#1  
Old 01-11-2021, 12:54 PM
mchell's Avatar
mchell mchell is offline
Ultimate Warrior
 
Join Date: Jul 2003
Location: North Port, FL
Posts: 2,432
Default Air flow

Some may find this useful:

Playing around at the track recently, Iíve discovered a HUGE difference in Performance using different air cleaner bases.

Using the same 3Ē air filter, I have found my engine will ONLY perform adequately with the stock base dual snorkel and a filter top that just covers the filter, NOT the entire base like a stock lid.

Tried a whole pile of combos and nothing bested this combo.

The worst base( Alluminum with a sharper roll into the carb) reduced et by .3 and 4mph!!

Drop bases produced the same poor results.

Seems my qjet is VERY Sensitive to the base and will not tolerate anything but a stock shape??

Question:
Have any of you found a base and lid that will work better than stock ?

...wondering what Iím leaving on the table by not being able to use a 4Ē filter with a stock base?

This is all based on a qjet carbed engine.

On a good note I was able to get my first 6.981 1/8 mile et and a best 60í of 1.52 on a different pass...not terrible for this old pig

Thanks for any insight

__________________
71 GTO, 463, KRE 295 cfm heads ported by SD Performance, RPM intake, Qjet, Dougs Headers, Comp cams HR 246/252 ...11 to 1 , 3.55 cogs, 3985lbs.....day three- 11.04 at 120mph ....1.53 60', 6.98 1/8 mile
The Following 2 Users Say Thank You to mchell For This Useful Post:
  #2  
Old 01-11-2021, 01:04 PM
steve25's Avatar
steve25 steve25 is offline
Ultimate Warrior
 
Join Date: May 2008
Location: Westchester NY
Posts: 12,352
Default

This chart may help explain your experience in picture form, and also folks should make note that once a given mass of air reaches a certain velocity it will not follow along anything greater then a 15 degree radius without sheering away from where you want it to go!

Just like water air wants to take the path of least resistance.

Also not that with Q-jets that the speed of the air entering the primary's is far faster then those big secondary's, so a air cleaner base with a bigger gentler radius around those small primary's helps a bunch!!

Don't hesitate to aid that radius shape with some epoxy.

Weather more air cleaner area will help you out all depends on how much HP the motor is making and how much air that perticular brand filter your running flows
Attached Thumbnails
Click image for larger version

Name:	IMG_0310.jpg
Views:	187
Size:	55.2 KB
ID:	558147  

__________________
You can cut out a man's Tongue from his Mouth, but that does not mean heís a liar , it only shows that you fear the truth he might speak about you!

Wernher Von Braun warned before his retirement from NASA said that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!

Last edited by steve25; 01-11-2021 at 01:22 PM.
  #3  
Old 01-11-2021, 01:24 PM
Formulajones's Avatar
Formulajones Formulajones is offline
Ultimate Warrior
 
Join Date: Jan 2012
Posts: 8,166
Default

Quote:
Originally Posted by mchell View Post
Some may find this useful:

Playing around at the track recently, Iíve discovered a HUGE difference in Performance using different air cleaner bases.

Using the same 3Ē air filter, I have found my engine will ONLY perform adequately with the stock base dual snorkel and a filter top that just covers the filter, NOT the entire base like a stock lid.

Tried a whole pile of combos and nothing bested this combo.

The worst base( Alluminum with a sharper roll into the carb) reduced et by .3 and 4mph!!

Drop bases produced the same poor results.

Seems my qjet is VERY Sensitive to the base and will not tolerate anything but a stock shape??

Question:
Have any of you found a base and lid that will work better than stock ?

...wondering what Iím leaving on the table by not being able to use a 4Ē filter with a stock base?

This is all based on a qjet carbed engine.

On a good note I was able to get my first 6.981 1/8 mile et and a best 60í of 1.52 on a different pass...not terrible for this old pig

Thanks for any insight
Exactly what I like playing with at the track and enjoy reading posts like this.
I did this years ago with a couple different cars. I'm surprised you found gains with that filter top lid. I never could get those to work good for me.

Makes me wonder what kind of clearance you have from the top of the carb to the bottom of the lid when you're running stock lids? I've found that to affect performance just as much as the base used. With some cars it's impossible to get the lid far enough away from the carb to make any difference. So dropping the base for more filter is the only solution, but as you found, that has mixed results, sometimes not so good. I think the proximity of the lid to the carb is a big player. In fact tests have shown that a flat base works best with a 3 or 4 inch filter, which gives copious amounts of room above the carb, and lack of drop base gives a straighter shot of air to the carb, but that setup never fits under a stock hood.

