So I just finished installing an m62 supercharger from a Frontier/Xterra into my s13. This wasn't from a Knight kit, but the design is similar. I'll pprobably make a more detailed post about it when everything if perfect. Mechanically, everything works great, but I am having what I believe to be an ignition problem. To start, its running 8psi of boost controlled by a manual controller and that is supported by 480cc injectors, 255lph Walbro fuel pump and an SAFC-NEO. On the dyno we retarted the base timing until we couldn't hear any pinging. Essentially, the afr is pretty steady up until 3500 rpms where it all goes to hell. I think whats happening here is that the spark is being blown out. The NGK iridium plugs are all gapped to ~28 or so, but I dont think they are getting enough power. I plan on getting an msd coil to help, but do you think it could be problems with the distributor/related parts? The dyno tuner also recommended I get some form of timing control, since I need base timing retarted to help low down I need to put it back in at higher rpm. He says that an MSD BTM wouldn't be useful for what I need, since the boost level stays constant for all but the end of the graph I have. What I'm looking for is an ignition that I can program a timing map for, any suggestions? The best I have found so far is the MSD 8979 MSD Multi-Function Ignition Controller, programmable from a laptop.
Anways, here is the dyno run. Since there was the obvious AFR problem starting around 35-3800, we only ran it to 5000rpm.
Supercharger - Ignition/Timing help
Re: Supercharger - Ignition/Timing help (Mad_Man)
There are a few things wrong with this whole deal, and I'm just gonna start from the top.Mad_Man wrote:So I just finished installing an m62 supercharger from a Frontier/Xterra into my s13. This wasn't from a Knight kit, but the design is similar. I'll pprobably make a more detailed post about it when everything if perfect. Mechanically, everything works great, but I am having what I believe to be an ignition problem. To start, its running 8psi of boost controlled by a manual controller and that is supported by 480cc injectors, 255lph Walbro fuel pump and an SAFC-NEO. On the dyno we retarted the base timing until we couldn't hear any pinging. Essentially, the afr is pretty steady up until 3500 rpms where it all goes to hell. I think whats happening here is that the spark is being blown out. The NGK iridium plugs are all gapped to ~28 or so, but I dont think they are getting enough power. I plan on getting an msd coil to help, but do you think it could be problems with the distributor/related parts? The dyno tuner also recommended I get some form of timing control, since I need base timing retarted to help low down I need to put it back in at higher rpm. He says that an MSD BTM wouldn't be useful for what I need, since the boost level stays constant for all but the end of the graph I have. What I'm looking for is an ignition that I can program a timing map for, any suggestions? The best I have found so far is the MSD 8979 MSD Multi-Function Ignition Controller, programmable from a laptop.
Anways, here is the dyno run. Since there was the obvious AFR problem starting around 35-3800, we only ran it to 5000rpm.
First of all, I'd say you're not blowing out the spark, you're just running ridiculously rich from about 3500 on. When the spark blows out, it shows as a lean spike, not a rich spike. Remember, the AFR's are monitored via wideband O2 sensor, so you if the spark is gone, regardless of fuel content in the cylinder, the O2 reading will be lean, since none was burned and the amount of oxygen is abundant.
Additionally, the lower rpm areas could also use some smoothing.
Secondly, how did you go about pulling the base timing? Did you go through the steps detailed in the FSM, or did you simply just crank the distributor without going through these steps? If you did the latter, then there's a pretty solid chance that your timing is now all jacked up (I did this when I very first turbocharged my KA, 2 yrs ago...).
I agree that a BTM might not be the best option here. I'd say you need to look into things such as:
MegaSquirt 2 ver. 3.0Daughterboard installed in the stock ECU (EEPROM programming)AEM EMS full standaloneHaltechF.A.S.T.MoTec
and any other standalone system you could find.
I currently use a daughterboard setup on my S13, but I'm soon to upgrade to a MS2 (MegaSquirt).
