[jblackburn]

And that's what won out I think.

30k or like a year and a half for me. They take about 10 min to change and cost $10 so I'm perfectly fine with that.


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[jblackburn]

Well, spent part of the day hooning around back roads, then part of the day running errands with the AC on in-town.

There is NO bog off the line in 1st gear with the AC on 3 or 4 like there was before, power delivery is smooth in between gear changes as well, and no jerking/apparent heat soak problems (90F outside). I thought that all of this was just characteristic of this car in hot weather, so I'm completely surprised. The midrange torque between 3000-4000 RPM feels great too.


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[jblackburn]

Honestly, those of you that are tuned...I'm not sure if this will make a difference. It sounds like Vince (and others) have done pretty well with improving the drivability of these engines on the stock plugs.

Most people I've heard complain about jerky acceleration seemed to be using regular gas. Unless anyone else here has this issue on a stock Cruze, I'm wondering if I have a knock sensor that is just overly sensitive.


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[jblackburn]

Well, if an A/B comparison with the stock and copper plugs makes a big difference for you then you've improved something with the coppers, whether or not you have a hyper sensitive knock sensor.

It makes me think that the plugs themselves ran on the hot side and were definitely causing pre-ignition when the IAT was super hot. On top of that, Chevy's stock tune is ULTRA-conservative (makes sense, for warranty reasons) in terms of cam timing and knock retard. "What was that?!? A ping?! PULL POWER NOW!". Unfortunately, while it may keep the engine very safe and Chevy out of replacing it, it makes for crap drivability since it both dumps off boost and changes the cam timing, especially on the octane they rate the Cruze to run on with the stock iridium plugs.

When I first got the Cruze, I was running regular on the wildly-out-of-spec gaps on the plugs, and it just about stalled out when taking off in the summer on a hill with the AC on. Even still, with the intake resonator and re-gapped plugs with high octane, it seemed like it struggled to get going from a stop.

If smoothness is much improved with the Trifecta tune, he essentially dialed back that sensitivity at low RPM, much in the same way that replacing knock sensors on the early Toyota 1MZ-FE yielded significant power gains (not many people were interested in tunes then - it just wasn't "easy" like it is with a laptop and OBD cable these days). I think that's what Chevy's updated tune did to my car as well - some engineer realized that they had built way too much of a precautionary buffer into the tune.

 

[jblackburn]

Filled with 87 E10 today just out of curiosity and switched on the AC (3-max). 85 F outside.

It actually drove completely fine. No bog from a stoplight, no jerkiness or hesitation. I felt heat soak once after sitting at a light for 5 minutes, but it was just slightly slower acceleration and no jerk-you-around knock retard.

Next weeks supposed to be in the 90s again, so I'll see how it behaves.

I really can't believe all this knock was a result of the plugs themselves. Kinda makes me think Chevy got their programming right and the plugs were just a marketing decision.


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[jblackburn]

Well, it still hates 87 when the AC's on (yup, I expected as much, just wanted to test it). Initial throttle bog/tip-in from a stoplight is now instantaneous - no huge lag like before, but it starts jerking a little between 1800-2500 RPM when the turbo picks up.

However, with the last tank of premium in hot weather, it was smooth sailing throughout the entire RPM range.

Blk88verde, what are your impressions?

 

[jblackburn]

Probably put 150 miles on the new plugs this week end. Still running real good. Zero hesitation /lag w/AC running. Seems to hold speed on long hills better in top gear than with the iridium's. Temps in low to mid 80s and humidity 80 to 90 %.

Awesome...mods, can we move this to the 1.4 tech section? I think this is a worthy "upgrade" for power delivery with the 1.4 turbo.

 

[jblackburn]

I had to use AC on my way back to Ottawa yesterday. It wasn't too hot (mid-70's) but it was probably clost to 100% humidity a lot of the way. We drove through some pretty crazy downpours.

Anyway, with the AC on and 91 in the tank, even accelerating easily I noticed some "uneven" acceleration starting somewhere around 1700 RPM. Maybe the high humidity had something to do with it (probably did), but I was surprised to feel it none the less. I wonder if the engine mapping changes as soon as the AC is engaged? I've been driving with the same 91 V-Power gas for the last few tanks and felt nothing in the way of hesitation.

For the record I'm not tuned and I have my gaps set to .038" and my plug resistors removed and replaced with all-thread to lower the ignition circuit resistance.

I may just order a set of those coppers and try them out... for $10 it can't hurt.

