Clio 172 without VVT?!

[Fred@BTM]

why do you need different heat grade plugs when mapping an engine? if its mapped bollock on then there will be no heat difference over stock IMO

stociometric in a standard engine Vs stociometric in a wild race engine is the same thing

you must be mapping to run lean if the temps are creeping up to cause the use of different plugs

 

[Dan@SJM]

Sorry to Gatecrash this post.

I thought the 172/182 would have triple fire plugs ?:S

Would the standard plugs that came with my car ,be ok for my car mate ?

With the mods i have ?


I have a full stainless stealth system with de-cat and uprated panel filter with no acoustic valve and uprated feed.

Or when would i have to change spark plugs types ?

If i got a Remap and matched inlets or would it be when i get more mods down line ?

Like cams etc etc.

Dont use triple electrode plugs, they are shite basically..

all thera re there for is to increase service life, triple and quad electrode plugs can loose performance as they are shielding the spark from the mixture. single electrode NGK's are perfect.

 

[stan*]

why do you need different heat grade plugs when mapping an engine? if its mapped bollock on then there will be no heat difference over stock IMO

stociometric in a standard engine Vs stociometric in a wild race engine is the same thing

you must be mapping to run lean if the temps are creeping up to cause the use of different plugs

No, a "race" engine will have higher Cr, therefore higher burn temps. So you want to run a cooler plug to dissipate electrode heat better...so as to avoid pre-ignition. If you dont, as said, you will be knocking back ign adv in order to reduce peak temps as a measure against det.

Also a leaner burn will be cooler (unless your go soo lean as to induce misfire, which you wouldnt do). Reason being a leaner burn gives better fuel conversion efficiency...its more efficient basically. Proof is the very reason you run leaner...to aid fuel economy. Efficiency is defined as output/input...since we are talking about thermal engines, this means the ammount of heat exchange is reduced i.e. it burns cooler.

The mis-informed tales of running lean causing det problems is from turbo engines, where fuelling beyond max torque figures is used to reduce temps and so prevent det...so when you run leanER you increase temps and risk det. This isnt a problem on NA engines.

 

[MarkM]

as long as you use the correct heat grade, i.e. nkg grade 6 they will be fine... the platinum bit only helps the plugs last longer...

for mild tuned engines we use BKR7EIX plugs...

for higher revving and hard working engines we use BCR8ES (same as used in cossie engines)

without the correct heat grade when mapping there is a serious risk of turning the plug into a plasma torch.... you end up chasing the timing back as the plug cant take the heat.... we have done alot of testing on this on the rollers....

on std or mild modded engines the std PFR6.... is fine..

BKR7EIX are for modified turbo cars arent they?

What is the spec of these that were fitted by you during my engine conversion?

 

[MarkM]

Just for some information on spark plugs -

Operating temperature for a plug is 500-850 degC

Go above and you get detonation
Go below and you get fouling

An increase in the plug heat grade takes off 70-100degC of temperature.

I am unsure as to why an increase in heat grade is required on a mild tuned engine used on the road. Its not a race engine that spends all its time over 6000rpm generating alot of heat it is also going to cool down on light load and low rpm.

Andy you say you have proven it testing on a rolling road. Surely a road car will go through a much larger heat range when used as a daily driver and a test over say a month of driving and checking the state, visually, of the plug after this period would be more conclusive.

I swapped those plugs for the standard 1*2 plugs. What effects would you expect to see by dropping a heat grade?

Actually regarding the test. I will check the state of the standard plugs I have fitted in my car after a month of driving. Thats unless my engine has blown

 

[Fred@BTM]

we swapped back to 6E plugs and gained 2hp, go figure

 

[MarkM]

we swapped back to 6E plugs and gained 2hp, go figure

The 7 and 8 grade plugs are used on Turbos as far as I can see.

20bhp gain on a mild tuned road car and you jump a grade. So on your 240bhp cup you have made 3 times the power so need to jump to grade 9?

What grade do they put in 400bhp turbo cars?

:S :S :S

 

[Fred@BTM]

i want to see what plugs they put in F1 engines!

 

[stan*]

its all abit subjective here!

you will increase burn temps by increasing say 20bhp, but whether that warrants a colder plug, I personally wouldnt think so. C220-250bhp NA (2.0/4v) and I would think you would have to start delving into controling heat ranges.

But ive never dyno tested them, so I cant say