils are stronger than the Fab9 setup. Get a CDI ($$$) or a real ignition system upgrade. LS coils, FM big spark, IGN1A coils, etc.
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Old 12-26-2015, 05:35 PM   #55
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Well, that's disappointing since I got the Fab9 setup to avoid misfire under boost. But it's not a huge surprise considering some of the issues we've had with it. Bryan from Fab9 suggested playing with the dwell and duration a bit but my tuner found the suggested settings increased heat in the coils to an unacceptable level. His website also says the kit should support ~19psi with the included module. I guess that's not true, eh? I'd thought we'd fixed the misfires by switching to sequential spark but that appears not to be the case.

Either way, thanks for letting me know. I take it you're not a fan of the Toyota CoPs then?

Fab9 suggested an AEM Twin Fire module if more spark is needed from the system. It appears this would be the item in question. https://www.acceleratedperformance.c...odules-30-2821. So yes, pricey, but potentially less expensive than the FM kit since I already have the Fab9. On the other hand, it also appears to be discontinued from AEM, although I can't tell what they replaced it with.

Either way, it seems like this is a secondary problem to the fuel consumption at this moment. I'm seeing 3 issues that need to get resolved pertaining to that:
1. Understand why the AFR readings in TS are reading .3 leaner than the gauge.
2. Verify what's going on with the timing.
3. Retune with a leaner mixture in the 15.1 - 15.4 range as suggested.

Then I'll focus on the ignition and avoiding misfires.
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Old 12-26-2015, 05:58 PM   #56
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GL getting a CDI for under 600. That AEM one is impossible to get buy new, maybe you could find a used one though. Truth is nobody uses those anymore outside of bike engines.

I don't know much about the toyota COPs. I know the ones I listed are hot nasty coils that work- they can put out 100 mJ all day with 3ms dwell and 200+ with lots of dwell. I run mine at 3-4ms at cruise, 6ms at idle and very high load. 30 thousands plug gap. Might up that to 40, I tested it earlier this year and it took 5.5ms to fire a 40 plug gap with absolutely no misfires in boost at 28 PSI.

It's possible your car has a misfire at cruise. If so, that would absolutely affect your mileage in a negative way. So I wouldn't write that off as a secondary issue just yet. What spark plug gap do you run? What plugs?

I get 15-19 mixed driving on E85 with an extremely lossy suprecharger setup dragging my fuel economy down. And this is my AFR table.



EDIT: I'm only running 4.5ms of dwell at high load with .030 gap. Next set of plug I may go back to 40 and 6ms dwell up top, we'll see.
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Old 12-26-2015, 06:22 PM   #57
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I tried the fab9 coils with there old module. It did blow out spark above 6 psi. Fab9 sent me a new module to try. How old is your kit? Do you have there newest ignition module?
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Old 12-26-2015, 06:36 PM   #58
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Double post oops
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Old 12-26-2015, 06:39 PM   #59
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@patsmx5, I did find a couple of websites offering the AEM module for $400-$450 so maybe they're offering old stock. In any case, what are people using as replacements for these CDI modules?

Wouldn't I notice if I had a misfire at cruise? I sure noticed when I had the misfire issue with the Fab9 CoPs before and it seems like I'd notice even more under acceleration. More to the point, wouldn't misfires show up on the datalogs with squiggly RPM lines like you pointed out?

Right now, the MS is configured for 3.5ms dwell and 1.5ms duration, which is consistent with Bryan's suggestions. This is up from 3ms dwell before. I recall I'm running a .030 gap, although I can't remember for sure. The gap had been smaller before too.

@90_Turbo, I verified with Bryan that I have the newer module so I'm all good there.
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Old 12-26-2015, 06:48 PM   #60
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@patsmx5, I did find a couple of websites offering the AEM module for $400-$450 so maybe they're offering old stock. In any case, what are people using as replacements for these CDI modules?

Wouldn't I notice if I had a misfire at cruise? I sure noticed when I had the misfire issue with the Fab9 CoPs before and it seems like I'd notice even more under acceleration. More to the point, wouldn't misfires show up on the datalogs with squiggly RPM lines like you pointed out?

Right now, the MS is configured for 3.5ms dwell and 1.5ms duration, which is consistent with Bryan's suggestions. This is up from 3ms dwell before. I recall I'm running a .030 gap, although I can't remember for sure. The gap had been smaller before too.

@90_Turbo, I verified with Bryan that I have the newer module so I'm all good there.
Motec makes a 4 cylinder CDI box but it's $$$. I would go with something cheaper like the coils I suggested before I did a CDI.

You posted a log here with a misfire in it and you didn't know it. So I can't say you would notice it at cruise.

Look at the pic of the log I posted. See how the RPMs are smooth, and the AFR trace (second graph, white trace) is dead-flat smooth too? That's because I don't have a misfire. Open your log and look at yours and compare. RPM and AFR jumping around is the common sign of a misfire. And **** mileage. Could be something else but you've got 3 out of 3 on obvious signs of a misfire.

If you have stock coils try them. Or try gapping your plugs to .020 and see if it's any better. Or just put some better coils on there. Or run more fuel in cruise, it's easier to light off a 14.7 mixture vs a leaner one thus less chance for a misfire.
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