Several AP logging questions. Any one help?

Raceghost · Jun 30, 2009, 10:30 PM

So, I have been using the live data logging tool in the AP.
I am trying to understand the readings I am getting.

Knock Sum: 8 counts in 20 miles, mostly in low gears and in low RPM range.
Knock Volts: What am I looking at?
Timing: Seeing as high as 33/36 and up, as well as -4/-2, this is on the screen when it is logging, in the lower left hand corner...?
MAF: as low as 69, and as high as 900?
EGR: 505 at 65mph cruising, as high as 700+ depending on day, location, and speed.

Mods: TBE 3", Turbo Manifold, Perrin 100 cell cat, oversized Intercooler, K+N filter, Stock intercooler piping, but with upgraded hoses or connectors, Forge BOV.
I have not installed the boost pill vacuum line that was supplied with the tuner...? could this cause an issue?

Thanks in advance.

Colin_L · Jul 15, 2009, 12:47 PM

I haven't posted on here in years, and I can't get into my old id. So here's a post from a 'total noob'.

The preamble that must be spoken is that it seems like your mods are beyond the Cobb Stage 2 maps. In my opinion your K&N filter and turbo manifold are the biggest issues. I think you really need a custom tune, but it looks like you're in SLC so that should be easy enough to get sorted...

But, on with it..

I assume you have the Access Tuner Race program. If you don't, get it from Cobb: http://www.cobbtuning.com/info/?id=4214

Read the manual that comes with it-- start the program then Help->Help to open the pdf.

Now, search here and Cobb (or just Google) for Knock Sum and you'll see that the community regards less than 5 as desirable, and less than 10 mandatory. This is when the engine is fully warmed up.. when cold, you'll get a lot more knock sensor action because of several reasons, including the mechanical noise of a cold engine.

In general, with a warm engine, you should see 0-1 knock sum under heavy throttle.

It is normal for timing to vary with rpm and load. What you'd look for is evidence of timing never reaching the tables (which you can see in AccessTuner Race), or being withdrawn after knock sensor activity.

EGR is exhaust gas recirculation. It's an emissions control device and you should be around 500-510 while cruising on a warm engine. Under WOT you might see it dip, this is normal. On a cold engine it's hotter because the EGR valve is fully opened.

EGR isn't totally useless but it's definitely not Exhaust Gas Temperature. EGT is extremely useful assuming it's plumbed in the right place.

I don't know about the vacuum lines. I ran stage 1 for a month and no problem, but I just installed a full TBE Monday and I think I do need the lines. So.. I would guess, that yes, you need them for stage 2. My AccessPort didn't come with any, so I need to call up Cobb.

Raceghost · Jul 15, 2009, 11:19 PM

Thanks for that.

Quote:

I don't know about the vacuum lines. I ran stage 1 for a month and no problem, but I just installed a full TBE Monday and I think I do need the lines. So.. I would guess, that yes, you need them for stage 2. My AccessPort didn't come with any, so I need to call up Cobb.

I actually just switched out the cobb vacum lines for an 18 psi WGA. I then preloaded 3 clicks, and if I were to compare the pill to the WGA, I would have to say, the WGA is doing a better job on the control than the pill does. However, I might be switching to ECUFlash for I really want the use of some of the Tephra mods. Do you know if a similiar mod is available utilizing the COBB AP Pro Tune. I am also after the utilization of an ECU based Boost Control. I have the 3 port solenoid and 4 bar map sensor, as well as an upgraded WGA. I wish to utilize the Cars ECU to controll this, or the COBB Tune to controll this utilizing the ECU? Possibilities? If you know, of course.

THanks again,

Colin_L · Jul 16, 2009, 08:22 AM

The AccessPort can do what you're after, with the right person tuning it, so I wouldn't necessarily go out any buy a different ECU solution. That seems kinda wasteful.

I believe Perrin sells an electronic boost control with pre-made maps for the AccessPort. Check their mods list though, you could be beyond that too. The Cobb Stage 2 map uses the factory solenoid with new hoses, but like I said before you already needed a Pro Tune anyway, so no harm if you proceed with all the stuff you mentioned.