41willys

Would appreciate inputs on when spark plugs are usually/should be replaced. In the 2 instances I replaced my plugs, I noticed a big difference in power. The 1st one was after 8 months, about 7000 kilometers. I installed Denso iridium IW24's. It sure made a great difference in acceleration and complete elimination of misfiring at WOT. After some 9 months and about 8000 km, I noticed misfiring again at WOT. This time I used IW22 which what the recommended straight replacement is for EVO's. Again the vehicle reverted to great acceleration and no WOT misfiring. Now I'm beginning to get that sluggish performance again though no misfires.
I am told that iridium plugs should last 25,000-30,000 km.
I have an EVO5 RS (Philippines), all stock except for a KN open air filter and a Tanabe exhaust (4" I think).
I just wonder if any of you have experienced this. Also, will an aftermarket ignition system help?
Thanks. This site is great. I pick up a lot of helpful stuff.

Compjoc

iTrader: (21)

Same thing happened to me with my NGK plugs, car ran great for about 1000 miles then started to get sluggish. I'm thinking of changing to a longer lasting plug. These NGK plugs are supposed to be changed out every 5k miles.

KILTERMAN

iTrader: (9)

Also What is the gap for a Stage 1-2 car? What would be the recomended plugs for said car. With all the different Plugs out there some has to have had some success or bias toward one set with a certain gap. any help?

plokivos

iTrader: (3)

anything between .024 ~.028.

.024 is too much for stock car or actually for any car.

iridium ones come pre-gapped. don't gap those. easiest ones to install due to no gapping.

KILTERMAN

iTrader: (9)

Would Iridium's be overkill for a stage 1-2 car? Or am I thinking the colder BRES7S . I am confused. NGK Iridium plugs, are these the plugs your referring to Plok? Is there something better out there?

plokivos

iTrader: (3)

what do you mean, your stock plugs are iridium.

ngk BPR7IEX = iridium.

ngk BPE7ES = Protruding, non-iridium (platinum i think)

ngk BR7ES = Copper

Stocker = iridium R X or some shlt like that.

plokivos

iTrader: (3)

iridium is suppose to last about 50k miles, unless you drive hard with a lot of boost.

mine as well get some copper plugs, change it out every oil change.

cheaper in a long run for ya, maybe.

JoeA

iTrader: (44)

I still havew stock plugs and have no problem

41willys

I'm already thinking that maybe, iridiums are not worth it as they cost 5X more and the period for peak performance is about the same. Can anybody really say that they are better than ordinary plugs?

plokivos

iTrader: (3)

compromise, that's all.

like stock brembo pads.

very expensive, but if you ask me they're the most streetable and track worthy pads then most aftermarket pads. they're dual purpose.

like the stock advan tires. they hold like a **** but don't last that long.

iridium will last a long time, and it sparks very good.

but i'm sure it doesn't spark good as the copper ones, but copper ones you have to change very often.

rsboy

iTrader: (48)

I have a set of the Denso IW22 and will most likely change out the stock iridium plugs soon...maybe at 20K miles. But honestly the stock plugs looked pretty good at 14K miles when I checked them, that I might actually just hold off until 30K miles. The Denso's came pre-gapped at .025 from the box, so those should just "plug" in without gapping, unless you really want to run something different.

I would guess other factors might be affecting your cars performance moreso than the sparkplugs. I mean the PI gets hot and humid, especially in Manila, big, congested city, greenhouse effect, etc. I would imagine your car would be working harder, turbo gets hotter, cause of the environment. That open air filter might actually cause your car to feel sluggish because it might not be getting/providing sufficient cooling. My car feels that way right now just driving around Detroit cause it been so damn hot and humid, my car feels like it's boosting to 1bar rather than 1.45bar.

41willys:
When you pulled out the plugs at 7-8K KM...did they look bad at all?
Also, are you tuned for the open air filter?

41willys

RSBOY,
Thanks for your inputs. When I took out the IW24plugs, they seemed OK ... brownish red. You may be right on the hot climate here thus the necessity of more frequent changes. I did find however that the IW22s work better. The car may feel sluggish after a time but no misfires.
The car has not been tuned to anything. I got it almost 4 years ago at 7000km. It is now at 28,000km.
How will it be tuned for an open air cleaner and larger exhaust. I got it that way and a vent- to-atmosphere blow off. I have not introduced any modification whatsoever.
Appreciate all your replies, guys. Thanks

plokivos

iTrader: (3)

I boosted 23psi peak down to 21 psi for a while before mbc on stock plugs making about 280 to the wheels in GA heat.

after 40k, the stock plugs looked still new, minus I was running little lean.

The service manger, a good one, told me that change at 60k miles, but that's really just for mitsu realiability thing.

awdjunkies

iTrader: (3)

Not to hijack this thread but since we are on the subject of plugs, I just bought the BPR7ES's and I am getting ready to dynoflash with these mods:
HKS Cat-Back, DP, either drop-in filter or the BR short ram cone filter, walbro 255lph, maybe an MBC @ 21, along with the NGK's as well.. Is this advisable or should i just stick with a fresh set of stock Iridium's ???
Ps: car has a little over 20k miles and crappy 91 octane...
............ Oh and the stockers(Iridium's) were replaced at around 12k miles....




Thanks

rsboy

iTrader: (48)

awdjunkies:
If the stock iridiums worked well for you, why not stick with it? The BPR7ES should be good, but will require changing out sooner, but at least it's cheaper than stock or the other iridiums.

41willys:
Tuning would definitely make your car run better, much, much better. I was told that the IW22 is pretty much like the stock iridium but maybe a bit colder(?), so that's why it runs better with smaller mods than the IW24. The IW24 is a step colder, so unless you have better mods or running higher power, you don't really need it, yet.

As far as tuning goes... maybe talk to those autogroups in Manila running some fast-azz Evos. Maybe they can suggest some engine management that would work for you. If I go back there to visit, I'll definitely be checking out some of those shops to find some good deals for my Evo.:devil: