Strokercharged95GT 13b-REW Build
#652
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I would love to upgrade to the modular, but the $1500 price tag just isn't worth it for me. I am trying to keep from spending a lot of money on this car because inevitably the motor will completely destruct one of these days and I will not spend 5k on a rebuild. I will just strip the car and sell parts off at that point.
#653
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Nice little easy tug tonight. Having to dial in some of my fuel since the new flex fuel sensor reads a bit less ethanol (runs leaner/needs about 5% more fuel to compensate).
The light blue line (flex fuel sensor) seems to be reading more accurate with less signal loss..
Wasn't able to pull it above 6k in third because it would be way to fast for my area. No weird issues with the sensors, took the dwell down a bit into the high 3 ms at 6, 7, and 8k.
Can really see the boost ramp up like a centrifugal supercharger.
The light blue line (flex fuel sensor) seems to be reading more accurate with less signal loss..
Wasn't able to pull it above 6k in third because it would be way to fast for my area. No weird issues with the sensors, took the dwell down a bit into the high 3 ms at 6, 7, and 8k.
Can really see the boost ramp up like a centrifugal supercharger.
#654
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Took the car out last night and still getting the sensor issues. At WOT and 25-26 psi feels like the car isn't pulling that hard and sensor are acting up. I'm thinking changing the plugs next. Would fouling plugs cause these symtoms. On my old coils the car would simply misfire hesitate under heavy loads. With the smart coils, would it stand to reason that if the spark doesn't discharge into the plug that this would havoc on the grounds/sensors?
What i'm getting at is misfiring due to fouling plugs disguise itself as a coil problem/sensor issue and not necessarily simply misfiring?? These issues always occur under heavy boost and high RPMs....
What i'm getting at is misfiring due to fouling plugs disguise itself as a coil problem/sensor issue and not necessarily simply misfiring?? These issues always occur under heavy boost and high RPMs....
#656
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AFR is going a bit wacky. Autolite 3932 (heat range 10) Leading, 3931 (heat range 11 trailing)....
I will change out plugs sometime this week and see if it gets better....
I will change out plugs sometime this week and see if it gets better....
#657
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World class ignition, dirt cheap plugs. What could go wrong
even though they’re racing plugs, a reciprocating engine is never going to see the abuse that a turbo rotary will have. You might at least consider a better plug electrode material like platinum. That nickel electrode is probably wearing fast. It really shouldn’t be causing associated electrical issues with other sensors. What gap are you running? Looking at some threads on RX7 Club, people there seem to be running some substantial dwell settings for a direct-fire configuration.
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even though they’re racing plugs, a reciprocating engine is never going to see the abuse that a turbo rotary will have. You might at least consider a better plug electrode material like platinum. That nickel electrode is probably wearing fast. It really shouldn’t be causing associated electrical issues with other sensors. What gap are you running? Looking at some threads on RX7 Club, people there seem to be running some substantial dwell settings for a direct-fire configuration.
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Last edited by TeamRX8; 02-16-2020 at 07:47 PM.
#658
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Gap is 18-20 thousands. I will try some new plugs first so see if the car is better. If it is, I will move to better plugs. I still have a bad taste in my mouth from spending $120 on new plugs and having them foul in literally 100 miles after a rebuild...
#659
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Well it turns out those Autolite plugs are not resistor type. I’d suspect it could be part of an interference issue if that’s what is really going on.
Also, those plugs fouled on what ignition setup? Fouled plugs can be cleaned, so hopefully you still have them around. No saving eroded plugs, but the gap seems a bit low imo. I was thinking somewhere around 0.025 was more appropriate. Also, it seems to me that this being a street car on E fuel that’s rarely ever wound out in 3rd or higher that it likely doesn’t need to be so cold. Cold plugs are more for extended loads where heat builds up over time (racing). 11T for a street car under your circumstances seems rather extreme.
Also, those plugs fouled on what ignition setup? Fouled plugs can be cleaned, so hopefully you still have them around. No saving eroded plugs, but the gap seems a bit low imo. I was thinking somewhere around 0.025 was more appropriate. Also, it seems to me that this being a street car on E fuel that’s rarely ever wound out in 3rd or higher that it likely doesn’t need to be so cold. Cold plugs are more for extended loads where heat builds up over time (racing). 11T for a street car under your circumstances seems rather extreme.
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strokercharged95gt (02-18-2020)
#660
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Thanks for the info, didn't even think about the resistor/non resistor plug type. Its obvious that the heavier the load (more RPM/more boost) = more ECU/sensor interference which is not good.
I can post some graphs of this ECU/sensor interference. It causes the RPMs to spike (not wheel spin), caused the injector duty cycle on all 3 stage to go bonkers, AFR starts heavily fluctuating likely due to the injectors getting interference, I will even see some times that the ECU will show a rev limit cut when i'm 2000 RPMs short of 8200/8300...... This started with the new coils, but the issue went away once I ran a dedicated ground to the battery in the truck. Now its back
What plugs would you recommend? (preferably gap-able) I plan on pushing this thing up to 29-30 psi if I can get the motor to fire correctly. Heat range 10 on the trailing position (only 1 heat range colder than stock) seems a bit hot for 2 bar of boost? I also don't want to have a plug that only gets me 100 miles before fouling... I know there is no magic bullet here, I am just trying to avoid an expensive plug that I have to change monthly.