Which dual snorkel are you using? I may experiment with the filter lid again next time at the track now that I have changed the setup around a bit. Basically most every car here is now using a stock air cleaner base setup with taller filters, stock lids. Mainly for fitment and functionality more than anything else. Waiting for the track to open again for more testing.

__________________
2019 Pontiac Heaven class winner

https://youtu.be/XqEydRRRwqE
  #4  
Old 01-11-2021, 01:44 PM
Skip Fix's Avatar
Skip Fix Skip Fix is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: Katy,TX USA
Posts: 19,163
Default

When I pulled off the L-88 base and the 4" filter ion the 500" IA Camaro I picked up 0.3 seconds!

__________________
Skip Fix
1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever!
1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand
1965 GTO 4 barrel 3 speed project
2004 GTO Pulse Red stock motor computer tune 13.43@103.4
1964 Impala SS 409/470ci 600 HP stroker project
1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs
  #5  
Old 01-11-2021, 01:53 PM
Formulajones's Avatar
Formulajones Formulajones is offline
Ultimate Warrior
 
Join Date: Jan 2012
Posts: 8,166
Default

Quote:
Originally Posted by Skip Fix View Post
When I pulled off the L-88 base and the 4" filter ion the 500" IA Camaro I picked up 0.3 seconds!
You were using the L88 base with a full diameter filter and lid?

Those things were originally designed for a small screen and lid the diameter of the throat of the carb, with a filter in the hood. Just like in the picture of the one I built for dad's GTO.

Used this way they are very effective as the outside air coming in has a straight shot to the throat of the carb when the hood is closed. I think what helps this design is what I eluded to in my first post. The small lid holding the base to the carb is about 2 or 3" above the carb itself. Plenty of room. I forget how far that drop base is now, but it's alot. I would have to check but seems even a 4 inch filter wouldn't put the lid very far above the carb??
Attached Thumbnails
Click image for larger version

Name:	PA150026.jpg
Views:	205
Size:	78.0 KB
ID:	558153  

__________________
2019 Pontiac Heaven class winner

https://youtu.be/XqEydRRRwqE
  #6  
Old 01-11-2021, 01:56 PM
mchell's Avatar
mchell mchell is offline
Ultimate Warrior
 
Join Date: Jul 2003
Location: North Port, FL
Posts: 2,432
Default

Another thing to add...

I did try NO filter and I also tried a stock base and lid with NO filter.

Both of these resulted in very poor et and loss of MPH

__________________
71 GTO, 463, KRE 295 cfm heads ported by SD Performance, RPM intake, Qjet, Dougs Headers, Comp cams HR 246/252 ...11 to 1 , 3.55 cogs, 3985lbs.....day three- 11.04 at 120mph ....1.53 60', 6.98 1/8 mile
  #7  
Old 01-11-2021, 02:02 PM
Formulajones's Avatar
Formulajones Formulajones is offline
Ultimate Warrior
 
Join Date: Jan 2012
Posts: 8,166
Default

Quote:
Originally Posted by mchell View Post
Another thing to add...

I did try NO filter and I also tried a stock base and lid with NO filter.

Both of these resulted in very poor et and loss of MPH
LOL yep!!

I tried no filter in the stock base with the stock lid. It absolutely KILLED ET and MPH. When I tried that scenario, mine was in a ram air situation (70 RA Formula) with fresh air pushed in. Led me to believe the filter does act in slowing down the air flow and possibly straightening it to some degree to be more beneficial.

__________________
2019 Pontiac Heaven class winner

https://youtu.be/XqEydRRRwqE
  #8  
Old 01-11-2021, 02:39 PM
mchell's Avatar
mchell mchell is offline
Ultimate Warrior
 
Join Date: Jul 2003
Location: North Port, FL
Posts: 2,432
Default

Action shot ....trying to unload..........getting closer............bwaaaaaaaaaaaaaa
Attached Thumbnails
Click image for larger version

Name:	33D8946D-FD2B-482E-B68D-C1AA7EEDCE2A.jpg
Views:	151
Size:	70.5 KB
ID:	558155  

__________________
71 GTO, 463, KRE 295 cfm heads ported by SD Performance, RPM intake, Qjet, Dougs Headers, Comp cams HR 246/252 ...11 to 1 , 3.55 cogs, 3985lbs.....day three- 11.04 at 120mph ....1.53 60', 6.98 1/8 mile
The Following User Says Thank You to mchell For This Useful Post:
  #9  
Old 01-11-2021, 07:26 PM
mchell's Avatar
mchell mchell is offline
Ultimate Warrior
 
