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No April fools joke!

I never said it was the blowers fault.
93 octane, that is what it was tuned for.
 
Argg, yeah I saw you don't have the AEM logs or a wideband. Maybe #5 was damaged pre-AEM as suggested. I'm curious as to what AF is considered safe on 93 octane as many of the dynos posted here are just way too lean. I don't go past 11.0 on the dyno on a non intercooled car as that will typically yield 11.5 on the actual road.
 
For a person who only has 4 post's, you look like you know a little bit about FI.
Name change?
Here is the A/F chart, my car was NA until we installed the Aem.

brian_af.jpg
 
Sorry to hear about your engine, fortunately it was not as bad as it could have been.

Certainly A/F's are important. However, timing has a huge impact with this engine. I would imagine your AEM was tuned with safety in mind, so A/Fs and timing should have been under control.

What were your timing settings?

Also, what was the ambient air temperature difference between the day you tuned vs. the day of the incident?

I thought the AEM EMS had internal controls to adjust for air temp differences, anyone familiar with the AEM know if there is a point in which the AEM's controls can not adjust enough? For example, tuned in 100 degree heat and then driven in 30 degrees.
 
"If not, there may have been ringland weakness pre-AEM"

There could have been a problem with a valve seal, that might have been weak before the bbsc was installed.
As for the ringland it blew when there was denation.
If it was bad before the AEM/bbsc it would have been scraping the walls. imo
Don't forget I had 2 bent valves as well, so there was allot of fore three to cause all that damage at once.

The bbsc was fine as Armando said.
 
Pretty safe looking....:( I assume timing was pretty conservative as well? The bent valves are a mystery if there were no signs of contact with the piston. Its the ones from a Dynojet (no load inertial style) showing 12.5 AFRs that are scary. You're right, we may never know why it failed. Definately get that wideband in there in case there was a fluke in the fuel system. Good luck!
 
Sig said:

I thought the AEM EMS had internal controls to adjust for air temp differences, anyone familiar with the AEM know if there is a point in which the AEM's controls can not adjust enough? For example, tuned in 100 degree heat and then driven in 30 degrees.

It has adjustable correction factors that should handle this, as long as the sensor is mounted after the compressor.
 
Marshall1 said:
Pretty safe looking....:( I assume timing was pretty conservative as well? The bent valves are a mystery if there were no signs of contact with the piston. Its the ones from a Dynojet (no load inertial style) showing 12.5 AFRs that are scary. You're right, we may never know why it failed. Definately get that wideband in there in case there was a fluke in the fuel system. Good luck!

It was a Mustang dyno that has load, I should have had the wide band in, and a boost gauge.
That was my mistake.

Thanks, Netviper for your kind words.

I don"t think we will ever know why it happened, did the valve seal fail before the denation?
Or was it because of the bent valves?

What caused it to detonate?
Was it oil coming from the vale seal?
Or was it oil coming from the catch can that was sucked into the blower then into the #5 piston.

Its like asking did the chicken come before the egg?
 
what are your plans then? I saw you were selling the AEM a while ago.. are you scrapping all FI plans for now?

oh, did you have the aftercooler?

sorry to hear the bad news.
 
I am selling the AEM if anyone wants it make me a offer.
Devin is fixing it and it is going back to stock.
I did not install the aftercooler that Devin was going to sell me, I think he has sold it to someone else.

NA for me at this point, that is until I get a ride in Len's car. :D
 
prova4re said:
I am selling the AEM if anyone wants it make me a offer.
Devin is fixing it and it is going back to stock.
I did not install the aftercooler that Devin was going to sell me, I think he has sold it to someone else.

NA for me at this point, that is until I get a ride in Len's car. :D

B-man, you know I feel for you.
You can ride in mine, no probs.
I will be rolling before the summer ends.
 
The AEM in your car at the time of the incident was the second AEM unit to run in your car, correct? At least, that was my understanding from reading Devin's post in your other thread. One possibility is that your original Aem, which apparantly was doing some screwy things, damaged your ringland but not catastrophically. Then over time, it finally gave way.

Glad you were able to pick up most of the pieces you need to fix the engine for a good price. Good luck getting everything back together.
 
Brian,

Sorry to hear what had happened. I hope your NSX will be up and running in no time.
 
Hmmm...as I too am puzzled by the failure discussed in this BBSC equipped NSX...I have my own opinions on it.

#1) Like already mentioned, the BBSC and/or tuning behind can't entirely be blamed (partially perhaps*)

#2) Ringlands failures can happen for a multitude of reasons...the mains ones being : Excessive cylinder temps/detonation/excessive cylinder pressures.

Here's the question I have for you guys....how many INTERCOOLER/AFTERCOOER equipped BBSC NSX's have ever had this type of failure ??

...I'm from the old school, which religiously believes in intercooling an F/I system. ESPECIALLY when converting a motor originally meant for N/A (i.e. 10.2-to-1 compression, less water jackets/cooling built into the heads ,etc...) to F/I.
.....obviously having a properly tuned AEM with a safe A/F ratio and timing settings will lessen the risk of detonation and reduce cylinder temps but intercooling *by itself* is just as effective (if not more) at lowering cylinder temps and the chance for detonation. At the very least intercooling will give you a MUCH larger safety margin (despite the HP increases) toward eliminating this type of failure ever again...IMHO.


I believe even 6PSI WITH AEM and proper tune @ 10.2-to-1 compression is pushing it without intercooling. While perhaps 7-or-8 PSI on the same set-up WITH intercooling would be still be more gentle on the motor than 6PSI without*

...personally, I wouldn't take it past 5PSI on the stock motor/pistons *without* intercooling. I rather do my re-build on my OWN schedule, not my ringlands ;)
 
...I would just like to add, NO F/I system builder/manufacturer can say with a straight face that they can/will garauntee your motor wouldn't be compromised at 6 PSI of "NON-intercooled" boost !!


Furthermore, if you look at computech's base blower kit (which does assure their clients motor longetivety)...in the field it's proven that their kit only makes about 4.5 PSI at the manifold** (right in-line with what I considered "safe" for non-intercooled PSI on a stock motor...= or < than 5 PSI) ...and their "high-boost" kit which makes about ~7 PSI they state "no warrantees" for.


Remember...at 6PSI you're seeing an effective compression ratio of approx. 14.3-to-1 :eek: :eek: in addition to the significantly higher intake tempratures that NOT using an intercooler creates. And all this on pump gas...it's no wonder the poor stock rings have a difficult time coping...intercooling takes away the cyinder "heat"...and hence, the expansion of the ringlands* :cool:
 
NSXTASY_MD said:
...in addition to the significantly higher intake tempratures that NOT using an intercooler creates. And all this on pump gas...it's no wonder the poor stock rings have a difficult time coping...intercooling takes away the cyinder "heat"...and hence, the expansion of the ringlands* :cool:

Not to argue with most of what you said, but I would quibble with your explanation of what the intercooler/after cooler does. (I’m sure you know, but your choice of words could mislead) Obviously the cooler lowers the temp of the intake charge before it gets to the cylinders, but relative to the actual combustion temps in the chamber it is insignificant. The point, in terms of safety, is to reduce the risk of pre-ignition and/or detonation because they are the cause of soaring temperatures and pressures, and outright breaking of things. Until that happens all the extra IAT does is cost you power. Timing and AFR on the other hand can have a big impact on combustion temps even without the deadly pings.

The other benefit of course is that cooler = more dense = more air/fuel mix at a given PSI.
 
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