Today I was doing some more tuning and decided to take my boost dependent retard down from 1.25/psi to 1*/psi. This made a huge difference. Traction in second is almost non-existant.

I did notice some knock in my logs so I decided to do a pull and check the plugs @ 5500 rpm. Well, on a brand new plug, the porcelain had some black carbon looking specs on it. Funny thing is, datalogging showed no knock at all when this happened???

Is it possible for me to be knocking at 15.75* total timing @ 7.5 psi. Motor is a bone stock JDM b16a w/ log mani and t3/t4 hybrid. Closed loop dump, 2.5" dp, 3" exhaust.

 

Ok, pulled the timing to 14* @ 7.5psi, still getting knock. Im at 12:1 afr...??

 

im not a tuning expert by no means, but isnt your timing under boost supposed to be 11:1? Also i think you may be running to much timing retard. Most people ive talked to are running .5-.9 degrees retard per lb of boost. you are currently running 1.8 degrees of retard per lb of boost.

Also, what type of gas are you using? are you plugs gapped correctly? What type of plug wires are you using?


if any of you expert tuner guys know other wise, please feel free to correct me!

 

I have run 15-18* total timing on simular setups with no knock problems. AFR was more like 11.4:1 though. 93 octane and more like 10-13psi on 50 and 57 trim t3/t4s

 

thats too much timing pulled imo. stock B16 timing at 0psi and high rpm is about 26 degrees. so if u take out 1 degree per psi u should be at around 18-19* total timing at 7.5 psi.

tune for a little richer a/f like 11.6-11.8 and get urself on a dyno to see if u r loosing or gaining torque when u advance timing

 

Your from NY right? come on down to T&R Racing in queens NY for some dyno time. i work there if u need any info

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted k20 &raquo;</TD></TR><TR><TD CLASS="quote">thats too much timing pulled imo. stock B16 timing at 0psi and high rpm is about 26 degrees. so if u take out 1 degree per psi u should be at around 18-19* total timing at 7.5 psi.

tune for a little richer a/f like 11.6-11.8 and get urself on a dyno to see if u r loosing or gaining torque when u advance timing</TD></TR></TABLE>

I belive its 25* at atmospheric, and he said he was getting possible knock @ 15.75*, so it seems reasonable to lower it a bit to see if it disapears.

In any event, what plugs were being used?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTC_CiViC &raquo;</TD></TR><TR><TD CLASS="quote">I belive its 25* at atmospheric, and he said he was getting possible knock @ 15.75*, so it seems reasonable to lower it a bit to see if it disapears.

In any event, what plugs were being used?</TD></TR></TABLE>

The plugs were NGK 8's. Already had them, thats why there a little cold, ill probably step down to 7's next time.

What I ended up doing was pulling timing to 15*, and still saw the same knock. Then I said "what the heck" and pulled even more to 14*. STILL knock. Like I said, black specs. The specs were on the porcelain, but they looked exactly like the carbon on the base ring. The only thing I can think of was the instantaneous spike @ 5k (peak torque!) to 12.6:1 afr. Either way, I added almost 5% more fuel at 5k and put the timing up to 16.25 total, did a few pulls and only once did I see a lone black spec. I really want to post pics of the plugs to see if it even is knock. Ive read like 30 articles on reading plugs and never seen a decent pic of detonation on a plug...

Thanks for the responses guys, and if anyone has a pic of plug w/ detonation, post it up.

P.S. Im not in NY, just paranoid :-P

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cobra2326 &raquo;</TD></TR><TR><TD CLASS="quote">The only thing I can think of was the instantaneous spike @ 5k (peak torque!) to 12.6:1 afr. </TD></TR></TABLE>

So you were leaning towards mid 12's at peak VE.. sounds plausible.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTC_CiViC &raquo;</TD></TR><TR><TD CLASS="quote">So you were leaning towards mid 12's at peak VE.. sounds plausible.</TD></TR></TABLE>

Yeah, I pretty much disregarded it b/c it would only show up about half the time, and almost never in third, but I think that may have been the issue.

 

What compression? What Fuel are you running?

i think if you have a normal compression ratio around 9:1 - 9.8:1 its not possible to get knock with 16* or less ignition advance on a b16 at 7.5psi

please post some pictures of the plugs.

i noticed some very very small black spots on the porcelain when looking at the plugs... even at 8:1 cr engines with 8-9psi of boost and 96 octance and very conservative timing. but as you mentioned, they look like the carbon on the base ring so i guess thats NOT knock. but maybe a professional can give some comments about this

Best regards

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mrx &raquo;</TD></TR><TR><TD CLASS="quote">What compression? What Fuel are you running?

i think if you have a normal compression ratio around 9:1 - 9.8:1 its not possible to get knock with 16* or less ignition advance on a b16 at 7.5psi</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cobra2326 &raquo;</TD></TR><TR><TD CLASS="quote"> Motor is a bone stock JDM b16a </TD></TR></TABLE>

IIRC, that's 10.4:1 or 10.6:1

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mrx &raquo;</TD></TR><TR><TD CLASS="quote">
i noticed some very very small black spots on the porcelain when looking at the plugs... even at 8:1 cr engines with 8-9psi of boost and 96 octance and very conservative timing. but as you mentioned, they look like the carbon on the base ring so i guess thats NOT knock.
</TD></TR></TABLE>

This is my question. Ive always heard that black specs on the porcelain meant knock. I was getting black specs with 11.5 - 12:1 afr and 14* total timing on 7.5psi. 10.4:1 compression. To me, this doesnt even seem possible. Jeff evans is talking about safe timing being .5* - .75*/psi retard on 10.x:1 compression, and that would put me in the neighborhood of 18* - 20* total timing at 7.5 psi. If anyone has pics of what detonation on plugs looks like, help us out here!