Join Date: Jul 2003
Location: North Port, FL
Posts: 2,432
Default

Two of the base variants that produced very poor results....had to beat one into submission to clear the qjet linkage
Attached Thumbnails
Click image for larger version

Name:	6541CD19-191C-48AD-AD20-E3DFB55F9FB7.jpg
Views:	203
Size:	66.3 KB
ID:	558181  

__________________
71 GTO, 463, KRE 295 cfm heads ported by SD Performance, RPM intake, Qjet, Dougs Headers, Comp cams HR 246/252 ...11 to 1 , 3.55 cogs, 3985lbs.....day three- 11.04 at 120mph ....1.53 60', 6.98 1/8 mile
  #10  
Old 01-11-2021, 07:31 PM
mchell's Avatar
mchell mchell is offline
Ultimate Warrior
 
Join Date: Jul 2003
Location: North Port, FL
Posts: 2,432
Default

This is the variant that provided the best performance....

Unfortunately, with a RPM intake it is the only setup Iím able to run without modding the hood.
Attached Thumbnails
Click image for larger version

Name:	810A661D-2BEB-4C58-ABDB-306400569CBE.jpg
Views:	278
Size:	70.8 KB
ID:	558182  

__________________
71 GTO, 463, KRE 295 cfm heads ported by SD Performance, RPM intake, Qjet, Dougs Headers, Comp cams HR 246/252 ...11 to 1 , 3.55 cogs, 3985lbs.....day three- 11.04 at 120mph ....1.53 60', 6.98 1/8 mile
The Following 2 Users Say Thank You to mchell For This Useful Post:
  #11  
Old 01-11-2021, 07:42 PM
Formulajones's Avatar
Formulajones Formulajones is offline
Ultimate Warrior
 
Join Date: Jan 2012
Posts: 8,166
Default

Okay, so a stock style Pontiac dual snorkel base and a standard 14" diameter lid (not a filter lid)



I've seen setups similar to this at the track that worked well. I had a theory that keeping the stock base like you have sort of insulates the carb from ingesting a ton of heat, especially any heat soak coming up from the bottom.

Rather than a simple open element that isn't shielded.

__________________
2019 Pontiac Heaven class winner

https://youtu.be/XqEydRRRwqE
  #12  
Old 01-11-2021, 08:22 PM
mchell's Avatar
mchell mchell is offline
Ultimate Warrior
 
Join Date: Jul 2003
Location: North Port, FL
Posts: 2,432
Default

Quote:
Originally Posted by Formulajones View Post
Okay, so a stock style Pontiac dual snorkel base and a standard 14" diameter lid (not a filter lid)



I've seen setups similar to this at the track that worked well. I had a theory that keeping the stock base like you have sort of insulates the carb from ingesting a ton of heat, especially any heat soak coming up from the bottom.

Rather than a simple open element that isn't shielded.
Yep.....works best on my rig with a qjet

__________________
71 GTO, 463, KRE 295 cfm heads ported by SD Performance, RPM intake, Qjet, Dougs Headers, Comp cams HR 246/252 ...11 to 1 , 3.55 cogs, 3985lbs.....day three- 11.04 at 120mph ....1.53 60', 6.98 1/8 mile
  #13  
Old 01-11-2021, 08:24 PM
ta man ta man is offline
Ultimate Warrior
 
Join Date: Apr 2006
Location: Clinton,Ontario,Canada
Posts: 4,813
Default

Nice testing..fun part of the hobby! With that 1/8th mile time that is a sub 11.0 time

__________________
  #14  
Old 01-11-2021, 08:41 PM
indymanjoe's Avatar
indymanjoe indymanjoe is offline
Ultimate Warrior
 
Join Date: Nov 2009
Location: Milford Michigan
Posts: 1,545
Default

Quote:
Originally Posted by mchell View Post
This is the variant that provided the best performance....

Unfortunately, with a RPM intake it is the only setup Iím able to run without modding the hood.
What base is this off of? My dual snorkel looks longer in the snorkel? Did you cut it back some?

