kindafast

Hi.
I was checking out my spark plugs and they are black on the end, can't scrub it off. Is it okay if they are like this?
I think they are the reason why I'm 1/2 second slower in 1/4 mile than what I am supposed to be.


What is the difference if i replace them with $2 than $14 ones?
The stock ones are NGK R R1 yes? Those are the ones I have right now, just making sure.

c32used

I say they are ready to be replaced(especially if you drag car)...stick with good plugs cause you have a high performance engine...I picked up 8 Denso Iridium IK20s for $74 shipped from Ebay a week ago. Look for cheapest in sets of 4 and just add 8 more cause shipping and price will be cheaper compared to buying sets of 6 or even 8. Gap should be around .33-.37 Denso part# 5304

splinter

Excellent advice, Victor. They’re working well on mine, but I’m not in the big league ~22 PSI ranks.

I was going to ask to ask your plug solution in the “misfire” thread, but didn’t want you to give away any speed secrets. ;=)

c32used

Secrets??? Never...maybe from Newzchpsy

I prefer to be open so others know what Mods can do...this way others can choose the right go fast Mods the first time around...with mods getting cheaper and cheaper by day there are so many selections in mods but not all mods are for all and some mods work great with a combination of mods.

60n5pt1

There is a thread way back about Denso Iridiums and the discussion was how to R & R the plugs and about differences between IK16s and IK20s. I know one of them is a cold plug and the other one a hotter plug, or so. But, it was also mentioned there was no need to gap them. I can't remember exactly why I chose the 16s but I believe it was more practical to go this route.

c32used

To my understanding the IK20s are a colder plug...they are pre-gapped but just recently found out by a gearhead on the C32 that .33-.37 is the desired range for engines with our performance.

D_Star

Kindafast,

I am no expert on spark plugs, but I am using Beru plugs right now. Apparently this brand has a pretty good reputation for meeting the European car standard.

If you are interested, I am selling a set of Denso IK20 and a set of NGK IX. Let me know if you want them.

Newzchspy

Vic, why just 8????

loungn14

good point!

Newzchspy

The best thing about secrets is that you can be secret about secretly keeping the secret!!!!

I am going the same plug route as Victor did since mine have never been changed in 29 K miles. Jake talked me into it at the last meet!! When I had an old RD 400 Yamaha, cold plugs made all the difference in the world in that thing.

60n5pt1

found the thread;

I did mine a year or so ago. The IK 16 is the plug to get. People with the IK 20 have not been happy with it. I literally dropped .2 seconds off of my 1/4 mile time and added 2-3 MPH with the plug/wire change. You are right, the big change seems to be in the high RPMs, where the car now seems to pull really hard right into the limiter (even the limiter raised with the Evo mods)

For those of you considering: I am a hardcore automotive DIYer, and this task, IMHO, is not as easy as 1Fast makes it sound. The plugs closest to the firewall are a major PITA, unless you are limber like a noodle and have a vast assortment of socket extensions. Even then, it is installation by feel, not by sight. Plan on at least a few hours for the whole job (the first time, at least). Plan on some knucklebusters. If you are over 30 and/or not very flexible, plan on a backache too. In any case, make sure you have a variety of socket extensions available.

c32used

I had bought a set of 4 about 6 months ago so only needed eight more to buy...while researching on Ebay I saw alot of 4,6,8 per set for sale but comparing prices from a set of 4 to 6 or 8 plugs price jumpped from like $9.10 to over $10 a plug including shipping so I found cheapest set of 4 and added more to quantity thus making it cheaper as to oppose to buying sets of 6 or 8. Understand now

c32used

I read up on that a long time ago but if you aren't at the drags alot and you go at times then the .2 really don't matter...yes the firewall ones are a major PITA but with proper tools its not as hard...I believe it didn't take more then an hour to remove old plugs, regap new plugs and install them...but the first time can definitely be longer some people use the Denso IK22s but it seems that one runs hot one runs cooler and one runs colder so I chose the middle

c32used

Answered

Newzchspy

Barely!!! Now where/s my phenolics so I can beat you even more???

c32used

I thought we were planning on meeting so I can give that and the other stuff to you...but if you prefer shipped let me know and I will text,call or PM you a shipping price for the other stuff so you can paypal it

60n5pt1

I read about the difficulties R n R the plugs but I got through it with hardly any problems ( the key is proper tools!!).

Question is: which one of these three plugs 16s, 20s or 22s, makes a difference by gapping or regapping so that it's worth going thru the removal/reinstall process?

c32used

Honestly to answer that is beyond me...I am sure they all perform better depending on gapping

Newzchspy

Speak of the devil, see the ad below for the 24 Densos.

60n5pt1

I looked at Denso's website and found this:

Denso Iridium IK20 for C32 AMG OE gap is .035".

That falls within your .033 - .037 range.

Denso does not specifiy IK16s for C32 AMGs.
I may have to replace my IK16s with IK20s afterall.

Gramma_Benz

See this thread:

https://mbworld.org/forums/showpost....9&postcount=83

SilverBulletAMG

I did a LOT of research on this a year or so ago. At that time it was decided by most everyone in the "know" on the boards that the IK22s were the way to go. IK16s were NOT recommended.
There is an old thread with a couple hundred pages on the topic. The IK22s came pre-gapped perfectly and I've put over 15k miles on them with no issues at all.
At the end of the day, they're spark plugs...as long as they are clean and fire I really don't think there is all that much of a difference unless you are on a dyno looking closely or counting hundredths of a second on the strip.

kindafast

I just changed the old ones with NGK IX. They are .44 so that's quite more than recommended I guess, but they were the closest to what I was looking for. Car felt easier and smoother at startup. I'm gona go for a run in it really fast. I was supposed to go to class at 5:30 but the car was only ready by 5:35

kindafast

Oh and thanks for the help guys! I appreaciate it!
Especially the chit chat part betwen Victor and Newzchspy
kidding, kidding!

c32used

It don't specify the IK22 either but don't jump ship