BCS limit upper RPM boost?

[daveyfx]

Just out of curiousity, does the factory BCS limit boost in the upper revs any? I have witnessed this on the EVO and began to wonder if Mitsu. decided to hinder DSMs in the same manner.

 

[blackGSX2g]

The factory BCS limits the boost when it detects high knock. Once knock is reported, the BCS will limit boost to its lowest setting for a set period of time. Back when my car was mostly stock I only hit it once, and my boost went from 15psi to 10psi for the rest of the day. I added a bit more fuel and never had the problem again.

 

[wret]

It has kind of fallen out of favor but many dsmers have hooked up an LED to the bcs to get a visible indication of what the bcs is being told by the ECU. This was often (erroneously) called a "knock light." In the course of playing around with home built electronic boost controllers, I hooked one up. Actually the only information I really wanted to get was the long-term effect of long term knock that Matt mentioned above. I haven't yet seen this condition since the installation, but the light always pulses in higher rpms indicating that the ECU is trying to gently lower the boost. I haven't done enough logging to understand if this is associated with knock count or just higher rpm's.

 

[daveyfx]

The factory BCS limits the boost when it detects high knock. Once knock is reported, the BCS will limit boost to its lowest setting for a set period of time. Back when my car was mostly stock I only hit it once, and my boost went from 15psi to 10psi for the rest of the day. I added a bit more fuel and never had the problem again.

Interesting... thank you. Seems the stock SMIC really can't take much. I've got a 14b on my 2G with just the BCS restrictor removed and a WOT pull in one gear is all it takes to heat soak that little guy.

It sounds like a really need an FMIC to really see what the 14b can do.

 

[blackGSX2g]

It has kind of fallen out of favor but many dsmers have hooked up an LED to the bcs to get a visible indication of what the bcs is being told by the ECU. This was often (erroneously) called a "knock light." In the course of playing around with home built electronic boost controllers, I hooked one up. Actually the only information I really wanted to get was the long-term effect of long term knock that Matt mentioned above. I haven't yet seen this condition since the installation, but the light always pulses in higher rpms indicating that the ECU is trying to gently lower the boost. I haven't done enough logging to understand if this is associated with knock count or just higher rpm's.

I actually forgot all about that light. I did that as well, but didn't find it blinking at all in the higher RPM range. It would blink frantically around 2-3k as the solenoid was actuated to smooth out power as boost started to kick in. From my logs, it was purely knock related, though it would kick in at such a scary timing retard that one should feel the power loss way before the light will go off.

The only time you would become worried is when the light came solidly on, which meant your solenoid was fully actuated and boost was limited to its lowest setting.

The blinking eventually got old and I unplugged it as soon as I became familiar with a datalogger.