__________________
72 Luxury Lemans nicely optioned
  #15  
Old 01-11-2021, 09:51 PM
mchell's Avatar
mchell mchell is offline
Ultimate Warrior
 
Join Date: Jul 2003
Location: North Port, FL
Posts: 2,432
Default

Quote:
Originally Posted by indymanjoe View Post
What base is this off of? My dual snorkel looks longer in the snorkel? Did you cut it back some?
Yes, the dual snorkel Iím running had been cut down in the late 70ís by the original owner of the car.

Although I have an original one thatís uncut, Iíve grown fond of this one and have been running it for 20 years or so..... Iím no purist by any stretch

__________________
71 GTO, 463, KRE 295 cfm heads ported by SD Performance, RPM intake, Qjet, Dougs Headers, Comp cams HR 246/252 ...11 to 1 , 3.55 cogs, 3985lbs.....day three- 11.04 at 120mph ....1.53 60', 6.98 1/8 mile
The Following User Says Thank You to mchell For This Useful Post:
  #16  
Old 01-11-2021, 10:24 PM
slowbird's Avatar
slowbird slowbird is offline
Ultimate Warrior
 
Join Date: Jan 2001
Location: Montgomery, IL
Posts: 9,968
Default

Great thread, loving seeing threads like this, real world testing!

Based on my testing years ago q-jets seem to be pretty sensitive to how the air enters. We made a top that was very nice, by cutting the choke tower off and really smoothing out the entry (like a holley) and it hated it.

  #17  
Old 01-11-2021, 10:47 PM
mchell's Avatar
mchell mchell is offline
Ultimate Warrior
 
Join Date: Jul 2003
Location: North Port, FL
Posts: 2,432
Default

Makes me want to find that old pic of Jim hands carb and air cleaner base. He made some forms that fit to the carb and blended it to the base. I’ve seen it and thought “how much difference could that make”

Now I want to duplicate it....it could make much more of a difference than first thought....

__________________
71 GTO, 463, KRE 295 cfm heads ported by SD Performance, RPM intake, Qjet, Dougs Headers, Comp cams HR 246/252 ...11 to 1 , 3.55 cogs, 3985lbs.....day three- 11.04 at 120mph ....1.53 60', 6.98 1/8 mile

Last edited by mchell; 01-11-2021 at 10:53 PM.
  #18  
Old 01-11-2021, 11:22 PM
Steve C. Steve C. is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: Liberty Hill, Tx. (Austin)
Posts: 9,373
Default

Are they here ?

https://pontiacstreetperformance.com...455jh2006.html

.

__________________
'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 )
Old information here:
http://www.hotrod.com/articles/0712p...tiac-trans-am/

Sponsor of the world's fastest Pontiac powered Ford Fairmont (engine)
5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension
https://www.youtube.com/watch?v=qDoJnIP3HgE
  #19  
Old 01-12-2021, 08:08 AM
mchell's Avatar
mchell mchell is offline
Ultimate Warrior
 
Join Date: Jul 2003
Location: North Port, FL
Posts: 2,432
Default

Quote:
Originally Posted by Steve C. View Post
Thanks !

Looks more complex than I thought.....give me something to play with

The base he’s using looks exactly like mine.

__________________
71 GTO, 463, KRE 295 cfm heads ported by SD Performance, RPM intake, Qjet, Dougs Headers, Comp cams HR 246/252 ...11 to 1 , 3.55 cogs, 3985lbs.....day three- 11.04 at 120mph ....1.53 60', 6.98 1/8 mile
  #20  
Old 01-12-2021, 08:52 AM
OCMDGTO's Avatar
OCMDGTO OCMDGTO is offline
Chief Ponti-yacker
 
Join Date: Sep 2014
Location: Ocean City Md
Posts: 866
Default

Holy cow 3/10s and almost a full tenth on your 60' is huge! That air cleaner setup looks great and I wonder how it would perform on a Holley. Great pics and I'm jealous of you guys down south that can still go to the track now.

__________________
Chris D
69 GTO 467, 850 Holley, T2, Edelbrock Dport 310cfm w Ram Air manifolds, HFT 245/251D .561/.594L, T400, 9" w 3.50s 3905lbs 11.64@ 114, 1.59/ 60'
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

Forum Jump


All times are GMT -4. The time now is 11:46 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 

Cold Case Radiators

Cold Case Radiators is a Max Performance company that produces high end aluminum performance radiators at a price point that won't break the bank. Polished and stamped tanks. 2 rows of 1" tubes. Lifetime Warranty.

GTOG8TA.com

GTOG8TA.com is a Max Performance company that manufacturers parts for the 04-06 GTO, 08-09 G8, and 93-02 Firebird/Trans Am platforms.

Copyright © 2017