The Intake System - Chevy Cobalt Forum / Cobalt Reviews / Cobalt SS / Cobalt Parts
Register Home Forums Photo Gallery Garage Search Today's Posts Mark Forums Read Auto Escrow
Engine Mods Talk about Chevy Cobalt Engine Modifications here.

YourCobalt.com is the premier Chevrolet Cobalt Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 01-15-2008, 08:16 PM
gibsonj4's Avatar
Veteran
 
Join Date: Oct 2006
Location: Florida
Posts: 575
Send a message via AIM to gibsonj4
The Intake System

What does the intake system do for your car?
The Intake system in any car is responsible for allowing the engine to breathe and helps your engine run cool. Why would you want to replace your stock intake system? It's a great DIY to get your hands dirty on your cobalt, it's a cheap easy mod that frees up some ponies, and it can improve your fuel economy as well.
--Your basic intake system (such as on our cars) includes--

1. The Intake
2. The Filter
3. The MAF Sensor (Mass Airflow Sensor) which we have or a MAP sensor (Mass Manifold Pressure Sensor).
4. The Throttle Body
5. The Intake Manifold

(*)SAI or Secondary Air Injection (On late 2006+ Cobalt L61 equipped)



The Intake
Why get an aftermarket intake system? Our stock airboxes are very restrictive. By allowing our engines to run cooler and breathe easier, we can FREE UP more power. It is important to note that an intake is not a power adder but a power free-er. There are also two types of intakes which are explained in this write-up: A Starter's Bolt-On Performance Mod List

The Filter
There are two major types of filters. The first type offered by AEM is a dryflow filter meaning there is no additive oil. The problem with this oil is that it can effectively ruin the Mass Airflow Sensor. Of course many companies offer oiled filters with their systems such as K&N. The filter does just what it states: it filters the incoming air so we don't get any junk in the air in our combustion chamber. The stock filter is somewhat restrictive and doesn't let as much air into the intake piping as teh material that is used in aftermarket filters.

The MAF (Mass Airflow Sensor)
The MAF sensor senses the intake charge coming into the engine so the ECU (Engine Control Unit) knows how much fuel to deliver via the fuel injection system. The air mass coming into constantly changes from temperature (cold air is denser than warm air). Why is this important? If your ECU supplies too little or too much fuel, your performance is greatly effected and detonation can occur. That's why you MAF sensor is your friend.

The Throttle Body
The Throttle body allows the incoming air from the intake into the intake manifold via a butterfly valve. The butterfly valve is opened when the electronic throttle receives the signal that the gas has been pressed. Throttle body size can have an effect on throttle response, horsepower, and torque. The usual rule of thumb is a larger TB will yield better throttle response and higher horsepower because of the larger airflow. However, if you cannot tune for this and you increase your throttle body dimensions by a substantial amount, you can make your car run lean and possibly cause a fuel surge. A fuel surge is a surge of fuel from the ECU because the engine senses a lot more air so it delivers a large amount of fuel at once but sparactically. I'm not sure if our cars do this or not. It may throw the car into Limp mode because of running too lean meaning the car is at a reduced power level.

The Intake Manifold
What is the intake manifold? An intake manifold receives the air coming from the intake, through the butterfly valve of the throttle body, and evenly distributes the air into the ports in cylinder head via runners (true for port injection). There has been much debate on here about the 2.4L SS/NA manifold swap onto the 2.2L L61 motor. The major problem is that low end torque is decreased when longer, thinner runners of the SS manifold are sending the air charge to the ports. There is an increase in upper RPM horsepower and small increase in torque but a low end loss in torque is evident. That is why it is a better idea to get a free flowing exaust as well as a free flowing Intake system. Though this may sound like a lot, for roughly 800 dollars, you can gain approximately 20-25hp which isn't bad.

Here is the SS/NA manifold replacement kit for the 2.2L: Ecotec HO Intake Manifold Kit 2.2MMGF - Crate Engine Depot

The reason this changes the low end torque is because the incoming intake velocity is altered.

