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Old 01-10-2011, 11:53 PM
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Quote:
Originally Posted by Cliff R View Post
I think what happens is that the huge secondary throttle plates extend too deep into the plenum. Being deeper than the primary plates, some turbulence is created, or something that effects airflow and distribution into the cylinders.
It is a loss of vacuum signal to the carb when the secondary blades open suddenly that causes the stumble.

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Old 01-11-2011, 07:12 AM
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We only had a "stumble" during our testing when the air cleaner lid, stock or the X-Treme lid was too close to the carburetor. If no lid was used at all, there was no stumble....Cliff

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Old 01-11-2011, 08:39 AM
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Another air cleaner base incident Cliff helped me clear up was the vent tube(7044266). Someone had cut the vent tube down to clear the bottom of the air cleaner and had a screen in it, the car had a stumble. Cliff recommended to put a new vent tube cover on and drill a hole in the air cleaner base as it should be, and it helped the stumble.. Amazing how something that small can change how the carb works..

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Old 01-11-2011, 08:28 PM
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David Jones
Which drop base air cleaner are you using?

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Old 01-11-2011, 09:32 PM
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1.5" aluminum. 4" filter.

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1969 GTO, 455ci, 230/236 Pontiac Dude's "Butcher Special" Comp hyd roller cam with Crower HIPPO solid roller lifters, Q-jet, Edelbrock P4B-QJ, Doug's headers, ported 6X-8 (97cc) heads, TKO600, 3.73 geared Eaton Tru-Trac 8.5", hydroboost, rear disc brakes......and my greatest mechanical feat....a new heater core.
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Old 01-12-2011, 12:01 PM
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Which Brand / Model?

Thanks

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Old 01-13-2011, 06:36 PM
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I've been away from here awhile, and HTML doesn't seem to work, and I can't get these pics to upload

Anyway, I recently dyno tested three different aircleaner bottom plates. I used the same filter element and top housing on all three tests. Same car, same gas, same dyno, all tested within a reasonable time of each other.

One pic of bases at
http://i235.photobucket.com/albums/e...xzrewq/073.jpg

Another
http://i235.photobucket.com/albums/e...xzrewq/074.jpg

And results
http://i235.photobucket.com/albums/e...q/SCAN0001.jpg

IMHO, you'd be better off with a flat base and no spacer.

Lee Atkinson

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'73 T/A (clone). Low budget stock headed 8.3:1 455, 222/242 116lsa .443/.435 cam. FAST Sportsman EFI, 315rwhp/385rwtq on 87 octane. 13.12 @103.2, 1.91 60'.

'67 Firebird [sold], ; 11.27 @ 119.61, 7.167 @ 96.07, with UD 280/280 (108LSA/ 109 ICL)solid cam. [1.537, 7.233 @93.61, 11.46 @ 115.4 w/ old UD 288/296 108 hydraulic cam] Feb '05 HPP, home-ported "16" D-ports, dished pistons (pump gas only), 3.42 gears, 275/60 DR's, 750DP, T2, full exhaust

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Old 01-14-2011, 11:10 AM
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Quote:
Originally Posted by Lee View Post
I've been away from here awhile, and HTML doesn't seem to work, and I can't get these pics to upload

Anyway, I recently dyno tested three different aircleaner bottom plates. I used the same filter element and top housing on all three tests. Same car, same gas, same dyno, all tested within a reasonable time of each other.

One pic of bases at
http://i235.photobucket.com/albums/e...xzrewq/073.jpg

Another
http://i235.photobucket.com/albums/e...xzrewq/074.jpg

And results
http://i235.photobucket.com/albums/e...q/SCAN0001.jpg

IMHO, you'd be better off with a flat base and no spacer.

Lee Atkinson
Interesting Lee. Which one are you calling the flat base, Blue or Black?

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Old 01-14-2011, 11:30 AM
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Greg,

The "Flat" is the blue one. It is steel, and I took it off a little 302 Ford years ago. It was just laying around, and I tested it for giggles. I was REALLY shocked when it made the best power! It has the rounded "berm" between the filter and carb opening, but it is effectively zero-drop/zero-rise.

The "black" base is the "Medium drop" and is actually chromed, it just is a little darker than normal. It is ~1" drop.

The rounded aluminum is the big drop, and I measure it at ~1.5" drop. Ironically, I also *thought* this one would be a great performer, and is the unit I used to make my air cleaner assembly! I've got alot of time and money invested in my current assembly, and now need to give serious thought on whether or not to change it all out....

Additionally, on the same car/motor, on the same day, I found ZERO performance when using a 4" tall K&N over a 3" K&N.
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'73 T/A (clone). Low budget stock headed 8.3:1 455, 222/242 116lsa .443/.435 cam. FAST Sportsman EFI, 315rwhp/385rwtq on 87 octane. 13.12 @103.2, 1.91 60'.