Oh yeah, lose the iridium plugs. Go with NGK plug: BKR6E gapped to abou .030" and don't use the BKR6E-11 because the -11 tag means the ground strap is indexed higher from the electrode to accomodate .044" gapping. This prevents the strap from being parallel to the electrode when you squeeze it down to .030"
The stock coil should be just fine for the boost you're running. Many people make 400whp on the stock coil.
Re: Supercharger - Ignition/Timing help (KATwo40)
The dyno tech explained to me that the wideband would read rich because there was all the unburnt fuel in the exhaust if the spark was blown out. These aren't my words, just what he knew.KATwo40 wrote:There are a few things wrong with this whole deal, and I'm just gonna start from the top.
First of all, I'd say you're not blowing out the spark, you're just running ridiculously rich from about 3500 on. When the spark blows out, it shows as a lean spike, not a rich spike. Remember, the AFR's are monitored via wideband O2 sensor, so you if the spark is gone, regardless of fuel content in the cylinder, the O2 reading will be lean, since none was burned and the amount of oxygen is abundant.
Additionally, the lower rpm areas could also use some smoothing.
Secondly, how did you go about pulling the base timing? Did you go through the steps detailed in the FSM, or did you simply just crank the distributor without going through these steps? If you did the latter, then there's a pretty solid chance that your timing is now all jacked up (I did this when I very first turbocharged my KA, 2 yrs ago...).
I agree that a BTM might not be the best option here. I'd say you need to look into things such as:
MegaSquirt 2 ver. 3.0Daughterboard installed in the stock ECU (EEPROM programming)AEM EMS full standaloneHaltechF.A.S.T.MoTec
and any other standalone system you could find.
I currently use a daughterboard setup on my S13, but I'm soon to upgrade to a MS2 (MegaSquirt).
Oh yeah, lose the iridium plugs. Go with NGK plug: BKR6E gapped to abou .030" and don't use the BKR6E-11 because the -11 tag means the ground strap is indexed higher from the electrode to accomodate .044" gapping. This prevents the strap from being parallel to the electrode when you squeeze it down to .030"
The stock coil should be just fine for the boost you're running. Many people make 400whp on the stock coil.
The low rpm settings are rough because I may have a small vacuum leak, and the IACV that I added on recently may not be completely closing.
I didn't pull the base timing myself, the dyno techs did. They loosened the bolts but the disty didnt want to twist. The lightly knocked it by the top along the slot the top bolt is in as they watched with a timing light. I think they said it was back 2 lines, but I may not remember correctly.
Are standalones/Roms the best option here? I was hoping not to have to go to those lengths, as I should only make a little north of 200 whp. The engine runs really smooth, the only real issue is the crazy afrs after 3500ish and the need to put back some timing to get power. The tech said all I should need for timing is something that can set a map based on rpm and boost if possible.
Not trying to be rude in any way whatsoever, but your dyno techs are wrong. The sensing device used to measure AFR's measures oxygen content in the exhaust. If the spark is blown out, the oxygen is unburnt, and WILL show as a lean spike. The wideband O2 sensor doesn't measure the fuel content in the ehxuast.
As for just turning the distributor without following the FSM directions, it doesn't necessarily always work out. In my case, I could change the dizzy and watch the marks fly around, but then the car ran really crappy under load. Use the FSM directions to set the timing to around 12-15* BTDC if you're dead set on having no timing control and using only the SAFC.
Having way too much fuel can also result in knock, so you gotta get the AFR out of the way first.
Any fully tuneable system is always a better option over a piggyback system. Despite shooting for small hp numbers, the tuning platform is the most critical part of the entire setup.
I'd say go with a low budget standalone such as the MS2. It provides live tuning, full maptrace and a multitude of other functions. It can be wired to use the stock sensor array, eliminates the MAF (uses speed density) and comes with an on-board MAP sensor (located within the ECU).
Plus, the MS2 is less than $400.
