f20kills

I used to have an EMS when it first came out...its a lot to know!

What I think he is saying is the graph will consider it "knock" above 3 volts. So if the graph "shows" 2-3, that would be considered 5-6 actual volts. If your under 3, the graph will show nothing.
A lot more than you want.

I would think that if the tuner is well rounded on the EMS, he would have calb the tables correctly.

Stratocaster

In short, (Mind you I am still learning so I could be wrong) the knock sensor, is just a mic. As your RPMs rise, so does the voltage comming from the knock sensor. As each spark plug fires, the the sound is turned into voltage. When it knocks, the sound is louder so the voltage of the sensor peaks. EMS will allow the tuner to set the threshold that will be considered a knock, and how much timing to pull when that happens.

So if your EMS was set to sense 4v as a knock and to pull 1 degree of timing. It may have been set at too high of a threashold, and when it did it may have not pulled enough timing.

The AEM Log graph that you posted does not show the value of Knock RAW. That is the vaule that the sensor sends to EMS.

Asura

Elevation and Barometric Pressure is an issue on your car due to the ITBs.

Not such an issue on Rob's car.

wadzii

there are several knock parameters that you can log with the ems. Ill try to explain them as clearly as i can. I was a little off in my explanation before, ill go edit that post.


Knock #1
Displays the amount of current detonation which is determined as Knock #1 Raw – Knock Noise Table. Basically this is the amount of knock voltage OVER whats set in the knock table.

Knock #1 Tooth.
This gives you the crank tooth that the ecu is filtering by, this helps to determine exactly which cylinder is knocking. IMHO useless on a PC log, the logging rate is too slow to pick up all the crank teeth.

Knock #1 Raw
This is the raw unfiltered voltage data coming from the knock sensor. IMHO this is what you want to look at. You look for "spikes" above the background noise levels to decide if there is knock or not. This is the parameter you would use to find a standard noise level and setup the knock tables.

Knock #1 Volts
This parameter uses the knock tooth information to filter the knock data so that it only takes knock samples AFTER the spark plug fires. useful for picking up detonation, but not preignition and usually results in MUCH quieter data than knock raw. This is not very useful IMHO. Log both knock raw and knock volts, overlay them, you will see what i mean. Also because the PC logging is too slow to pick up the crank tooth data, its too slow to get anything meaningful out of this.

vapors2k

I didn't read your original thread, hopefully none of my questions were answered there. Judging by how quickly your engine grenaded, I have an itch to wonder about your gas or octane degradation after the tune. Were you using fresh or relatively fresh gas at Buttonwillow? Octane degrades over time but at the same time I have a hard time believing the tuner setup your map on the ragged edge; that a few weeks or months after your intial tune + degraded gas could equal that much detonation. It just doesn't make sense. Unless you're compression ratio was much higher than 12.5:1, resulting in an increased sensitivity to octane. It's odd that the engine felt great depsite all the blowby and ring damage, makes me wonder if the compression was uber high.

A friend enlightened me about the quality of race gases on the market. I don't know what brand you were running but he seemed to blast the unocal 76/sunoco/vp ~100 octane gases. If you were running more compression, fuel might be the culprit. You can't tell the quality by color.

Depending on your AEM EMS settings, wouldn't the EMS pull back timing if it sensed knock? Unless that was turned off or not activated?

bellwilliam

with my limited knowledge.
for a track car:

1. Knock sensor don't work. period, not on track. it is just a microphone, with r-comp tire noise, engine vibration due to stiffer aftermarket engine mount, stiff suspension, CAI intake noise, loud header, test pipe and no muffler. they don't work on a track car. tuner has to set a threshold, too high, it blows up. too low, it goes to limp mode every time you hit Bus Stop.
2. tune for 91 (or 1/2 91, 1/2 100), but run 100 on track. 100 octane is not always 100, it is as low as ~98.
3. I would get an EGT, temp and a/f, and wire them into ECU for safety, as soon as the parameter is exceeded, it goes into the limp mode. much better than unreliable knock sensor.

Rob, I feel for you, but I personally would not trust 90% of the engine builders, along with most tuners. how many builder/tuners you know turns a faster lap time than you. you see a few turbo/sc car come out to track and slower than na car, and claim their superior track reliability. they are reliable because they are SLOW. you blew the engine in 23 laps at BW. if you were at AAA Speedway ROVAL, it would of been done before you finish your out lap. front straight alone is ~30 seconds of WOT (dyno is like 3 seconds), most tuner don't even know 30 seconds WOT is possible. track is a LOT harder than a dyno.

Tune conservatively, you have to take in variables of bad filter, bad fuel pump, bad injector (Sav recently lost a motor, because 1 injector flows 5% less), heat (not in a dyno room, with hood open, 90" fan blasting), heat soak, bad fuel, etc... never tune on the edge. again, tune for 91, run 100. last time Shawn Church tuned my FI Miata (just a month ago), we ran 260 on his dyno after many back to back runs. he then pulled timing and added a little bit of fuel, so it drops ~10whp, that becomes my track tune. track tune should never be the same as dyno tune, imho.

rob.ok

^^ Yeah I pretty much investigated every avenue in regards to the failure (and spent a good deal of time looking into fuel). I consulted multiple professionals from manufactures, builders, machinist, and tuners and have come to a final decision. Nothing was overlooked, however I am not a pro so I can only draw my conclusion from their analysis.




Anyways, I think I've decided to have a little fun with this motor. So stay tuned.

I have a sneaking suspicion that I will be able to get new rings to seal. If that works out there will be more to the story. Since everything is trash; I have no qualms in blowing it up in real style after I have the chance to do some testing (which by the way will be done with an external knock sensor). I'll keep you guys updated.



-Rob

josh7owens

nice read guys. Im really sorry rob. I couldnt imagine lossing 8k, months of research and labor in 23-24 laps. I also feel really bad for this tuner because anyone that actually races s2ks prolly post on here and its safe to say that if he doesnt take a huge loss and provide some amazing CS then hes looking at being black listed. Who would take thier 8k motor to a tuner that blow up another s2kis members car and didnt offer to cover the cost to build another one. when they cant just go else were.


Its also crazy he would come to our forum and try to lie and say he tuned it when another member reading the thread did the tuning.

maybe we should sticky this if the tuner doesnt step it up on the CS...

rob.ok

The reason I posted it, is simply to share my story in an attempt to put the power of the consumer back in our hands and push business to deliver the best possible product and and services. It also turns out that there are other "stories" that are very questionable but they are not publicly known.

You have misunderstood a portion of the discussion...The argument between the tuners has nothing to do with my car. That is their past. I was just under the impression that certain event s that had taken place.

The tuner has made me an offer, but it is not necessarily one that I can accept as there are stipulations. I feel wronged and I should be compensated but that is unlikely at this time.



-Rob

josh7owens

i understand rob, are you going to just take this as a loss or do you think he will step up and fix this or is it gonna be a court issue like a previous member did and got the place to source a used motor.