Spark plugs??

[kvcicca]

I have a 2001 330ci with an ESS supercharger kit and I want to change my spark plugs (preventive, car has 50k). I have heard from some people that platnuim plugs are not good to run with Fi, so I was wondering if there is any truth to this, and why. Thanks.

[seat_time]

It's been so long, I can't remember the source, but I do
remember reading that "long life" plugs are not the best
choice with FI. It was recommended to go with an appropriate
high-performance plug. I went with DENSO Iridium (very
expensive, though). The recommended replacement
for them is every 30K miles.

Also, check this from iridiumpower.com (DENSO):
A "cold plug" has a shorter insulator nose, which
minimizes the amount of surface area exposed to the
combustion gases. Cold plugs are typically used in
racing conditions because of its ability to transfer
heat out of the cylinder chamber quickly. Most turbo,
supercharged and nitrous oxide applications use this
type of plug because of the tremendous heat they
generate. A colder plug can also minimize the risk
of pre-ignition and detonation, however if the plug
is to cold there is risk of fouling during extended
periods of idling and low-speed operation.

I use one level "colder" than stock.

[kvcicca]

Thanks for the info. I read up on them and have only found good write ups on them. So I ordered up a set. I'll let you know how they go.

[kvcicca]

Well, I installed those Denso Iridium plugs, and I am very impressed with the results. I never thought plugs could make such a noticable difference. I kinda want to dyno it again to see real number gains, but the power is way more consistent and the car pulls harder at all RPM's. My freinds thought I was crazy, until I took them for a ride. I did go one heat range colder than stock, so I'm sure that helped out. Thanks for the advice seat_time.

[ridgeracer]

I wouldn't go with those plugs unless you are running high boost applications and high octane gas.

Mario

[kvcicca]

Originally posted by ridgeracer
I wouldn't go with those plugs unless you are running high boost applications and high octane gas.

Mario

Why? I am running 93 octance, and 7 psi. So far the car has only improved.