I can post some graphs of this ECU/sensor interference. It causes the RPMs to spike (not wheel spin), caused the injector duty cycle on all 3 stage to go bonkers, AFR starts heavily fluctuating likely due to the injectors getting interference, I will even see some times that the ECU will show a rev limit cut when i'm 2000 RPMs short of 8200/8300...... This started with the new coils, but the issue went away once I ran a dedicated ground to the battery in the truck. Now its back
What plugs would you recommend? (preferably gap-able) I plan on pushing this thing up to 29-30 psi if I can get the motor to fire correctly. Heat range 10 on the trailing position (only 1 heat range colder than stock) seems a bit hot for 2 bar of boost? I also don't want to have a plug that only gets me 100 miles before fouling... I know there is no magic bullet here, I am just trying to avoid an expensive plug that I have to change monthly.
Last edited by strokercharged95gt; 02-18-2020 at 06:56 AM.
#661
Modulated Moderator
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BR10EIX 6801 NGK
These are the plugs I run for street and light duty track on mine. The only issue you will have is you need to make a thin wall socket so you can install them... otherwise they interfere with the ridge around the spark plug hole. You can also machine the housing to remove the ridge..... that's the easy way if you are building a new motor and want to use them
I use the expensive NGK race plugs when I'm running strictly track in an 11 or 11.5 heat range.... but they tend to foul really easily
These are the plugs I run for street and light duty track on mine. The only issue you will have is you need to make a thin wall socket so you can install them... otherwise they interfere with the ridge around the spark plug hole. You can also machine the housing to remove the ridge..... that's the easy way if you are building a new motor and want to use them
I use the expensive NGK race plugs when I'm running strictly track in an 11 or 11.5 heat range.... but they tend to foul really easily
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strokercharged95gt (02-18-2020)
#664
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Plugs ordered, should be here Monday.
#666
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Spark Plug - Racing :: NGK R6725-10.5
Here they use these for more than 450hp.Not recommended for street use, unless you are running a highly boosted turbo-charged engine.
But they are delicate.
Last edited by gamaliel31; 02-21-2020 at 11:14 AM.
#667
Boosted Kiwi
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Spark Plug - Racing :: NGK R6725-10.5
Here they use these for more than 450hp.Not recommended for street use, unless you are running a highly boosted turbo-charged engine.
But they are delicate.
#668
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Yes, those are the $40 each plugs he specifically posted about not wanting to buy.
Just FYI that there’s a similar L/T racing plug set made specific for the Renesis due to the slightly different reach and they’re also iridium. Of course general retail price tends to be higher than those 13B race plugs.
the grounding strap that the electrode discharges to is much finer on these racing plugs, almost a thin wire, compared to a standard plug ground strap. Too hot, too lean, detonation, mishandling during gapping, etc. can result in it disappearing ...
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Just FYI that there’s a similar L/T racing plug set made specific for the Renesis due to the slightly different reach and they’re also iridium. Of course general retail price tends to be higher than those 13B race plugs.
the grounding strap that the electrode discharges to is much finer on these racing plugs, almost a thin wire, compared to a standard plug ground strap. Too hot, too lean, detonation, mishandling during gapping, etc. can result in it disappearing ...
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Last edited by TeamRX8; 02-23-2020 at 07:52 AM.
#671
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Don't think it would be fair if I didn't provide an update.
New 6801 plugs in gaped at 0.024-0.025"
A few pulls and I don't see any of the weird sensor interference anymore, but the car doesn't seem very fast in the upper RPMs. I'm around 10 MPH/S and should be over 11 MPH/S with this weather and boost level, and the car almost seems like its drowning in fuel even though the AFR shows around 11.5:1.... It is acting like i'm 10-10.5 :1. The old autolites showed a rich condition, but that could just be the premix...
Even though I replaced the 4.9 sensor, I am now thinking that the Prosport gauge is outputting the wrong voltage to the ECU....
I mean just look at the injector duty cycle.... near the top of 2nd gear at 7500 RPMs wit 40% ethanol it should that I am at 90-100% DC on a 1000/1000/1650 cc of injector???? (that seems very high to me)
It kinda makes sense because the drives like a beast at 12:1+ AFRs
Anyways it looks like the new plugs are helping with sensor interference, but I may be chasing my tail on a AFR that is too rich (while logging its normal).....
My next step may be to try a better wide-band like a MTX-L.... The horror of chasing horsepower
New 6801 plugs in gaped at 0.024-0.025"
A few pulls and I don't see any of the weird sensor interference anymore, but the car doesn't seem very fast in the upper RPMs. I'm around 10 MPH/S and should be over 11 MPH/S with this weather and boost level, and the car almost seems like its drowning in fuel even though the AFR shows around 11.5:1.... It is acting like i'm 10-10.5 :1. The old autolites showed a rich condition, but that could just be the premix...
Even though I replaced the 4.9 sensor, I am now thinking that the Prosport gauge is outputting the wrong voltage to the ECU....
I mean just look at the injector duty cycle.... near the top of 2nd gear at 7500 RPMs wit 40% ethanol it should that I am at 90-100% DC on a 1000/1000/1650 cc of injector???? (that seems very high to me)
It kinda makes sense because the drives like a beast at 12:1+ AFRs
Anyways it looks like the new plugs are helping with sensor interference, but I may be chasing my tail on a AFR that is too rich (while logging its normal).....
My next step may be to try a better wide-band like a MTX-L.... The horror of chasing horsepower
Last edited by strokercharged95gt; 02-23-2020 at 10:08 AM.
#672
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So for the 13B (non-Renesis) the NGK R6725 race plug is platinum-platinum and the NGK R7420 is identical except iridium-platinum
From what I’ve seen the iridium plug sells within a couple of dollars of the platinum plug. Iridium is probably the better choice.
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From what I’ve seen the iridium plug sells within a couple of dollars of the platinum plug. Iridium is probably the better choice.
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