E38 Basic Questions

[Matt68]

I hooked up the EFIlive to my 2010 Silverado and made some logs on the dyno before and after a K&N cold air intake change. Just looking at some of the logs I had some basic questions I hoping to get some help on.

TP%: During all of my logs, the max throttle opening I was getting was 83%. Is there a reason why I would not be getting close to 100%? Shouldn't this impact some of the WOT entry points like D1250 - D1257 in the trans tune

PE Mode Delay: When going WOT there would be a delay, and I would see some KR around this time on some of the pulls. I took {B0164} to 3000RPM which I read as once it reaches this RPM the delay is disabled, but it still takes until 3500RPM until PE is enabled. I also took {B0167} from 1.0 to 0.5s to reduce the delay with a little improvement.

KR on stock tune: I was kind of suprised to see this much KR on a stock tune (4* on one pull). I have also seen KR on a stock 09 Vette. It seemed like the KR followed PE delay and when I reduced the delay it got better, but was still present (<1*). Is GM setting their stock tunes closer to MBT and relying more on the knock sensors?

I tried to keep all of the pulls as close as possible on temps. The wideband was placed in the the drivers rear O2 bung so there is a delay in the readings and a shift in the overall values at WOT. Any insight on these would be appreciated.
11059 - Log with PE Delay changed
11061 - Log with stock tune and 4* KR
11060



Thanks,
Matt

[izaks]

Set B0169 to 1
Lower B0164 to 1000 and see if that helps.
Lower values in B0156 at the RPM you want PE to kick in (start at 50 and work down unitil you are happy)
Lower values in B5112 at the EQ/RMP cells you are getting knock

[Matt68]

Thanks for the info izaks!

Is there any logical reason why the throttle % in my logs would not go over 84%? I see that B0156 is a throttle area ratio vs. actual throttle position. Is there a PID for this or would you have to create a calculated PID using throttle % and throttle body diameter?

I haven't seen table B5112 before. Is there a reason why you would modify this over the high octane table? From the values I see in my tune it appears it is set to only add timing (positive numbers) and I would have to put negative numbers in there to remove timing?

One thing I thought was odd was that the PID E38_APCYL_DMA was not a supported parameter, but it logged data anyway?? Actually none of the PID's in the E38 menu were available when I was selecting PID's to log.

Matt

[Taz]

Hello Matt,

Regarding logging %TP with an E38 ECM .... you selected the SAE.TP PID in your log ... try using GM.ETCTP as the PID - should provide accurate data of the actual throttle blade position.


Regards,
Taz

[izaks]

or GM.APP

B5112 ADDS timing to the high octane table, based on RPM/EQ, exactly where you are getting knock.