Spark Plugs

[Black Magix]

So dumb question. So my brand new car. Would it be better to buy new plugs close the gap on the stock plugs that have 2000 miles on them?

I ask because I'm ok buying the HKS plugs but I don't want to effect the warranty on the car.

 

[robz32]

Unless you are installing a piggy back system or getting an ECU tune then you have no need to touch the spark plugs.
Closing the gap on the factory plugs or spark plug replacement is required if you are increasing boost levels.

 

[Black Magix]

That's why I posted in the JB4 area I'll be putting the JB4 tune on my car. I just didn't know if the stock plugs would be good enough if I just closed the gap.

I currently run Shell's premium (93? octane) in my tank.

 

[robz32]

Oops my bad, should've checked the thread section

In that case then, BMS recommends using the Mil40s or the Densos they offer. Re-gaping stock plugs has been hit or miss but more miss.

 

[Black Magix]

Is there any difference between the Densos or the HKS'? This is a job I don't want to repeat based on the upfront work

 

[robz32]

The only "negative" (use that word loosely) reports I've seen about the Densos is that the idle is rough, however I think they fixed it with their latest firmware release, not sure.
No negatives reported with the HKS, that I know of.

 

[KLR STINGER]

HKS and Denso's will idle the same.it a function of OEM plugs being extended or extra projected tip design vs standard projected tip. Di motor seem to be particularly sensitive to the placement of the spark kernel location in the combustion chamber. I've run stock plugs regapped to 18.5 PSI with JB4, intakes, downpipes and exhaust with no misfire issues. Stock plugs are a heat range 7 and should be plenty fine for 450whp. After that you may want the extra insurance of colder plugs.

 

[Black Magix]

Awesome. I went ahead and got the HKS M45iL plugs. That's going to be a fun weekend in the garage having never replaced spark plugs before. Luickily I have a mentor who knows his way around engines so it'll be a learning experience. On that note, where can I get the gap tool since apparently the radial one is a no go.

 

[DaBears4Lyfe]

Zero Issues with the Densos close to 1k miles.

 

[Black Magix]

another dumb question. If I revert to the stock tune with the HKS's installed at 0.024, will I have issues?

 

[StingerNYC]

I have the HKS M40iL at .028 and no issues anywhere. I only run map 2 though. Idles smooth whether the jb4 is hooked up or not.

 

[KLR STINGER]

I would not run the HKS 45's on a stock motor. Way to cold of a plug, and will eventually foul early. I don;t even think they are needed on a highly tuned motor. M40s or Denso's are the way to go.

 

[Black Magix]

I would not run the HKS 45's on a stock motor. Way to cold of a plug, and will eventually foul early. I don;t even think they are needed on a highly tuned motor. M40s or Denso's are the way to go.

The idea behind this is when I take it in for oil changes/service what have you, I can pull the tune off.

 

[Kamauxx]

I've run the JB4 for 5+ months and 8k miles with stock plugs re-gapped to .025. I've yet to have any issues with them. I know there are quite a few of us also running stock re-gapped plugs and have never seen anyone report problems with going that route.

...just in case you haven't already purchased new plugs...

 

[robz32]

On which map?

 

[Kamauxx]

On which map?

Me? I ran map 1 with stock plugs for a few hundred miles. After re-gapping them I've ran map 2 for over 7k miles. And now I've been running map 2 + fuel control wires/firmware for about 500 miles.

 

[Black Magix]

Sadly, it's a bit late. HKS plugs are on the way. I think of it as some extra insurance. I'm just worried about taking the tune off. I guess at 0.0028 they should be ok even being 1 step colder?

 

[KLR STINGER]

M45s are two steps colder actually. Gap should be .022-24

 

[Black Magix]

ok, does that mean I should never take the tune off?

 

[Terry@BMS]

ok, does that mean I should never take the tune off?

You can run stock tuning on the Denso 5346 plugs gapped at 0.022.