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[ifly87]

I finally got my setup back up and running and after a new wastegate/IM/TB it was still "fluttering" or surging, so I started adding in timing (alot) and its mostly gone, it seems to pull real hard and boost is almolst 100% steady, only flutters maybe 1-2psi.

I am running it now with a stock z6 timing map with only .1psi per pound retard. this is about 18psi and 11:1 afr
right at the top of a pull I killed the ignition and coasted into my driveway, pulled out the plugs and this is what they look like.

[Joseph Davis]

Fluttering?  Vitara engine with smallish Mitsu turbine?

The yellow-ish on the ground strap is oil.  This is common for a lot of Honda engines, if you look down your plug holes your pistons are either wet around the outside (!) or are totally wet all the way across (!!!).  Seek some goddamn crankcase ventilation.

Where the yellow breaks up... breaks up in two places between the 90 bend and the base of the plug well, I'd call the top and bottom clean bands the extents of your heat markings.  Depending on the temperature of the plug, you either need a colder plug or you need more timing.

The clean ceramic up top (on a fresh plug) is good, it shows that the idle and part throttle burn is clean.  Down deep in the well, where the burn reaches under boost, should have a nice golden brown or darker "burn ring," which can be very difficult to see with the hotter plugs as they recess further... you may need an otoscope or to cut the well away in order to see this correctly.  The fact that you have a smoke-like black residue makes me think your injector atomisation is shit, or you have a borderline misfire under load problem - not uncommon in a D-series, especially when you're running s 10.x:1 or lower AFR and it's misfiring smoothly so that the wideband reads 11:1 without the butt dyno throwing alarm bells.  To make any given horsepower figure, compared to any of the other Honda engines with bigger bores, you have to run a lot more combustion pressure... combustion pressure = high plug gap resistance, leads to misfires earlier.

Seriously, dude.  I could do a better job if you told me what engine, what plugs, what gap, hell what setup? 

[Joseph Davis]

Also, are those plug threads glommed with anti-sieze?  Wipe that shit off.  It's GOOD to have on your plugs as you will wear out an aluminum head by yanking steel plugs in and out a lot, but you don't need much at all.  If that's a layer of anti-sieze, it's going to interfere with the plug's ability to shed heat, as it acts as an insulator.

[ifly87]

Yeah sorry, I know I went a little crazy with the anti sieze, anyway

d16z6 stock length rods, vitara pistons. these are ngk bkr7e with about .029 gap. Those plugs have about 15 miles on them as pictured.
 
Yes I know I need a better crankcase vent setup, and today I had 2 an fittings welded to the VC and will be running them to a breather box as soon as i can find one that I can make fit somewhere.

its got a big turbo on it, t3/to4e .63/.70ar .57 trim

here's a screenshot of my high cam ignition map, it pulls nice and smooth up past 7,500rpm no ignition breakup.



Like I said the timing map is stock except I only pulled .1deg/lb you are saying it needs "more timing" as in advancing it furhter? I will hopefully get it on the dyno this coming weekend.

[Joseph Davis]

Too much plug gap, try 0.24" and less if the problem still persists.

That's scary ignition timing.  I don't know how you aren't detonating, unless you are so rich you are misfiring in the higher boost.  Or.  Something else is wrong, as compressor surging that is fixed by adding timing is a sign that your timing is too retarded.  Got a Y8 cam in that sucker?

Where is your wideband grounded?

Here's a picture of the eCtune timing for a Vitara motor (that means stock length rod, the FJ long rod Vitara motors are called ABORTIONS aka defeating the purpose) with a T25.  I think the inertia dyno let me down, as this car also compressor surged in the midrange and adding 4-5 degrees into the lowcam (not pictured) as well as 2-3 degrees more in the high cam took care of that problem and the plugs/piston tops still looked tits.  This extra timing was added at a later IAT trim touchup session, and is not pictured.  FYI, car hits 17-18 psi by 3K and tapers to 12-13 psi by 6500-7000K, as well as eCtune does things a hair differently (as does Neptune, or Hyundaidata, etc) so take the timing figures as general idea and not directly applicable.