Btw, fuel is chevron 93 and always has been since I bought the engine, about 10k miles ago.

 

thought black specs "pepper" on the plugs was a sign of detonation or pre-ignition

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 88da3 &raquo;</TD></TR><TR><TD CLASS="quote">thought black specs "pepper" on the plugs was a sign of detonation or pre-ignition</TD></TR></TABLE>

As did I.

Just in case nobody ends up posting pics, heres plenty more info on reading plugs:

From wikipedia (http://en.wikibooks.org/wiki/R...acing):



From what Ive read, not only do black specs indicate detonation, so do tiny ***** of aluminum on the insulator nose or the center electrode. A center electrode which has been burned clean 1 mm from the tip will also indicate ignition timing which is too advanced, causing high cylinder temps. Theres more, so Ill post some articles and info that I believe are accurate:

From evans-tuning (http://forums.evans-tuning.com...ensor):
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
The base of the spark plug should have a black soot evenly lining it. You should not see any metal flakes at all. If you do, its an indication of knock.

At the ceramic surrounding the electrode of the spark plug (the white part), you should not see any metallic flaking or black pepper looking speckles. If you see these, you are getting pre-ignition or your running lean.

If the white electrode is turning an amber color, the plugs either need to be stepped up the next heat range (cooking the plugs), or you simply need to replace them.

Just remember, the only way to check the plugs is shutting the engine down under WOT/load condition, turn the ignition key off, push the clutch in, and take the car out of gear. If you let the engine cycle itself at all, you risk burning off any traces of the knock with the cylinder pressures built up from simply letting the engine cycle.</TD></TR></TABLE>

http://www.strappe.com/plugs.html

http://www.sentra.net/tech/sparkplugs.php

And theres more, if you do a search on google for "spark plug detonation".

 

Actually from the above diagram, where it says "spark plug too cold", that looks a lot like my plugs. Perhaps I need to step up 1 heat range to 7's instead of 8's?

From the article:
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
A hot plug does not make an engine run hot, nor a cold plug make an engine run cold. A hot plug merely means that the insulator nose will run hotter and keep itself clean by burning off deposits.

A plug which is too cold collects carbon and fuel deposits on its insulator, which leaks energy from the ignition, causing loss of power, if allowed to continue it will foul(not spark at all)

The length of the insulator determines the heat range of a plug. Use the hottest plug that doesn't burn the tip of the center electrode.

If your plug is too cold, you will see deposits on the nose of your plug. Figure 6 illustrates this. If your plug is too hot, the porcelain will be porous looking, almost like sugar. The material which seals the center electrode to the insulator will boil out.</TD></TR></TABLE>


Modified by cobra2326 at 11:19 AM 2/20/2006

 

Maybe this will help you....

ATTN: These are not my pictures.

Tools and Parts needed:

Your Integra
Fresh spark plugs
Dyno time
A 10X power light magnify glass
Appropriate tools to pull plugs after WOT run

Lets begin....

[RED]It is best to read plugs when they are fresh AND after a WOT dyno pull AND the engine is turned off immediately. Please don't tune your car WOT in public areas such as roads or highways.... Let's keep it safe people.[/FONT]





The picture below has correct heat range, but is also the leanest that will make best HP. It has a full-turn of very light soot color on the base ring and heat range mark is half way up on ground electrode strap. Most engines can't run this lean and make their best power curve, but engines that are highly efficient, without any dead areas or fuel air separation spots in cylinder heads, will like to run this lean.



The spark plug picture below.... shows the "Richest" a spark plug can be and make good Horsepower and Torque curve, any richer than this will definetly hurt Peak Horsepower mainly, but not so bad for peak Torque.



The spark plug picture below.... shows a "Too Rich" spark plug. Horsepower and Torque will definetly start to be reduced .



In all the above photos of spark plugs you will notice that the white porcelain looks the same color. The white porcelain does not indicate jetting!! Do not look at the porcelain insulator for jet changes.... instead look at the plug's base ring, the last thread ring that has the ground strap welded to it.


Now there are a few KEY words that need to be explained here....

