MHD Tune + NGK Spark Plugs

[travis94ZX]

I recently bought a used 2015 M4 with 50K on it. About a week after purchasing, I flashed the stage 1 tune from MHD Tuning. The car ran like a bat out of hell for a couple weeks and I noticed the low end power was becoming a little hesitant. I decided to start researching replacing the spark plugs.

I came across this article over on bootmod's website: https://bootmod3.atlassian.net/wiki/...+and+which+gap

I believe these were the same plugs I used when I had my 335i N54 a few years back, so I decided to give the NGK SILZKBR8D8S (97506) a try.

I purchased them, gapped them to .018" and popped them in. I noticed that the power came back some what at first. After having them in the car for about a month though, it seemingly feels like I am back to where I was. Low end hesitation most of the time and power feel inconsistent.

My question here is, is .018 too small for a stage 1? Should I go back to the factory spark plug or get a new set and gap to something bigger? The only reason I feel like it has something to do with plug and gap spec is my experience with the N54 (or any forced induction engine really) being very sensitive to plug gap spec. I just feel like .018" is too close for a stage 1 tune and the ignition timing is probably is not right.

I have searched all over the place with inconsistent answers. So, I was just seeing if there might be anyone on here that might have advice or may have experienced the same thing.

Thanks in advance!

[behindthen0thing]

I don't know about your question but is it possible you're just used to the power of your car so it feels slower after a while?

[travis94ZX]

Originally Posted by behindthen0thing

I don't know about your question but is it possible you're just used to the power of your car so it feels slower after a while?

No, definitely intermittent hesitation on the low end. The car should be wanting to violently break the tires loose in 2nd and 3rd gear with DSC completely off. The engine almost feels like it is lugging in these lower gears. Trust me, there is no placebo going on and the low end torque is noticeably lower.