Modified by KATwo40 at 8:00 PM 1/4/2007
As for just turning the distributor without following the FSM directions, it doesn't necessarily always work out. In my case, I could change the dizzy and watch the marks fly around, but then the car ran really crappy under load. Use the FSM directions to set the timing to around 12-15* BTDC if you're dead set on having no timing control and using only the SAFC.
Having way too much fuel can also result in knock, so you gotta get the AFR out of the way first.
Any fully tuneable system is always a better option over a piggyback system. Despite shooting for small hp numbers, the tuning platform is the most critical part of the entire setup.
I'd say go with a low budget standalone such as the MS2. It provides live tuning, full maptrace and a multitude of other functions. It can be wired to use the stock sensor array, eliminates the MAF (uses speed density) and comes with an on-board MAP sensor (located within the ECU).
Plus, the MS2 is less than $400.
Modified by KATwo40 at 8:00 PM 1/4/2007
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Florida240sx
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Back 2 lines? each line is 5 degrees.... for 8psi you only need to be back 2-3degrees. A btm would work fine. Sounds like these tuners don't know what they are doing.Is there anyway for you to have no boost built by the supercharger? Get you daily driving tune first......so everything is smooth. Then do quick pulls and slowly work your way up the rpms, don't take it to redline all the time.
The same rules for turbocharging don't necessarily apply here, Florida. Remember, the supercharger is quite inefficient, and there's no significant cooling on this system (if I remember seeing this posted in the KA section a while back), so the IAT's are going to be pretty high.
Therefore, the BTM and/or 2-3* per 8psi rule don't really work here.
Therefore, the BTM and/or 2-3* per 8psi rule don't really work here.
Re: (KATwo40)
he did say they retarded the base timing until they couldn't hear any pinging, so 10* is probably what they need.
Re: (crzycav86)
This is not a very good way to get it tuned. Where were they hearing the ping? Under what load/rpm point? If they heard it at peak torque (prolly around 4000rpm), then they don't need to lose a whole 10* across the entire board. Running base timing at 10* BTDC sucks.crzycav86 wrote:he did say they retarded the base timing until they couldn't hear any pinging, so 10* is probably what they need.
The best thing for this particular setup is going to be a fully tuneable system. There's no way around that.
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WDRacing
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Re: Supercharger - Ignition/Timing help (Mad_Man)
Wow...I just read through everything here and I'm not really sure what to post.
First off, we need to get ALL of the facts straight. What are you running for timing?
Is the 8psi steady all the way up and from what rpm do you achieve full boost?
You're not blowing out spark, so lets ignore that. In fact, I'd increase the gap to .036 and decrease it only when I ran into stuttering issues. The less gap you have the smaller the spark, so always run the most gap possible. 8psi is not that much.
The SC is fairly large, so its not that inefficient. So I doubt its output temps are any hotter then then a turbo. I've seen several diy setups with no intercooler run just fine with no timing retard at all at about 6 psi. If you are actually hearing the knock, you've got more problems then timing retard. Especially with that much fuel being pumped in. You should be running full base timing IMO until you lean out the fuel mixture and get it into the high 11's.
At 3500 or so you're hitting peak torque, which is where everything goes awry.
Did you mess with the SAFC at all and try to level out the AFR's.
So far, I'm going to say the guys doing the Dyno tuning don't really have a clue.
At most, you'll need a couple of degree's timing retard on boost. If you're still getting knock, timing is not the issue.
WD
First off, we need to get ALL of the facts straight. What are you running for timing?
Is the 8psi steady all the way up and from what rpm do you achieve full boost?
You're not blowing out spark, so lets ignore that. In fact, I'd increase the gap to .036 and decrease it only when I ran into stuttering issues. The less gap you have the smaller the spark, so always run the most gap possible. 8psi is not that much.
The SC is fairly large, so its not that inefficient. So I doubt its output temps are any hotter then then a turbo. I've seen several diy setups with no intercooler run just fine with no timing retard at all at about 6 psi. If you are actually hearing the knock, you've got more problems then timing retard. Especially with that much fuel being pumped in. You should be running full base timing IMO until you lean out the fuel mixture and get it into the high 11's.