[Minor Threat]

Yeah, Neptune with the ign adjustments turned off needs a fuck ton of timing in the maps.

20 pounds, 20 degrees is the rule I've been going by.

[sewell94]

Put in a fresh set of plugs, and lean it out some and then post some more pics. Your idle and part throttle fat also? The yellow/white you see on the plugs is cadmium coating that ngk puts on their plugs.

[Joseph Davis]

I've not compared Neptune (never touched Neptune) but S300 and eCtune locks ignition in an entirely different fashion.  There's a ~4 degree difference between the two... the ~ is because S300 drifts around in an obviously inept fashion.

Timing varies a bit between setups with eCtune, seems most closely related to horsepower/torque than boost pressure (the theory that temps go up with higher boost requiring less timing as the heat accelerates the burn)  but there's still variance.  It is what it is.

I have NO experience with Crome that I care to stand by, as it's been over 3 years since I touched the application.  I know it works damn fine for some folks, but timing is handled differently and I can't comment without ever doing one comparo.

[Joseph Davis]

The yellow/white you see on the plugs is cadmium coating that ngk puts on their plugs.

Disagree.  It might be caused by coating + the presence of a quantity of oil, but the engines I see leaving it behind are the ones with wet pistons that burn oil without smoking.  There are plugs that it never forms on, and the pistons are always dry.

[sewell94]

Most vitara engines i've done at that boost level require a a really small gap, if i know i'm going about 10lbs on a d series at gap them at .017.  Try a new set of plugs gapped down and pull a couple of degrees of timing.

[sewell94]

The yellow/white you see on the plugs is cadmium coating that ngk puts on their plugs.

Disagree.  It might be caused by coating + the presence of a quantity of oil, but the engines I see leaving it behind are the ones with wet pistons that burn oil without smoking.  There are plugs that it never forms on, and the pistons are always dry.

  Tell that to the ngk rep at pri next year, thats who told me what it was.  Its used as a heat indicator burns off when your getting close to the correct heat range.   Autolites dont do this, they dont have the coating.

[Joseph Davis]

Hrm....

[sewell94]

look into it, (as im sure you are currently)

your oily piston theory my be true due to the oil cooling the cylinder down, hence it still having the coating compared to the other cylinders.

I'm guessing hes right inbetween 6 and 7 heat on the heat range on the plugs, which is why 1 cylinder is burning it off and the others aren't.

[Joseph Davis]

Actually, I'm thinking oil induced detonation is causing temp and pressure spikes that do nothing to affect the average temps (ground strap coating) while resulting in the tiny flaws in the piston's carbon coat that alarm me.

And, like I said about the Vitara motor that I posted pics of, I think the inertia dyno let me down.  I added a couple degrees in on the street a year later, dude bought slicks and two weeks later set FTOD at the local auto-x.

[ifly87]

Yeah its got the stock rod length. If I take any more ignition timing out of it, it starts surging again and I know its already pushing it with that much timing, I'm afraid to turn the boost up any higher until I can get this resolved.

The cam in it is the stock z6 cam, I sent it to delta and they put a 272 grind on it, thats what they told me anyway honestly I couldnt tell they might have just shipped it back to me and did nothing. I have the adjustable cam gear set at 0, I've tried retarding it a few degrees since I decked the head and block.

I dont have the wideband grounded to the t-stat housing so I guess I could do that. I'm stumped I just want to be able to crank the boost to nog mode.

I wonder if the fluttering I experience with the ignition timing pulled back has to do with a weak ignition system, I never gapped lower than .029 and its all stock ignition. sometimes it idles ok sometimes not, I know I need to work on the injector battery offset tables but I'm not quite sure how, I've read through pgmfi and there isnt any real good info on tuning injector battery offsets. Where do I put a voltmeter? I'm using precision 1000's mostly since I was planning to use ethanol when I bought them.

