[bbnks2]

Originally Posted by houtan

Good discussion. Just to clarify, I would say my misfires are due to too much boost in the mid to upper rev range. I think they are occurring due to fueling or the dct flywheel. None of which is surprising as I know it will happen and the experiment right now is to find out where that tipping point is for my car. My bad if I described it differently.

Anyway, I should have some more logs to share tonight 👍🏽

Yeah I tried to look specifically where yours occur but you don't have misfires logged. Defintely add those parameters it won't effect polling rate at all.

[JETmn]

Originally Posted by bbnks2

I don't understand what you are saying because in the context of this conversation it's completely moot. I said what I did, and followed up by linking to what I did, because I think it's plausible voltage isn't sufficient to ignite the mixture.

Since you are so adamant about me being the one not understanding why this might not be true, please provide some context around your statement that voltage may not necessarily be lower with a tighter gap. I already know why and demonstrated that. so, it's your turn if you actually want to add some value.



Reading comprehension is not your strong point.

I said I opened my gap and DID NOT introduce any misfires... so what's the point of keeping it unnecessarily tight at .018"??? In fact, I think opening the gap may have contributed to eliminating misfires. Hence, why I ask if anyone else has tried it.

My misfires became more prevalent as we leaned my tune out to the 13:1 point which is where Houtan is at now with his tune. Rail pressure was way up (up from 1400 to 1800psi) because of the leaner mixture yet I was still getting misfires. Since I opened my spark plug gap, I have not had a single misfire. That's my basis for suggesting Houtan try opening his gap a bit as an experiment. It doesn't take that much effort to confirm/deny if it will help and it's free.

He said he is still getting misfires at low rpms and high load/boast over 21psi, which is what this might help. The high rpm misfires are probably his rail pressure tanking (out of fueling) or the DMFW like he suggested... different issues altogether that spark plug gap isn't going to fix.

Maybe a video will help you understand...

If you are getting misfires are cruise or idle, then you may have too SMALL of a gap. If you are getting misfires under boost, then you may have too LARGE of a gap. Opening up your gap will not help eliminate misfires under boost (unless you have a stupid small gap to start with). Our ignition system isn't very strong, so we have to run on the small side.

[bbnks2]

Originally Posted by JETmn

Maybe a video will help you understand..

Maybe you should re-watch that video a few more times and maybe you'll realize how it supports everything I've said.

Originally Posted by JETmn

If you are getting misfires are cruise or idle, then you may have too SMALL of a gap. If you are getting misfires under boost, then you may have too LARGE of a gap.

These statements are just generalizations and NOT absolutes. To reference the very video you linked to, see @1:39 where he explains how a lean car with too tight a gap will "not run smoothly..." For whatever that comment is worth... aka fuel will be harder to ignite and will cause misfires. Are you starting to understand the asterisk that is attached to your statement about gap yet? You are only arguing 1 side of things and ignoring that there is a complete opposite scenario.

Originally Posted by JETmn

Opening up your gap will not help eliminate misfires under boost

IT WILL if... oh wait I can just quote you... "unless you have a stupid small gap to start with."

Go figure! You just restated exactly what I have been saying. Congrats you're starting to understand the concept!

Originally Posted by JETmn

Our ignition system isn't very strong, so we have to run on the small side.

You've been drinking too much of the Coolaid. .018" gap was recommended for N54 cars running ~600whp. In what way, shape, or form does that translate to this thread where logs are being posted of 18-20psi for 350whp LOL You clearly didn't read any of my posts, or the link I referenced to support what I said. Here, I did a google search for you: https://www.google.com/search?q=lean...+gap+too+small

I'll even reference another technical article for you: " A narrow gap may give too small and weak a spark to effectively ignite the fuel-air mixture, while a gap that is too wide might prevent a spark from firing at all."

http://www.gsparkplug.com/shop/spark-plug-gap-settings/

I am clearly suggesting the FORMER is possible in the context of this thread, whereas, you are only willing to accept that the later is the only option that exists.

Originally Posted by JETmn

Man, I remember why I don't respond to most of your comments no matter how wrong they are.

