phatmitzu

This thread got me thinking of getting colder plugs.
https://mbworld.org/forums/w211-amg/214432-reducing-engine-heat.html

I had them on two of my previous turbocharged vehicles and they worked well.

Thoughts??

BrianS

Me too. On my previous turbo car I had to go two steps colder. I went from an NGK 6 to an 8 but I was tuned for 26psi boost too.

What are the stock plugs?

rflow306

The stock plugs are NGK ILFR6A, I changed to NGK Iridium LFR7AIX. Mercs use very hot plugs to begin with.

chiromikey

was n2o behind you switching to a colder plug or was there anther reason?

Jrocket

But you needed to go from a 6 to a 7...to help out with that 500 shot your running..

BrianS

What gap are you using?

rflow306

30

Zod

forgive me on this but could some one please explain how spark plugs been cold helps ?

Are they not use to spark and ignite only?
or am i way off

stevebez

What is the next colder plug equivalent for the OEM plugs ???

Also how does the dual sparkplug thing come into it ? Why dual to start with ?

stevebez

When the spark plug shorts / sparks the electrode gets very hot. How hot this electrode stays is what is meant by a hot v cold plug. A cold plug will dissapate its heat from the electrode into the head very quickly. What is perhaps more important is when a plug runs too hot than what its designed for because of higher boost, leaner mixture etc... will wear much faster and in itself possibly promote knocking as the electrode remains too hot for the conditions in the cylinder.

There is greater chance of detonation and wear on a hot plug under higher cylinder temps than for which it was designed. A cooler plug is almost always safer ... but you cannot go too cold or the sparkplug will start fouling up, and the spark will degrade....

So typically if you add decent power to your motor via mods its safer to go with a one step cooler plug than OEM

This is how I understand it ...

phatmitzu

Some info from the NGK website

http://www.ngksparkplugs.com/techinf...000&country=US

Ghostrider

Would this be the same thinking for a N/A motor???

stevebez

Nice idea these Iridiums that Albert uses ... not a cheap sport though when you need 16 of these puppies ...!

rflow306

Changing them is a lot of fun also. lol

rflow306

Dam.... I can't tell you anything.

AdamG@NorCal

Oh yeah...

waxking1

I checked and these plugs are $30 plus each, although there are some on ebay quite a bit cheaper. Can you tell any difference in performance?

phatmitzu

No one else except rflow306 uses colder plugs?

Jrocket

Theres no need,Rflow uses them due to the Nitrous unit.

phatmitzu

I see. Thanks.

Zod

so with pulley, header , tb and ecu done... there is no need to play with plugs?
are they only meant to be changed with nos?
or a specific hp reached?