8.76@156 69 Nova 5.3
Again, thanks guys.
I’ve been reviewing my data logs, not liking what I’m seeing.
At 20 psi it went 153. AFR trace was clean.
At 22 psi it went 156. AFR trace showed lean spikes. I assumed it was noise.
At 24 psi no mph change. But a lot more lean spikes.
I’m reasonably sure I’m losing spark. So need to investigate further. Plug gap, coil condition (D585) etc.
Will have to wait till next year though. That was the last race of the year. Unless I throw it on the dyno over the winter.
And Joe, I remember when the old nitrous rat motor felt pretty good going 143. My mph shows 158 just past the stripe and it’s still pulling. Pretty wild. And the old turd drives well at speed.
Ron
I’ve been reviewing my data logs, not liking what I’m seeing.
At 20 psi it went 153. AFR trace was clean.
At 22 psi it went 156. AFR trace showed lean spikes. I assumed it was noise.
At 24 psi no mph change. But a lot more lean spikes.
I’m reasonably sure I’m losing spark. So need to investigate further. Plug gap, coil condition (D585) etc.
Will have to wait till next year though. That was the last race of the year. Unless I throw it on the dyno over the winter.
And Joe, I remember when the old nitrous rat motor felt pretty good going 143. My mph shows 158 just past the stripe and it’s still pulling. Pretty wild. And the old turd drives well at speed.
Ron
Thread Starter
Joined: Aug 2011
Posts: 4,729
Likes: 814
From: Portland, OR
Thanks. I’m on the stock ecu so the dwell settings are from the L33 truck. It’s two tables one has dwell the other is a multiplier. I’d have to decipher it to see what the actual dwell is.
My plugs are NGK 8 heat range non resistor race plugs. Gap is .022 out of the box.
Wires are AC Delco 7mm spiral core. 700 ohms.
I saw saw this last year too, but sadly suffered a hard drive crash and lost all my logs. Even though I shelled out $600 to a data recovery company.......I did get all my tunes, photos etc back.
So what was your issue?
My plugs are NGK 8 heat range non resistor race plugs. Gap is .022 out of the box.
Wires are AC Delco 7mm spiral core. 700 ohms.
I saw saw this last year too, but sadly suffered a hard drive crash and lost all my logs. Even though I shelled out $600 to a data recovery company.......I did get all my tunes, photos etc back.
So what was your issue?
Thanks. I’m on the stock ecu so the dwell settings are from the L33 truck. It’s two tables one has dwell the other is a multiplier. I’d have to decipher it to see what the actual dwell is.
My plugs are NGK 8 heat range non resistor race plugs. Gap is .022 out of the box.
Wires are AC Delco 7mm spiral core. 700 ohms.
I saw saw this last year too, but sadly suffered a hard drive crash and lost all my logs. Even though I shelled out $600 to a data recovery company.......I did get all my tunes, photos etc back.
So what was your issue?
My plugs are NGK 8 heat range non resistor race plugs. Gap is .022 out of the box.
Wires are AC Delco 7mm spiral core. 700 ohms.
I saw saw this last year too, but sadly suffered a hard drive crash and lost all my logs. Even though I shelled out $600 to a data recovery company.......I did get all my tunes, photos etc back.
So what was your issue?
Mine was actually my PID settings. They were off enough to keep the wastegate fluctuating trying to hold target boost which made the car feel like it was breaking down. Same thing happened to Bad68ss who was the one who told me to check them. I spent the whole 2017 year changing coils, plugs, wires, electrical, grounds.....sucked!
Thread Starter
Joined: Aug 2011
Posts: 4,729
Likes: 814
From: Portland, OR
Ah. Got it.
I’m using an EBoost 2 and the boost is rock solid.
I have this basic tune in 2 other turbo cars I tune, and don’t see this issue. Both run in the 8’s. I finally caught up with them!
I use the std BR7EF plugs in those. They have different GM coils as well.
My plugs being a semi projected tip might be more picky on plug gap.
Ron
I’m using an EBoost 2 and the boost is rock solid.
I have this basic tune in 2 other turbo cars I tune, and don’t see this issue. Both run in the 8’s. I finally caught up with them!
I use the std BR7EF plugs in those. They have different GM coils as well.