I can't help you if you still don't understand why you aren't adding any value to the conversation. People regurgitating random crap they read without any understanding of the underlying concept do more damage to this community than you realize. How do you think this myth of needing a .018" gap got perpetuated?

Thank you for making a simple suggestion way more complicated than it needed to be. Hopefully other people reading will learn a thing or two about how to slowly gap down plugs instead of just taking a random number at face value without testing. It can only benefit you to open the gap up a bit.

[JETmn]

Originally Posted by bbnks2

Maybe you should re-watch that video a few more times and maybe you'll realize how it supports everything I've said.



These statements are just generalizations and NOT absolutes. To reference the very video you linked to, see @1:39 where he explains how a lean car with too tight a gap will "not run smoothly..." For whatever that comment is worth... aka fuel will be harder to ignite and will cause misfires. Are you starting to understand the asterisk that is attached to your statement about gap yet? You are only arguing 1 side of things and ignoring that there is a complete opposite scenario.



IT WILL if... oh wait I can just quote you... "unless you have a stupid small gap to start with."

Go figure! You just restated exactly what I have been saying. Congrats you're starting to understand the concept!



You've been drinking too much of the Coolaid. .018" gap was recommended for N54 cars running ~600whp. In what way, shape, or form does that translate to this thread where logs are being posted of 18-20psi for 350whp LOL You clearly didn't read any of my posts, or the link I referenced to support what I said. Here, I did a google search for you: https://www.google.com/search?q=lean...+gap+too+small

I'll even reference another technical article for you: " A narrow gap may give too small and weak a spark to effectively ignite the fuel-air mixture, while a gap that is too wide might prevent a spark from firing at all."

http://www.gsparkplug.com/shop/spark-plug-gap-settings/

I am clearly suggesting the FORMER is possible in the context of this thread, whereas, you are only willing to accept that the later is the only option that exists.



I can't help you if you still don't understand why you aren't adding any value to the conversation. People regurgitating random crap they read without any understanding of the underlying concept do more damage to this community than you realize. How do you think this myth of needing a .018" gap got perpetuated?

Thank you for making a simple suggestion way more complicated than it needed to be. Hopefully other people reading will learn a thing or two about how to slowly gap down plugs instead of just taking a random number at face value without testing. It can only benefit you to open the gap up a bit.

No, the video does not support what you are saying. It is saying the exact opposite, which is what I have been saying. Also, .018" is not a stupid small gap. If it didn't work, then why are many people switching to it and solving misfire issues and custom tuners recommending that gap?

Also, you still don't understand that "lean" they are talking about in your link is beyond stoich (as I mentioned before, which is higher than 14.7:1) and we are NOT that lean under boost. As I said last time that would be issues if you were at cruise or idle. You like to try and take bits and pieces out of different posts to try and make it look like you are right, but nobody around here is buying it. I am done with this, hopefully anyone else reading has seen this objectively and won't believe what you are saying. Misfires under boost will not be fixed by widening the gap above .018", period.

[bbnks2]

Originally Posted by JETmn

No, the video does not support what you are saying. It is saying the exact opposite, which is what I have been saying. Also, .018" is not a stupid small gap. If it didn't work, then why are many people switching to it and solving misfire issues and custom tuners recommending that gap?

Also, you still don't understand that "lean" they are talking about in your link is beyond stoich (as I mentioned before, which is higher than 14.7:1) and we are NOT that lean under boost. As I said last time that would be issues if you were at cruise or idle. You like to try and take bits and pieces out of different posts to try and make it look like you are right, but nobody around here is buying it. I am done with this, hopefully anyone else reading has seen this objectively and won't believe what you are saying. Misfires under boost will not be fixed by widening the gap above .018", period.

Can you please actually reference something that supports what you're saying instead of speaking in these generalities that you're still wrong about? You also seem to think I've said things that I never did so please directly quote me if you're going to try to make me out to be some kind of jerk. I simply rebutted all the statements you made. I didn't cherry pick anything to make myself sound like anything.

Please reference a single source that states only mixtures leaner than stoich will be harder to ignite when spark plug gap is decreased.

