Knock when coming into boost

[joecar]

B3618 had been set to the figures below but it still didn't move into PE mode or have any effect when in open loop yet will change commanded AFR when in closed loop. We changed them all to 0.99 to rule out any changes which might effect our VE calibration. Im running COS5 and was under the impression this is 2BAR as I have a 2Bar MAP installed. The Boost VE is table A0009.

1.000000
1.000000
1.000000
1.000000
1.000000
1.000000
1.000000
1.000000
0.949907
0.930064
0.910222
0.889661
0.870008
0.849793
0.849793
0.849793
0.849793
0.849793
0.849793

Anything higher than lambda 0.87 is too lean for NA, anything higher than lambda 0.78 is too lean for boost.

[joecar]

Did you edit the MAP scaler for the 2-bar MAP sensor...?

[Boost]

Anything higher than lambda 0.87 is too lean for NA, anything higher than lambda 0.78 is too lean for boost.

Does this apply only to his setup or my directed injected "knocker" as well? Also, is this under all conditions? Thanks!

[joecar]

Does this apply only to his setup or my directed injected "knocker" as well? Also, is this under all conditions? Thanks!

Yes, applies to you too

[Rich Z]

Anything higher than lambda 0.87 is too lean for NA, anything higher than lambda 0.78 is too lean for boost.

What will a B3618 table look like on a typical boosted car? Sloped downwards sharply when boost kicks in and then flat lined out to redline with 0.78?

[barbermi]

Hi Joecar. The MAP scaler is done too. Out of curiosity we logged current gear when doing a power run. We noticed knock at the exact time the gearbox downshifted from 2nd to 1st when first applying power. The next few runs we held first then applied power with no knock. Whats the odds the shift change is giving us false knock?

[ddnspider]

Hi Joecar. The MAP scaler is done too. Out of curiosity we logged current gear when doing a power run. We noticed knock at the exact time the gearbox downshifted from 2nd to 1st when first applying power. The next few runs we held first then applied power with no knock. Whats the odds the shift change is giving us false knock?

Ive seen several cars knock right at the shift or on the downshift, it is more than likely the sensors picking up the mechanical sound of the transmission shifting that is in the same frequency range as the sensors are monitoring.

[ddnspider]

What will a B3618 table look like on a typical boosted car? Sloped downwards sharply when boost kicks in and then flat lined out to redline with 0.78?

You need to know what RPM the car will make boost at first. If you don't generate hardly any boost at all below 3k rpm's theres no point in dropping to .78 at 2k.

[Rich Z]

You need to know what RPM the car will make boost at first. If you don't generate hardly any boost at all below 3k rpm's theres no point in dropping to .78 at 2k.

Well, the last time I did a run that went into boost, I simply put it in fourth gear and just ran up the RPMs. At 69% throttle at 1751 rpm I was already at 105kPa. I was at 182kPa at 3700 rpm when the wastegates said "enough!". My log file is on this page -> http://forum.efilive.com/showthread....-please/page14, post #135. Boost starts around frame 11920.

So I'm hoping I'm OK in that department.

[barbermi]

Thanks again spider.

So far we have completed the main VE and the BEN factor is great. The boost VE we have adjusted so that our AFR is where we want it under boost. We still cant get the PE working unless it is in closed loop. So the BEN factor when in boost is way off but our end result is good. If we put the tune back to closed loop and disable the PE how will the AFR react when in boost. Seeing the engine is a lot richer than the commanded AFR will the PCM lean out our tune under boost? If so how much could we expect the tune to lean out during a power run?