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Old 05-21-2018, 07:55 AM   #1
esmth
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Default trying for exhaust pops on downshift lh2.4

I'd post this in the tunerpro thread but nobody seems to look in there anymore.

I'm trying to be a dumbass kid and get some pops and bangs out the exhaust on downshift. I've retarded the ignition on my 207 ezk at the lowest load from 4500RPM to 1600RPM but it didn't seem to make any change. And yes i've applied the change to the other 3 maps on the bin file.

Should I retard more?
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Old 05-21-2018, 10:05 AM   #2
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Never go full retard. If you call it anti-lag it's grown up.
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Old 05-21-2018, 10:46 AM   #3
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Never go full retard. If you call it anti-lag it's grown up.
Megasquirt forums say to do -5 degrees ish to get some anti-lag. I put 173 in the data table to get -4.875 on the degrees table. i'm gonna test tonight
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Old 05-24-2018, 10:40 AM   #4
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My stock 87 244 did this on it's own when the exhaust broke before the cat.

My 93 +T on TLAO will blast a fireball just cruising around honestly. I wish it would do it at shifts... too much cat and too much injector I suspect.
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Old 05-24-2018, 09:19 PM   #5
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My stock 87 244 did this on it's own when the exhaust broke before the cat.

My 93 +T on TLAO will blast a fireball just cruising around honestly. I wish it would do it at shifts... too much cat and too much injector I suspect.
When I was running just an open downpipe it had all the pops and crackles like your 87. But now I have a full exhaust with no cat and am trying for a similar effect.

I haven't updated the thread yet because I came down with a bad cold and i've been too fatigued to experiment more. Hopefully I can play around with it this weekend
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Old 05-25-2018, 11:59 AM   #6
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When I was running just an open downpipe it had all the pops and crackles like your 87. But now I have a full exhaust with no cat and am trying for a similar effect.

I haven't updated the thread yet because I came down with a bad cold and i've been too fatigued to experiment more. Hopefully I can play around with it this weekend
It's cool.

Fwiw, I'm running 577cc's on TLAO chips with an 012 AMM. I have a 3 inch downpipe into a high flow cat, a straight through muffler and then a 45 turn right out the side of the car.

It seems to just do it at completely normal cruising now which kind of sucks. I end up shouting SORRY to a lot of people walking about in the neighborhood.
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Old 05-25-2018, 02:25 PM   #7
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It's cool.

Fwiw, I'm running 577cc's on TLAO chips with an 012 AMM. I have a 3 inch downpipe into a high flow cat, a straight through muffler and then a 45 turn right out the side of the car.

It seems to just do it at completely normal cruising now which kind of sucks. I end up shouting SORRY to a lot of people walking about in the neighborhood.
Just get a "hearing protection required" sign and display prominently on your car.
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Old 05-26-2018, 10:09 AM   #8
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I'd post this in the tunerpro thread but nobody seems to look in there anymore.

I'm trying to be a dumbass kid and get some pops and bangs out the exhaust on downshift. I've retarded the ignition on my 207 ezk at the lowest load from 4500RPM to 1600RPM but it didn't seem to make any change. And yes i've applied the change to the other 3 maps on the bin file.

Should I retard more?
I'm no expert with tunerpro for lh2.4, but I've looked at it some.
It occurs to me that you might be modifying the wrong line.
Is it possible that the lowest load in that chart is actually the next one down from the one that you modified?
Also, when you say downshift, are you wanting to downshift to reach 4500 rpm and then backfire, or wanting to downshift from 4500 rpm to a lower gear and higher rpm and then backfire? If the latter, then you probably want to make the timing change to the higher rpm, not the 4500 and down range.
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Old 05-26-2018, 02:45 PM   #9
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update: EZK doesn't like negative degree value (173 or -4.875deg) in the table. car doesn't start. I'm going to try 160 for 0 degrees

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I'm no expert with tunerpro for lh2.4, but I've looked at it some.
It occurs to me that you might be modifying the wrong line.
Is it possible that the lowest load in that chart is actually the next one down from the one that you modified?
Also, when you say downshift, are you wanting to downshift to reach 4500 rpm and then backfire, or wanting to downshift from 4500 rpm to a lower gear and higher rpm and then backfire? If the latter, then you probably want to make the timing change to the higher rpm, not the 4500 and down range.
I may be modifying the wrong line. But looking in the .xdf file source it looks like the TORQUE line is just a label for the entire Y column. ill try the next line anyway.

When i say downshift I actually meant on throttle letoff and coasting down. But downshift should essentially be the same thing, just a quick rev-match then a letoff & coast? I usually only rev out to 2800 to 3000 when driving like a sane person daily, but occasionally I take it to 4500+ for fun but it's clear my 13c is restricting the top end too much
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Old 05-30-2018, 09:20 PM   #10
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another update: 0 deg aka 160 in the data fields definitely made it sound different at the start of decel. I think not much is happening because of the default decel fuel cut. Might temporarily pull the plug from the throttle switch to stop that behavior for testing
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Old 05-30-2018, 09:53 PM   #11
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Where's your maf? My hks ssqv venting to atmosphere made the car run rich momentarily due to the turbo still pulling air through the maf and it not making it all the way to the engine. This made some pretty decent exhaust pops.
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Old 05-30-2018, 10:02 PM   #12
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Where's your maf? My hks ssqv venting to atmosphere made the car run rich momentarily due to the turbo still pulling air through the maf and it not making it all the way to the engine. This made some pretty decent exhaust pops.
stock location in front of the turbo. I'm still using the 13c CBV as well. I've been buttoning up a super 60 t3 to put on soon but haven't gotten around to putting it and the blowoff valve on yet
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Old 05-30-2018, 10:02 PM   #13
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Just to be clear, I'm not encouraging this, or at least not on my engine....