[JETmn]

Originally Posted by bbnks2

Can you please actually reference something that supports what you're saying instead of speaking in these generalities that you're still wrong about? You also seem to think I've said things that I never did so please directly quote me if you're going to try to make me out to be some kind of jerk. I simply rebutted all the statements you made. I didn't cherry pick anything to make myself sound like anything.

Nothing I have said is wrong. Simply put, you said to increase his gap to .026" from .018"as it may solve his misfire. There has not been one case where this has happened, and it is not possible this could happen in our cars. Tons of us are running .018" gap and it has fixed misfire issues for us.

Originally Posted by bbnks2

Please reference a single source that states only mixtures leaner than stoich will be harder to ignite when spark plug gap is decreased.

The autolite source you provided says :

• If the gap is too narrow, the spark may not ignite a “lean” air/fuel mixture, which would also result in a misfire


It is common knowledge that lean is a AFR higher than 14.7:1. Please look up "lean burn technology" in google for tons of info.

Garrett has it written out well:

15.0:1 = Lean
14.7:1 = Stoichiometric
13.0:1 = Rich

Link to above. https://www.turbobygarrett.com/turbo...g_rich_vs_lean

I am not going to run around digging up data trying to prove something that is common knowledge.



This is a good writeup also, but for american V8's so the actual numbers listed are too big, but same premise.

http://www.badasscars.com/index.cfm/...prod/prd73.htm

[bbnks2]

Originally Posted by JETmn

Nothing I have said is wrong. Simply put, you said to increase his gap to .026" from .018"as it may solve his misfire. There has not been one case where this has happened, and it is not possible this could happen in our cars. Tons of us are running .018" gap and it has fixed misfire issues for us.



The autolite source you provided says :

• If the gap is too narrow, the spark may not ignite a “lean” air/fuel mixture, which would also result in a misfire


It is common knowledge that lean is a AFR higher than 14.7:1. Please look up "lean burn technology" in google for tons of info.

Garrett has it written out well:

15.0:1 = Lean
14.7:1 = Stoichiometric
13.0:1 = Rich

Link to above. https://www.turbobygarrett.com/turbo...g_rich_vs_lean

I am not going to run around digging up data trying to prove something that is common knowledge.



This is a good writeup also, but for american V8's so the actual numbers listed are too big, but same premise.

http://www.badasscars.com/index.cfm/...prod/prd73.htm

Wow this entire conversation has gone way over your head. You're clearly too narrow minded to grasp the concept. Everything is relative. The term lean is relative. The spark plug gap required to operate misfire free is relative.

The recommended gap of .018" came about from testing 600whp+ builds. You're not even close to providing anything relevant to this thread. You linked to basic concepts. You still fail to apply them. Keep quoting generalizations and ignoring my questions...

Will your head explode if Houtan opens his spark plug gap up from .018" to .025" and the world doesn't end? Should I gap my plugs back down from .025" to .018" because you can't possible fathom my car runs misfire free without needing to run your one size fits all spark plug gap? I'll let you go back and re-read this thread so you can soak in how far youve derailed it with conjecture.

[JETmn]

Originally Posted by bbnks2

Wow this entire conversation has gone way over your head. You're clearly too narrow minded to grasp the concept. Everything is relative. The term lean is relative. The spark plug gap required to operate misfire free is relative.

The recommended gap of .018" came about from testing 600whp+ builds. You're not even close to providing anything relevant to this thread. You linked to basic concepts. You still fail to apply them. Keep quoting generalizations and ignoring my questions...

Will your head explode if Houtan opens his spark plug gap up from .018" to .025" and the world doesn't end? Should I gap my plugs back down from .025" to .018" because you can't possible fathom my car runs misfire free without needing to run your one size fits all spark plug gap? I'll let you go back and re-read this thread so you can soak in how far youve derailed it with conjecture.

I think you need to head back to grade school and work on the reading comprehension. I never said going to .025" gap would cause a misfire, I said it would not FIX one. You keep going around saying different things and you don't even understand the concepts behind what you are saying. You seem to have picked up a few terms from forums, but you don't have enough knowledge to actually put the concepts in to real world applications.