'67 Firebird [sold], ; 11.27 @ 119.61, 7.167 @ 96.07, with UD 280/280 (108LSA/ 109 ICL)solid cam. [1.537, 7.233 @93.61, 11.46 @ 115.4 w/ old UD 288/296 108 hydraulic cam] Feb '05 HPP, home-ported "16" D-ports, dished pistons (pump gas only), 3.42 gears, 275/60 DR's, 750DP, T2, full exhaust

My webpage http://lnlpd.com/home
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Old 01-14-2011, 11:56 AM
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Did you dyno the 4" or 3" filter with the big drop base?
What shape was the lid?

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1969 GTO, 455ci, 230/236 Pontiac Dude's "Butcher Special" Comp hyd roller cam with Crower HIPPO solid roller lifters, Q-jet, Edelbrock P4B-QJ, Doug's headers, ported 6X-8 (97cc) heads, TKO600, 3.73 geared Eaton Tru-Trac 8.5", hydroboost, rear disc brakes......and my greatest mechanical feat....a new heater core.
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Old 01-14-2011, 12:31 PM
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Quote:
Originally Posted by DaveD View Post
Which Brand / Model?

Thanks
DaveD, I bought off of Ebay a year or so ago from a "dirt track racing" equipment supplier. It was a no number, in a plastic bag kinda thing. I bought it because I liked the shape and wanted to run a 4" filter.

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frittering and wasting the hours in an off hand way....



1969 GTO, 455ci, 230/236 Pontiac Dude's "Butcher Special" Comp hyd roller cam with Crower HIPPO solid roller lifters, Q-jet, Edelbrock P4B-QJ, Doug's headers, ported 6X-8 (97cc) heads, TKO600, 3.73 geared Eaton Tru-Trac 8.5", hydroboost, rear disc brakes......and my greatest mechanical feat....a new heater core.
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Old 01-14-2011, 01:50 PM
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Quote:
Originally Posted by David Jones View Post
DaveD, I bought off of Ebay a year or so ago from a "dirt track racing" equipment supplier. It was a no number, in a plastic bag kinda thing. I bought it because I liked the shape and wanted to run a 4" filter.
I bought mine the same way (eBay), probably from the same place, and for the same reasons!

David, I tested all 3 with the nicely domed lid that cam with the rounded base. All 3 were tested with a 3" K&N that is virtually brand new.

I did not test the rounded base (1.5" drop) with both height elements, but I did test the medium-drop (1") with both the 3 and 4 with the rounded top, and they performed virtually identically.

Lee

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'73 T/A (clone). Low budget stock headed 8.3:1 455, 222/242 116lsa .443/.435 cam. FAST Sportsman EFI, 315rwhp/385rwtq on 87 octane. 13.12 @103.2, 1.91 60'.

'67 Firebird [sold], ; 11.27 @ 119.61, 7.167 @ 96.07, with UD 280/280 (108LSA/ 109 ICL)solid cam. [1.537, 7.233 @93.61, 11.46 @ 115.4 w/ old UD 288/296 108 hydraulic cam] Feb '05 HPP, home-ported "16" D-ports, dished pistons (pump gas only), 3.42 gears, 275/60 DR's, 750DP, T2, full exhaust

My webpage http://lnlpd.com/home
  #33  
Old 01-14-2011, 02:15 PM
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If I may.... Can a 4" filter be used with a flat bottom in a 68 GTO ? I am running a 1" drop (maybe...?) and a 1" spacer with 2" filter. Or can I use a 4" With current set up and I am running a RPM.

Didn't know that significance of using 4" to 2"...

Thank you.

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Old 01-14-2011, 02:28 PM
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Quote:
Originally Posted by Lee View Post
I bought mine the same way (eBay), probably from the same place, and for the same reasons!

David, I tested all 3 with the nicely domed lid that cam with the rounded base. All 3 were tested with a 3" K&N that is virtually brand new.

I did not test the rounded base (1.5" drop) with both height elements, but I did test the medium-drop (1") with both the 3 and 4 with the rounded top, and they performed virtually identically.

Lee

So the 3" filter was effectively a 1.5/2" filter with the 1.5" drop base?
I'm not trying to argumentative, but wonder if those recommending a flat base are comparing apples to apples.

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1969 GTO, 455ci, 230/236 Pontiac Dude's "Butcher Special" Comp hyd roller cam with Crower HIPPO solid roller lifters, Q-jet, Edelbrock P4B-QJ, Doug's headers, ported 6X-8 (97cc) heads, TKO600, 3.73 geared Eaton Tru-Trac 8.5", hydroboost, rear disc brakes......and my greatest mechanical feat....a new heater core.
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Old 01-14-2011, 03:25 PM
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I just went back through my notes. This illustrates the importance of taking good notes on such a project!

Now, I had 3 different bases (plus a second 1.5" drop rounded-base bottom that is now attached to the bonnet that seals to the hoodscoop), and actually 5 different filter elements that I tested. I had some different lids, but ran out of time and enthusiasm before I could test those.

