Plug Reading: Should I add more timing/fuel?

ninezeroteg · Post by **ninezeroteg** » Mon Sep 07, 2009 2:21 pm

As stated in another post, the setup is as follows: 84.5mm B20 vtec (block was decked) Stock B17 Head (head was milled) 12.5:1 Compression RS Machines Type R Replica Pistons Prelude 345cc Injectors Skunk2 Type R IM AEM Ram air Intake 4-2-1 Egay Header 2.5\" Mandrel Bent Exhaust Stock Ignition (brand new distributor/cap/rotor) Stock Plug Wires NGK 4554 gapped to .032\" AFR = 15 at idle to 13.8 at WOT I put these plugs in today, and did four WOT pulls in 3rd gear (low cam only). On the last one, shut the car off at 7k RPM. Pulled the plugs and brought them home to take pics. From what I've read, It looks like I can add about 1 to 2 degrees timing? Also, it looks like I maybe need to run one step (edit:) hotter of a plug? There are no heat rings that I can see on the threads. PLEASE, correct me if I'm wrong about these things. The porcelain is white on all 4 plugs, no aluminum or pepper. The porcelain pretty much looks the same as when I put the plugs in. I went over them well with a 10x magnifier. Pics posted, as well as my datalog from the runs, and a screenshot of the low cam ignition. Appreciate any input.

ninezeroteg · Post by **ninezeroteg** » Mon Sep 07, 2009 2:21 pm

other images.

Post by **Bugermass** » Mon Sep 07, 2009 2:33 pm

For that boost level you should be running a #7 heat range plug.. What does the insulator look like way down inside the plug where it meets thebase? Is there a ring of carbon on it? If so, about how thick would you say it is? 1-2mm ?

Post by **Gaskleppie** » Mon Sep 07, 2009 3:41 pm

boost level?

ninezeroteg · Post by **ninezeroteg** » Mon Sep 07, 2009 4:47 pm

Edit: Bugermass, sorry man.. I had the scalars setup wrong. This is all motor. I updated the image above to show the correction. As far as the insulator where it meets the base, I didn't see any carbon ring at all. I know my AFR's are pretty decent though according to my LC-1. That's what is confusing to me. I thought if I was running a plug that was too cold, I would have lots of carbon build up on the insulator?

Post by **Bugermass** » Mon Sep 07, 2009 11:17 pm

Ahh haha thats cool.. Yeah you should have a pretty good ring.. Mabey they just wern't in there long enough to get a good coating on em

ninezeroteg · Post by **ninezeroteg** » Mon Sep 07, 2009 11:47 pm

Right on, I'll put them back in tomorrow and do another 4 or 6 runs to see if I can get the fuel ring to show.

ninezeroteg · Post by **ninezeroteg** » Wed Sep 09, 2009 12:05 am

I put the plugs back in tonight, and drove around doing some data logging for about 20 minutes or so. Then I did four 7k rpm WOT pulls in a row, turning the engine off at 7200 rpm the last time and pulled the plugs. Still no fuel ring at the base of the porcelain, but not seeing a whole lot of color change from the heat on the threads either. I'll post up pics tomorrow. I have a set of R5671A-9's, should I try those out, or go to a R5671A-7?

Post by **Bugermass** » Wed Sep 09, 2009 1:42 am

I just noticed you said your runing 13.8 @ WOT. there won't be any fuel ring at those AFRs lol.. you could probably put the 7s in there and be fine. are you just doing like 1 gear pulls? or are you going through all the gears really loading up the motor?

ninezeroteg · Post by **ninezeroteg** » Wed Sep 09, 2009 7:01 am

I've only been doing mainly 3rd gear pulls when doing the plug reading. Yea, I have 13.8 @ WOT but am thinking maybe I should add a little fuel there. Maybe 13.1? I'm tuning the low cam first, trying to get it perfect and then moving on to the high cam.

9400RPMS · Post by **9400RPMS** » Wed Sep 09, 2009 8:50 am

Better richen that WOT mixture up, before you melt a piston at least 13.1's..

Post by **Bugermass** » Wed Sep 09, 2009 5:38 pm

yeah just single pulls in one gear isn't gonna uild up enough heat in the cylinder to really get a good plug reading.. you need to go beat on the car a bit.. I'd richen it up a bit as well.

ninezeroteg · Post by **ninezeroteg** » Wed Sep 09, 2009 6:27 pm

Now that I think about it, and check my .cal out, I tried to set the target AFR's to 14.7 at light load, 13.8 at medium, and 12.9 at high load in low cam. I noticed yesterday when I tried to set my high cam target AFR's in settings that the table wasn't being populated with the numbers I programmed. I should have paid more attention the first time. I caught it on the high cam and did it all by hand. I did 13.8 at light load, 13 at medium load, and 12.2 at high load. I'll work on getting my AFR's corrected. Here are pics of the plugs from last nights pulls. Still no real heat rings that I can see, and not a whole lot of color on the ground straps either. I might go get some 7's tonight and try those out. I'll start doing my WOT pulls for plug reading in all gears I can get in as well. I'm already at 90mph in 3rd gear at 7200 rpm.

98vtec · Post by **98vtec** » Wed Sep 09, 2009 11:16 pm

you will need to be looking to the bottom of the porcelain in order to see WOT fueling. What you are looking at in those pictures is idle and light acceleration.

Post by **Bugermass** » Thu Sep 10, 2009 2:37 am

^^ correct.. and those are still too cold.. Not likely to get acurate indications with that heat range.