You want links, I provide links. I even gave you a video if you are bad at reading. You still can't understand that closing the gap to .018" CANNOT cause a misfire under boost in our engines. This was your original premise that is completely wrong. You tried to say that opening it up to .025" might fix it. That is not possible period. Quit going off on tangents trying to take the focus away of the real thing we started talking about. I am done, if you are too ignorant to be able to realize the issue then I am never going to be able to open up your eyes. I just didn't want other people to read your nonsense and think it was actually true.

[houtan]

Alright fellas, back on topic.

Here is what i believe to be my final e30 tune. I am on the edge of my car's fueling i believe. I have a version with everything the same and 13.0 afr and the car runs great (logs are earlier in this thread or in datazap map v3.2). If i keep everything the same and try to run 12.5 afr, rail pressure dives at the top end. We bumped the afr up to around 12.8 and everything looks good. I can probably run a PSI or two more without having the flyhweel misfires, but i would have to drop timing advance down so the fueling can support. I will ask Ken if he thinks there is an advantage for doing that.

I am considering adding the AEM3350 meth injection setup and spray through the chargepipe. Will update if i go that route once i get logs.

Wedge E30 PS2 v6 logs (3 logs): http://datazap.me/u/houtan/wedge-e30...og=1&data=3-21

[weehe126]

Only 17psi at 13 AFR? Do you have a stock LPFP and old hpfp? I'm running flat 20psi at 12.5 tapering to 12.2 AFR on E30-40 and have no fuel problems. Also have timing at 8 increasing to 13 with basically 0 timing pull, so know I'm at least E30. I have a bucketless stage 2 lpfp and newish hpfp.

[houtan]

Originally Posted by weehe126

Only 17psi at 13 AFR? Do you have a stock LPFP and old hpfp? I'm running flat 20psi at 12.5 tapering to 12.2 AFR on E30-40 and have no fuel problems. Also have timing at 8 increasing to 13 with basically 0 timing pull, so know I'm at least E30. I have a bucketless stage 2 lpfp and newish hpfp.

I am taking credit for the .5 psi you missed; that is 17.5 psi! haha. In third that is where i am at, in 4th it goes up a little bit to 18 ish. AFR is 12.7-8.

My HPFP is fairly new; <10K miles.

I am on 100% stock fuel system. I have not upgraded my LPFP because it is not clear to me if it makes a difference.

I know of other JB4 cars that can hold 20psi on stock fuel system, so not surprised you can do the same. But I am flash only so it doesnt tell me much. And while boost, timing, trims, etc should be the same, who knows if the two platforms are actually interpreting the information the same. I will tell you I dont trust the jb4 at all; i know it works, actually the fastest n55 i know runs jb4, but i dont trust it one bit.

I dont see many cars flash only on stock fuel system with PS2, so i really need to compare where i am at with someone with a similar setup.

Robert may do an E30 tune with Ken as well. He is same turbo, stock fuel system, flash only. It will be nice to compare with his results if he decides to do so.

Of course if you guys know of any other flash only ps2 cars running an ethanol mix please share the logs.

[JETmn]

Originally Posted by houtan

I am taking credit for the .5 psi you missed; that is 17.5 psi! haha. In third that is where i am at, in 4th it goes up a little bit to 18 ish. AFR is 12.7-8.

My HPFP is fairly new; <10K miles.

I am on 100% stock fuel system. I have not upgraded my LPFP because it is not clear to me if it makes a difference.

I know of other JB4 cars that can hold 20psi on stock fuel system, so not surprised you can do the same. But I am flash only so it doesnt tell me much. And while boost, timing, trims, etc should be the same, who knows if the two platforms are actually interpreting the information the same. I will tell you I dont trust the jb4 at all; i know it works, actually the fastest n55 i know runs jb4, but i dont trust it one bit.

I dont see many cars flash only on stock fuel system with PS2, so i really need to compare where i am at with someone with a similar setup. You are also running a different turbo. Probably not much difference, but still different setups.

Robert may do an E30 tune with Ken as well. He is same turbo, stock fuel system, flash only. It will be nice to compare with his results if he decides to do so.

Of course if you guys know of any other flash only ps2 cars running an ethanol mix please share the logs.

