Fueling Procharged 2002 Camaro........from idle to WOT

[slarsen47]

Speed density, open loop, 2 bar 411 PCM, D1SC 2002 Camaro, 4L60e, 3600 Yank, 3.70 gear, 26.4 drag radial

Just had the car out on Saturday first time and ran great, but a few issues to tweak/resolve.

The first issue is that I am way lean at the launch according to the data log. But not lean enough to cause a stumble or hesitation.

Pulls hard up to 6600. Logged peak boost of 8 psi. Best 60 ft was 1.62 with no traction issue, so a bit lazy.

What is the best way to get an accelerator pump like hit of fuel when going from idle to WOT almost instantaneously?

Power enrichment table only or a combination of VE and PE?

[horsepowerguru427]

Id try going through PE table first.

[slarsen47]

Thanks, here is a data log on a single where I ran it out to 6600 in first and let off and shifted to od.

AF is 14.0 at idle in gear and at the hit and spikes a bit to 14.9 before gradually working down to 11.4 at 6600.

First part is light burnout at 42 seconds and footbrake launch at 1 min 42 sec.


June 10 run 4 elim single.hpl

[horsepowerguru427]

without having the tune i cant say for sure but it looks like PE is doing what i would expect. its coming on around 2100rpm @about 12.5AFR when it sees WOT and after you hit about 4000rpm its dropped fully to 11.6AFR. you can readjust your settings to make it come on faster or without delay and change WOT settings as well. and you could always add some to the VE table in those WOT areas that youre not happy with til it gets to where you want it to be. I assume you have a WB because i dont see any fuel trims on the data log, i was just looking at commanded AFR.

[slarsen47]

I am reading the data slightly differently. I am seeing 14.1 at 2000 and 13.1 at 4000.

Which is way lean.


Screenshot 2000.jpgScreenshot 4000.jpg

[5FDP]

Post the tune.

[slarsen47]

June 5 2023 Copy HPTuner.hpt

[5FDP]

In your screen shots, why is your battery voltage so low?

12.7 is pretty damn low if you have a high powered fuel pump. I'd get that in control for sure. Then start adding fuel to the VE table. Use the data log with a wideband error to show you were fuel is needed. I can already tell at 2,000rpm and 100kpa, you need more fuel there.

[slarsen47]

In your screen shots, why is your battery voltage so low?

12.7 is pretty damn low if you have a high powered fuel pump. I'd get that in control for sure. Then start adding fuel to the VE table. Use the data log with a wideband error to show you were fuel is needed. I can already tell at 2,000rpm and 100kpa, you need more fuel there.

I am well aware of the importance of battery voltage. The logged parameter is described as "Control Module Voltage".

Is "Control Module Voltage" the same as battery voltage or is it modulated down from 13.5-14.5 charging voltage?

The stock 4th Gen F body alternator (bad rectifier/diode design) is having a tough time and is due for replacement.

Will swap in a truck 145 amp alternator that has a much improved rectifier/diode design.

But the procharger needs to come out along with the support bracket to get to the alternator and I have not had time to do the swap.

To compensate, I had the charger on the battery between rounds to make sure it was fully charged for each pass.

Yes, agree about the VE table as you have noted.

Also the Power Enrichment needs to be increased from 1.17 to 1.27 or more from 800 to 3600. It is 1.27 above 3600.

Would it help the foot brake launch to go richer than 1.27 (approx 11.5 AF) from 800 to 2000?

Thank you for your input.

[slarsen47]

without having the tune i cant say for sure but it looks like PE is doing what i would expect. its coming on around 2100rpm @about 12.5AFR when it sees WOT and after you hit about 4000rpm its dropped fully to 11.6AFR. you can readjust your settings to make it come on faster or without delay and change WOT settings as well. and you could always add some to the VE table in those WOT areas that youre not happy with til it gets to where you want it to be. I assume you have a WB because i dont see any fuel trims on the data log, i was just looking at commanded AFR.

I re-read your comments a few times and looked back at the data again and the tune file and you are correct in your assessment that the PE is coming in at 12.5 AF (PE table has 1.17 at that rpm) and then dropping to 11.5 AF (PE table has 1.27 at that rpm).

Yes, using a WB with no PCM feedback from stock O2 sensors.

Thank you and agree with your comments about adding fuel in those VE area's where it is too lean.

[slarsen47]

In your screen shots, why is your battery voltage so low?

12.7 is pretty damn low if you have a high powered fuel pump. I'd get that in control for sure. Then start adding fuel to the VE table. Use the data log with a wideband error to show you were fuel is needed. I can already tell at 2,000rpm and 100kpa, you need more fuel there.

I just did a little CMV test with an identical 2002 Camaro that is stock.

The stock Camaro voltage at the CMV is about 0.4v less than what alternator is putting out.

So not going to run the procharger car until the alternator is replaced and producing correct voltage.

I posted the scanner log on another thread talking about voltages.