Boosted C5 tune/running assistance and idle information

[E55Amg]

Car: 2000 C5, stock internal LS1, Procharger D1SC w/twin intercoolers running A&A bracket - 4.38" pulley, big BOV, 60# injectors, Speed Engineering headers/X-pipe, Magnaflow axle-back, No MAF, 2-bar OS and 2-bar MAP (GM 12615136) Notable: NO Meth, Stock clutch O.o

Car starts, runs, idles, and drives OK, but I know it could be better (obviously, I just started tuning from the base)

Question 1: What *should* I be seeing for idle MAP/vacuum? My analog gauge shows 15-18", MAP never goes below 43-45 KPA unless decelerating, which seems off. Initially went after vacuum line on the back of the intake manifold, found some issues with plastic tubes, and got it all solid (and fully functional AC now!). Readings are EXACTLY the same as before. Took apart boost/vac gauge/brake booster/BOV supply line and taped and sealed every connection. No change. I've sprayed carb cleaner all over the intake with no effect. Is this just where MAP should be sitting? (I've been looking for normal idle MAP using search for a significant period of time and not coming up with much). I seem to recall low 30's from before I put the supercharger on. I'm hesitant to continue trying to "fine tune" if there's something wrong with my setup and I end up just wasting a bunch of tuning time.

Question 2: When I talked with Procharger, they suggested I would see right at 6psig. That's what the gauge appears to be showing at redline/WOT, but the logs of the MAP aren't showing anything that high. Can I get a check on that MAP part number/anyone use the same thing?

Question 3: Should I need to tune the idle? I do register throttle actuation, so if I have a vacuum leak it shouldn't be that bad. I have been resetting and/or taking out the battery a lot, but it sure seems to idle down VERY low before catching itself a significant portion of the time. I know it has to re-learn everytime I reset it all though so I'm trying not to read too much into that. Also at very low speeds it can get a bit surgy/jerky in 1st gear (but not 2nd).

Question 4: Knock retard - I get NONE in whatever gear I start out in. Immediately after a shift I get .5-3 degrees of retard almost every time and then it slowly decays away.

I'll add in my tune and a log or 2 tomorrow when I have access to my computer. The VE tables are a little ugly as I haven't blended in my changes yet but in general I'm taking fuel back out, hitting almost dead on 11:1 on the wideband and 16 degrees of timing when in boost.

PS, probably better for another thread, but has anyone with a supercharger tried running SD Open loop and running lean at idle for mileage? I'm not too concerned about it, but something I'd like to toy with once I have it running safe and clean. Getting 22mpg right now on tuning setup (no DFCO, running rich everywhere but cruise).

[corvet786c]

I have a 2002 c5 a4 procharged with twin ic and a 4.38 pulley, My tune is not perfect but good imo, Its already on this site if you want to look at it, just let me know.

[kevin87turbot]

Car: 2000 C5, stock internal LS1, Procharger D1SC w/twin intercoolers running A&A bracket - 4.38" pulley, big BOV, 60# injectors, Speed Engineering headers/X-pipe, Magnaflow axle-back, No MAF, 2-bar OS and 2-bar MAP (GM 12615136) Notable: NO Meth, Stock clutch O.o

Car starts, runs, idles, and drives OK, but I know it could be better (obviously, I just started tuning from the base)

Most experienced tuners will not respond to this thread, because there's no tune file or datalog attached. I'll help out, but can help you more if you attach them.

Question 1: What *should* I be seeing for idle MAP/vacuum? My analog gauge shows 15-18", MAP never goes below 43-45 KPA unless decelerating, which seems off. Initially went after vacuum line on the back of the intake manifold, found some issues with plastic tubes, and got it all solid (and fully functional AC now!). Readings are EXACTLY the same as before. Took apart boost/vac gauge/brake booster/BOV supply line and taped and sealed every connection. No change. I've sprayed carb cleaner all over the intake with no effect. Is this just where MAP should be sitting? (I've been looking for normal idle MAP using search for a significant period of time and not coming up with much). I seem to recall low 30's from before I put the supercharger on. I'm hesitant to continue trying to "fine tune" if there's something wrong with my setup and I end up just wasting a bunch of tuning time.
The kPa at idle on a stock LS1 will typically be low to mid 30's. However, the tune will affect this greatly. It could also be an issue with the list of channels in your Scanner.

