Nitrous plugs run like crap, please help!
Nitrous plugs run like crap, please help! I am trying to spray but cant please help!!!!
The engine is a perimeter bolt head 97-98 vette LS1 swapped into an s10. I have made quite a few adjustments to the calibration with great success and it runs phenominal on TR55 plugs. I threw in a Zex fogger kit and TR6 plugs prior to researching and learning about the BR7ES plug. Started and ran fine, I went to spray the nitrous and it immediately started misfiring and then never would go away after. Pulled plugs, checked compression, everything good, put back in TR55 plugs and everything was back to normal. I put in the BR7ES plugs this morning, ran great to work, then went to spray nitrous after work and it started misfiring and wont go away since....I dont get it. I have put stock ignition dwell tables back in to be sure....played with my timing maps....im stumped. It is now misfiring mostly at idle and off idle and at high load, low RPM. I dont want to spray with TR55 plugs but thats the only thing that runs well. Btw the TR55 plugs are gapped at 0.054 and the BR7ES at 0.034. I have to put the TR55 plugs back in if I cant resolve this and will sell the nitrous....
Do you think gapping these smaller or larger will help? Btw I have tried brand new MSD wires and the cheapies I have, no change.
The engine is a perimeter bolt head 97-98 vette LS1 swapped into an s10. I have made quite a few adjustments to the calibration with great success and it runs phenominal on TR55 plugs. I threw in a Zex fogger kit and TR6 plugs prior to researching and learning about the BR7ES plug. Started and ran fine, I went to spray the nitrous and it immediately started misfiring and then never would go away after. Pulled plugs, checked compression, everything good, put back in TR55 plugs and everything was back to normal. I put in the BR7ES plugs this morning, ran great to work, then went to spray nitrous after work and it started misfiring and wont go away since....I dont get it. I have put stock ignition dwell tables back in to be sure....played with my timing maps....im stumped. It is now misfiring mostly at idle and off idle and at high load, low RPM. I dont want to spray with TR55 plugs but thats the only thing that runs well. Btw the TR55 plugs are gapped at 0.054 and the BR7ES at 0.034. I have to put the TR55 plugs back in if I cant resolve this and will sell the nitrous....
Do you think gapping these smaller or larger will help? Btw I have tried brand new MSD wires and the cheapies I have, no change.
Yes I am self tuning with a wideband.
Plugs look reasonable, are not lean or rich, and no damage to electrodes. I am not sure what is going on. I have never "damaged" a plug by running it rich for a couple seconds. This must be the case because a new set of plugs runs fine until i try to spray it. Its only a 75 shot and my AFR is around 11:1 when it sprays. Yes thats rich but safe to start...then i will dial it back.
Plugs look reasonable, are not lean or rich, and no damage to electrodes. I am not sure what is going on. I have never "damaged" a plug by running it rich for a couple seconds. This must be the case because a new set of plugs runs fine until i try to spray it. Its only a 75 shot and my AFR is around 11:1 when it sprays. Yes thats rich but safe to start...then i will dial it back.
And no I do no believe all cylinders at misfiring. It feels like 1 or 2 are misfiring at different loads and engine speed. Higher rpm and lower load and it clears up.
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Okay, I will buy new plugs (because they always run just fine when they are new until I hit nitrous 1 time).....and lean it out a little and get a new fill on the bottle. The nitrous in the bottle IS at 900psi, but its probably a few years old, and I am not exactly sure how much is in it, I need to weigh it. I cant imagine a compressed and sealed bottle would go "bad" over any reasonable period of time like a few years.
But the BR7ES plugs have not been removed since, and it STILL misfires cruising around with a solid tune (via wideband) with proper AFR's everywhere, after about 500 miles. Apparently, I have "damaged" the plug(s).
But the BR7ES plugs have not been removed since, and it STILL misfires cruising around with a solid tune (via wideband) with proper AFR's everywhere, after about 500 miles. Apparently, I have "damaged" the plug(s).
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Verdad Gallardo There is a lot more timing than stock in there already. It idles around 24 degrees and shortly off idle and at lower rpms when cruising I am between 30-45 degrees depending on load. I consistently have 5-10 degrees more than a stock map almost everywhere, at least in the areas that are accessed by the majority of driving.
