Pics of my cracked piston
May 1, 2006, 11:54 AM
#31
Originally Posted by Ted B
Using an unusually large injector is a band-aid fix, and is almost certainly responsible for the hard starting issues with the EMS that have been discussed here. I don't know of any reported reliability issues, although I'd do it differently, as trying to control a peak and hold injector with a high-impedance driver is said to create high current loads that can shorten both the life of the drivers and the injectors.
Like anything else, it has its strengths and weaknesses. IMO, its strength is its logging ability, while its primary drawbacks are the high impedance injector drivers, the relatively weak ignition section, and the price.
Like anything else, it has its strengths and weaknesses. IMO, its strength is its logging ability, while its primary drawbacks are the high impedance injector drivers, the relatively weak ignition section, and the price.
I have an AEM EMS and only 750cc injectors. Most people know what I have in the car but in short a GT35r @ 26-32 psi.
I have never ran out of gas with those injectors yet (I see mid 90% duty cycles) but havent run out yet (Unless I run the car at 10.5:1 AFR).
The unusually long crank is due to the EMS synching while startup. You could turn it off and force it to fire spark and fuel based on what it is assuming its at... it may run strange for a bit afterwards... dont really know why they do it this way. If you look at older cars they dont have as many crank pickups... the reason for more of them is so stock cars can fire faster. Perhaps the EMS only uses one of them... Im not sure but it has nothing to do with the fuel.
You could tell the EMS to open the injectors till they hit a static state. They will not close ever which is obviously the most fuel they could shoot out with a given pressure.
I think the biggest reason people put larger injectors in cars with an EMS is because they can. If I did it over again I would have went with at least 1000cc injectors because I could... not because I need it. I can post up plenty of logs of my car at well over 25psi with the 750cc injectors and I am not running them static. I think another reason alot of people need such huge injectors are because they think a Whinebro fuel pump can supply endless amounts of fuel.... well it cant. The Whinebro will start to run out of the needed supply pretty early on... it just still gives the car enough but it isnt technically the correct amount. When I switched over to the cell and A-1000 I had to lean out my map considerably... this shows how much the Whinebro was not supplying enough.
Anyways, back to your blown motor... I would like to know more about what happened. From the little I know it seems like you had a tune that was extremely aggressive (The reason you would run 100octane alot) and for some reason you got yourself a bad batch of gas, or the fuel mix wasnt as rich of race gas as normal.
May 1, 2006, 12:11 PM
#32
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Well.....trina the tune was slightly agressive as it was tuned on 100 octane. I asked the tuner to make the map for 91 and he thought he did. This was a problem of the guy not being an Evo specific tuner. Not a problem of him not know what he was doing. He is AEM EMS certified and an authorized HKS tuner.
Now....with me thinking the tune was set for 91 was part of the problem, I put 91 in the car and the next day is when this happened after a month of running on 100. The afr's were 10.8-11.2 but the timing was set high thru the midrange. I believe it was at 14 degrees at the top end. I dont really know enough on how to read the maps so I cant say for sure. kcevo looked them over and that is what he told me.
I still dont believe that to be the cause of the leaning out that occurred. I saw this happen at peak boost, the afr's went to 13.5-13.7 when it was always at 11.2 this is when the detonation occurred and the motor popped.
Now....with me thinking the tune was set for 91 was part of the problem, I put 91 in the car and the next day is when this happened after a month of running on 100. The afr's were 10.8-11.2 but the timing was set high thru the midrange. I believe it was at 14 degrees at the top end. I dont really know enough on how to read the maps so I cant say for sure. kcevo looked them over and that is what he told me.
I still dont believe that to be the cause of the leaning out that occurred. I saw this happen at peak boost, the afr's went to 13.5-13.7 when it was always at 11.2 this is when the detonation occurred and the motor popped.
May 1, 2006, 12:59 PM
#34
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becareful, I have seen and Evo pop just like that in cyl 4, rebuilt it, and a month later the connecting rod from cyl 3 broke in half. It may have been a freak incident, but non the less a short block was put in it.
May 1, 2006, 01:26 PM
#35
Originally Posted by TrinaBabe
If I did it over again I would have went with at least 1000cc injectors because I could... not because I need it.