It certainly is plausible that a LPFP could help increase the output. If the LPFP is running out of delivery before the HPFP, then the HP will have to try to suck the fuel in instead of the LP pushing it in. That takes power to do and will reduce the output of the HPFP. I plan on upgrading mine in the near future and probably PI after that.

[bbnks2]

Originally Posted by weehe126

Only 17psi at 13 AFR? Do you have a stock LPFP and old hpfp? I'm running flat 20psi at 12.5 tapering to 12.2 AFR on E30-40 and have no fuel problems. Also have timing at 8 increasing to 13 with basically 0 timing pull, so know I'm at least E30. I have a bucketless stage 2 lpfp and newish hpfp.

Are you JB4 or any logs to actually share?

What's you HPFP pressure at? Houtan's is over 2000psi across the pull...

[houtan]

Originally Posted by JETmn

It certainly is plausible that a LPFP could help increase the output. If the LPFP is running out of delivery before the HPFP, then the HP will have to try to suck the fuel in instead of the LP pushing it in. That takes power to do and will reduce the output of the HPFP. I plan on upgrading mine in the near future and probably PI after that.

totally agree it's possible. I guess i would like to know for sure before taking the plunge.

What i do know is meth will help. And i can tell you if you are going to Meth PI, you are fine on your stock LPFP up to at least 24psi (i am sure more as my buddys car sprays very little meth at this boost) from my experience. If you are going fuel PI, then the LPFP upgrade is a must as you know.

I think i am going to give Meth a whirl, CP only for now. See where that gets me.

[DrRobert]

Originally Posted by houtan

Alright fellas, back on topic.

Here is what i believe to be my final e30 tune. I am on the edge of my car's fueling i believe. I have a version with everything the same and 13.0 afr and the car runs great (logs are earlier in this thread or in datazap map v3.2). If i keep everything the same and try to run 12.5 afr, rail pressure dives at the top end. We bumped the afr up to around 12.8 and everything looks good. I can probably run a PSI or two more without having the flyhweel misfires, but i would have to drop timing advance down so the fueling can support. I will ask Ken if he thinks there is an advantage for doing that.

I am considering adding the AEM3350 meth injection setup and spray through the chargepipe. Will update if i go that route once i get logs.

Wedge E30 PS2 v6 logs (3 logs): http://datazap.me/u/houtan/wedge-e30...og=1&data=3-21

I see that in the E30 logs you posted earlier Ken had you at ~20 PSI, looks like he had to decrease boost as he was dialing in your tune. Same thing happened with my car when he was tuning for 91. But I like how your E30 boost curve stays flat.

How much boost do you have on 91? On 91 octane w/ PS2 and stock fueling system Ken has me at 18.7 psi peak tapering to 16 at redline (log posted in post #31 of this thread). At that point he said he was pushing the limits of the OEM fueling system with this crap pump gas we have here in CA.

I do plan on trying an E30 tune with Ken in the next few weeks in response to this thread. I gave up on it before with Cobb and didn't realize it was worth another try with MHD. I'd probably install stage 2 LPFP if I had better access to E85, but the closest station to me is 30 miles away. Might still do it anyway, but will see how it goes with the E30 tune on stock fueling first.

[weehe126]

Originally Posted by houtan

I am taking credit for the .5 psi you missed; that is 17.5 psi! haha. In third that is where i am at, in 4th it goes up a little bit to 18 ish. AFR is 12.7-8.

My HPFP is fairly new; <10K miles.

I am on 100% stock fuel system. I have not upgraded my LPFP because it is not clear to me if it makes a difference.

I know of other JB4 cars that can hold 20psi on stock fuel system, so not surprised you can do the same. But I am flash only so it doesnt tell me much. And while boost, timing, trims, etc should be the same, who knows if the two platforms are actually interpreting the information the same. I will tell you I dont trust the jb4 at all; i know it works, actually the fastest n55 i know runs jb4, but i dont trust it one bit.

I dont see many cars flash only on stock fuel system with PS2, so i really need to compare where i am at with someone with a similar setup. You are also running a different turbo. Probably not much difference, but still different setups.

