Another spark plug thread...

[Ba82Ep3]

OK. I read Jimmy's sticky on plugs... good info too. I even researched the NGK site... and looked at their RACE plugs breakdown. But there is no info for comparing the NGK Iridiums to the "lesser" copper NGK plugs.

Here lately i have been running the Bosch Fusion pt#4508 (k24a1/k20a3- plat/irid+4 electrodes) and they seem fairly decent. Gas mileage on my last road trip to N.C. was 28mpg with three people in the car and about 250lbs of luggage. I was really happy considering i did 100mph+ for almost 1/2 the trip down I-95.

I would like to try using standard NGK plugs tho. I can change them more often and have fresh plugs, but have similar replacement costs in the long run compared to the Bosch or NGK Irid's.

Can anyone tell me which NGK coppers would work in my EP and also my FG? Or at least where i can find this info? Thanx!

[talonXracer]

Unless you have Kpro to properly retune for those other inadequate plugs you will suffer many drivability issues.

I have tried coppers and platinums and found they make less power as you have to detune the ignition advance to keep knock under control.

The cost per mile is much much much greater with non-iridium plugs.

There are many who will argue this point and say the coppers and platinums will work fine. But my tests and personall experiences show me otherwise.

[Ba82Ep3]

Good info Doug. Yah i definitely wasnt looking to start a debate over which plugs to use. If there are peeps using the NGK coppers (k24a1/k20a3), passing on the part #'s would be appreciated tho!

I never even thought about needing to adjust ignition advance when changing plugs... but it seems logical. I wouldnt mind the experimentation though...

[talonXracer]

Yeah I had thought since I had such great luck with coppers and platinums in the 419AWHP Talon that they would be great in the K20, but I lost WHP every where but up top no matter how much tuning I tried. I also had alot of misfires with the platinums. I will gladly sacrifice some top end for low/mid range power and drivability.

I look at it this way, the Iridiums work fine and last far, far longer, so why try something that wears out super quick? I would have tried the Iridiums back then when I had the Talon, but they were very scarce and cost both legs and one arm at that time! LOL

[Ba82Ep3]

Interesting you say that... i had random misfires and cyl 3,4 misfires when i was street tuning the 480cc injectors. Went back to the 270cc injectors and the problem was solved. So then either the Bosch plugs are at fault (same set) or there was injector issues. The injectors were cleaned and flow tested prior to install, so im leaning away from them as the issue.

This is partly why i was asking about the cheaper coppers. Installing the RBB will require street tuning, and it would be nice to drop in fresh plugs each time i swap a part out... w/o breaking the bank in the process (i can get the NGK coppers thru work for like $1.50 each). If they reduce power though... then im pretty much back to square one eh?

:faint:

Do you think your misfires were from the compression snuffing out your spark? (Im assuming the Talon was boosted). Its a fairly common issue amongst SC'd Stang owners. If so... my situation wouldnt be the same since im N/A on a very reasonable amount of compression.

[talonXracer]

Do you think your misfires were from the compression snuffing out your spark? (Im assuming the Talon was boosted). Its a fairly common issue amongst SC'd Stang owners. If so... my situation wouldnt be the same since im N/A on a very reasonable amount of compression.

Oh yeah the Talon was boosted, all awd's were turbo'd. 18g bigwheel and a 3.5 exhaust and a stealth sidemount intercooler with alky spray.

The only time I could say for sure the flame was blown out was when the plugs were close to the end of their life with the Talon and that was at WOT at higher rpm's and boost levels only. With the K20, I had misfires at part throttle.

[Ba82Ep3]

The only time I could say for sure the flame was blown out was when the plugs were close to the end of their life with the Talon and that was at WOT at higher rpm's and boost levels only. With the K20, I had misfires at part throttle.

Makes sense on the Talon... the electrode being worn and the gap surely more than optimal under that kinda combustion chamber stress... i can imagine. Part throttle with the k20 though... hmm. Do you recall your A/F at part throttle (open loop i assume)? Im just wondering if i can go back to the 480's with a different plug... and find answers to a few of the questions i had about that whole ordeal...

[talonXracer]

My A/F was perfect across the board on all maps, no more than 1-2% max short term fuel trim anywheres while in closed loop, and open loop was as precise as well. Hours of dyno and street tuning.

And with the current A2/Z3 cammed hybrid, it hates the platinums even more than the A3 did.