Secondary Air Injection
In Late model 2006 and up models of the L61 level cobalts, GM implemented a system called SAI or Secondary Air Injection. SAI is basically an emissions conrtol device and is basically a hose after the MAF and before the throttle body connection to the engine on a small port. Basically (from what I understand) air comes into the intake from the filter, up the intake piping and the SAI takes some of that air and pumps that to mix with the exaust fumes to affectively lower the emissions. It's important to note when buying an intake system if you have SAI or not.

I hope this sheds some light into why an intake system is so important. Again, a cooler engine is a happier engine! Happy modding.
__________________
2V Mustang GT - Cammed/Sprayed - The "Mustake" - Sold
2010 Cobalt 2LT - SOLD!
Chrysler 300C Hemi K&N & Tune
2005 Cobalt SS Supercharged - E85 TVS 2.9 - SOLD!
2001 Corvette C5 6MT

Last edited by gibsonj4; 01-16-2008 at 07:32 AM.
Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old 01-15-2008, 11:33 PM
Cobalt Specialist
 
Join Date: Oct 2006
Location: New York
Posts: 1,388
Send a message via AIM to Chester
Great Write Up ....Any newbies to Modifying should read up on this
__________________


Mod's So Far: AEM CAI, C.A. Header, 2.50 Magnaflow Catback Exhaust , ZZP Catless Downpipe, DC Carbon Strut Bar, Dropped on Progress Springs. Tinted, Fully Debadged, Custom front SS bumper,2 Audiobahn 10" w/JL amp, Lower Billett Grille, Sengen 18 x 8 rims wrapped in Capitol Sport UHP 225/40/18.

Reply With Quote
  #3  
Old 01-16-2008, 10:49 PM
gibsonj4's Avatar
Veteran
 
Join Date: Oct 2006
Location: Florida
Posts: 575
Send a message via AIM to gibsonj4
Thanks chester just tryin to help
__________________
2V Mustang GT - Cammed/Sprayed - The "Mustake" - Sold
2010 Cobalt 2LT - SOLD!
Chrysler 300C Hemi K&N & Tune
2005 Cobalt SS Supercharged - E85 TVS 2.9 - SOLD!
2001 Corvette C5 6MT
Reply With Quote
  #4  
Old 01-17-2008, 12:23 AM
dduffy2005's Avatar
Expert
 
Join Date: Oct 2007
Location: White Bear Lake, MN
Posts: 768
nice write up.
__________________
Reply With Quote
  #5  
Old 01-17-2008, 11:16 AM
gibsonj4's Avatar
Veteran
 
Join Date: Oct 2006
Location: Florida
Posts: 575
Send a message via AIM to gibsonj4
Thanks man this may eliminate what intake is better, wha is an intake, blah blah kinda questions. We used to have tons of those.
__________________
2V Mustang GT - Cammed/Sprayed - The "Mustake" - Sold
2010 Cobalt 2LT - SOLD!
Chrysler 300C Hemi K&N & Tune
2005 Cobalt SS Supercharged - E85 TVS 2.9 - SOLD!
2001 Corvette C5 6MT
Reply With Quote
  #6  
Old 01-18-2008, 02:57 AM
domin8
Guest
 
Posts: n/a
I have a question.

Last summer I had a friend (before he was reassigned by the Air Force) who was running stage 2 on his 07 IRL and got the saturn motorsports big bre throttle body. He said he noticed the difference between before and after installation. He claimed he ran faster than the supercharged police dodge chargers with the 5.7's. Anyways, he said it came with a tune that was done by the dealership. Just how beneficial would a larger throttlebody be on the LSJ's? I've been considering purchasing this very soon, then getting stage 2. Also, due to the fact that the diameter of the tb is larger than oem, it has been recommended that i have the snout of the supercharger be machined to the same diameter. Is this going to be necessary?

Here is the part I'm referencing:
Saturn Motorsports
Reply With Quote
  #7  
Old 01-18-2008, 07:21 AM
IMADreamer's Avatar
Veteran
 
Join Date: Jan 2007
Posts: 673
Quote:
Originally Posted by domin8 View Post
I have a question.

