Angel Of Mercy

Err.. ok.. 1st... mods up to stage 3 do not require pumps until you start putting in turbine kits... we are already running super rich as stock... and we are using SAFCs to reduce fuel.... no, thank you for the thought but i dont think that is the problem... i think the problem is more on the heat production...

I'm just wondering if you guys with cams and cam gear with higher lifts and durations ever thought about how the increased pressure on the compression will increase probabilities of detonation... i hope you guys are not putting these stuff in just coz your tuner says so... think about the logic behind it... more power always comes with more risk...

As far as i understand so far.. detonation is the effect of these variables

1) Excessive compression (Compression type 1)
2) Bad Fuel quality
3) Excessive heat (Compression 2
4) Excessive boost (Compression 3)

From my own analysis, pre-ignition/detonation occurs with these variables are at a certain point.. i.e. when too much compression occurs causing too much heat to the point where the A/F mixture ignites prematurely....

From this, the only way we can stop this is to:

1) Reduce compression (Compression 1 and 2)
2) Reduce heat
3) Improve fuel quality

1 and 3 are things we cannot do much about.. we want power and we dont make our own fuel... therefore the only thing we can do is to improve cooling to reduce heat....

Logical step for this...

1) Add intercooler (done this)
2) Bigger radiator (working on this)
3) Decrease thermostat open temperature (now at 71c but apparently not enough
4) add water mist injection into intake manifold

I dont know what else but if anyone has any ideas.. would be helpful..

Angel Of Mercy

These are my rules of thumb..

1) i dont let any tuner tell me what i think or feel... reason.. its my car.. i paid a lot of it.. and who are these people who think they know better than what i feel with a car i drive everyday....

If i can feel the ECU retarding timing.. if i can hear a zinging sound when the SAFC II told me detonation just occurred... then i say its detonation... tuners want your money and they will say anything to get it.. some say sorry afterwards... others give more excuses.. sorry.. new pistons, conrods, cranks or a new engine destroyed due to some tuner's word is not my cup of tea...

2) The SAFCII uses the same knock sensors as the ECU... are you tell me that the ECU is wrong... that the knock sensors are BS? Why in the world would MMC put in those in the 1st place? Why would the ECU use it to retard timing? I agree that the SAFC may not be excellent in measuring knock levels but when the ECU retards timing when the SAFC measures a knock level of 120+.. i'
d say that was pretty good...

Guys.. FFS.. its YOUR EVO!! How would you feel when a conrod appears jutting out of your engine or your head gasket blows? What would your tuner say? Oh.. that's strange... or hmmm... that shouldnt be.... or even worst.. it was the fuel.. you must have put in bad fuel.... come on... prevention is better than cure...

berkel

iTrader: (5)

Hi,

I've had my SAFCII for awhile. Silver, I read one of your posts about installing, and STILL managed to screw it up. I didn't install the wires backwards, I installed them upside down.

Anyway, if your rpm wasn't reading right, it was the wrong wire. In fact, I think I pointed it out in that other thread. The wiring chart you were refferring to had the wrong pin to splice. Anyway, it doesn't matter since you sold it I guess.

I haven't dyno tuned the SAFC yet, but what I did was start with a baseline from here, then watch my knock readings at various rpm. If I get knock, I add a little fuel. If I get fuel cut, I turn down the boost. Car seems to run pretty well. Sometimes the knock reading will be 4-5 after the car is really warmed up at idle. This doesn't really matter, but make sure you calibrate the knock readings at ~1500 rpm and ~3500 rpm after the car is really warmed up. As stated, low readings are mostly just noise , but if you get too aggressive, you will see a higher number and probably feel less perf from ign retard. If you have high readings but no ign retard, perhaps it's wired wrong or it wasn't calibrated with the car really warmed up.

Anyway, I'm pretty happy with is, since I have noticeable sotp improvement. I will definitely try to get it properly dyno tuned later this year.

Oh, on a side note, with the colder weather lately here in New England, definitely need to adjust the settings. Car will hit fuel cut at 10 degrees with settings that were ok at 30 degrees, with my MBC anyway. Also, prob don't want to lean it out too much when it's so cold since there will be a lot more air... If you're in Brunei or somewhere more consistent, may not be an issue. I didn't have my SAFCII last summer, but I'm sure I can lean it out more in the the summer heat to improve perf.

Take care,

FB

bluevilevo8

If you want to keep accurate tabs on detonation, just shell out the 150 for a knock link. REALLY cheap insurance if you ask me.

Rob W.

iTrader: (8)

Hey AngelOfMercy: I don't think anyone's arguing that you're knocking. But I think you're really wasting your money on the radiator and t-stat. Coolant temp is the least likely thing to cause detonation. Yeah, sure, when an engine is REALLY hot it'll knock, but you've long since already pegged the temp gauge and boiled out most of your coolant at that point. If your engine is so sensitive that it'll stop knocking by running the coolant temp 10 degrees cooler, then you have much bigger problems.