Originally Posted by althemean
I saw this happen at peak boost, the afr's went to 13.5-13.7 when it was always at 11.2 this is when the detonation occurred and the motor popped.
May 1, 2006, 01:31 PM
#36
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Same crap happened to me in Dec 05, piston 1 and 4 took a ****, I am rebuilt now, but after driving for 2k, I have rod knock, gotta pull that f*cker out again....and yes I have an 05....
May 1, 2006, 04:07 PM
#40
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ah....yes. My beautiful girl friend who was so kind to take that picture in her bra and panties for me. She still works.....havent destroyed that one yet.
May 1, 2006, 04:11 PM
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Originally Posted by Ted B
IF that is the case, and you are certain you witnessed said phenomenon, it doesn't appear to have anything to do with the tune. The fuel system is suspect.
May 1, 2006, 10:00 PM
#42
Originally Posted by althemean
IT IS the case.....please do not question my integrity.
Not long ago I was driving a car when it popped the headgasket. I had to replay the sequence of events (which happened very quickly) in my head several times to be sure that I had an accurate recollection of what happened in the correct sequence, which is important in determining the cause. In your case, I would want to be absolutely certain that you positively saw the lean mixture reading before engine damage took place and not in response to an unusual noise or immediately afterward. One sequence of events points toward the tune, the other toward the fuel system. As you can see, this has nothing to do with integrity, just human memory. Of course, if you are reading this from a data log, then it's a moot point.
Last edited by Ted B; May 1, 2006 at 10:09 PM.
May 2, 2006, 06:01 AM
#43
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right....thats is why if you read the original thread (link to it on the first page of this thread) I got the motor to repeat the event twice before it blew but at different rpms. The first time it happened the afr gauge caught the corner of my eye right as the detonation hit, I wasnt sure what happened. I floored the car again ( I was in the fast lane of the highway) and was looking right at the gauges. I know it wasnt the tune because for one month I had been driving it and watching the afrs the whole time. In fact for the first week I was only on 10psi while we worked out the part throttle issues (which were extremely rich 12-14mpg rich) You also gotta remember I had auto-x the car the weekend before on the same tune. If it was a problem with the tune, it would have let go at that event, not while just pulling onto the highway.
May 2, 2006, 11:18 AM
#44
Originally Posted by althemean
right....thats is why if you read the original thread (link to it on the first page of this thread) I got the motor to repeat the event twice before it blew but at different rpms. The first time it happened the afr gauge caught the corner of my eye right as the detonation hit, I wasnt sure what happened. I floored the car again ( I was in the fast lane of the highway) and was looking right at the gauges. I know it wasnt the tune because for one month I had been driving it and watching the afrs the whole time. In fact for the first week I was only on 10psi while we worked out the part throttle issues (which were extremely rich 12-14mpg rich) You also gotta remember I had auto-x the car the weekend before on the same tune. If it was a problem with the tune, it would have let go at that event, not while just pulling onto the highway.
It does sound like the fuel pump quit on ya but I would try to learn something from this whole deal. Mainly being if the car has a problem.. especially running lean dont floor it
Also, make sure you find the problem and fix it... dont just assume you figured it out.
May 2, 2006, 11:37 AM
#45
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Originally Posted by althemean
you are right. The answer was there in front of my face. Sometimes it takes an outside look to see things. The rocker arm came off the intake valve (which was hanging slightly open when I pulled the head off) on the cylinder with the cracked piston. Thats how the metal spread.
It has already been verified it was not the tune for all those who are asking. Timing was a little agressive thru the midrange (probably a contributing factor but not the main cause) but I normaly run 100 octane all the time. The afr's were fine. The biggest cause of this was simply my fuel pump giving out and causing a lean condition. Boost levels were at 19psi so nothing crazy happening there.
I will post some pics of the cylinder head in a little while.
It has already been verified it was not the tune for all those who are asking. Timing was a little agressive thru the midrange (probably a contributing factor but not the main cause) but I normaly run 100 octane all the time. The afr's were fine. The biggest cause of this was simply my fuel pump giving out and causing a lean condition. Boost levels were at 19psi so nothing crazy happening there.
I will post some pics of the cylinder head in a little while.