FredR

Blipping the throttle at no load will show advance at those levels and possibly more so the data point is somewhat meaningless. At full load full rpm's you will likely be close to 30 degrees assuming your knock sensors and Hall trigger are working of course. ST2 tells you that the minute you fire up.

mark kibort

thats what i was afraid of.... doing a full load timing test is hard ,because i would need an assistant that would be able to operate the timing light. but i can do full load.. im guessing the ECU takes into account MAF voltage and RPM and plays with timing, right? so, i wonder if the test Bill did with the Shark tune, finding out that there were no knocks was able to detect the knock sensor and hall sensor working. however, this doesnt explain the fact that there was no difference in time from 60-100mph on a video taped set of runs. times were identical, with and without the knock sensor connected..
by the way, what is the function of the hall sensor?

Rob Edwards

Speedtoys

Then other things were broken, because that test result on a functional car, is not possible.

mark kibort

well that can be good news and bad news... good that if isnt possible then i have some HP to be found. the bad new is, what is allowing me to achieve such high levels of power without the knock sensor connected? this is the same tested power level ive had since ive built the engine and dynoed it the first time. i just dynoed it recenty as well what other things were broken? (or are broken) temp sensor? hall sensor , i think thats about it? how can i test it?? does it have to be on a full load to see the timing pull back? what does the timing normally run at at 4000rpm , WOT? could something in the ecu be ignoring these feedback loops? when billl checked it, he saw no knocks and i assume he saw that the sensors were connected and firing and that could be determined by the shark tuner. correct?

what if the hall sensor is not working... it would pull 6 degrees out, that would negate the function of the knock sensors. but can it run fine without the hall sensor? does it pull timing out other spots other than full load as the knock sensor does ? (as fred says) i also dont why the knock sensor doesnt work at part throttle , as thats when a lot of knocks can occur too... lugging the car, hot day, ive heard the gregory 6 liter knock like crazy.

edit: the reason i ask about dyno testing or other folks testing, is that im wondering the effects of pulling timing at higher RPM ranges remember i did this test on the 2 valves and got the timing from 42 degrees down to 39 degrees, lost 7ftlbs of peak torque but gained 3hp at the higher RPM ranges. if that is the case for me, then there may not be an issue. i guess what i need to find out, is if under load, the timing is dropping 6 degrees. il have to do the WOT 4000rpm test and see if the timing is changing 6 degrees vs part throttle.

Speedtoys

For like the Nth time, if any of those dont work, the whole map is -6 degrees.

Why are you focused on load?

mark kibort

Because fred said it was only on a load map. ( dont see how that is possible, due to knocks happening in part throttle that are dangerous for the motor as well)

so, with my tests, im not seeing a 6 degree change at all... you mean even at idle, it would go from 10 degrees to 4 degrees? (that's "whole map" , right?)
i see the 4000rpm at being near 37 degrees.. that seems like where it should be, with and without the removal of the knock sensor. could there be a setting in the ezk that ignores this function, or gets a signal that they are connected even though they are not? OR, could it be something funky in that Holbert LHjet box? this thing is driving me up the wall now....... is there a simple tool to register if the knock, Hall , temp sensors are connected? or if the timing is not being altered?. the two outcomes is that those sensors are being ignored and my power is not alteed , or im sitting on some potential HP gains if i can get them to work IF the timing is being retarded.

IcemanG17

Sharky had this issue.....one dead knock sensor (rear) and the hall sensor.....so I was losing 3' from knock sensor on rear 4 cylinders and 6' on all cylinders from the hall sensor....the knock sensor is pretty easy to fix once intake is off.....the hall sensor is a bit of a PITA as its difficult to get too, I'd imagine worse with headers

The difference in performance on sharky was HUGE....I didn't have dyno data, but it just felt stupid flat above about 4500rpm....acceleration times were way slower.... unfortunately the old performance app's I used back in the day don't run on Iphone right now....

Speedtoys

Fred's cool and all and may be right, but the ECU documentation is pretty clear, thats why multiple people are quoting it. (except idle, its not a base map)

Knock can happen anywhere, if the ECU cant trust it's data, it pulls it ALL out.

mark kibort

so, if i am idling at 10-12 degrees BTDC at 1000rpm.. and the knock sensor is not connected and i reconnect it, it doesnt change, it points to two things...........either there is another problem and the timing should be 6 degrees higher, which is 16 degrees. ( thats not correct), OR, the faults are not being recognized. (for some reason or other issue) by knowing what the timing is for a stock S4, wouldnt that give us a baseline to judge from? I'm surprised no one has done these kind of tests before. especially before "shark tuner"
what do YOU suspect is going on. plenty of power. values that have been constant for 10 years. ive had power issues of near 15hp and they were very noticeable, due to improper cam timing when i put the 85 cams in, resolved with changing timing. (and all 60-100mph test /goal values were restored.
I'm loosing it over this one.
are you free to check this out sometime? could we do a quick check with the shark tuner or that other simple tuner that uses a test port?

