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I have gone to a tuner shop twice and had the same results of losing a lot of power right after 4K RPM. They originally claimed that I have valve float which I find hard to believe. I have checked my timing wheel and found it to be advanced, so I reset that, however I had my intake cam (MSM intake cam I ordered from you guys) advanced by 1 degree, cam gear is from FM, and my exhaust cam retarded by 1 degree, cam gear by Fidanza, The second time I went to the tuner, they tried to do a couple of pulls and still the same thing. However, now they claim that it could be a clogged catalytic converter, I will place a list of engine mods down below, right now I am letting the car cool off, they also claimed the cams are not timed properly, I explained to them that they were only off by one degree, as I explained earlier. I told them I can adjust them back to zero in literal seconds but they wouldn't let me back on due to another car needing to be tuned.
Here are the modifications for the engine:
Custom Short ram intake
Racing Beat 4-1 exhaust header
Flyin' Miata 2.25" exhaust with catalytic converter
MSM intake camshaft
Fidanza exhaust cam gear
FM intake cam gear
FM ignition timing wheel
Autoexe triple core spark plug wires
Megasquirt PNP2
Brisk Multi Spark plugs
MaxG water pump pulley
QMax coolant reroute.
Any other modifications are irrelevant to the engine.
Prior to the ECU, I was on the dyno as of March of 2021 and didn't see the HP drop in any of my range, I was at 126HP before the ECU, and the ECU was the last thing I have done.
I can send over the tune files (I believe this is it since I have yet to receive a copy of it let alone the datalog). I hope you can help me out here.
To answer questions:
I reset the ignition timing wheel back to 10 degrees BTDC. The intake cam was at 1 degree advanced, the exhaust was at 1 degree retard, reset those to zero after second dyno tune.
I will attach any info that I hope will be helpful to this forum. I apologize for the potato quality photos.
Thank you all for taking your time to read this and guide me through my odd enough struggles.
Update: I checked the catalytic converter to see if it was burned up. The honeycomb is still in good condition and you can see right through it no issue. This is a high flow from FM I ordered a few years ago. So the next step would be replacing spark plugs for a different brand. NGKs are next.
I have pulled my datalog info recently since the tuner has yet to send his. I was only able to pull on third gear because:
A. There was a giant *** truck on my *** and he wasn't having it
B. I was entering a toll road, and tolls are stupid expensive at the time.
C. Damnit I am in a Miata, give me some space!
Since last night: I have checked the catalytic converter, I can see through the honey comb just fine. My intake cam and exhaust cam are completely zeroed out, I verified that the markings all match up when it came to the timing belt. I reset the timing wheel to 10 degrees BTDC (back from 14 total). I am running 91 octane, have been for quite some time. I verified all connections with the ECU, MAP hose, the serial cable, everything. No vacuum leaks are present.
For those confused about this post, I have posted on this subreddit about my dyno concerns and losing power past 4K RPM. The build's info is on that post too. One thing that struck interesting to me is the spark advance (green noodle third chart) sticking at 29.4 degrees from 4-7K RPM. So my next step will be checking spark plugs. I know they are new spark plugs from Brisk, being the multi-spark style, if these are at the limit then I will be going NGKs, luckily they aren't expensive.
TLDR: Did a pull, retrieved the datalog from pull, no word from the tuner onto their datalog. Checked stuff and everything was good. This is the pull.
How are you handling the vics? Did you remember to switch the ignition timing from "fixed" to "use table" on your ms?
Alright, so the VICS is set to open at 5200 RPM, that basically wasn't touched, I talked to Greg Peters as well as Emilio on a different forum, and quite a few people. A lot of speculations on what is going on, the ignition timing is on "use table" as well. Long story short the tuner isn't tuning the VICS as well but that isn't the real issue here.
He would have had to, since although it flat lines, it’s changing a lot before that.
what altitude are you at? You hit a peak of 81kpa, which indicates you’re well above sea level, or youve for a nasty intake restriction.
Denver basically, the VICS is opening at 5200 RPM, but the tuner isn't tuning the ECU with the VICS. Or wait... Tuning the VICS to the ECU. That way. Before the ECU the engine was able to perform just perfectly fine.
Fair warning, you've got the terrible MAT air density table that comes with some of DIY's base maps. You'll regularly run in the 120-140 range on hot days, pulling 10-15% fuel. There's a lot of other changes I'd make, but that's a big one.
Nothing that would cause it to kill power like it is though. I might check your crank sensor gap to begin with, then start looking for a new tuner.
Fair warning, you've got the terrible MAT air density table that comes with some of DIY's base maps. You'll regularly run in the 120-140 range on hot days, pulling 10-15% fuel. There's a lot of other changes I'd make, but that's a big one.
Nothing that would cause it to kill power like it is though. I might check your crank sensor gap to begin with, then start looking for a new tuner.
I like how you suggested the crank sensor gap, ironically that has already been checked prior to the ECU ordeal since I swapped timing wheels when I was on stock ECU. I will begin checking other tuners as well and try a base line pull to see what happens.
