The great spark plug question

[PetroleumJunkie412]

Ok, so to ensure I cause a tremendous amount of chaos, I'm looking for some input of heat ranges of plugs.

Engine is a 2.9. It is NOT stock:

DIYAutotune Megasquirt PNP v1.5
24lb Bosch 4 hole injectors from a Saleen
Spartan Wideband Controller and Bosch 4.9 LSU Wideband O2 sensor
Phenolic upper intake spacers
J & C Enterprises Performance Heads
Ported lower intake
Ported Upper intake
1986 Throttle Body
Free floating Rockers
Polished rocker assemblies
Melling (I think...) lifters
JBA Headers
2.5" exhaust with Flowmaster FlowFX
PCV catch can
Stupid cone air filter
Bosch iridium plugs
"Performance" Cap, rotor, and wires
MSD Blaster Coil


Current ignition table:

Current air fuel ratio table:

Not currently having any detonation issues (knock/ping). I'm also running 93 pump gas.

I have heard that I will need to run colder plugs once I put the supercharger on. Looking at running NGK 7993 plugs. They are heat range 10. Plug chart:

My questions are:

Are these too cold? Am I going to wind up carbon fouled to hell and back?

Current tune is untested on 87 pump gas, but previous attempts weren't great. It would knock. The again, I had my O2 settings majorly fouled up and the Megasquirt was confused as hell.

If I can avoid fouling, will a colder plug help with knock and running lower grades of fuel?

And is this range of "cold" cold enough to use with the blower?

Thanks all!

 

[Dirtman]

Put a 4.0 in it...

 

[PetroleumJunkie412]

Put a 4.0 in it...

I just plain don't like you anymore ??






Joking!

 

[Dirtman]

I haven't delt with plug temps since I use to race quads when I was a teenager. I always remeber the higher compression I ran the colder the plug though.

 

[RonD]

2.9l used the Motorcraft AWSF-42C, so heat range of 4, Motorcraft used 10 as HOT, 1 as Cold

Cross reference to NGK shows NGK TR5 as the match, so NGK heat range of 5

Rule of thumb is 1 heat range cooler for 75-100hp increase, so 10 sounds a little too cool

Stock 2.9l is 140HP, if you were at 340HP(+ 200HP) now then an 8 would be better

Its always BEST to run too cold a spark plug, you just get a fouled plug, if plug gets too hot then engine damage can be the result

 

[PetroleumJunkie412]

2.9l used the Motorcraft AWSF-42C, so heat range of 4, Motorcraft used 10 as HOT, 1 as Cold

Cross reference to NGK shows NGK TR5 as the match, so NGK heat range of 5

Rule of thumb is 1 heat range cooler for 75-100hp increase, so 10 sounds a little too cool

Stock 2.9l is 140HP, if you were at 340HP(+ 200HP) now then an 8 would be better

Its always BEST to run too cold a spark plug, you just get a fouled plug, if plug gets too hot then engine damage can be the result

THANK YOU ROND!

Figured I was a little too cold, but would rather be on the safe side.

Not sure where I'm at on hp, but the stock 14lb injectors would not run the engine. 24lb are doing it well.

Let's see where the supercharger puts me.

Probably ahead of a 4.0.





Until I blow a head.

 

[O No 3.0!]

What is the compression ratio? How much boost do you plan on running? What kind of camshaft are you running? Is it made specifically for supercharged engine or a n/a engine? Lots of questions to answer.

 

[PetroleumJunkie412]

What is the compression ratio? How much boost do you plan on running? What kind of camshaft are you running? Is it made specifically for supercharged engine or a n/a engine? Lots of questions to answer.

All that, and more, may be found here!

Johnny, tell him what he's won!

Really, really bad forced induction idea...

Yes, this is about a 2.9L. No, I'm not just going to put a 4.0L in it. Yes I understand it's easier. Yes I understand the 2.9 is a turd. This is about feasibility, not cost and time effectiveness. ...because I like banging my head against a wall. JEEZE MOM! Ok, now that I've gotten that out...

www.therangerstation.com

 

[Bird76Mojo]

Doesn't MS tell you info about the injectors and what % of duty cycle they're seeing?

 

[PetroleumJunkie412]

Doesn't MS tell you info about the injectors and what % of duty cycle they're seeing?

Yessir.

With the 14 lb, they were maxing out at WOT, and data logs showed lean condition.

I've had an AFR gauge in the truck for a while on the narrowband, and it would show lean at just about any throttle position when cold, then show "out of range" when warmed up. Guessing I exceeded the stock ECU a while back, and was exceeding the injectors at first with the MS.

Nice and healthy now at WOT.

 

[PetroleumJunkie412]

Doesn't MS tell you info about the injectors and what % of duty cycle they're seeing?

Also, I should post some screenshots of the log viewer program. Whole different ballgame when it comes to diagnostics.

Now that I'm getting used to it and getting better with it, I don't think I'll ever be able to go back to carburetors or even a new vehicle that can't take a megasquirt. This thing has completely spoiled me.

 

[Bird76Mojo]

There are better programs out there than MS for newer vehicles.. You're entering an expensive world of tuning...












Me waiting for your 2.9 to blow it's lid...

 

[Dirtman]

Honestly, who here thought this thread would end in actual scientific discussion... what have we become?

 

[PetroleumJunkie412]

There are better programs out there than MS for newer vehicles.. You're entering an expensive world of tuning...












Me waiting for your 2.9 to blow it's lid...

Tell me more about these other systems.





Also, we shall see. But there's plenty more of them around.

At this point, I think I'm going to just keep one around at all times just to give you something to do.

 

[PetroleumJunkie412]

Honestly, who here thought this thread would end in actual scientific discussion... what have we become?

Well, I'm still curious if this will assist with a ping/knock issue. I'd really like to be able to not keep using 93 to avoid knock without backing my timing off.