The Project Pad

Yep, so it's shutting off over 120kpa and 4000rpm.

It's completely off. 0% rich and lean corrections.

That's not necessarily bad at all. It prevents things like exhaust leaks and bad sensors from leading you down the garden path. Which is what I had been wondering about.

mushasho wrote:

dana wrote:so was this just one hole that melted the plug, or did multiples look like that?
crazy that the 3 prong plugs look so good!

I just didn't have the 5th in the picture... all 5 looked good, were just worn as it started to misfire at 6800rpm... I replaced them with these NGK R5671A-9 as part of being a responsible owner that maintains his vehicle... Had soo much better luck with BKR7E as well...

I think this tells all. I was quick to blame bosch plugs for this exact same failure on another tread and after investigation it was definitely detonation that caused it. It's likely you just swapped in plugs at the inflection point where things were really going downhill. I think the end result would have been the same with no plug swap, but maybe the bosch plugs would have held together better even though the cyl died.

FWIW, I swapped in these plugs with no modifications, I think they came gapped to .030 so I just tossed them in and they have been flawless.

The cooler heat range could be causing them to foul on your car and look like that if you don't get them up to temp before you pull them out. I have not experienced fouling, but I also live in Cali where the temperature is pretty stable. This is something you just have to play with, they also make an 8 heat range which may better for you on E85.

The NGK 7 heat range work pretty well but I would always get slight shiny deposits on them over time which showed pre-detonation which was impossible to tune out even around 18 psi. Moving to the 9 heat range plugs has eliminated this.

Just trying to help as you move forward, which you must Fix it up, get a new batch of plugs and tune by plug till everything looks good. It is a pain swapping them in and out, but like Chris said it is really the only way to see what is really going on inside the motor.

Just pulled my #5 for reference. Pump fuel, water injection, 2bar of boost. 1 dyno day, 2 track days, probably 500 miles on them.

now thats a nice plug jim!

Thanks, it's taken a while to get there! It's easy to ignore the little signs when the car appears to be running so well. Larger injectors that were not on the edge, reliable water injection and a plug that the motor likes. All kind of obvious but I think we all tend to set it and forget it at the dyno sometimes and you have to really stay on top of it with these projects.

One more thought if you can stand it. I would not completely rule out the Launch control and Anti-lag. I stopped using it because it's a pretty punishing process on the motor if everything is not perfect, and there is no way to really tune it on a dyno or in real life other than by EGT which may or may not be all that accurate. It was fun on disposable 20v motors, but not my build 20v.

Jim, what part number are you using in heat range 8? R5681a-9 doesn't exist from my searching. I never had good luck with the bk.... line, which you can get in a variety of heat ranges.

Pretty funny that basic carburetor tuning techniques are still so relevant today, makes sense though. Rubi is still teaching us all something even while in a coma.

Marc wrote:Jim, what part number are you using in heat range 8? R5681a-9 doesn't exist from my searching. I never had good luck with the bk.... line, which you can get in a variety of heat ranges.

8's are NGK 4554.

Yep, it's R5671A-8 or 4554 I have a set here so I know they are orderable

They stopped making the BKR8E which is how I landed on these race plugs.

I get them locally from Advance Auto. In stock always.

I also run the R5671A-8 or 4554 on my S362 at 2 bar and they look exactly the same as Jim's. Cheap, effective plugs.

Fwiw, with NO other changes on the dyno, my car made 20whp more on the R5671A than the (old) BKR7EIX. Yes, 20whp. Brady and I looked at each other like wut

chaloux wrote:Fwiw, with NO other changes on the dyno, my car made 20whp more on the R5671A than the (old) BKR7EIX. Yes, 20whp. Brady and I looked at each other like wut

Did you change the plugs on the same day at the dyne? If so that is fucked up!

themagellan wrote:

chaloux wrote:Fwiw, with NO other changes on the dyno, my car made 20whp more on the R5671A than the (old) BKR7EIX. Yes, 20whp. Brady and I looked at each other like wut

Did you change the plugs on the same day at the dyne? If so that is fucked up!

mild misfire you sometimes will not feel. the dyno however can see the difference.

Marc wrote:

themagellan wrote:

chaloux wrote:Fwiw, with NO other changes on the dyno, my car made 20whp more on the R5671A than the (old) BKR7EIX. Yes, 20whp. Brady and I looked at each other like wut

Did you change the plugs on the same day at the dyne? If so that is fucked up!

mild misfire you sometimes will not feel. the dyno however can see the difference.

Exactly that. It was just getting to the point where we thought we could feel something.

Dyno runs were 15 minutes apart.

For Reference...

R5671A7 stock #4091
R5671A8 stock #4554
R5671A9 stock # 5238
R5671A10 stock # 5820

EDIGREG wrote:

mushasho wrote:And if you want the safety of an OEM ECU, get a custom Motronic tune and forget about it.

Should we overlook the fact that many aftermarket ECU's can provide this level of safety? I mean I know at the core there's only soo much one can ask from a $700 ECU, but still it's a much newer design that's feature packed... just saying...

You could really go off the deep end and try running a new ECU from a Jetta B-)

Mcstiff wrote:You could really go off the deep end and try running a new ECU from a Jetta B-)

For that full "deep end" effect I'd need the accompanying 2.5L tho....

Sent from my HTC One using Tapatalk

mushasho wrote:Should we overlook the fact that many aftermarket ECU's can provide this level of safety? I mean I know at the core there's only soo much one can ask from a $700 ECU, but still it's a much newer design that's feature packed... just saying...

VEMS provides a ton of flexibility, easy tuning, and lots of cool features, but it's never going to provide equivalent knock detection to Motronic. That's just a compromise you have to make.

Standalone ECUs are not for everyone.

EDIGREG wrote:

mushasho wrote:Should we overlook the fact that many aftermarket ECU's can provide this level of safety? I mean I know at the core there's only soo much one can ask from a $700 ECU, but still it's a much newer design that's feature packed... just saying...

VEMS provides a ton of flexibility, easy tuning, and lots of cool features, but it's never going to provide equivalent knock detection to Motronic. That's just a compromise you have to make.

Standalone ECUs are not for everyone.

In laymans terms - why is that? Is it simply that because it's a basic nuts and bolts hardware there was just never and R&D put into that sort of monitoring?

Aren't there such things as standalone knock boxes that you could run alongside to remove this disadvantage to vems?

There are, but each engine has it's own knock profile based on displacement, CC design, stroke, CR, etc. Basically everything that is part of an engine plays into the knock profile. This is why the factory Motronic is always best, because the manufacturers are the only ones with the resources to do this in such detail.

A ton of noise comes through a knock sensor, filtering out all of that noise to detect knock is incredibly difficult, and is different for every engine/sensor combination. Universal devices such as SEM ECUs or knock boxes attempt to use a knock-detection algorithm that "works" universally - these will never function nearly as well as as an engine-specific factory ECU which has gone though thousands of hours of R&D for the safety of that specific engine.

Detection takes careful listening even for trained human ears, for all but extreme knock. Here are a couple sound samples of what a knock sensor sounds like

AAN

2JZ

924