hi guys, my evo's been runnin like sh*t for a month or so. it has been backfiring with huge flameballs coming out the exhaust when im boosting high etc. at first i thought it was a vaccum problem so i tightened all the vaccum lines w/ clamps, it ran a lil better afterwards but still flameballs left and right. i heard from the "dealership" that they've had few evos w/ same problems and they found out their spark plugs were just old and not working. so i am hoping it's the sparkplugs, i have 30k miles on my evo w/ stock sparks. i have no idea what sparks to get, i heard NGK ones are good but what model is the best out there for my evo. thx

 

Your level of modification would determine the spark heat range.

if you have like TBE/Intake etc I would go with ngk br7es sparks. they're copper so you need to change them about every 6000 miles

If you have cams or more you should get br8es, same deal, copper

You can also get bpr8es or bpr7es these are recessed.

 

bump

 

I am a new person to the forums so to speak and I have a question about the right spark plugs for the Evo. My current mods are Injen Intake with upper and lower intercooler piping, Perrin Turboback exhaust, Walbro 255 lph, HKS 272 camshafts, NX intercooler sprayer, Turbo XS manual boost controller, ARP headstuds, Apexi turbo timer, and a Jester Flash. I also have AEM cam gears that are not installed(new in box) and a AEM EMS system which is brand new and never opened.

 

Always run copppers, NGKS, depending on the modifcations you can run 7s or 8s. I would suggest changing them out every other oil change as they are like 8 bucks.

 

The stock style plugs will last quite awhile and if you feel your getting knock a colder plug may be a better option. It sounds like this guy is getting blow out which means replace the plugs and gap them to specs .26 .

 

I just replaced the plugs to br8es I started her up and it seems like it idles better I will take pictures of the old plug and post them up.

 

ok I took the car out today still the same issue. Do you think it might be something with the BOV open to air. There is a lot of black smoke at the point when the car starts to bog.

 

BR or BPR7ES gapped at 26 and your good to go. Since you said after tightening some things up it got better so i would think you still have a leak somewhere. Try the plugs first naturally.BTW thats NGK plugs.

 

VTA's have a seeming nasty habbit of making the car run rich to the point of stalling.

The evo 9 BOV handles something around 24psi unless your running over that its kind of pointless to change it.

 

Is it because of the stock BOV. will the single spring mod to the greddy work?

 

I run br7es religously, Alky made copper plugs a necessity for me. Stock plugs would foul almost instantly. If you think you are having a misfire I would suggest these plugs with a relitavely tight gap, .22/.25. My car also does'nt like the 8 range in the extreme cold we have had over the past few months here.