I noticed few days ago when i was data logging in 3rd gear around 6700 - 6800 rpms it felt like a kinda hit a rev limit or a lose of power fo a spilt sec and then it kept pullong to 7k rpms this is the second time iv noticed this but this dont happen very often, it felt it also once before when i was stock so im not sure if its the spark plugs are not, im running the NGK-BKR6EIX 1 step colder gapped at what the website claims is .33, got them from zzp. Im running gm stage 2 with custom tune and cai/full exhaust.

 

I want to stress this rarely rarely ever happens so thats why iv never worried about it till now, i done a bunch of 3rd gear pulls with no loss of power for a spilt sec, so i dont know if that means anything.

 

I would tighten the gap to .032 and test it out. How old are the plugs?

 

the plug have about 2k miles on them I put them in like December 2011.

 

Lots of LSJ don't like those plugs, period.

Try the BKR7E. Still one step colder, but it's copper.

A gapping tool is like a dollar, it's worth it to learn to double check the gap yourself as well, just for peace of mind.

 

6 is the stock heat range.... 7 is one step colder.

Anyways, tighten up the gap on your plugs.

What are your plugs gapped at now?

Don't just gap down to 0.032" like everyone says.

Test some gaps out yourself. You want the largest gap possible w/o spark blowout.

0.032" is a common gap for modified SS/SC's, but being your are on a 77.9mm pulley, you might be able to get away with a larger gap.

 

The number I gave for the plugs was the number zzp listed, they have a drop down menu to pick stock, 1 step, and 2 step. I ordered the 1 step plugs. Ill have to plug the plugs and test the gap but according to zzp they come gapped at .033 and it advised to not change the gap due to it may break or something.

 

I maybe wrong but I don't know if it sounds like spark blow out. You car hits a stumble, recovers, then continues on like it should. Sounds like something else maybe effecting it.

 

Well ZZP has them listed wrong then.... 7 is the one step colder plug for our cars.

Anyways, don't always believe people that say they come pre-gapped....

Always check the gap before installing plugs.

ZZP prob said that, because people "claim" u can't gap iridium plugs, when infact you can.

If they are infact 0.033" that should be plenty small enough for your setup....

When did this issue start happening, and was it cooler out when you noticed this? Did you notice any knock in your logs?? Almost sounds like your car was pulling timing vs. actual spark blowout.

 

im running 1 steps on a 2.8" full bolt ons and all that jazz. haven't had a single issue with the plugs i got from ZZP. just throwing that out there...

 

It was not really cold, i dont have my logs with me due to the fact that the guy doing my logging has not sent me the logs yet. Would pulling timing feel like u hit a rev limiter for a sec and then come back on strong?

 

Yes.

I had an upper rpm knock issue when I ran the Injen intake.

Once kr kicked in I felt the car slow down a bit & it seemed like I hit the limiter, but I wasn't there yet. Once the kr stopped it regained pulling power. It was annoying.

But since you said it was cold out, spark blow out can also be a factor due to the denser air.

I would still check your plugs & log your car.

I think my kr issue was due to piston protection kicking in due to a lean condition caused by the Injen in the upper rpm band.

 

I had this happen 2 nights ago at the top of second. It periodically occurs. same RPM as yours. it misses hard like I hit the rev limiter but then continues on north of 7k just fine. no KR, no timing pulled. It's done this for years.

BKR7E is 1 step colder. Regardless of what ZZP lists.

 

Did u figure out what caused it? cause like I said in my first post this also happened a few times when I was stock. I think its happen in 2nd for me before also its hard to remember.

 

I had a knock at exactly 6K, changed my plugs to the step colder and it went away.

 

Still no idea what caused it. I can assume maybe blowout or just shitty fuel. I also noticed it would do it if I hadn't gone w0t in a while. Not sure if related or not.