I will take a screen shot of my timing map for you. It works great on TR55's
I will take a screen shot of my timing map for you. It works great on TR55's
24* at idle is what is clouding the plugs up.
if it can cruze around with 45* it wont hurt it to have that much at idle.
Try 38-40* at idle, it should help.
You want it to be LEAN and a good bit of timing at idle to keep plugs clean.
We can idle around on -11 plugs and not cloud them up.
if it can cruze around with 45* it wont hurt it to have that much at idle.
Try 38-40* at idle, it should help.
You want it to be LEAN and a good bit of timing at idle to keep plugs clean.
We can idle around on -11 plugs and not cloud them up.
I've never had to run more than 22-28 degrees of timing and 14.2-14.6 a/f all the way up to -9 plugs on a stock compression motor.
I can't see you having to run 38-40 degrees of timing with a -7 plug.
I can't see you having to run 38-40 degrees of timing with a -7 plug.
40 degrees at idle??? Wtf. That is so much timing for idle. My 3.0 v6 engine I made 532whp with ran 14 degrees at idle. Anything over 20 and it stalled. I just looked again and im running like 25 degrees at idle. I will turn it up a bit. But the point here is the plugs worked fine when initially installed and then hitting nitrous 1 time rich damaged them apparantly. I pulled them and visually inspected. They look good.
Additionally, the other point being discussed here is the colder plugs take longer and higher combustion temps to self clean. Advanced ignition timing DECREASES your EGTs directly. Every degree more drops your EGTs on average about 10 to 20 degrees F depending on load and RPM. I experimentally validated this on an engine dyno with both a diesel engine and spark ignited natural gas engine at work. People commonly think advanced ignition timing equals hotter exhaust temps....wrong. so if anything, advanced ignition timing would be less likely to self clean, at least from a temperature stand point. Yes emissions are directly affected by ignition timing and things like total hydrocarbons might be reduced with increased ignition timing, reducing deposits on the plugs....
Additionally, the other point being discussed here is the colder plugs take longer and higher combustion temps to self clean. Advanced ignition timing DECREASES your EGTs directly. Every degree more drops your EGTs on average about 10 to 20 degrees F depending on load and RPM. I experimentally validated this on an engine dyno with both a diesel engine and spark ignited natural gas engine at work. People commonly think advanced ignition timing equals hotter exhaust temps....wrong. so if anything, advanced ignition timing would be less likely to self clean, at least from a temperature stand point. Yes emissions are directly affected by ignition timing and things like total hydrocarbons might be reduced with increased ignition timing, reducing deposits on the plugs....
40 degrees at idle??? Wtf. That is so much timing for idle. My 3.0 v6 engine I made 532whp with ran 14 degrees at idle. Anything over 20 and it stalled. I just looked again and im running like 25 degrees at idle. I will turn it up a bit. But the point here is the plugs worked fine when initially installed and then hitting nitrous 1 time rich damaged them apparantly. I pulled them and visually inspected. They look good.
Why is it too much?
What the hell does HP have to do with it?
Then your nitrous tune is probably rich and retarded
Additionally, the other point being discussed here is the colder plugs take longer and higher combustion temps to self clean. Advanced ignition timing DECREASES your EGTs directly. Every degree more drops your EGTs on average about 10 to 20 degrees F depending on load and RPM. I experimentally validated this on an engine dyno with both a diesel engine and spark ignited natural gas engine at work. People commonly think advanced ignition timing equals hotter exhaust temps....wrong. so if anything, advanced ignition timing would be less likely to self clean, at least from a temperature stand point. Yes emissions are directly affected by ignition timing and things like total hydrocarbons might be reduced with increased ignition timing, reducing deposits on the plugs....
Why is it too much?
What the hell does HP have to do with it?
