slash128's Top Mount Build
#1726
n3rd
Thread Starter
We had an impromptu cars and coffee this weekend. Our buddy brought his 3 rotor turbo FD out that he built himself. He did a meticulous job with this thing, it is beautiful and powerful!
On my way home I made an interesting discovery. I went to pull a 3'rd gear log. Well, I am not entirely certain exactly what happened, but I suspect my MBC was to blame. Boost spiked to 20psi. AFR looked good, in the low 10's, but it started acting like it was hitting the rev limiter between 6-7K RPM. After I left off the gas it seemed to drive fine. The peak load on the AP showed 254%. Unfortunately, when I got off the freeway I could tell I had lost the motor. When I got home I tried to download the log it was corrupt My fuel and ignition tables max out at 250%. I am theorizing that if the load of the tables is exceeded the car does a fuel cut, which might be fine on an NA car, but not at 20psi Hope this helps the community. I'll be tearing it down soon to see if it is salvageable for rebuild or get another reman...
On my way home I made an interesting discovery. I went to pull a 3'rd gear log. Well, I am not entirely certain exactly what happened, but I suspect my MBC was to blame. Boost spiked to 20psi. AFR looked good, in the low 10's, but it started acting like it was hitting the rev limiter between 6-7K RPM. After I left off the gas it seemed to drive fine. The peak load on the AP showed 254%. Unfortunately, when I got off the freeway I could tell I had lost the motor. When I got home I tried to download the log it was corrupt My fuel and ignition tables max out at 250%. I am theorizing that if the load of the tables is exceeded the car does a fuel cut, which might be fine on an NA car, but not at 20psi Hope this helps the community. I'll be tearing it down soon to see if it is salvageable for rebuild or get another reman...
#1728
n3rd
Thread Starter
No worries man this is my hobby. I'd prefer that it hadn't happened but I've been kinda itchin' to do something. It's been a bit boring with it running great lately
I used to run straight waste gate, no BC, never had an issue. In fact, I prerred it that way because it was one less failure point. I only put it back in last December when I was playing with ethanol so I could tweak the boost. I should've taken it back out. This BC is one of those ball and spring deals.
I used to run straight waste gate, no BC, never had an issue. In fact, I prerred it that way because it was one less failure point. I only put it back in last December when I was playing with ethanol so I could tweak the boost. I should've taken it back out. This BC is one of those ball and spring deals.
#1730
n3rd
Thread Starter
I'm pretty happy about how it stood up too. At the very least I got some data about what abuse it can take. It will be back on the road eventually hope yours is too!
#1732
n3rd
Thread Starter
I don't think 250% is the definitive max. I'm speculating that since all my tables are only scaled out to 250% that perhaps the ECU imposes a limit. It felt exactly like bouncing off the rev limit. Theoretically we can scale up to 400% in ATR and 800% in ME, IIRC. I could have added higher load areas to my tables, and probably should have in retrospect since I had been approaching 250% while playing with ethanol. I just didn't expect to boost spike. I am using the stock MAF scale trended out to 5V using that curve software I posted about in the load vs airflow thread so I believe this load is accurate and not inflated. I wish I had the log!
But this is purely speculation on my part. Anyone want to test to confirm?
But this is purely speculation on my part. Anyone want to test to confirm?
#1739
Nice pictures
sorry about the motor, but now you have the opportunity to build a motor
I had a EBC once and it boost spiked to 18 psi, I promptly removed it. I will never run an EBC again.
weird stuff certainly happens at the limits of this ecu. I am under the impression that if the maps have a limit and an event causes the system to go beyond that limit, the ecu just takes the value of the max limit and uses that. so if timing is 10, at 250% load, and 280% load was achieved, it would still be 10, at the same RPM.
sorry about the motor, but now you have the opportunity to build a motor
I had a EBC once and it boost spiked to 18 psi, I promptly removed it. I will never run an EBC again.
weird stuff certainly happens at the limits of this ecu. I am under the impression that if the maps have a limit and an event causes the system to go beyond that limit, the ecu just takes the value of the max limit and uses that. so if timing is 10, at 250% load, and 280% load was achieved, it would still be 10, at the same RPM.
#1740
n3rd
Thread Starter
Yeah, I didn't like having the boost controller in as a point of failure. I shoulda pulled it out.
I'm purely speculating at what might have happened, so you may very well be right. If my timing was right on the edge at 250% and it stayed static as load went beyond 250% then perhaps it resulted in a rapid succession of detonation events. There was no boom. The only way I can describe it was it felt and sounded just like hitting the rev limit.
Oh, and most of those are the pics you took. I downloaded them off my camera and I will send them to you. They are nice
I'm purely speculating at what might have happened, so you may very well be right. If my timing was right on the edge at 250% and it stayed static as load went beyond 250% then perhaps it resulted in a rapid succession of detonation events. There was no boom. The only way I can describe it was it felt and sounded just like hitting the rev limit.
Oh, and most of those are the pics you took. I downloaded them off my camera and I will send them to you. They are nice
#1746
this way it's all together. Maybe adding a table of contents to the first page with different milestones in the build... i.e. lost motor one, lost motor 2 (which is kinda motor 3), etc...