Even without AC, I felt that jumping at low RPMs at times. Iridiums were @ .032, haven't removed the resistors. I now feel it on 87 oct., but nothing on 89 and above.

My guess would be that the engine just runs with a lot more load on it at low RPMs with the AC running, meaning it's running into more knock @ low RPM. The compressor sure does affect how hard the engine seems to have to run at idle.

 

[jblackburn]

So you put in these? Going to pick up a set then. Probably why I get hesitation all the time.

NGK 4644 BKR7E Nickel Spark Plug
SKU: #BKR7E
ITEM: # NGK4644
BRAND: NGK

Yup, that's them!

 

[jblackburn]

My old ep civic came with iridiums stock. I swapped them for coppers cuz they were cheaper. The car drove fine but i lost 20whp on the dyno and they fouled out after a few weeks

You were clearly running the wrong gap/heat range for that application. I've run them on a Honda D-series with no problem at all.

Titan, I wouldn't expect more than a 25-30,000 mile lifespan. Thats a year or two of driving for me, which I am fine with. Gap on the low side - the gap will widen with time.



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[jblackburn]

Based on this:

http://www.cruzetalk.com/forum/34-1-4l-turbo/9634-ngk-plugs.html#post138469

GM may have already gone one heat range colder in early 2012. Maybe another step in that direction is in order? I've been wondering about this for some time... it's about the only thing that makes sense as to why a plug would cause knock.

Interesting...mine were a 7 though.

 

[jblackburn]

Ok I went to the parts store tonight and picked up the plugs. They were $2.59/plug from Advance Auto Parts. Just out of curiosity I checked the gaps on them and they are all gapped at 0.35 in the box. I'm going to knock it down to 0.30 before I install them in my Cruze. I am curious to see how this works out also.

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Cool - let us know how they work out for you.

 

[jblackburn]

I'm actually suprised those who are tuned aren't running 1 step colder plugs... I ran colder coppers in my cobalt, supercharged corolla and built n/a focus.. They would last about 10 k but that meant swapping them once a year at the time.

Yes - I did the same with my turbocharged, tuned Volvo to alleviate a stumble @ high RPM when the boost hit full-force.

 

[jblackburn]

Im going to try some copper ones out which would y'all recommend me to try.

Sent From An Antique,
My Original Droid.

The Cruze originally came with NGK's heat range "6" (a hotter plug). They moved it up to the 7 in 2012, according to a link Blue Angel posted earlier.

I *think* the 7 would be fine with a tune with a copper plug (or it would be nice to have someone that is tuned to test - maybe see what Titan has to say)...or an 8 with the iridium plug since the 7-IX's perform like crap.

Comparing heat ranges between different brands of plugs is a little more difficult. There are charts for it, but they don't translate 100% to the same plug.

 

[jblackburn]

So I'm going to pick up a set of Honda dirt bike plugs for my Cruze turbo next week, gap them to some crazy spec that will never work, drive so easy they will never get up to proper temperature, and try to set GOLD Hypercruzer status before they foul up. That sounds like just the right amount of dumb. Wish me luck.

I remember ordering light bulbs for a non-Honda vehicle through their dealers too for about 1/3 the cost.

LOL, good luck with that. Run em up to redline before you fill up and see how they do.

 

[jblackburn]

I think those arent for a old ford pick up truck. That plug is real popular in dodge dakotas. Iirc they are a heat 6 or 7. My build date is 9/11 but its considered a 2012 so i wonder what heat range i have.

10/11 here with the 7's.

H3ll, those translate to a "5" heat range with NGK.

Go to a NAPA - they should have them.

 

[jblackburn]

Bkr7e-4644.

 

[jblackburn]

i am tuned and are looking to take out the stock plugs...what what ones should i put back in to try this time

I think you drive pretty hard, right?

See what Blue Angel comes back with on the 8's.

 

[jblackburn]

I can lug this little 1.4 down to 900 rpm and it doesn't shudder at all! Nice and smooth the whole way down. I drove down part of my commute route as a test, and this area has several spots where I usually have to work hard to keep it happy in 6th by keeping my speed up. Now it just pulls up those inclines without protest where it would be shuddering and vibrating before. It even feels like it has more torque down low than before. This is now one happy little motor!

Nice - the low RPM drivability improvement is the first thing I noticed as well. I've even found with the cool weather we've been having (50s-70 max), it's running smoothly on regular gas @ low RPMs too. I may consider running it all winter if it holds true down to lower temps as well.

Turn on the AC or drive in 80's, however, you get some timing pull there on 87, so I'll go back up a grade on the next tank.