Yes but it's USER defined instead of factory defined like a stock ecu with a piggy back or reflash. So intern you the user or tuner can't not have it active at all.

I read alot hear that because of the MAP based fuel triming it's smoother a bit but I can feel the diffrence and on the dyno graphs it is a bit smoother looking curve.

 

Again USER TUNEABLE

 

Eric, I appreciate your enthusiasm for the XEDE and all, but please don't highjack my thread. I trying here to find solutions to a real problem and not to debate engine management systems

 

ok exit stage left

 

by the way I'm not promoting exed in anyway you were asking why your car does not like timing. I ask to see your ignation map witch you have yet to provide.

Bottom line here are your possiable problems

A you have a hardware issue (Boost leak ect.)
B your tune is no good and you might be to lean for the gas your using
C you have some kind of restriction that is limiting your ablity to run timing.

Or a far out D
you are just trying to run more timing then you really should be. it happens

 

SilverEvo8, what Eric is talking about is the user tuneablility of the knock sensor using the AEM. I find that to be on topic since the knock sensor is what "pulls the timing". Maybe you should find out what other people with AEM have there knock sensitivity at.

 

yep

 

Back on Topic...

The MON of the fuel is very important, and unfortunately tends to vary quite a bit with pump gas. What gas are you using? Have you tried running Sunoco 100 (which is known to be very consistent from batch to batch) with a race fuel tune to make sure the car does not prematurely knock? Obviously the threshhold will be different than with pump gas, but it may still be an indicator.

Also, I've found that poor head cooling can also induce premature knock. How many miles is on your car? How does the coolant look? I might try running a cooler thermostat, just to see if it has any effect.

yes, both of my ideas are grasping at straws....

The "off a tooth" for the cam timing is also a very good idea, and has merit.

One other thing that just popped into my head, but I don't know if it applies to the 4g63 (I come from a different turbocharged background) is the CAS and/or ECU timing reference. Have you checked the timing? (yes, the old fashoned way, with a timing light)

-Ryan

 

Its not how much timing you "CAN" run, its how much you "MUST" run.
Low advance requirement = GOOD.
High advance requirement = BAD.

Ignition advance = NEGATIVE TORQUE.

When you have a really good combustion chamber with good tumble characteristics and quench, you don't need alot of advance because the burn rate will be fast enough to obtain peak cylinder pressure at the proper crank angle (~20-30* ATDC) without alot of advance.
Any cylinder pressure before TDC delivers negative torque to the crank.

Show me someone who's bragging about how much timing they CAN run and I'll show you someone who doesn't really understand internal combustion engine dynamics.

Large, low swirl (or tumble), low quench combustion chambers require lots of advance. That requirement is a patch, not an asset.

You must also remember that we have a relatively high mechanical compression ratio and we have a small efficient turbo that will make peak boost before the torque peak of the engine. This makes for extremely high cylinder pressure in the 3800-4k rpm range.

Having said all that, I will add that if you are knocking especially in the high rpm range, install colder plugs.

JDB

 

That is also a good suggestion, colder plugs. I think everyone will agree that your target for timing should be MBT.

 

That might be good to help the knock resistens a bit, but not a solution for the overall problem.

 

It is possible that your knock sensor it torqued too tight. The spec for an Eclipse is only 7 ft-lbs. Any tighter, and the ECU's knock retard can get a bit overactive.

Also, the ECU filters out background noise, so I doubt that any non-RPM related noise could cause the ECU to retard timing. That basically rules out 90% of the driveline.

Noisy lifters can cause knock retard, though.

You have flexibility over the knock sensor with the EMS. You have to figure out what sort of noise spikes really are knock on your car. This will take plug readings, listening to the engine, etc... You can't just trust the knock sensor outright.

And you should really tell us what your timing map is, and how much it is being retarded by the EMS because of knock, and what the final timing advance numbers are throughout the RPM range. Then we can get a clearer picture of what is going on.

If two people have identical engines (which never happens), and one makes more power with more advance, and another guy starts knocking at the same advance and can't make the same power as the other guy, then something is suspect.

In general, with DSMs, I have found that a peak timing of 23 or 24 degrees usually works pretty well on C16 race gas or the like. But, obviously, I wouldn't advocate it for all cars. Hell, from week to week at the track, I usually start off with lower advance than that and work my way up, because you just never know what might have changed or what might work better. I also have a 30psi boost spike that I have to retard my timing for. And, actually, there is a hell of a lot more than just that to go into it.

Basically, you have to tune each car individually and find out what it likes.

 

First of all Eric, thanks for your input. I don't want to sound pissy or cranky. I do appreciate all of you guy's advise and input.

Thanks a lot for your input here... I really need more education about these things. All I know is what others tell me. I was under the impression that large timing advance was imperative for good power (at least that's what the majority of "tuners" that I've spoken with say). As far as the timing curves, I would ask George to post them if he can. He should have the map I'm running now in his computer (how about George?). I really am not in a position to explain and respond these important questions. That's part of the problem, I'm not at all a mechanic or a tuner. All I know is what I'm told and what the dyno pulls show about my car. So far I'm only talking about maps created for 93 octane gasoline. At first I thought it was case of bad gasoline since I bought Quick Trip 93 octane swill, but I still appear to have the same problems after running nothing but Amoco Ultimate 93 octane gasoline almost exclusively (OK, I've run maybe 3 or 4 tankfuls of Chevron or Texaco under emergencies). I've also run 100 octane race gasoline and added octane boosters from time to time, but only to make sure I'd not get ping. I noticed the car pull timing a lot back when I was stock. I've also noticed it pulled timing on some of the more aggressive maps since the advent of the AEM EMS, but not now. The problem is that the last person who tuned it as well as two orv three previous tuners, all ran into the problem that whenever they attempted to add timing, the engine would appear to ping and the ECU would pull timing.

Frankly, I don't know if more timing is actrually needed or wanted. All I know is that up to now my car makes pretty sorry power for the number and scope of the mods I've had done to it.

Here are my mods and the last result of the dyno pulls (with a bad clutch)
AEM EMS w/3.5 bar boost sensor
AEM IAT sensor
AEM Uego/AF display
HKS Cam gears
HKS 264/264 cams
HKS RS intake (no MAF)
680 cc Blitz injectors
Walbro pump
Perrin Fuel rail
3" turbo back exhaust
Greddy R-Spl IC
Boost Solutions tune

259 hp on 93 octane....

 

Never know that but it makes sense. But it he is a AEM user he might not even have the knock sensor on.

 

Eric, the AEM EMS definiterly senses knock and pulls timing. The data logs clearly show voltage spikes from the knock sensor as well as other forms of knock events. I guess I neglected to mention that the knock or pre-knock was detected with datalogs as well as noticing the timing pull during 2nd & 3rd gear pulls on the road as well as on the DD dynamometer.... I'm not sure I believe that the AEM or other standalone EMS's do away with the knock sensor..... Anyway, still there is some knock or knock sensor voltage activity that precludes the using of more aggressive timing advance.