Spanky's 2.2 Turbo Build....Stage 2
10-22-2010, 02:24 PM
#211
Cobalt & Ion ---> ZZ Performance
Originally Posted by ZZP
So how and why does this kit work? What is it actually doing?
The PCM doesn't compensate for boost over 17.5psi (12psi on LE5), so the car goes lean after that. This is unless you raise fuel pressure the same amount as boost. You can try and tune around this but it's guess work and a poor solution.
What we did is leave the factory regulator in place then the PCM works just like stock and all the tuning is stock (or whatever your PCM is). Then we added an adjustable regulator in the rear of the car. Because the factory regulator is still in place (using install option 1) and keeps it at 60, the car operates just like our regulator was invisible. Then when boost hits about 17psi, our regulator is at 60psi matching the stock one. Again ours isn't doing really anything but when the boost passes 17psi, ours go up with boost. So at 18psi ours adds say 1 psi of fuel pressure.
Fuel flows based on pressure differential. So if you have 60psi of FP and 17psi of boost, the injector only flows like as if it's running at 43 psi. The PCM normally compensates for this but stops at 17.5 because the tables don't go any higher. So if you run 18.5psi of boost, the PCM is fueling the car as if you have 17.5psi of boost or 42.5lbs of pressure. When you go past that the PCM still fuels as if the injectors are at 42.5lbs of pressure differential but they aren't. The more boost you run past 17.5, the farther off your fueling.
On the 2.4 liter kit, we adjust the regulator to kick in at 12psi instead of 17, but the function is still the same.
Our kit makes pressure rise 1:1 past 17.5 and therefore requires no tuning. Optionally, we use the stock EVAP line to send boost/vac to the additional regulator in the rear so there is no line to run but you have to disable EVAP codes in the PCM. If you run new line, EVAP stays stock.
The PCM doesn't compensate for boost over 17.5psi (12psi on LE5), so the car goes lean after that. This is unless you raise fuel pressure the same amount as boost. You can try and tune around this but it's guess work and a poor solution.
What we did is leave the factory regulator in place then the PCM works just like stock and all the tuning is stock (or whatever your PCM is). Then we added an adjustable regulator in the rear of the car. Because the factory regulator is still in place (using install option 1) and keeps it at 60, the car operates just like our regulator was invisible. Then when boost hits about 17psi, our regulator is at 60psi matching the stock one. Again ours isn't doing really anything but when the boost passes 17psi, ours go up with boost. So at 18psi ours adds say 1 psi of fuel pressure.
Fuel flows based on pressure differential. So if you have 60psi of FP and 17psi of boost, the injector only flows like as if it's running at 43 psi. The PCM normally compensates for this but stops at 17.5 because the tables don't go any higher. So if you run 18.5psi of boost, the PCM is fueling the car as if you have 17.5psi of boost or 42.5lbs of pressure. When you go past that the PCM still fuels as if the injectors are at 42.5lbs of pressure differential but they aren't. The more boost you run past 17.5, the farther off your fueling.
On the 2.4 liter kit, we adjust the regulator to kick in at 12psi instead of 17, but the function is still the same.
Our kit makes pressure rise 1:1 past 17.5 and therefore requires no tuning. Optionally, we use the stock EVAP line to send boost/vac to the additional regulator in the rear so there is no line to run but you have to disable EVAP codes in the PCM. If you run new line, EVAP stays stock.
10-22-2010, 02:42 PM
#212
Senior Member
Haha yeah I just read that on the ZZP website...
IDK I guess let me know how it works and if it's really worth 200 ******* dollars...
I'd rather let Vince try and tune through it. I will be going to 25 PSI as soon as I have a built tranny..
IDK I guess let me know how it works and if it's really worth 200 ******* dollars...
I'd rather let Vince try and tune through it. I will be going to 25 PSI as soon as I have a built tranny..
10-22-2010, 03:01 PM
#213
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$200... psh. Just be resourceful, for instance, using one of these would be alot cheaper. These are really archaic pieces, and very simple things. No reason to pay out the ass for one.
MSD Ignition - 2222 - Adjustable Fuel Pressure Regulator w/Boost Reference - Team C Performance
MSD Ignition - 2222 - Adjustable Fuel Pressure Regulator w/Boost Reference - Team C Performance
10-22-2010, 04:22 PM
#216
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10-23-2010, 12:18 AM
#224
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Lol, hell yeah! Dang, if you're still getting blowout at .028 on 2 steps colder, I would start looking at the coils and ****. That would mean there is either not enough spark, or something else. Too much fuel could do it, what is your afr?