Chuck,17.4k on my set with no problems.I recently took them out and went back to the stock plugs but as soon as i get time,a new set of splits are going back in. Every brand of plug has burned up on these truckks,you just don't here it mentioned when it is ngk or autolite.This has everything to do with your tune job,and nothing to do with your plug brand.The ngk's have NO added throttle response PERIOD. None of the plugs iv'e tried do squat except make your motor miss or run similar to the stock plug.These are the plugs iv'e tried[both ford platinums,tourqemaster,ngk,and the splits,The splits have more than a little throttle response,certainly more from a stoplight than the p.o.s. throttle body that is practically worthless. The plug you run should be discussed with your tuner,not on this board for the 50th time.If your tuner says ngk or autolite then that is probably what there using to tune there chips so it only makes sense to go with what they recomend.I love the splits in my L and the pro-m and most tuners don't.But at my track most L's[all but high roller] are 1-3 tentghs slower with equal mods so i stick with what works for me.

 

On MY truck the NGK's made a noticeable difference in throttle response! When I installed them I did so just to put what I had heard was a better plug in, expecting no performance increase! I was stunned at the difference Let's just say on MY truck the NGK's felt as if they gave me more than the single bore throttle body

 

In 1996, I had a Porsche 944 Turbo, and I was a senior in high school, so I would jump on any car at any time, and sometimes I won, and sometimes I got handed my hiney. Anyway, I was always trying to do stuff to get a little faster then, and I decided to try Splitfires, and I didn't notice the difference, but they ran, so I left them in there. I ran them for six months, and they burnt three of my pistons very bad, and the car was screwed. I ended up part of a class action lawsuit around 1997, because it turns out that many many cars had been screwed up by the Splitfires. Splitfire admitted the wronging, and they paid for it. This wasn't because they were bad plugs, this was because the engine that people were running them in were designed to run at cooler temperatures than the plugs ran at, so it burnt the pistons. If it is a hot running engine, Splitfires are very good plugs, but if it isn't, they can do more bad than good. I have read this on a post here somewhere else, I think it was in the Engines Forum, but someone posted that the F-150s ran way too cool for the Splitfires. Point being, even if they don't tear your truck up, your truck can't benefit from a hotter running plug, so there's no point in using them. Maybe nitrous calls for something different, I don't know, but I do know that the engines in these trucks aren't designed to run as hot as the Splitfires burn, and that is why they cause problems, not because they are bad plugs. NGK is a cooler running plug, and would probably be better-suited to use in the F-150, but it's your truck, you do what you want. Not trying to knock anything, just my 16 cents' worth...

 

L_Acious,

There have been several L motors trashed and yours is the only one I know of that had Splits installed. If something is bad enough to burn a hole in a piston then what makes you think the plugs would fare any better?

The big question is were you running a chip?

Pickup Man,

I can't speak for 944 turbo Porches or a regular F150 but Lightnings burn Splits great. They burn leaner at WOT with a chip
but this has not been a problem for my tuner. I have posted pics of the plugs a WOT for him see and he said actually I could stand to go a little leaner. I decided for safetys sake to stay where I'm at. These plugs can't take detonation or burning too lean as well as a solid electrode plug. They will fail sooner if these conditions exist. The other plugs will fail too it just takes them a little longer. Just pulling a plug and reading it may give you a false sense of security. Regular street driving will give you a dark tan color which is great but after a few WOT blast you will find a much leaner plug. This is what you should be looking for to see how lean you really are.

This is what they look like after normal driving.



This is a WOT reading.

 

agree with totaled
ngk-tr6-4177 gap .040
JDM recommend price paid there $32 set [ouch]

 

Spark plugs don't destroy engines, detonation does.

Now with that being said, I beleive that under certain circumstances, the splitfires may actually cause or enhance detonation. Its the nature of the beast, the splitfires are designed to start the fire better and faster than a standard tip plug. Sooo if your lean or have crapy gas or what ever, the plug might be a detriment.

Maybe they should come with some kind of warning sticker on them. FOR GEARHEADS ONLY or something.

If your the type of person that doesn't under stand what detonation is or what causes it and most of all why you should avoid it, then you should stay with the stock stuff.

I have a good friend in the Buick turbo camp, that can't hear detonation, he has no clue. Its a good thing he has deep pockets, cause he has wasted more good engines than I can remember.

For what its worth, if the chip tuners ever start making real race chips for these trucks, by that I mean a chip that takes uncut/unmixed 100+ octane fuel, then I think they will have the ingition timing set to the point that I will probably be forced to take out the splitfires and run standard plugs.
Dale

 

What Dale said.

Here is other WOT pics at a different angles.

 

All this talk about bad Splits got me worried. So, I went out and checked my Splits.....AGAIN. LTNBOLT, you wish your plugs looked as good as mine! Now my L is STOCK (unless you call Splits a "mod") and the plugs looked soooooooooo chocolately that I had to go and get an ice cream. And it was good too! They diffentely show MY L still runs rich.

 

Redneck Ferrari,

That's pretty much how my Splits ran before the chip. In the second group of pics that I posted you can see the tan color at the bottom of the top electrode. That is the color the whole electrode is if I pull a plug after normal daily driving.

The pics posted were from 5 or 6 WOT blast then a cooldown to pull the plug. I wanted to show that all plugs go leaner with a chip at WOT but you don't want to go much leaner than what's in the pics or there could be trouble.

 

It's all about risks, $$, and your willingness and comfort level with each, irregardless WHAT plug, chip, driveshaft, pulley, or tuner you select/prefer.

>>off to the garage to wrench mine back to complete stock trim and put it on the block.....


have a nice day.

 

and what are you thinking of buying to replace it?

 

Bob,

You sound a little distraught. What's up?

 

'neck,

The comment was mostly sarcastic in nature but the tought has crossed my mind...although brief. Possible replacement???? Subaru WRX but the wife says NO WAY!

 

I just replaced the stock plugs today with the NGK's The job wasn't as bad as I thought it would be, but still a pain in the but.

My stock plugs were all redish color, with the gaps ranging fron .032 all the way to .045. The left rear post(what ever you call it) has a small peice missing and is pritty fouled. Becides that they look ok.

What causes the insulators to turn red?

 

Don,

My stock plugs were the same way when I pulled then out (talking about the color). I never ran additives so I know that's not it. I've ran two different brands of plugs and they stayed white. I ran the same brand of gas also. I've never run anything but pump gas either. I wonder if the platinum electrode isn't getting so hot that it is discoloring the insulator. Go Figure!!

In the first pic I posted you can see the darkness of the insulator on the stock plug but what you can't really see is the redness of it.