Brian, each knock sensor, or temp sensor, or hall sensor, if bad, will pulll 6 degrees. it looks like the knock sensors when hearing a knock, pull 3 degrees of the individual cylinder. but if there is a failed knock sensor, or hall sensor, 6 degrees is pullled out. (its not 6 or 3 degrees for each). .............. if you felt that was a big power looser, why when i pulled 3 off the euro 5 liter from 42 degrees to 39 degree and i gained hp up top (peak) and lost a little torque at torque peak would i feel such a dramatic problem if i had an issue with the sensors that i can feel. i measured timing at 4000rpm and it was near 37-39 degrees today!
im not giivng up... i need to get to the bottom of this.

Speedtoys

Idle maps are not running maps.

The running map is the baseline, WOT map is referenced from running map, just like fuel.

mark kibort

Ok.... so i would think "running map" is some level of throttle , so can you reveal what that level is ? maybe that is the issue, i was running the "idle" map and not the "running map". i can simulate the WOT map too. maybe things are fine, i just was not able to run the right Map to see if the timing was puled out.

Speedtoys

Are you familiar with how the 928 idle switch operates?

mark kibort

yes, but i have the white wire going through a selectable switch. (For start up , warmup, and shut down, i leave it stock connected.. for . racing, i have the idle switch disabled). so, are you saying, that if the idle switch is not providing continuity, the engine uses the "non-idle" or "running map"? if so, that blows the chance that the knock sensors are actually working. if the running map is everything but when idle switch is engaged, im back to square 1.

FredR

Mark,

Without the likes of ST2 you are "radar blind" as to what is going on inside your motor engine management wise. I have lost count of the number of times I have tried to convince you about this but I do understand the concept that your "senses" are telling you the motor is running just fine and if that works for you all well and good.

As I am aware the Hall trigger enables the system to know which cylinder is knocking when a knock event occurs. If the system logic detects a fault in either a knock sensor or the Hall trigger it pulls timing 6 degrees across the board as a safety measure assuming that the fuel being fired is going to be no less than a certain octane no matter what type of witch **** it is.

As to the idle condition I have no idea whether any timing correction is applied to such - the likes of John or Jim will likely know that. I believe you are aware of the mapping system and how it works but for those that do not, the ignition system applies a certain amount of pre-defined advance based on a cell bounded by rpms and load [MAF reading]. The point of this map is to try to ensure that maximum cylinder pressure occurs at 14 degrees after top dead centre. Thus the faster the motor is running the more advance is applied and the lighter the load the more advance is applied - presumably because the mixture burns slower at lighter loads. Some operating cells buck the trend because of resonance effects or whatever else practical experience influenced the mapping in the factory. The stock mapping is a one size fits all type of thing and has a degree of conservatism built in for engine longevity reasons. Thus sharktuner permits tapping into that margin which is not an awful lot but is definitely present. I have no clue what mapping you are currently running on but my guess would be you have a custom EEPROM burnt using the original version of sharktuner- that or you simply have a stock map. If you have a custom chip then chances are further tuning will do nothing more for you performance wise but that does mean the likes of ST2 will do nothing for you- far from it. The ability to record data and analyse it is a huge plus in my opinion. Thus trying to assess what is going on when you blip the throttle on no load is just about meaningless unless you know the advance value for the cell the system is operating on when blipping the throttle which clearly you do not.

The other thing you need to remember is that what applied to your 2 valve motor does not apply to a 4 valve motor. The later models will have a more efficient [faster] burn characteristic thus need less advance on full load cells. Thus any notion that on full load and max rpms that you can run levels of advance much more than the stock mapping [27 degrees on a non cat model and 29 degrees with cats?] would be pure folly or so I would think. Similarly a race [faster] exhaust facilitates less advance- an interesting dynamic.

To summarise- you need to know whether your engine management system is working correctly and chances are that can only be reliably ascertained with some kind of system diagnostic capability. The hammer tells you whether it is working but little more than that. ST2 tells you this and so much more. Max power is seemingly delivered at around AFR 13 so running at AFR12 or less is for the most part a waste of fuel and at some point will actually cost you power. Stock mapping seems to give an AFR of about 12.4.