At 3500 or so you're hitting peak torque, which is where everything goes awry.
Did you mess with the SAFC at all and try to level out the AFR's.
So far, I'm going to say the guys doing the Dyno tuning don't really have a clue.
At most, you'll need a couple of degree's timing retard on boost. If you're still getting knock, timing is not the issue.
WD
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Florida240sx
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BTM would work 10x better than current set-up of base timing way back. BTM .5 for every psi puts him at 4degress off. give him better idle and protection.How would that not work??? Yes A/F needs to be monitored and exhaust temp and knock etc. But that is needed in all set-ups.Guy in Nopi with knights kit was runnign an sr tune I beleive, but he had something different I beleive larger injectors so he only had like 11mpg, but he was able to make it to the show
Re: Supercharger - Ignition/Timing help (WDRacing)
After hearing your comments, I agree with the criticism of the dyno techs and am thoroughly unimpressed by them.
The tech pretty much put all his faith in a poor spark and timing but it seems to be otherwise. I'm actually thinking that there may be a leak somewhere now. It runs rough around idle, but does idle with the help of the IACV, which is indicative of a vacuum leak. Does that sound correct? And so, assuming that there is a leak, that would become a boost leak when its under boost and that would explain why it goes crazy after hitting full boost? Well, thats my new theory and I'll soon test it by pressurizing the whole intake.
To answer your questions:
I am not positive what the timing is at because I don't have a light. But the procedure they followed was to mess with the SAFC and then do a baseline run. You could hear the light ping when at max boost. They then loosened the two bolts on the disty and then knocked the top of it to the right until we couldn't hear anything. I think this was around 2 lines, but they didn't use a light when they added a little bit more timing.
As for boost, immediately upon hitting the gas theres 5 psi. If in fourth gear (what we did all the pulls in) starting at 2000rpms, theres 5psi immediately and 8-9psi by 3000rpms.
The tech was messing with the SAFC to smooth out the AFRs and to smooth the idle, but i think those problems are, again, caused by some sort of leak.
I fairly disappointed with the techs on this one and it surprises me. They have been around quite awhile and are actually like 3 minutes from my house. They are nice though, only charging me 1.25hrs on the dyno though I was there from 3pm to 6pm. He was pretty confident in the whole spark being blown out, so thats discouraging if he was dead wrong. He said that he could fix the tune problems if he could customize the timing based on rpm and secondly boost.
The tech pretty much put all his faith in a poor spark and timing but it seems to be otherwise. I'm actually thinking that there may be a leak somewhere now. It runs rough around idle, but does idle with the help of the IACV, which is indicative of a vacuum leak. Does that sound correct? And so, assuming that there is a leak, that would become a boost leak when its under boost and that would explain why it goes crazy after hitting full boost? Well, thats my new theory and I'll soon test it by pressurizing the whole intake.
To answer your questions:
I am not positive what the timing is at because I don't have a light. But the procedure they followed was to mess with the SAFC and then do a baseline run. You could hear the light ping when at max boost. They then loosened the two bolts on the disty and then knocked the top of it to the right until we couldn't hear anything. I think this was around 2 lines, but they didn't use a light when they added a little bit more timing.
As for boost, immediately upon hitting the gas theres 5 psi. If in fourth gear (what we did all the pulls in) starting at 2000rpms, theres 5psi immediately and 8-9psi by 3000rpms.
The tech was messing with the SAFC to smooth out the AFRs and to smooth the idle, but i think those problems are, again, caused by some sort of leak.
I fairly disappointed with the techs on this one and it surprises me. They have been around quite awhile and are actually like 3 minutes from my house. They are nice though, only charging me 1.25hrs on the dyno though I was there from 3pm to 6pm. He was pretty confident in the whole spark being blown out, so thats discouraging if he was dead wrong. He said that he could fix the tune problems if he could customize the timing based on rpm and secondly boost.
