Power increase
08-16-2007, 08:21 AM
#51
Senior Member
Join Date: 07-25-2006
Location: Enid, Oklahoma
Posts: 1,198
Prerequisite Disclaimer: Not meant to be a personal bash of any kind. It's just my opinion on capitalism in general. 
The way I see it, you have experts and then you have middleman retailers. The experts want to be proven, and they want the products to be top quality and actually do what they were designed to do. They usually have no reason to try to falsely gratify one product over another, since they have no profit in it.
The middleman retailers, on the other hand, are there to make a profit. Some do care if what they are selling is worth it or not, but most just like to make money. They will try to sway your attention and bias towards their product, and try to put down the competitive products.
I honestly don't see why I am posting my opinion, since it won't make a difference to to stubborn disbelief or top-notch auto-modders. People will believe what they want to, and if they were lead to believe one way in the past, it is always much harder to swerve their eyes to the truth. I'm not saying in this argument which is right or wrong. Like I said, this is just a part of my views on people and money...
The way I see it, you have experts and then you have middleman retailers. The experts want to be proven, and they want the products to be top quality and actually do what they were designed to do. They usually have no reason to try to falsely gratify one product over another, since they have no profit in it.
The middleman retailers, on the other hand, are there to make a profit. Some do care if what they are selling is worth it or not, but most just like to make money. They will try to sway your attention and bias towards their product, and try to put down the competitive products.
I honestly don't see why I am posting my opinion, since it won't make a difference to to stubborn disbelief or top-notch auto-modders. People will believe what they want to, and if they were lead to believe one way in the past, it is always much harder to swerve their eyes to the truth. I'm not saying in this argument which is right or wrong. Like I said, this is just a part of my views on people and money...
08-16-2007, 08:22 AM
#52
Senior Member
Join Date: 05-26-2007
Location: ...
Posts: 1,554
EnOoNmaI is correct. This is why intercoolers are used in forced induction, to bring down (or help correct for) the temp rise the compressor puts on the air. The IAT reads the temp of the intake air charge and sends the info to the ECM. The ECM then takes this into consideration along with the all important info from Oxygen sensor(s) and adjusts fuel trim. What is sought is what is known as the stochiometric air/fuel ratio of approx 14.7:1 This is a constant process happening many times per second. At WOT (Wide Open Throttle) the ECM usually goes into a Power Enrichment Mode (PE) and runs the A/F mixture off of lookup tables, and the mixture is richened usually somewhere in the 11:1 - 13:1 range to avoid valve damage during WOT.
Someone clean this up if I am in error it has been a while since I was into tuning. I had Tunercat, an AKM cable, and an old laptop that I used on my Vette. I bought a tune from PCMFORLESS that I used as a baseline and made some adjustments from there. That was all OBDI though. OBDII I need to learn more about.
Someone clean this up if I am in error it has been a while since I was into tuning. I had Tunercat, an AKM cable, and an old laptop that I used on my Vette. I bought a tune from PCMFORLESS that I used as a baseline and made some adjustments from there. That was all OBDI though. OBDII I need to learn more about.
08-16-2007, 09:35 AM
#53
Senior Member
Join Date: 08-06-2007
Location: NJ
Posts: 135
The ECM then takes this into consideration along with the all important info from Oxygen sensor(s) and adjusts fuel trim. What is sought is what is known as the stochiometric air/fuel ratio of approx 14.7:1 This is a constant process happening many times per second. At WOT (Wide Open Throttle) the ECM usually goes into a Power Enrichment Mode (PE) and runs the A/F mixture off of lookup tables, and the mixture is richened usually somewhere in the 11:1 - 13:1 range to avoid valve damage during WOT.
during normal operations the pcm takes in all data from the sensors and tries to keep the mixture at the standard 14.7...
then at wot (usually 95% and above) the computer goes into a closed loop mode when it usually goes into a predetermined fuel "dump." it usually runs fairly rich here to keep things safe but not 13:1 - that's too lean. usually anywhere from 10-11.5:1...
my .02
08-16-2007, 12:10 PM
#56
Senior Member
Join Date: 05-26-2007
Location: ...
Posts: 1,554
close...
during normal operations the pcm takes in all data from the sensors and tries to keep the mixture at the standard 14.7...
then at wot (usually 95% and above) the computer goes into a closed loop mode when it usually goes into a predetermined fuel "dump." it usually runs fairly rich here to keep things safe but not 13:1 - that's too lean. usually anywhere from 10-11.5:1...
my .02
during normal operations the pcm takes in all data from the sensors and tries to keep the mixture at the standard 14.7...
then at wot (usually 95% and above) the computer goes into a closed loop mode when it usually goes into a predetermined fuel "dump." it usually runs fairly rich here to keep things safe but not 13:1 - that's too lean. usually anywhere from 10-11.5:1...
my .02
The only way to dial in optimal A/F is with a wide-band O2 sensor installed and doing some dyno pulls, tune as you go.
08-16-2007, 01:31 PM
#57
Senior Member
Join Date: 08-06-2007
Location: NJ
Posts: 135
My bad. I was thinking of the upper end of A/F when tuning the PE tables and let that pollute my memory as far as what the factory usually programs. Fuel dump = Power Enrichment mode, same thing. I have seen A/F's @ 13.1 on modded LT1's. 12.7 is as high as I took mine. and there are/were multiple entries to formulate vs. rpm if I remember right.
The only way to dial in optimal A/F is with a wide-band O2 sensor installed and doing some dyno pulls, tune as you go.
The only way to dial in optimal A/F is with a wide-band O2 sensor installed and doing some dyno pulls, tune as you go.
i have a boost gauge and an afr gauge to monitor everything... but even with those you can still melt pistons if you're not careful. i think if you're really going to push the envelope you'd need to get an egt gauge as well... at least what i understand from the normal stock pistons a 12:1 ratio will be completely safe in a daily driver... 13:1 i think would need some more robust pistons...
but i guess without actually looking at the pistons over time it will be hard to tell what is "daily driver safe..."
08-16-2007, 03:49 PM
#59
Senior Member
Join Date: 08-06-2007
Location: NJ
Posts: 135
i will admit that i don't have an hhr but i'm learning more about it... the ss from the factory is pretty neat stuff...
08-16-2007, 04:08 PM
#60
Banned
Join Date: 10-24-2006
Location: The Show-Me State
Posts: 1,761
Um, I'm failing to see any "personal" bashing actually going on here. I can understand if the CGS owners are seeing the information now and feeling like they got taken for a ride, but I was always pretty skeptical about the performance gains of that particular "system" and that's why I never laid down any green for one. I know a few CGS owners who are perfectly happy with the system because it LOOKS worlds better than the stock airbox, and that's more important to them than losing 3-5 HP depending on the season.
3-5 HP isn't a huge loss, and if you're showing your car off like Deb and Mike do, it's probably worth it. What I have a problem with are vendors who tell people that it's going to give you a substantial increase in power and the people who choose to perpetuate those myths when someone has taken their own time and money to independently test the product, and found that the claims are hype.
3-5 HP isn't a huge loss, and if you're showing your car off like Deb and Mike do, it's probably worth it. What I have a problem with are vendors who tell people that it's going to give you a substantial increase in power and the people who choose to perpetuate those myths when someone has taken their own time and money to independently test the product, and found that the claims are hype.