E90Post
 


The Tire Rack
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > CAI vs. DCI



Reply
 
Thread Tools Search this Thread
      05-29-2009, 02:54 PM   #23
Former_Boosted_IS
Major General
307
Rep
5,175
Posts

Drives: 4 Wheels
Join Date: Aug 2007
Location: Planet Earth!

iTrader: (15)

Quote:
Originally Posted by jonm42 View Post
Just trying to confirm that as a statement instead of an inference.
Terry from BMS suggested I look at the boost up top to infer flow.
Appreciate 0
      05-29-2009, 04:45 PM   #24
shifterboy45
Major
shifterboy45's Avatar
23
Rep
1,179
Posts

Drives: 2009 335i Coupe
Join Date: Feb 2009
Location: North by Northwest

iTrader: (0)

well that gives me a little more information .. i rarely run into that situation, but are a few intersections and notorious dips in the freeway to make me want to be sure.

even though many have tested and provided information to prove the DCI is just as effective as the CAI, i'm challenged to believe the results (not saying they are false or flawed) -- but to say the underhood temp factor plays no role in the intake air charge -- solely due to the intercooler, speaks too highly of the ability of the intercooler to exchange heat.

now if the intercooler was assisted by a temp control unit with a probe in the intercooler, and a refrigerant type system to provide a heat exchange medium then i would be more inclined to be swayed in that direction.

once the intercooler has reached its limit of heat exchange (heat soaked) the system loses effectiveness. case in point -- why place the air conditioning condensor in front of the radiator, how is the radiator able to live behind the condensor if the condensor gets hot also? the condensor needs the coolest air possible because its cooling ability is static (its volume is small and there is no additional medium to transfer heat) the radiator capacity is designed with a hot condensor in mind, it can accept being heat soaked because there is a cooling medium that is moving dynamically through it.

Take away the cooling fan for an a/c system the pressure rises to unacceptable level QUICKLY and the system losses its cooling ability, raise the ambient temp by 20 or 30 degrees and the system looses effectiveness --but with the radiator its totally different -- since its not just this a set of hollow tubes with fins, but hollow tubes that carry a medium that dissipates the absorbed heat.

So the test conducted on stock intercooler efficiency (or lack thereof) i think is correct, but the drawing in of "twice" (ambient + engine) heated air from under the hood, and coming to the conclusion that the AT after the intercooler varies only slightly compared to a cold air intake or the stock air box is not really plausible.

i know all my cars (f/i or n/a) run real good when the weather is nice and cool and when it warms up there is a preceivable difference in performance. so i figure driving around with nice cool ambient air which is then heated by a hot cylinder head and exhaust manifold is gonna have some kind of a performance impact.

But then again im a novice to all of this.. and this is only an opinion
my $.02 (which too could be flawed)
Appreciate 0
      05-29-2009, 05:50 PM   #25
Former_Boosted_IS
Major General
307
Rep
5,175
Posts

Drives: 4 Wheels
Join Date: Aug 2007
Location: Planet Earth!

iTrader: (15)

Quote:
Originally Posted by shifterboy45 View Post
well that gives me a little more information .. i rarely run into that situation, but are a few intersections and notorious dips in the freeway to make me want to be sure.

even though many have tested and provided information to prove the DCI is just as effective as the CAI, i'm challenged to believe the results (not saying they are false or flawed) -- but to say the underhood temp factor plays no role in the intake air charge -- solely due to the intercooler, speaks too highly of the ability of the intercooler to exchange heat.

now if the intercooler was assisted by a temp control unit with a probe in the intercooler, and a refrigerant type system to provide a heat exchange medium then i would be more inclined to be swayed in that direction.

once the intercooler has reached its limit of heat exchange (heat soaked) the system loses effectiveness. case in point -- why place the air conditioning condensor in front of the radiator, how is the radiator able to live behind the condensor if the condensor gets hot also? the condensor needs the coolest air possible because its cooling ability is static (its volume is small and there is no additional medium to transfer heat) the radiator capacity is designed with a hot condensor in mind, it can accept being heat soaked because there is a cooling medium that is moving dynamically through it.

Take away the cooling fan for an a/c system the pressure rises to unacceptable level QUICKLY and the system losses its cooling ability, raise the ambient temp by 20 or 30 degrees and the system looses effectiveness --but with the radiator its totally different -- since its not just this a set of hollow tubes with fins, but hollow tubes that carry a medium that dissipates the absorbed heat.

So the test conducted on stock intercooler efficiency (or lack thereof) i think is correct, but the drawing in of "twice" (ambient + engine) heated air from under the hood, and coming to the conclusion that the AT after the intercooler varies only slightly compared to a cold air intake or the stock air box is not really plausible.

i know all my cars (f/i or n/a) run real good when the weather is nice and cool and when it warms up there is a preceivable difference in performance. so i figure driving around with nice cool ambient air which is then heated by a hot cylinder head and exhaust manifold is gonna have some kind of a performance impact.

But then again im a novice to all of this.. and this is only an opinion
my $.02 (which too could be flawed)
There is no need for speculation though. Here is the test I personally conducted:

Appreciate 0
      05-31-2009, 12:06 PM   #26
jonm42
Captain
United_States
22
Rep
617
Posts

Drives: too fast for conditions.
Join Date: Feb 2007
Location: Portland, OR

iTrader: (2)

So my conclusion is that a good CAI (whatever that means ) can be used in place of DCI's. Dissent?
Appreciate 0
      05-31-2009, 01:37 PM   #27
ragingclue
One cam is enough
ragingclue's Avatar
130
Rep
6,801
Posts

Drives: VF
Join Date: Oct 2008
Location: mulletville

iTrader: (1)

They both work well enough for what you need.
Appreciate 0
      06-01-2009, 04:39 AM   #28
Former_Boosted_IS
Major General
307
Rep
5,175
Posts

Drives: 4 Wheels
Join Date: Aug 2007
Location: Planet Earth!

iTrader: (15)

Quote:
Originally Posted by ragingclue View Post
They both work well enough for what you need.
That is not an accurate statement. The true statement is the STETT Performance CAI produced an average of 9F colder IATs than the DCIs on an Active Autowerke Intercooler. That means it could be 15F - 20F colder on stock. We can infer on the stock turbos that the STETT CAI and DCI produce sufficient flow for the turbos. Basically all else equal, the STETT Performance CAI outperformed the DCIs it appears.
Appreciate 0
      06-01-2009, 10:14 AM   #29
jonm42
Captain
United_States
22
Rep
617
Posts

Drives: too fast for conditions.
Join Date: Feb 2007
Location: Portland, OR

iTrader: (2)

Quote:
Originally Posted by Former_Boosted_IS View Post
That is not an accurate statement. The true statement is the STETT Performance CAI produced an average of 9F colder IATs than the DCIs on an Active Autowerke Intercooler. That means it could be 15F - 20F colder on stock. We can infer on the stock turbos that the STETT CAI and DCI produce sufficient flow for the turbos. Basically all else equal, the STETT Performance CAI outperformed the DCIs it appears.
Thats the sort of statement I was looking for. Thanks!
Appreciate 0
Reply

Bookmarks

Tags
cai, dci

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -5. The time now is 01:06 PM.




e90post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST