Centrifugal C5 Won't Build Boost on 2 Bar Tune

[Rauq]

2001 C5 with a Carroll Supercharger kit, just a basic non-intercooled Vortech V2, guessing it will make 5-7 psi tops. Bought the car with the supercharger not installed and an NA tune on it, but we know the car was run previously on the stock MAP and 5-wire MAF. We tuned it on a stock OS, VE tuned without touching boost, and then pulled the limiter from 6750 down to 6200 just to stay under 12,000 Hz on the stock MAF. Car ran pretty well.

Today we installed an LS7 MAF with an IAT breakout located after the supercharger and a 2 bar MAP sensor. We applied the 2-bar OS and prepared for VE tuning with the MAF disabled and unplugged, populated the VE table, but couldn't go much past atmospheric- we got a couple hits at 110 kPa, but otherwise it wouldn't make any more power than that. Re-enabled the MAF and plugged it back in to try MAF tuning with a guesstimated VE table, same issue. We even tried an otherwise stock 2-bar tune with guesstimated VE table and no other changes like disabling DFCO and ran into the same issue.

I'm confident it's something in the tune, I'm sure it was making boost on the stock OS because we were maxing out the stock MAP sensor. But now with the 2-bar OS, 2-bar MAP sensor, LS7 MAF, and IAT breakout, it won't make boost anymore. Any direction would be appreciated.

[5FDP]

Post log file. Maybe post the file of how you setup the VE only tune.

Are you only logging the 2 bar map sensor in the logs?

Cut the VE way back after 100kpa. Use what you had before and stick something like 150 for the 210kpa row, then highlight from 105-210 and interpolate between vertical bounds. That should give the VE a smooth ramp up and not flood the engine with fuel.

Try settings up your PE and BE differently too. Have the PE kpa enable be 90kpa, boost enable is already where you want it at 110kpa. Set the enable torque to 50% because TM is disabled.

Have your PE be leaner than BE. So if you want it to be like 12.2 for power enrichment, then have the 105kpa of boost enrichment start at 12.2. As boost rises, bring more fuel in. So if you want 11.5 at 6-7psi you'd put that value there and interpolate from 105-140kpa so it brings in more fuel as the boost comes up.

The 2 bar OS returns the timing table functions to normal, so the high/low tables should not mirror each other. Remove 2-3 degrees from the entire timing curve for the low octane table, this way it can pull timing if it knocks.

[chemical]

you need to add a 2bar channel in the log and remove the stock one , also you need to work on your ve table throw wide band. i adjust on your tune to make it ve only. don't forget to write entire to tune it via (rtt).C5 2 bar tune.hpt

[Rauq]

We ended up going back to the old sensors and stock OS tune just to get it to drive home. When we make another attempt I'll post a log, and I know we're not going to make any more progress on the tune until then. The issue wasn't reading boost in the logs, we had the 2 bar MAP PID set up and could occasionally touch 110 kPa which was beyond the range of the standard MAP PID. It also made less power and seemed rev limited compared to stock sensors and OS. I knew the VE table would be way off (party my inexperience) but we weren't ever able to tune for the portion of the VE table that's in boost.