Last summer I had a friend (before he was reassigned by the Air Force) who was running stage 2 on his 07 IRL and got the saturn motorsports big bre throttle body. He said he noticed the difference between before and after installation. He claimed he ran faster than the supercharged police dodge chargers with the 5.7's. Anyways, he said it came with a tune that was done by the dealership. Just how beneficial would a larger throttlebody be on the LSJ's? I've been considering purchasing this very soon, then getting stage 2. Also, due to the fact that the diameter of the tb is larger than oem, it has been recommended that i have the snout of the supercharger be machined to the same diameter. Is this going to be necessary?

Here is the part I'm referencing:
Saturn Motorsports

Not to call your friend a liar but I don't believe what he is saying. The intake side of the LSJ flows very well and even with snout machining the supercharger is still the stumbling block and it's not due to air flow, but heat. In my opinion your money would be spent better elsewhere. Particularly on cooling and traction mods.
__________________
Repopulating yourcobalt.com one post at a time.

Reply With Quote
  #8  
Old 01-18-2008, 04:51 PM
Montecarloman's Avatar
Forum Regular
 
Join Date: Jul 2006
Posts: 135
Quote:
Originally Posted by IMADreamer View Post
Not to call your friend a liar but I don't believe what he is saying. The intake side of the LSJ flows very well and even with snout machining the supercharger is still the stumbling block and it's not due to air flow, but heat. In my opinion your money would be spent better elsewhere. Particularly on cooling and traction mods.
I agree that heat is the major drawback of any roots style blower. The great part is the LSJ intake manifold has a built in intercooler. There is a dual pass end plate offered for the manifold which should aid with cooling the intake charge. However I have not seen or heard how well it works. What I do know is its standard equipment on the race Cobalts so itís got to do something. I also agree that initial cash should be spent on traction modifications simply because if you canít put it to the ground, what good is it to you. Hereís where I'm going to disagree ever so slightly. People have ported and polished there blowers and do see increases. A larger TB would not be a bad idea if youíre going for big numbers.
__________________
2006 LS coupe, manual, Victory Red
Sportlines, FE5 struts, shocks, front swaybar, Progressive 22mm rear swaybar, Airlift load assist rear airbags, TWM ST shifter, smoothed TB, LSJ exhaust, debadged, demudflapped, Yokohama AVID Touring P195/60R15's. Soon to come 17x7 Motegi Tracklight 1.0. Best to date 15.402 at 90mph

"No friend ever served me, and no enemy ever wronged me, whom I have not repaid in full."
Lucius Cornelius Sulla
Reply With Quote
  #9  
Old 01-18-2008, 05:56 PM
06MACobalt's Avatar
Forum Regular
 
Join Date: Apr 2006
Location: Troy, OH
Posts: 126
Send a message via MSN to 06MACobalt Send a message via Yahoo to 06MACobalt
Nice write up!
__________________


Dan
Reply With Quote
  #10  
Old 01-18-2008, 06:04 PM
IMADreamer's Avatar
Veteran
 
Join Date: Jan 2007
Posts: 673
Quote:
Originally Posted by Montecarloman View Post
I agree that heat is the major drawback of any roots style blower. The great part is the LSJ intake manifold has a built in intercooler. There is a dual pass end plate offered for the manifold which should aid with cooling the intake charge. However I have not seen or heard how well it works. What I do know is its standard equipment on the race Cobalts so itís got to do something. I also agree that initial cash should be spent on traction modifications simply because if you canít put it to the ground, what good is it to you. Hereís where I'm going to disagree ever so slightly. People have ported and polished there blowers and do see increases. A larger TB would not be a bad idea if youíre going for big numbers.
The dual pass IC is good for about a 10 degree drop in IAT2s, which is significant. Also porting and polishing does do some good but it also helps drop your charge temp which is where some of the gains are coming from. I still don't think the restriction is in the snout however. I'd also have to say that by the time you have gotten around to having so much hp that you need to upgrade the throttle body you are WAY past the efficiency range of the superchager. The stock TB is very capable of flowing all the air the M62 can effectively use.

So again I'd say the TB upgrade is fairly useless.
__________________
Repopulating yourcobalt.com one post at a time.

Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 08:19 AM.


Powered by vBulletin® Copyright ©2000 - 2014, vBulletin Solutions, Inc.

Garage Plus vBulletin Plugins by Drive Thru Online, Inc.

Content Relevant URLs by vBSEO 3.3.2