Finally made it to the dyno

Reply Subscribe

Thread Tools

Search this Thread

Apr 17, 2020 | 02:56 PM

#16

Injuneer

Administrator

Joined: Nov 1998

Posts: 71,121

From: Hell was full so they sent me to NJ

Re: Finally made it to the dyno

A scanner or data log ONLY shows the timing commanded by the PCM. There is no feedback as to actual timing. The reason the scanner or data log doesn’t always match the programmed value is because there are additional “offsets” in other tables. Logically, timing advance should be reduced if coolant temp or inlet air temp gets too high, but I don’t know where those offsets would be in the program. And, if there is knock retard, the value shown by the scanner or data log will equal the programmed value minus the knock retard value.

Apr 17, 2020 | 04:34 PM

#17

The SRZ

Registered User

Joined: Sep 2007

Posts: 397

From: FL

Re: Finally made it to the dyno

Quote:

Originally Posted by Injuneer

Isn't a “reading”. It's the tabular timing values from the PCM program. It represents a 1 bar MAP sensor, and 100 kPa corresponds to roughly “1 atmosphere”, which is 14.5 PSIabsolute., not a gauge pressure.

Aaaahh...that's totally different than an aftermarket ECU then.

Quote:

Originally Posted by David94TA

That's correct. The numbers that I posted represent the values put into my timing table in my program. I did run a data log and I could probably see what the log showed during the run. Generally, it runs pretty close to what is commanded by the pcm. To monitor boost, I have a separate 2 bar sensor connected to my Innovate LM-2 wideband. The LM-2 provides 4 additional channels for data input and logging. I currently have it recording, psi (boost), throttle position, rpm and of course afr.

I'm still really surprised at you numbers with just 8lb's but I bet that car is fun on the street throughout the power band. I'm trying to get mine on a dyno in the coming months but want to fix my I pipe exh leak 1st. I have no idea what the car puts down currently but anything under 4K rpm is a monster on a mild tune. Above 4K it's lean but I don't play up top right now for the obvious reasons and frankly its got plenty of power down low.