[sewell94]

Yeah its got the stock rod length. If I take any more ignition timing out of it, it starts surging again and I know its already pushing it with that much timing, 

I wonder if the fluttering I experience with the ignition timing pulled back has to do with a weak ignition system, I never gapped lower than .029 and its all stock ignition.

Pulling timing out a few degrees wont hurt anything. 

Gap the plugs down. Take out some fuel, Like Joseph said you could be rich misfiring,  the plugs look ALOT richer than 11:1 afr.

What i'm thinking is that between the overly rich mixture and large plug gap is where your surging(misfiring) is comming from.

Did you synch your timing?

[ifly87]

Yeah with a timing light and adjusting the cam gear with the distributor centered you mean? When I do this it comes out I dont really have to adjust the cam gear any.

[Joseph Davis]

Reground your wideband at the thermostat housing, and do what Sewell said.  Especially yanking a little timing first - if you get a good burn going on with that timing, ouch.

[PhilStubbs]

The cam in it is the stock z6 cam, I sent it to delta and they put a 272 grind on it, thats what they told me anyway honestly I couldnt tell they might have just shipped it back to me and did nothing. I have the adjustable cam gear set at 0, I've tried retarding it a few degrees since I decked the head and block.

you need to advance your cam gear to compensate for the block and head machining, not retard it.

[92CXyD]

The cam in it is the stock z6 cam, I sent it to delta and they put a 272 grind on it, thats what they told me anyway honestly I couldnt tell they might have just shipped it back to me and did nothing. I have the adjustable cam gear set at 0, I've tried retarding it a few degrees since I decked the head and block.

you need to advance your cam gear to compensate for the block and head machining, not retard it.

No retard 1 degree for every 0.010" you take off the deck.
Advance 4.5 degrees if using a y8 head/cam  on a z6 block w/ z6 crank timing gear.

[92CXyD]

Right turning the gear towards the intake is retarding the timing. :yes:

[Joseph Davis]

Most D16 end up in a half tooth off disposition, people default to advanced when putting the timing belt on.

[ryan89crx]

The cam in it is the stock z6 cam, I sent it to delta and they put a 272 grind on it, thats what they told me anyway honestly I couldnt tell they might have just shipped it back to me and did nothing

you would definitely be able to tell if you adjusted the valves. you would almost run out of adjustment and only have about half the threads in the locking nut...

pic of how much adjustment a 282 requires

[ifly87]

Well I did have to re-adjust the lash, but not a whole lot. Anyway thanks for the responses guys, it has been pouring rain all day and I have to work in a coupple hours so there arent going to be any updates today.

[DmC]

I didn't read the whole thread but my take on the plugs is that you need to pull a few degrees of timing. the heat mark looks to me like it's about half way between the base and the turn down.  pull some timing install some fresh plugs and check it again. maybe it's time to break out a timing light to because with that much timing at 20psi basically the engine should have a big hole in it.

[danz]

i was running around the same timing on my vitara build... couldnt hear any detonation... took the head off and two of the pistons had melted on the intake side.. still 150psi across the mill but it wasnt long before they were going to turn into slag.

[ifly87]

well thats pretty scary...

Today I put a fresh set of plugs in gapped them down to .024, pulled timing and fuel out and the surge is back again. It surges as the boost rises but when it gets to about 20psi, it seems to hold seady. It also holds steady if the tires are spinning, but as soon as it loads up real good it starts surging a little bit again. I'm starting to thing that the turbocharger is just not properly sized for this engine or somthing.

[Joseph Davis]

It surges as the boost rises but when it gets to about 20psi, it seems to hold seady.

Then only add a little timing in the area where it's spooling.  3-4K in the low cam, right?

[ratcityrex]

Im looking at your screen shot, and looking at your timing map and i was wondering if you have the (idk what its called off the top of my head) extra map that is in the menu where you can change all you fuel injector timing vs ect there is a menu that with a stock mas will slope from 0* advance at idle and 16* advance at 8k. That could be why you have no timing pulled. Idk maybe just a guess. Still dose not fix your fluttering problem.

[Joseph Davis]

Fuel injector timing is irrelevant.