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Florida240sx
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Re: (Florida240sx)
Idle was never very good. At the moment, if the carhas been running for awhile, the IACV can keep thecar alive at 800rpms or so.
He unplugged the TPS, but nothing really happened. If anything, the engine speed surged a bit.
He unplugged the TPS, but nothing really happened. If anything, the engine speed surged a bit.
After work today I made the DIY boost leak detector.Apparently one of the fittings I made where the siliconintake bend connects to the blower was warped fromwhen I welded it. There was a decent leak there.
Also the IACV seems to be shot, as air escaped throughthe inlet when the engine was off. Suction can also be felton the inlet of the IACV even after 3000rpms. I'll abandonusing that for now, and fix the other leaking fitting.
The liquid gasket between the supercharger and plate isleaking in only two places and they are relatively minor.I'll soon seal those from the outside with sealant thatI'll pick up tomorrow. So this part would be a boost leak,not that big, but would even a small boost leak cause theproblems shown on the dyno graph?
I should be able to fix these tomorrow without issue. It would be nice to have more time to work on it, butafter all I am 17 and busy applying to colleges.
Also the IACV seems to be shot, as air escaped throughthe inlet when the engine was off. Suction can also be felton the inlet of the IACV even after 3000rpms. I'll abandonusing that for now, and fix the other leaking fitting.
The liquid gasket between the supercharger and plate isleaking in only two places and they are relatively minor.I'll soon seal those from the outside with sealant thatI'll pick up tomorrow. So this part would be a boost leak,not that big, but would even a small boost leak cause theproblems shown on the dyno graph?
I should be able to fix these tomorrow without issue. It would be nice to have more time to work on it, butafter all I am 17 and busy applying to colleges.
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nissanfanatic
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Re: (Mad_Man)
Connect the inlet of your IACV to a place that will see pressure as well i.e. after the compressor. Its not shot because air is leaking out of the inlet if you pressurize the intake manifold.. Its normal..Mad_Man wrote:After work today I made the DIY boost leak detector.Apparently one of the fittings I made where the siliconintake bend connects to the blower was warped fromwhen I welded it. There was a decent leak there.
Also the IACV seems to be shot, as air escaped throughthe inlet when the engine was off. Suction can also be felton the inlet of the IACV even after 3000rpms. I'll abandonusing that for now, and fix the other leaking fitting.
The liquid gasket between the supercharger and plate isleaking in only two places and they are relatively minor.I'll soon seal those from the outside with sealant thatI'll pick up tomorrow. So this part would be a boost leak,not that big, but would even a small boost leak cause theproblems shown on the dyno graph?
I should be able to fix these tomorrow without issue. It would be nice to have more time to work on it, butafter all I am 17 and busy applying to colleges.
I had one very minor leak just a couple weeks ago that caused me to run in the sub 10s as opposed to the normal 11:1 that I run.. Even small leaks can cause annoying problems...
Re: (nissanfanatic)
Should I still be able to feel suction from the IACV inlet when the motor is not idling? Like even at 3-5k rpms? Thats the main reason that I don't think it's alright.nissanfanatic wrote:Connect the inlet of your IACV to a place that will see pressure as well i.e. after the compressor. Its not shot because air is leaking out of the inlet if you pressurize the intake manifold.. Its normal..
I had one very minor leak just a couple weeks ago that caused me to run in the sub 10s as opposed to the normal 11:1 that I run.. Even small leaks can cause annoying problems...
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watty
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Re: (Chezedik)
Hey guys.
I'm running 370's and Bikirom. My base timing is stock(note: I'm not endorsing this without some sort of descent engine management) and I'm running 11psi. I've had no trouble with knocking and the plugs look great. Actually, I'm running an almost stock fuel map but the K value is modified. It definately sounds like you are drowning the engine. I'm still in the process of backing out fuel with only the 370's.
PS - On the trip to NOPI, I got 26 mpg and as of yesterday 22mpg in town.