Fair warning, you've got the terrible MAT air density table that comes with some of DIY's base maps. You'll regularly run in the 120-140 range on hot days, pulling 10-15% fuel. There's a lot of other changes I'd make, but that's a big one.
Nothing that would cause it to kill power like it is though. I might check your crank sensor gap to begin with, then start looking for a new tuner.
When you say MAT air density table, you're talking about the MAT based time retard right? If not then I may need to find where this table is at.
Fair warning, you've got the terrible MAT air density table that comes with some of DIY's base maps. You'll regularly run in the 120-140 range on hot days, pulling 10-15% fuel. There's a lot of other changes I'd make, but that's a big one.
Nothing that would cause it to kill power like it is though. I might check your crank sensor gap to begin with, then start looking for a new tuner.
I stubbed my toe on finding the actual table, so I will correct myself there. What would you do on this MAT table? I can try to share a photo of it if need be.
Make anything that’s currently under 100%….100%. It’s not the MAT retard table. It’s under basic settings
I just found it by running into the table. So let me get this right, between 120-140 under the air temp on the right side I want to put the correction % at 100? Or no? Just verifying the communication piece here.
Try the attached tune. I modified a lot that I don't like, pay attention to them on the difference report when you load it. Basic settings are all the same, just some tweaks that may or may not make any different.
Your spark advance is stuck at 29.1 degrees because thats what your 84kpa row is set to, although it's very slightly interpolating between 84 and 75. A quick google search tells me you must have dyno'd at 2000ft elevation. To put that in perspective, if you turbo charged your car, you'd need 3psi just to equal the horsepower of a naturally aspirated car at sea level, ignoring changes in torque curve.
I mainly updated more of the map because not only are you having power issues, but your idle sucks too. Hopefully my changes help. If you'd like, we can arrange a time for me to remote into your laptop to make sure the tune is actually working well.
The biggest change I'd recommend that I did NOT do, is changing to "include AFR". This makes your fueling calculation include your AFR target, so if you change it, your actual AFR should change with it. But that requires dividing (multiplying?) your entire VE table by your target before it's "right" again.
I will say, your drop in power does coincide with a dramatic change in VE, at 4000 you're at 64 with a decent AFR of 13:1. I would expect your VE to stay there or even drop of slightly with higher RPMs, as the BP runs out of breath. Instead, by redline, your VE is at 72, a 12.5% increase, with an AFR of 10.9. Smoothing that out may be all you need, but that's a long shot.
Try the attached tune. I modified a lot that I don't like, pay attention to them on the difference report when you load it. Basic settings are all the same, just some tweaks that may or may not make any different.
Your spark advance is stuck at 29.1 degrees because thats what your 84kpa row is set to, although it's very slightly interpolating between 84 and 75. A quick google search tells me you must have dyno'd at 2000ft elevation. To put that in perspective, if you turbo charged your car, you'd need 3psi just to equal the horsepower of a naturally aspirated car at sea level, ignoring changes in torque curve.
I mainly updated more of the map because not only are you having power issues, but your idle sucks too. Hopefully my changes help. If you'd like, we can arrange a time for me to remote into your laptop to make sure the tune is actually working well.
The biggest change I'd recommend that I did NOT do, is changing to "include AFR". This makes your fueling calculation include your AFR target, so if you change it, your actual AFR should change with it. But that requires dividing (multiplying?) your entire VE table by your target before it's "right" again.
I will say, your drop in power does coincide with a dramatic change in VE, at 4000 you're at 64 with a decent AFR of 13:1. I would expect your VE to stay there or even drop of slightly with higher RPMs, as the BP runs out of breath. Instead, by redline, your VE is at 72, a 12.5% increase, with an AFR of 10.9. Smoothing that out may be all you need, but that's a long shot.
I will give this a shot when I can today, and please don't get me started on idle lol, I had to fine tune that a bit to get it back and running as soon as I got the car back too. I will report back to you once I test this out!
Fair warning, you've got the terrible MAT air density table that comes with some of DIY's base maps. You'll regularly run in the 120-140 range on hot days, pulling 10-15% fuel. There's a lot of other changes I'd make, but that's a big one.
Nothing that would cause it to kill power like it is though. I might check your crank sensor gap to begin with, then start looking for a new tuner.
@curly So you perceive 30* over ambient as acceptable? I ask, because I have had difficulty knowing what people see as normal. I know that with enough intercooler, less rise is possible, but have always wondered what kind of MAT is too much, and brings in early det, and causes other problems.
I has the dumb. I forgot that this is about a N/A car. You are suggesting that track temps get that high... period. Sorry for this intrusion.
Make anything that’s currently under 100%….100%. It’s not the MAT retard table. It’s under basic settings
That's a good start. but will run the car a bit rich. OP, when you log at those temps, you could tweak the settings based on actual data, and tweak. Better rich than lean.
07-12-2021, 06:29 PM
This one maybe complicated... 99-00 MSMPNP2
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