Robert may do an E30 tune with Ken as well. He is same turbo, stock fuel system, flash only. It will be nice to compare with his results if he decides to do so.

Of course if you guys know of any other flash only ps2 cars running an ethanol mix please share the logs.

I'm running a PS2 as well, so not sure how the turbo is different. I am running JB4, but with my own BEF. All the JB4 does is control boost. But I can understand flash only maybe being different.

[weehe126]

Originally Posted by bbnks2

Are you JB4 or any logs to actually share?

What's you HPFP pressure at? Houtan's is over 2000psi across the pull...

I am JB4 with BEF. I have plenty of logs, just a pain to post here since you can attach the csv. My pressure stays above 11 on a JB4 log. Only had issues when I went below 9.

[houtan]

Originally Posted by weehe126

I'm running a PS2 as well, so not sure how the turbo is different. I am running JB4, but with my own BEF. All the JB4 does is control boost. But I can understand flash only maybe being different.

My bad, i was thinking of someone else running jb4 and VTT stage two. Updated my prior post.

Are you running meth? would be nice to see logs as well.

[houtan]

Originally Posted by weehe126

I am JB4 with BEF. I have plenty of logs, just a pain to post here since you can attach the csv. My pressure stays above 11 on a JB4 log. Only had issues when I went below 9.

datazap account is free.

[bbnks2]

Originally Posted by weehe126

I am JB4 with BEF. I have plenty of logs, just a pain to post here since you can attach the csv. My pressure stays above 11 on a JB4 log. Only had issues when I went below 9.

That could be the difference right there. Risk tolerance of the tuner. If you are dipping to 11's at 20/21 psi then it probably has nothing to do with your LPFP upgrade. Your rail pressure is crashing just as hard as Houtan's was before tune revisions to back off boost.

JB4 HPFP of 11 = 1650psi and dipping to a HPFP of 9 is 1350psi.... A HPFP value of 11's would put you right on the threshold where misfires start popping up... I am not talking about the car "breaking up" entirely. I am talking about DME shutting down individual cylinders due to lack of fueling. DME doesn't throw a code and JB4 has no way of logging misfires so you'd never even know it's happening... You won't feel 1 or 2 misses.

Also, what gear are you referencing?

[houtan]

Originally Posted by bbnks2

That could be the difference right there. Risk tolerance of the tuner. If you are dipping to 11's at 20/21 psi then it probably has nothing to do with your LPFP upgrade. Your rail pressure is crashing just as hard as Houtan's was before tune revisions to back off boost.

JB4 HPFP of 11 = 1650psi and dipping to a HPFP of 9 is 1350psi.... A HPFP value of 11's would put you right on the threshold where misfires start popping up... I am not talking about the car "breaking up" entirely. I am talking about DME shutting down individual cylinders due to lack of fueling. DME doesn't throw a code and JB4 has no way of logging misfires so you'd never even know it's happening... You won't feel 1 or 2 misses.

Also, what gear are you referencing?

So why is it that the jb4 will allow the car to run good enough at such a low rail pressure?

i remember when i was running jb4, stock turbo, e50, 100% wgdc, rail pressure was around 11 or even 10, and car ran perfect.

i know there could of been misfires going on that i wasnt feeling, but at 1500 psi, i am pretty sure my car will start misfiring where i would feel it. Just weird the jb4 is allowing such a low psi for an entire pull, and no major misfire.

[Turbod]

Originally Posted by houtan

i know there could of been misfires going on that i wasnt feeling, but at 1500 psi, i am pretty sure my car will start misfiring where i would feel it. Just weird the jb4 is allowing such a low psi for an entire pull, and no major misfire.

I agree that 11 or 12 (1,650 or 1,800) are normal and run completely fine on the JB4. I only saw misfires at 1,500 or lower. I have heard many people say that you want to see above 2,000 with MHD. I added a little E (1 gallon) to my pump flash and plan to log this evening. I am pretty sure rail pressure has dropped into the 1,***'s.

On pump and a stock fuel system I was able to hit 21.5 psi in 3rd and 4th while keeping the rail pressure above 2,000. Timing wasn't good enough due to it only being 92 octane but there is room for high boost without E and meth.