Watty
I'm running 370's and Bikirom. My base timing is stock(note: I'm not endorsing this without some sort of descent engine management) and I'm running 11psi. I've had no trouble with knocking and the plugs look great. Actually, I'm running an almost stock fuel map but the K value is modified. It definately sounds like you are drowning the engine. I'm still in the process of backing out fuel with only the 370's.
PS - On the trip to NOPI, I got 26 mpg and as of yesterday 22mpg in town.
Watty
Anybody have an idea at what a 16x2 (500rpm increments by high and low throttle) fuel table should look like? The dyno tech's settings are basically useless since there is no longer any leaks. Theres 8-9psi of boost by 3000rpms in 4th gear with 480cc injectors.
Another question....So the car would barely idle with the IACV on an plugged in. It would struggle and slowly move between 1k and 1.5k rpms. I took it off and plugged the hole and it wouldnt idle at all. When I put it back on and plugged the inlet to the IACV, it idled reasonably well at 700rpms. Why would it idle with the IACV on but plugged and yet not run with it off and the nipple plugged?
Another question....So the car would barely idle with the IACV on an plugged in. It would struggle and slowly move between 1k and 1.5k rpms. I took it off and plugged the hole and it wouldnt idle at all. When I put it back on and plugged the inlet to the IACV, it idled reasonably well at 700rpms. Why would it idle with the IACV on but plugged and yet not run with it off and the nipple plugged?
16x2 fuel tables would be awful. That means that you have 16 rpm boxes (which is okay), but only two load boxes (not at all good). Basically, you could tune fuel at every 500 rpm for 8000 rpm, but you could only tune based on MAFv or TPS output at two points. A good computer will interpolate based on a four box setup, but even then, your tune would be terrible. What computer are you talking about?
Also, on the IACV, apparently you have a secondary air path on the IACV. It is no wonder why you have no ability to idle with it removed and plugged, though.
Also, on the IACV, apparently you have a secondary air path on the IACV. It is no wonder why you have no ability to idle with it removed and plugged, though.
Re: Supercharger - Ignition/Timing help (Mad_Man)
Losing spark is defenitly not the issue. An O2 sensor reads O2 not fuel. If there is no combustion you have copious O2 so the sensor shows full lean.
Why not just learn to tune your ECU? If it is the DE just get a Bikirom. If it is the E and eprom socket.
Look real good for leaks and make sure your MAF is straight.
Why not just learn to tune your ECU? If it is the DE just get a Bikirom. If it is the E and eprom socket.
Look real good for leaks and make sure your MAF is straight.
Anybody think that I could fix the top end troubles and lack of powerwith adjustable timing? I'm thinking along the lines of the #121-8981MSD Programmable Timing Computer as I was thinking of upgrading theignition anyways with something like a MSD 6A or 6AL with Blaster Coiland some performance wires.
It seems like timing is the only thing not quite right. The leaks are all fixedand it idles when warm now (Soon going to put on the valve thats openwhen its cold, forget what its called). The torque up until 4k or so is great,so shifting at that on the road yeilds very satisfying performance. So, I thinkits down to the timing, to add some back in at the top end.
Anybody care to validate or shoot down these "conclusions"?
Any other theories are welcome as well, I have eliminated the boost contolleras the source of the top end troubles. I did that by setting it just above what the supercharger could produce (12psi) to prevent any spikes when theres no load on the engine.
It seems like timing is the only thing not quite right. The leaks are all fixedand it idles when warm now (Soon going to put on the valve thats openwhen its cold, forget what its called). The torque up until 4k or so is great,so shifting at that on the road yeilds very satisfying performance. So, I thinkits down to the timing, to add some back in at the top end.
Anybody care to validate or shoot down these "conclusions"?
Any other theories are welcome as well, I have eliminated the boost contolleras the source of the top end troubles. I did that by setting it just above what the supercharger could produce (12psi) to prevent any spikes when theres no load on the engine.
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Florida240sx
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