Spark Plug Heat Range

[Maraudermike1]

Can anybody tell me why it is beneficial to run colder heat range plugs? I have a tune and most people seem to run colder with a tune. Do you lose power or gain power by running colder? I'm looking at the xp103's and xp104's in particular. Thanks!

[rayjay]

Can anybody tell me why it is beneficial to run colder heat range plugs? I have a tune and most people seem to run colder with a tune. Do you lose power or gain power by running colder? I'm looking at the xp103's and xp104's in particular. Thanks!
If all you have is a tune run the XP104. The colder plug is to help prevent
detonation. I ran a colder plug and lost 30rwhp on the dyno. Returned to normal heat range and the 30 hp came back. It was a waste of a considerable amount of money... :mad2:

[risky]

what if you have a k&n cai,steeda underdrive pulleys php intake spacer,180 thermostat,& a lidio tune. should i go with the colder spark plug like the autolite xp103s or should i get the xp 104s ?

[Maraudermike1]

That's what I thought. My understanding was always the hotter the spark the better. But I have read in a few places that even with just a tune on a MM, you will disintegrate stock heat range spark plugs. Yea, and 30 rwhp is enough to make sure i'm getting this right! haha

[Pat]

If all you have is a tune run the XP104. The colder plug is to help prevent
detonation. I ran a colder plug and lost 30rwhp on the dyno. Returned to normal heat range and the 30 hp came back. It was a waste of a considerable amount of money... :mad2:

This is a first, for me, where dyno results Vs spark plug range have had that much of an impact, good info.

Most of the reports are SOP.

Was the gap the same on both heat ranges?

[rayjay]

This is a first, for me, where dyno results Vs spark plug range have had that much of an impact, good info.

Most of the reports are SOP.

Was the gap the same on both heat ranges?

Yes they were.

[fastblackmerc]

Running a colder heat range plug allows your tuner to add more timing. More timing = more horsepower. Just installing colder heat range plugs does nothing unless your tune compensates for the colder heat range.

[musclemerc]

Specifically if your running a Dennis Reinhart tune, you should run the colder plugs and a 180* tstat. If your running a Zack or Lidio tune then use the stock heat range.
Here is the info from Lidio's site:
http://www.alternativeauto.com/prodserv/marauder_tune.html

2nd paragrapgh under the dyno sheets

[tallpaul]

What is the stock heat range?

[fastblackmerc]

What is the stock heat range?

I don't know the specific heat range but here is my list of plugs:

Spark Plugs:
Stock Heat range
Autolite –104
Autolite Double Platinum – APP104
Autolite Iridium / Xtreme Performance – XP104
Champion Copper Plus – RS12YC
Champion Platinum Power – 3401
Champion Double Platinum – 7963
Champion Iridium – 9204
Bosch – BSH7571
Bosch Platinum – BSH4205
Bosch Platinum+2 – BSH4305
Bosch Platinum+4 – BSH4458
NGK V Power – TR55
NGK G Power Platinum – TR55GP
NGK Laser Platinum – PTR5C-13
NGK Irdium IX – TR55IX
AC Delco – R42LTS6
AC Delco Platinum – 41810

Colder Heat range
NGK – TR6 (+1 colder)
Autolite Iridium / Xtreme Performance – XP103 (+1 colder)

Here is some good info on spark plug heat ranges, etc.

http://www.autolite.com/carcare/techSpecs.php

[RF Overlord]

My understanding was always the hotter the spark the better. Heat range has nothing at all to do with the electrical characteristics or quality of the spark. It refers to the ability of the plug to transfer heat from the combustion chamber to the head. A "hot" plug retains more heat, while a "cold" (or cooler) plug transfers more heat to the head.
But I have read in a few places that even with just a tune on a MM, you will disintegrate stock heat range spark plugs.Uh...no. :rolleyes: If your tune is so radical that you have massive detonation you might disintegrate the pistons...

[rayjay]

If your tune is so radical that you have massive detonation you might disintegrate the pistons...


and most likely the cheapo oil pump that usually takes a dump with detonation causing engine failure... :rolleyes:

[Pat]

Running a colder heat range plug allows your tuner to add more timing. More timing = more horsepower. Just installing colder heat range plugs does nothing unless your tune compensates for the colder heat range.

Rayjay, I understand from your post that just the plugs were swapped and that no re-tune was involved. Is that correct?

[rayjay]

Rayjay, I understand from your post that just the plugs were swapped and that no re-tune was involved. Is that correct?

Thats correct. The dyno tuner was at a loss as to why the car lost 30rwhp. He pulled the XP-103's and asked why I put those in. I can't repeat what he said here. He put OEM plugs in and bingo, the HP came back. As I've said elsewhere here, it may be just my car, or it could be that they were not the correct heat range. For a long time I had listed $310 spark plugs in my sig. :rolleyes:

[RR|Suki]

Thats correct. The dyno tuner was at a loss as to why the car lost 30rwhp. He pulled the XP-103's and asked why I put those in. I can't repeat what he said here. He put OEM plugs in and bingo, the HP came back. As I've said elsewhere here, it may be just my car, or it could be that they were not the correct heat range. For a long time I had listed $310 spark plugs in my sig. :rolleyes:

How did plugs cost you $310 :eek:

[rayjay]

How did plugs cost you $310 :eek:

Dynotune...

[Maraudermike1]

This is really good info. I guess i'm not the only one that was curious. lol I run the Zach tune and I have stock heat range so I guess i'm in good shape. What I don't understand is if it is such a benefit to run colder plugs and advance timing, why don't all tuners do it?

[fastblackmerc]

This is really good info. I guess i'm not the only one that was curious. lol I run the Zach tune and I have stock heat range so I guess i'm in good shape. What I don't understand is if it is such a benefit to run colder plugs and advance timing, why don't all tuners do it?

Because if they send you a tune for colder plugs (more timing) and you don't install colder plugs the engine can go BOOM!

[musclemerc]

That only shows the diffrence in the tuning capabilities. DR's tune dances a little closer to the detonation range so the tstat and plugs reduces the chance of going boom. Lidio and Zack get there and then backed it down a little to keep within the stock detonation threshold. On Zack's tune the global spark is unlocked and you can increse/decrese the global spark, just listen for any signs of detonation.


This is really good info. I guess i'm not the only one that was curious. lol I run the Zach tune and I have stock heat range so I guess i'm in good shape. What I don't understand is if it is such a benefit to run colder plugs and advance timing, why don't all tuners do it?

[Maraudermike1]

I was messing with the my tuner and I think I saw that option. What exactly is global spark?

[musclemerc]

That will let you add/reduce spark. As I said earlier listen close for any dieseling (sounds like marbles being shaken) if you hear any then back it down or you run the risk of detonation