Question 2: When I talked with Procharger, they suggested I would see right at 6psig. That's what the gauge appears to be showing at redline/WOT, but the logs of the MAP aren't showing anything that high. Can I get a check on that MAP part number/anyone use the same thing?

That's the correct sensor. I suspect that your Scanner channels are not properly set up. Make sure that you aren't trying to datalog a 1 bar and a 2 bar MAP sensor simultaneously. Just datalog the 2 bar only.

Question 3: Should I need to tune the idle? I do register throttle actuation, so if I have a vacuum leak it shouldn't be that bad. I have been resetting and/or taking out the battery a lot, but it sure seems to idle down VERY low before catching itself a significant portion of the time. I know it has to re-learn everytime I reset it all though so I'm trying not to read too much into that. Also at very low speeds it can get a bit surgy/jerky in 1st gear (but not 2nd).
Yes you will.

Question 4: Knock retard - I get NONE in whatever gear I start out in. Immediately after a shift I get .5-3 degrees of retard almost every time and then it slowly decays away.

I'll add in my tune and a log or 2 tomorrow when I have access to my computer. The VE tables are a little ugly as I haven't blended in my changes yet but in general I'm taking fuel back out, hitting almost dead on 11:1 on the wideband and 16 degrees of timing when in boost.
This will help us to point you in the right direction.

PS, probably better for another thread, but has anyone with a supercharger tried running SD Open loop and running lean at idle for mileage? I'm not too concerned about it, but something I'd like to toy with once I have it running safe and clean. Getting 22mpg right now on tuning setup (no DFCO, running rich everywhere but cruise).Yes, you can squeeze a little more MPG out of it with a properly dialed in open loop tune.

[E55Amg]

I have a 2002 c5 a4 procharged with twin ic and a 4.38 pulley, My tune is not perfect but good imo, Its already on this site if you want to look at it, just let me know.

Absolutely good sir! All the reply emails went to my junk somehow and life happened before I could up load mine.

[E55Amg]

@kev - 100% understand. I intended to upload, then figured any responses would remind me but didn't get any. I hope to have them uploaded tonight.

I'm not understanding why idle tuning would be needed, as I didn't change any engine internals. Engine being more loaded due to having the spin the supercharger? I haven't put much time into determining a good path through there, so if you have a link or any brief pointers I would appreciate it. Individual MAP sensor output agrees with the scanner output, and my analog vacuum gauge agrees with it so I'm trying to "believe it" even though I have a hard time understanding it. Clearly more to research here.

On boost, I'm seeing well over 105kpa which I assume would mean I'm seeing the correct sensor. Or are you telling me that if you have more than one MAP listed in the channels that it might compute them somehow? I do think I have a few different looks at manifold parameters so if that's the case I can adjust.

I was consistently 27mpg+ for commuting. I'm just shy of 23mpg right now with DFCO turned off, which I've heard could be worth 3mpg or more. Again more just future musings but it's always nice to save a little gas money

[E55Amg]

I have a 2002 c5 a4 procharged with twin ic and a 4.38 pulley, My tune is not perfect but good imo, Its already on this site if you want to look at it, just let me know.

I found your file in one of your threads and downloaded. I looked through some of the differences, and many made sense (mine is a manual 6-speed, so that accounted for quite a few). Another major difference is you're still using MAF, and I'm running a 2-bar SD (and currently setup for tuning so DFCO, etc are turned off).

Looks like your total timing is setup about 3 degrees high on the top end. I read a good starting point was 16 to keep it safe without meth, and I'm in the A/F first pass portion of tuning - I've gotten it pretty steady around 11.0:1 under WOT. I'm still working on figuring out why my idle and cruise MAP is so high, so I haven't made much progress (since I don't want to repeat too many steps).

I did note (and it looks like others did as well) that your PE EQ ratios look VERY off. Which makes me question a lot of the other changes - as those improper ratios commanding your WOT fuel targets means something else in your tune is either arranged in a manner that doesn't make sense to me, or is compensating for another error somewhere else. Can you explain?