Cold Air Intake

[adavis12]

I have a 97 chevy 2500 with a 6.5 in it. I am looking to do some upgrades like turbo, exhaust, ect. I am currently looking for pro's / con's of using one v.s not. I am also looking for people that have different ones on there engine's and what they have done for them. I have done a search and haven't quite gotten the answers i am looking for so i decided to post.

Thank's in advanced.

 

[adavis12]

Also are there any intake/exhaust combo's that perform better together?

 

[DennisG01]

Did you find this thread?

http://www.dieseltowingresource.com/showthread.php?t=7725


If you have the round-style air filter, your fine the way it is. There's very minimal, if any, gains to be had by doing something else.

You'd be much better off to put your money into a turbo-back exhaust - only replace your crossover if it's crushed inside. However, to figure this out you need to remove it and try to pass a golf ball through from one end to the other. If the ball goes through fine, replacing the crossover will again only produce very minal gains.

 

[DieselCash]

I agree spend money on a 4" exhaust system. The filter does very little on power upgrade on our trucks.

 

[adavis12]

I am also thinking towoards a bigger turbo as well. Wouldn't the CAI help with the bigger turbo. This is my first diesel so i am looking for more input before I decide on what to do. Is 4 inch too big? I have seen alot of 3 inch and not many 4 inch exhaust. do you guys have any places i can research these as well?

 

[ak diesel driver]

4" exhaust best money spent so far

 

[trapp2012]

If you are going to buy a CAI i would buy a AFE they are priced at about $250.

 

[JMJNet]

x3 on the exhaust.

First do the exhaust. See if you still need the intake.

97 Air intake is already the round filter, you should be sufficient for this vehicle.

 

[Goldsburg]

I would like to echo what the others have said regarding the exhaust system and the 97+ cylindrical style GM filter "upgrade".

If you do feel however, that you would like to pursue a Cold Air Intake, please bear in mind that restriction is as important (actually more IMHO), than the temperature of the air. If you install a CAI that indeed does draw "cooler" air, you should take steps to verify that the restriction of such a system is lower than (or at least equal to) the factory system.

The restriction is even more important on factory W/G equipped trucks, as the factory system monitors the boost pressure through the MAP and attempts to achieve a preset level of boost at all conditions. If your intake is more restrictive than factory, even with drawing cool air, this could still result in higher IAT's than the factory setup. This is because turbo compressors operate on a pressure ratio basis and the the resulting manifold Intake Air Temperature is more than directly proportional to the pressure ratio through the compressor. For example, if there is no restriction on the inlet side of the compressor (P1 = 14.69PSIA), and the computer is calling for 9PSIG of boost pressure (23.69PSIA), then your turbo needs to operate on a pressure ratio of: (9PSIG + 14.69PSIA) / 14.69PSIA = 1.61

If you now incur just 30 inches of water column restriction (2.31inHg), that equates to a "loss" of 1.13 PSIA on the inlet side of the compressor. Since the computer still wants 9PSIG (23.69PSIA), then your compressor now has to "work" on a pressure ratio of (9 PSIG + 14.69PSIA) / 13.56 PSIA = 1.75. This results in higher IAT's, even with the cooler air at the inlet.

The preceding example underscores the importance of restriction when considering a Cold Air Intake.

If you don't want to measure the parameters used above to calculate the actual performance of your CAI, you can always monitor the IAT's and MAP readings with a scanner for your old intake versus your new intake to ensure that it does provide a benefit.

Regards,

 

[adavis12]

Thank you all

for your input. As this is mu first diesel i appreciate the help and suggestions.

Has anyone upgraded to marine injectors? are there any pro's and con's to them?