Most likely, the LH tables don't support negative numbers -- they'll wrap around to big positive numbers.

I don't know what LH does for idle mapping. Usually, it's a special case that switches to a different table. You could try very light throttle during shifting and see if it gives the desired results (just enough so that the idle TPS switch stays open).
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Old 06-01-2018, 10:55 AM   #14
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You could try very light throttle during shifting and see if it gives the desired results (just enough so that the idle TPS switch stays open).
This... on decel if you just rest your foot on the throttle where the plate opens but maybe the switch doesn't engage will generate pops. It's how I know real fast if an LH24 car needs the TPS and stuff adjusted.

Also, and exhaust leak towards the middle of the car will cause cool are to be drawn in and lots of popping will ensue.....
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Old 06-01-2018, 11:43 AM   #15
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Isn't there a circuit interrupter that can do something like this?

I was able to do this on my k-Jet 242t fairly easily.
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Old 06-02-2018, 02:35 PM   #16
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This... on decel if you just rest your foot on the throttle where the plate opens but maybe the switch doesn't engage will generate pops. It's how I know real fast if an LH24 car needs the TPS and stuff adjusted.

Also, and exhaust leak towards the middle of the car will cause cool are to be drawn in and lots of popping will ensue.....
+2 I get this on MS when I turn off decel fuel cut
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Old 06-10-2018, 06:07 PM   #17
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update: ran a couple tanks of gas though running 0deg ignition at the low load part of the map. definitely pops&crackles more but it's really quiet. Friend reports he cant hear or see anything when it happens from outside the car. I may try making the next row retarded to 0 for testing but I wont leave it like that for long. I'm about to return the table to stock because there's no point in this

For reference i'm running a stock 740 downpipe to a 2.5" exhaust and a meaty single straight though muffler at the rear location. no resonator or cat.

Quote:
Originally Posted by bobxyz View Post
I don't know what LH does for idle mapping. Usually, it's a special case that switches to a different table. You could try very light throttle during shifting and see if it gives the desired results (just enough so that the idle TPS switch stays open).
Holding the throttle barely open, triggering the TPS or disconnecting it entirely helps a bit but I don't like depriving the ecu of it's decel & idle routines

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Also, and exhaust leak towards the middle of the car will cause cool are to be drawn in and lots of popping will ensue.....
Ah, too bad my exhaust is fully welded
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Old 06-16-2018, 01:50 AM   #18
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Getting it consistently will be challenging without going crazy with your tune atmo. With my car it'll crackle and pop to varying degrees and then maybe once or twice per hard drive it'll let loose some real backfires. Even those though aren't just fireballs... it's like the super quick gunshot style flame that's gone in a millisecond.

On my latest LH reset (back on CBV) it hasn't done it at all though... yet.
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Old 06-16-2018, 12:14 PM   #19
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Another update

Went to cars and coffee in Boston and I pulled my single muffler off and tried my 0deg tune. Holy frig the crackling is insane. My muffler was hiding it all so well so I thought it wasn’t working, but it works and works great. My friend got some videos of it that he’ll upload later.

The way it’s set up im in complete control of the noise. Like the technique mentioned above I barely keep my foot on the throttle and it’s so friggin crazy sounding, yet it is easy to keep quiet if needed
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Old 06-18-2018, 09:04 AM   #20
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Quote:
Originally Posted by EivlEvo View Post
Getting it consistently will be challenging without going crazy with your tune atmo. With my car it'll crackle and pop to varying degrees and then maybe once or twice per hard drive it'll let loose some real backfires. Even those though aren't just fireballs... it's like the super quick gunshot style flame that's gone in a millisecond.

On my latest LH reset (back on CBV) it hasn't done it at all though... yet.
Did you just say atmo on tbricks, atmo?

That was, for me, a kind of "don't cross the streams" moment.
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Old 08-15-2018, 11:54 AM   #21
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Did you just say atmo on tbricks, atmo?

That was, for me, a kind of "don't cross the streams" moment.
lol... settle down.
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Old 08-15-2018, 11:55 AM   #22
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And where are these alleged videos.
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Old 08-26-2018, 08:55 PM   #23
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And where are these alleged videos.
edit NVM this was the stock ignition

sorry for the delay
3 angles of the same garbage, leaving cars and coffee last month

https://youtu.be/i71y-8ibiDw?t=30s
https://youtu.be/xj8qMfBEx5E?t=4m40s
https://youtu.be/R7EzNmxZ6Zw?t=5m5s

Last edited by esmth; 08-26-2018 at 09:01 PM..
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