C5 Air Intake Modifications
Race Director
Joined: Mar 2004
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From: Fort Wayne IN
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Outstandingly informative post!!! Really good info there.
Melting Slicks
Joined: Nov 2005
Posts: 2,071
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From: clackamas oregon
ok, i caught the problem with the four stroke theory. thinking that it goes around 4 times per intake stroke being incorrect that is. so the divide by 4 didnt seem correct to me. but duuaang Paul..... where did you get all that other stuff???? my mind is still in brain freeze mode trying to understand it.
allthough i am pretty sure you are correct.... i dont think very many could figure out if you where not
what in the world do you do????? are you the guy that builds space craft????
and how on earth did you figure this out that quickly
by the way.....VERY COOL POST!!!!!!!!
allthough i am pretty sure you are correct.... i dont think very many could figure out if you where not what in the world do you do????? are you the guy that builds space craft???? and how on earth did you figure this out that quickly
by the way.....VERY COOL POST!!!!!!!!
Thread Starter
Instructor
Joined: Mar 2004
Posts: 136
Likes: 5
From: Houston TX
I work as a Mechanical Engineer designing high pressure waterblast equipment that operates from 5000 to 40,000 psi so I use these formulas fairly often. Our 40K ultra high pressure pump and gun are very commonly used in removing hardened paint from overspray on carrier frames in the Auto industry. In fact, one of our first Ultra High Pressure installations was at the Nascote Fascia plant in Nashville Illinois in 1999 who, buy the way, made the front and rear Fascia's for the C5. I remember seeing them there during my visit. At times, this paint can build up over 1/2" thick and it just explodes when the 40000 psi waterjet is passed over it. Really cleans the frames well, and has many other applications as well.
At this plant, they molded and painted the bumper fascia's then shipped them to Bowling Green for assembly. I bought the flow bench as a hobby about 4 years ago and have been fascinated with airflow ever since.
Paul
At this plant, they molded and painted the bumper fascia's then shipped them to Bowling Green for assembly. I bought the flow bench as a hobby about 4 years ago and have been fascinated with airflow ever since.
Paul
Racer
Joined: Jul 2006
Posts: 427
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From: Chicagoland IL
All of this tech talk is cool and all. Now we need someone in the houston area to step up and offer their aftermarket system as a guinea pig so we can have some of this stuff broken down to simple english for the rest of us!
Le Mans Master
Joined: Oct 2005
Posts: 5,446
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From: Kailua HI
Originally Posted by RedHotZO6
Looks like the K&N was worth about 6 CFM over the stock paper filter. In addition, the flow did not increase when the K&N filter was removed (450 CFM). I did not have any aftermarket filters (Blackwing, etc) to compare at the time but I suspect there is some flow to be gained with a smoother coupler between the air bridge and Throttle Body. I was suprised how restrictive the stock airbox lid was since there is very little area for the air to enter the filter. GM must have done this for noise reduction and a simple way to up the HP for later models.
Paul
Paul
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Former Law Dawg Moderator
Joined: Jan 2005
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From: Eads, Tennessee
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St. Jude Donor '05 thru '24
Originally Posted by schoolyard
I Just Added Blackwing,smooth Coupler And Air Bridge Today To Stock Ls6,now I Wonder What Slight Gain I Will Feel.i Am Going To Drive Up Calif.coast And Report-great Thread!!!!!
Thread Starter
Instructor
Joined: Mar 2004
Posts: 136
Likes: 5
From: Houston TX
Actually from my flow testing results on cylinder heads, polishing the surface over a rough cartridge roll sanded finish yielded a zero increase in flow. The pretty high polished finish you see on aftermarket cylinder heads is for looks only, it does nothing for flow. The main impact on flow is how the cross sectional area changes as you move down the port and of course the cross sectional area itself.
A slight rough finish will result in a turbulent boundary layer and can help reduce drag which will help increase flow. Why do you think they put dimples on Golf *****?