Then your nitrous tune is probably rich and retarded
Additionally, the other point being discussed here is the colder plugs take longer and higher combustion temps to self clean. Advanced ignition timing DECREASES your EGTs directly. Every degree more drops your EGTs on average about 10 to 20 degrees F depending on load and RPM. I experimentally validated this on an engine dyno with both a diesel engine and spark ignited natural gas engine at work. People commonly think advanced ignition timing equals hotter exhaust temps....wrong. so if anything, advanced ignition timing would be less likely to self clean, at least from a temperature stand point. Yes emissions are directly affected by ignition timing and things like total hydrocarbons might be reduced with increased ignition timing, reducing deposits on the plugs....
So less timing = less heat ?
No. More advance or more timing, meaning increasing the degrees of crankshaft rotation before the piston reaches TDC at which spark occurs, will reduce exhaust gas temperatures. For example, If you hold a constant RPM and load, doesn't matter where you are, and you go from say 20 degrees BTDC to 22 degrees BTDC, your EGT's will go DOWN!
Last edited by roastin240; Jun 2, 2014 at 09:53 PM.
This will always be the case up to Max Brake Torque (MBT) for that given load and RPM, and then continued ignition timing advance beyond MBT can increase temperatures but typically continue to decrease. Obviously when you advance beyond MBT, you are also making less torque, as MBT is the point where maximum torque occurs for that load, rpm, and equivalence ratio (AFR). So there is no reason to put more timing in at that point. On some natural gas engines though, MBT would occur at over 55 degrees BTDC at low loads, and EGT's were 250 degrees lower than when running around 25 degrees BTDC at the same rpm and load. It wasn't linear but each degree of increased ignition timing, the EGTs decreased. Engine was instrumented out the *** including thermocouples in each exhaust port, in cylinder pressure transducers, etc etc
I don't think I need to explain this. Open an internal combustion engines book.
But thank you all for the feedback.
I don't think I need to explain this. Open an internal combustion engines book.
But thank you all for the feedback.
Last edited by roastin240; Jun 2, 2014 at 10:02 PM.
lol, thanks.
I am an engineer with master of science in mechanical engineering, with a focus on combustion emissions performance, so ya I kinda tend to like the theory ha ha.
I am an engineer with master of science in mechanical engineering, with a focus on combustion emissions performance, so ya I kinda tend to like the theory ha ha.
ATVracr knows a thing or two about LS engines and nitrous, if I were in a situation where he was trying to give me some advice, I would take it. Study theory all you want but the people trying to give you advice are the ones out there doing it and making it work.
You can have every degree in the world and it doesn't mean **** if you never actually had experience with it.
FWIW 11:1 is way rich like ATVracr said. My car runs same AFR on motor as nitrous. 12.7 - 13.0 AFR. Keep timing under load conservative until you get it to make a pass then start reading plugs. I've yet to burn a piston spraying 150 shot on 93 octane pump gas at 12.7-13.0 afr.
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If you wont take advice, why ask for it? I didn't need any of those qualifications to make my car idle and drive like stock on BR7EF plugs. You can talk theory all you want but don't ask for advice if you wont take it.
ATVracr knows a thing or two about LS engines and nitrous, if I were in a situation where he was trying to give me some advice, I would take it. Study theory all you want but the people trying to give you advice are the ones out there doing it and making it work.
You can have every degree in the world and it doesn't mean **** if you never actually had experience with it.
FWIW 11:1 is way rich like ATVracr said. My car runs same AFR on motor as nitrous. 12.7 - 13.0 AFR. Keep timing under load conservative until you get it to make a pass then start reading plugs. I've yet to burn a piston spraying 150 shot on 93 octane pump gas at 12.7-13.0 afr.
ATVracr knows a thing or two about LS engines and nitrous, if I were in a situation where he was trying to give me some advice, I would take it. Study theory all you want but the people trying to give you advice are the ones out there doing it and making it work.
You can have every degree in the world and it doesn't mean **** if you never actually had experience with it.
FWIW 11:1 is way rich like ATVracr said. My car runs same AFR on motor as nitrous. 12.7 - 13.0 AFR. Keep timing under load conservative until you get it to make a pass then start reading plugs. I've yet to burn a piston spraying 150 shot on 93 octane pump gas at 12.7-13.0 afr.
Really? lmao