Heat Range = Ground Strap, the ground strap indicates the heat-range of the spark plug. If the "color" of the ground strap "changes" too-close to the ground strap's end, (which is above the center electrode/ the tip), then the heat-range is "too-cold", meaning that the strap is loosing heat too-quickly to the base-ring, and is not able to burn-off deposits until near its end. If the "color" of the strap changes near where it is welded/attached to the base-ring (last thread ring),then it means that the plug heat-range is "too-hot", because heat is not being tranferred/cooled from the strap to the base-ring quickly enough!!!! The strap might begin to act like a "glow-plug", eventually causing preignition/and/or detonation later on. Proper heat-range is when the "color" is at the half-way point on the strap, neither too-cold or too-hot.
(Refer to the second picture for visual explination)

Color = meaning the evidence of heat/or lack of heat by the appearance dark vs lightened color of metal

Jetting = the air/fuel mixture ratio that shows up on the base-ring (the last thread ring, it has the strap
welded to it).
**IMPORTANT**
You want 1 full-turn of light-soot color on the base ring!!! If you want to tune for max. power, then you want 3/4 to 7/8ths of a full-turn of light soot color to show-up on the base-ring, but this is on ragged-edge of being too-lean, but will make the most HP on most engines. To be safe, leave it at a full turn of light soot color. If the base-ring has a full-turn of color, but there are "spots" of heavy build-up of "dry-soot" on top of color, then jetting is too-rich.

Porcelain = the porcelain shows preignition/detonation, hence the need for the 10x power magnifying glass, it will not accurately reveal jetting/air/fuel ratios. To look for the first/beginning signs of detonation, search the white porcelain for tiny black specks or shiny specks of aluminum that are stuck to the porcelain.
When detonation occurs, part of the air/fuel mixture explodes instead of burning, the explosion is heard as a "metallic-knock", this audible knock is the result of a sound shock-wave, this shock wave travels back and forth across the clearance volume "disrupting" the cooler boundary layer gases that cover the entire clearance volume area, this disruption allows "more" heat to be transferred into parts especially domes/piston tops. In conjuction you will have a very rapid rise in pressure like a hammer like blow, which is how pistons can get torched/melted and sleeves cracked!!!
One step beyond the black specks,will be tiny specks/***** of alumimum coming off-pistons that will be fused to the plugs white porcelain. The next phase to be reached is occasional pieces of the porcelain being broken-off as detonation gets worse.
Soon after that, there are holes, blown head gaskets, broken connecting rods, you get the idea....

Soooo to sum things up....
Ground-Strap = Heat Range
Plug's Base-Ring = Jetting
Porcelain = signs of preignition/detonation

Good luck and have fun!
Information source

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cobra2326 &raquo;</TD></TR><TR><TD CLASS="quote">Actually from the above diagram, where it says "spark plug too cold", that looks a lot like my plugs. Perhaps I need to step up 1 heat range to 7's instead of 8's?</TD></TR></TABLE>

Hallo Cobra,

i think thats also what i saw on my spark plugs... i run a 10.2 (stock edm b16a) at the moment at 7.5psi at the moment with more advance then you and have no problems since 20.000km and my plugs look fine... so i think i have no detonations at all. Fuel is also similar maybe a bit worse in my case.

just try the lower heat range and try again... i don't think you need more then 7's with this compression and that boost level. If the specs get less then you know the plug was too cold.

Best regards
Malte.

 

Are you running 7's as well? I have no clue why I ordered 8's, I thought I ordered 7's so maybe I just got the wrong ones. Ordered a set of 10 7's today.

I was telling tepid that after 5 or 6 full boost runs and pulling the plugs, the porcelain below the ground strap would be completely black, with the specs showing up closer to the center electrode. Apparently, the porcelain should be solid white. Im almost 100% now that Im running too cold a plug.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cobra2326 &raquo;</TD></TR><TR><TD CLASS="quote">Are you running 7's as well?</TD></TR></TABLE>
Yes, i run BKR7-EN11 in nearly every car i tuned... and in my own one... only if 7's are not enough i go colder but until now i had no car which needed 8's or 9's.

i think also that your plugs are only too cold and that you don't have detonations or knock or something... it seems that the black specs are despostits that can't be burnd from the porcelain because the plug looes heat to quick because of the heatrange...

try some hotter ones and give us a report - i'am curious as well...

hope we could help you :-)

 

Right you should be good with a BKR7E-11 and gap it @ .030 -.035

 

bump for more info on the black specs. I too have noticed these on some cars running very conservative tunes. In fact I noticed it on my own sohc after running a brand new set of plugs for a couple weeks. Recently I got paranoid about it so I bought a brand new set of bkr7e's, did a pull and pulled the plugs. They were perfect with no black specs at all. Now after a couple of weeks if I just pull my plugs out even when not doing a pull I can notice just a couple black specs like cobra is describing on each plug. There is no reason i should be detonating because my timing is about 1* per psi and 11.5:1 afr's. I am thinking they are something other than detonation too.

 

This is probably the most informative post about tuning I've seen on HT. Oddly enough.

 

keep it going

 

I will take some pics of my plugs today and also post pics of my timing map. What I ended up doing to fix most of the specs was retard timing at peak torque more than at the rest of the map. According to a post on pgmfi.org, whenever you see a peak in fuel, there should be a dip in the timing.

Unfortunately, like sohc has said, after a few weeks I notice detonation on my plugs. Mine dont have black specs, they have ***** of aluminum on the center electrode and ground strap.

I did a compression test yesterday and got 235, 234, 234, 236.