My plugs being a semi projected tip might be more picky on plug gap.
Ron
Originally Posted by 3 window
I haven’t pushed your boost numbers but I haven’t had any troubles with the ngk 4091 gapped to .020-.022.
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same thread pitch and reach, they'll fit.
gasket seal instead of taper and no resistor.
why do you guys run non-resisted plugs? i've always been told efi cars need resistor plugs
gasket seal instead of taper and no resistor.
why do you guys run non-resisted plugs? i've always been told efi cars need resistor plugs
Restricted User
Joined: Mar 2014
Posts: 7,192
Likes: 109
From: Ohio
I ran into this recently. I built a small engine dyno capable of 50 horsepower in my garage to test some "ideas" I have on $99 harbor freight engines.
I kept breaking optical sensors I was using for RPM when they would contact sprocket teeth during vibration. I swapped to a stock 5.3 crankshaft sensor to read the crank key on the engine for RPM.
I couldn't get a stable reading. RPM was all over the place. Come to find out, I was getting an RPM reading on my arduino even if I unplugged the crank sensor, from RFI from the spark plug during every spark.
Took me 2 days to program around it.
Not saying it can't be done, but I wouldn't even attempt to mess with that in an EFI car. It still messes with my analog sensors on the dyno, like wideband inputs.
Ah. Got it.
I’m using an EBoost 2 and the boost is rock solid.
I have this basic tune in 2 other turbo cars I tune, and don’t see this issue. Both run in the 8’s. I finally caught up with them!
I use the std BR7EF plugs in those. They have different GM coils as well.
My plugs being a semi projected tip might be more picky on plug gap.
Ron
I’m using an EBoost 2 and the boost is rock solid.
I have this basic tune in 2 other turbo cars I tune, and don’t see this issue. Both run in the 8’s. I finally caught up with them!
I use the std BR7EF plugs in those. They have different GM coils as well.
My plugs being a semi projected tip might be more picky on plug gap.
Ron
I tried 3 different plugs also trying to see if that might be the issue as well. Had the BRE7EF's, the BR8's and BR10's with no difference.
Hope you find the issue quickly Ron and don't forget to let us all know what it was!
Originally Posted by 3 window
Not sure where you got our info, but unless you consider the 243 head aftermarket, then no. Factory heads.
The heads actually have both seats in them. The tapered seat is a smaller diameter and the shoulder for the gasketed plug is around the outside of the taper.
Thread Starter
Joined: Aug 2011
Posts: 4,729
Likes: 814
From: Portland, OR
Thread Starter
Joined: Aug 2011
Posts: 4,729
Likes: 814
From: Portland, OR
On the RFI, that’s why I use high resistance stock GM plug wires. That and the fact imho, most aftermarket wires quality sucks!
I wanted an 8 heat range plug. Hard to find in a resistor plug with a semi projected tip.
The heat in the plug threads tell me I have the correct heat range.
I dialed my car in with TR6 when I first began. Tried the BR7 and it idled like ****. AFR went rich as well.
So I tried the NGK race plugs. I’ve run them ever since. They run so clean you can practically put them back in the box after a season
Are they causing this issue? Unknown. I’ll fess up if they are.
Ratical thanks. It will have to wait till next year, but I will report what I find.
Ron
I wanted an 8 heat range plug. Hard to find in a resistor plug with a semi projected tip.
The heat in the plug threads tell me I have the correct heat range.
I dialed my car in with TR6 when I first began. Tried the BR7 and it idled like ****. AFR went rich as well.
So I tried the NGK race plugs. I’ve run them ever since. They run so clean you can practically put them back in the box after a season
Are they causing this issue? Unknown. I’ll fess up if they are.
Ratical thanks. It will have to wait till next year, but I will report what I find.
Ron
I switched from 6's to 7's, more for a little added safety, gap set at .028. I was chasing a backfire
like sound out the exhaust above 14 PSI, datalog showed nothing out of ord. I wonder if I need to
tighten up the gap. I also use the projected tip, feel its cleaner on the street.
like sound out the exhaust above 14 PSI, datalog showed nothing out of ord. I wonder if I need to
tighten up the gap. I also use the projected tip, feel its cleaner on the street.