My guess is that your gas is the culprit.

silverEVO8

iTrader: (12)

Yeah, I know what you mean about the installation. I installed it backwards, and of course, it would not work at all.. But even after I corrected the wiring and everything was correctly (as well as I could understand it) wired and done, the rpm readings were still off by a good bit from the tach...... I called AMS and consulted with other users and basically I learned that it's not unusual for this to happen and that sometimes you had to choose a different number of cylinders than the 4 cyl it should be , etc. They also said "it does not matter, etc." Well, I was never actually convinced of that, but anyway, I guess the fuel trims will work eventualy after the SAFC is tuned so the rpms might not be so important... I don't know if the knock counts could be equally off so I'm not sure I'd trust them either

Angel Of Mercy

Hmm... so i guess then there is no solution to this...

silverEVO8

iTrader: (12)

No, there is a solution, you just have not found it yet I would tend to agree with those who blame the gasoline. Also, your timing curve might be too aggressive. I know from experience that those two factors are likely to cause knock. You seem to know your stuff very well and you also seem to be comfortable working with your car. Have you looked at the EGTs and F/A ratios?

Angel Of Mercy

My AF ratios are quite conservative with corrections only as much as -8% but producing 257whp (about right for the mods i currently have). The leanest AF is about 12.6:1 at low rpms to about 11.5:1 at max rpms... EGTs are used to measure the same.. higher EGTs tend to mean richer mixtures... and are used as gauges for AF...

Besides, when with stock AF settings (0% corrections)... and very low boost (0.9 bar), I'm still getting detonations at about 5000-6000 rpm.. my intercooler is already the top end version and on dyno runs, my intake temp is only about 40 C where ambient is about 30 C... and even after 10-15 runs.. it still remains the same temp. The air temp going into the engine is already at the lowest possible... the only other thing i can think of (apart from adding a water mist injector for the throttle body) is engine cooling via radiator with a lower temperature thermostat... the continuous circulation of the radiator coupled with the increased heat dissipating capacity should reduce over engine temp and theoretically reduce knock... but here racing radiators cost about $1300 (US$800) and thermostats around US$70-100... I guess, i have not much choice... since no one seems to have an answer to it or even seem to have this problem (or maybe they choose to ignore it)...

Strange...

4G63>OOOO

iTrader: (1)

You're thinking in terms of flow when you should be thinking in terms of pressure.

Get a fuel pump before dishing out all that money on a radiator, t-stat, etc. I'm willing to bet your leaning out on the top end due to lack of fuel.

silverEVO8

iTrader: (12)

I don't think that those A/Fs you quote are too conservative. 12.6 is very lean but might be OK under some conditions. 11.5 is the maximum A/F most tuners go for with 93 octane (USA fuel). Please don't get me wrong here, but your interpretation of EGTs is contrary to common wisdom. To wit, higher EGTs denote lean conditions, lower EGTs denote rich conditions. This is something I'm very sure about......
Also, you do not mention timing curves at all.... I've seen in the EVO 8, that with lean mixtures (11.5+) during hard acceleration, the ECU advances timing too aggressively and the car knocks which causes the ECU to pull timing right away. End result= loss of power.
I'm no expert and most of my knowledge comes from reading and talking with people, but I think you are not addressing the problem's source. The charge temperature is a contributing factor to knocking, but you already have a big IC.... Water injection might help, but why take chances with aggressive A/Fs and timing advance? It seems to me that you need to get either a stand alone, reflash or piggy back solution that will allow you to control the fuel and timing curves more effectively. I think you are threading on dangerous ground with your car....

just my $.02

GDB

Angel of Mercy - my bad, for assuming you have JDM Evo 7.

This is getting very interesting though, because it seems there answer is very elusive.

I can only say that:
1. I agree with someone who said that reducing coolant temperature likely won't SOLVE the issue.
2. Fuel pump is a very good investment, likely to improve the condition but may not fully solve it.

Point 2 is harder to convince those who have NOT had fuel pump upgrades before. But those who do, know that not only they reduce knock, but also improves throttle response across the RPM range. In fact my experience in STi even showed it improved fuel mileage.

On with the analysis:
- Your AFR is quite alright it seems (I assume they were all wideband readings?)
- The EGTs are in your opinion alright as well
- Yet you still knock at a low 0.9bar boost in midrange

That only leaves one thing: ignition timing. What do you guys think?

If so, somebody has done a screwed up job re-flashing your ECU to be compatible with 95+ RON.

Ryanmcd3

Also the xede is coming out with wideband O2 logging as well as Knock detection and logging. Just think you can say if knock is greater then 10 pull .05 of timing. Pretty cool.

WILDMAN

iTrader: (2)

Bad gas, bad plugs, fuel pump? I would start with the simplest fix and work my way up in that order.

Rallyman

We also suffer with low octane gas and this can easily be addressed. Just buy some "Toluene" and add about 1 gallon to every tank of fuel. You car will not pink, knock or detonate even with higher than standard boost.

Toluene is usually pretty cheap and can be obtained from agricultural merchants in large drums or from paint shops or print supply shops in smaller cans.

Just take car - it must be stored in a metal container and you should avoid getting it on your skin. javascript:smilie('')