Also, air does not like to change direction or pass through large changes in cross section, so larger radius bends and gradual cross section changes will improve flow.
Just some things I have learned over the years.
Paul
A slight rough finish will result in a turbulent boundary layer and can help reduce drag which will help increase flow. Why do you think they put dimples on Golf *****?
Also, air does not like to change direction or pass through large changes in cross section, so larger radius bends and gradual cross section changes will improve flow.
Just some things I have learned over the years.
Paul
Melting Slicks
Joined: Sep 2005
Posts: 2,625
Likes: 1
From: Rhode Island
Originally Posted by TSDuke
Great test!! Thanks.
I wonder what effect an aftermarket air bridge would have on flow numbers?
I wonder what effect an aftermarket air bridge would have on flow numbers?
Melting Slicks
Joined: Aug 2006
Posts: 2,167
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From: Powell TN
Cruise-In VIII Veteran
Originally Posted by 1Corvette
RedHotZ06, Thank you for taking the time and effort to put together this post! Very useful information. I love reading posts like this one that have facts to go along with the dialog.
Melting Slicks
Joined: Feb 2001
Posts: 2,804
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From: Northville, MI
To paraphrase what a LS1 engineer told our local club several years ago, The stock airbridge was designed to keep the engine quieter and create a designed airflow caracteristic that was built into the adapative stategy used in the PCM. He was talking about the LS6 engine vs the 97-00 vs 01+ LS1. He went further to state that many of the earlier silicone couplers they tested actually made less hp because they would partially collapse in driving tests. Your tests seem to support his statement.
Le Mans Master
Joined: Dec 2001
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From: Winchester TN
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St. Jude Donor '03-'04-'05-'06-'07-'11
Hi Paul -
Awesome post - Thanks!
I was wondering - did you test any aftermarket airbridges and the stock airbridge?
I have been told that the stock airbridge will flow as much as a stock ls1/ls6 engine can handle and I was wondering if that was your finding.
I would be willing to send one of my carbon fiber halltech airbridges and/or my entire Trap system down for you to test - I have a twin-ram setup coming I could install while the testing was being done -
Let me know if that is of interest to you.
thanks again for a great post -
best regards -
mqqn
Awesome post - Thanks!
I was wondering - did you test any aftermarket airbridges and the stock airbridge?
I have been told that the stock airbridge will flow as much as a stock ls1/ls6 engine can handle and I was wondering if that was your finding.
I would be willing to send one of my carbon fiber halltech airbridges and/or my entire Trap system down for you to test - I have a twin-ram setup coming I could install while the testing was being done -
Let me know if that is of interest to you.
thanks again for a great post -
best regards -
mqqn
Last edited by mqqn; Aug 31, 2006 at 04:39 PM.
Thread Starter
Instructor
Joined: Mar 2004
Posts: 136
Likes: 5
From: Houston TX
Only the stock air bridge was tested. I would like to test any aftermarket parts including throttle bodies, MAF's, air bridges, air cleaners, even LS1/LS6/LS7 heads and the results will be posted on this thread. You can PM me for the shipping address. Thanks,
Paul
Paul
Instructor
Joined: Nov 2005
Posts: 103
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From: Vacaville CA
Paul,
Excellent post! I installed a Blackwing, cold air screens and a smooth air coupler. I didn't want to cut into the air dam and take away any potential airflow from the radiator (like the "Ice Box"). This way I have colder air in front of the air dam (where the filter is) and no airbox to reduce airflow into the filter.
I'm marking this thread so I can see your future testing & results.
Excellent post! I installed a Blackwing, cold air screens and a smooth air coupler. I didn't want to cut into the air dam and take away any potential airflow from the radiator (like the "Ice Box"). This way I have colder air in front of the air dam (where the filter is) and no airbox to reduce airflow into the filter.
I'm marking this thread so I can see your future testing & results.