In reviewing my notes, I see that I actually did NOT test the 3" K&N on all three bases. The 3" K&N was used on the 1" drop and the "zero-drop" base, but it was the 4" K&N that was used on the 1.5" drop rounded bottom.

My apologies for the confusion.

Lee

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'73 T/A (clone). Low budget stock headed 8.3:1 455, 222/242 116lsa .443/.435 cam. FAST Sportsman EFI, 315rwhp/385rwtq on 87 octane. 13.12 @103.2, 1.91 60'.

'67 Firebird [sold], ; 11.27 @ 119.61, 7.167 @ 96.07, with UD 280/280 (108LSA/ 109 ICL)solid cam. [1.537, 7.233 @93.61, 11.46 @ 115.4 w/ old UD 288/296 108 hydraulic cam] Feb '05 HPP, home-ported "16" D-ports, dished pistons (pump gas only), 3.42 gears, 275/60 DR's, 750DP, T2, full exhaust

My webpage http://lnlpd.com/home
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Old 01-14-2011, 03:43 PM
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I suffer from CRS also!
Now we're doing apples to apples.
Well, at least the 1.5" base LOOKS good!
Thank you Lee.

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1969 GTO, 455ci, 230/236 Pontiac Dude's "Butcher Special" Comp hyd roller cam with Crower HIPPO solid roller lifters, Q-jet, Edelbrock P4B-QJ, Doug's headers, ported 6X-8 (97cc) heads, TKO600, 3.73 geared Eaton Tru-Trac 8.5", hydroboost, rear disc brakes......and my greatest mechanical feat....a new heater core.
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Old 01-14-2011, 03:50 PM
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David, maybe this will be of a little solice to you. The BEST power I recorded, was with the rounded base (the one installed in my bonnet, an AiRaid filter (4" high, 14" base, 11.5" at top, with an intergral "lid" made into it, with the hood closed and ALL the air coming through the hoodscoop.

Of course, this testing has me considering putting the zero-drop base into the bonnet, and making a bunch of other mods to make THAT all fit....

Lee

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'73 T/A (clone). Low budget stock headed 8.3:1 455, 222/242 116lsa .443/.435 cam. FAST Sportsman EFI, 315rwhp/385rwtq on 87 octane. 13.12 @103.2, 1.91 60'.

'67 Firebird [sold], ; 11.27 @ 119.61, 7.167 @ 96.07, with UD 280/280 (108LSA/ 109 ICL)solid cam. [1.537, 7.233 @93.61, 11.46 @ 115.4 w/ old UD 288/296 108 hydraulic cam] Feb '05 HPP, home-ported "16" D-ports, dished pistons (pump gas only), 3.42 gears, 275/60 DR's, 750DP, T2, full exhaust

My webpage http://lnlpd.com/home
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Old 01-14-2011, 05:00 PM
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I'm just going to use the 1.5" drop base and spacer like I have it. I don't have that much work in it (plumbed a breather line into it) and only few bucks (less than $20) including the $1.61 I paid for the spacer. And I like the way it looks. Probably won't miss 5hp out on the street. If I make one of my dragstrip runs (3 times in 10 years) I'll do something else.
I have the OEM dual snorkle air cleaner and also a steel drop base (about .75") that has a couple of holes in it in very inconvenient places.

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frittering and wasting the hours in an off hand way....



1969 GTO, 455ci, 230/236 Pontiac Dude's "Butcher Special" Comp hyd roller cam with Crower HIPPO solid roller lifters, Q-jet, Edelbrock P4B-QJ, Doug's headers, ported 6X-8 (97cc) heads, TKO600, 3.73 geared Eaton Tru-Trac 8.5", hydroboost, rear disc brakes......and my greatest mechanical feat....a new heater core.
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Old 03-05-2021, 10:32 AM
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UPDATE: Just in case somebody comes across this.

Two days ago I tuned a car what had the rounded drop-base filter that I mentioned in my testing. Holley HP carb on a mild 6.0 LS. This motor put 330hp to the wheels. The filter was a 14x3" paper element. On THIS car/combo, the drop base caused ZERO loss of power.

I've warned people against using that particular drop-base in the past, so felt behooved to provide results that showed positive results for it.

As they say on commercials, "Your results may vary" so don't be afraid to do your own testing!

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'73 T/A (clone). Low budget stock headed 8.3:1 455, 222/242 116lsa .443/.435 cam. FAST Sportsman EFI, 315rwhp/385rwtq on 87 octane. 13.12 @103.2, 1.91 60'.

'67 Firebird [sold], ; 11.27 @ 119.61, 7.167 @ 96.07, with UD 280/280 (108LSA/ 109 ICL)solid cam. [1.537, 7.233 @93.61, 11.46 @ 115.4 w/ old UD 288/296 108 hydraulic cam] Feb '05 HPP, home-ported "16" D-ports, dished pistons (pump gas only), 3.42 gears, 275/60 DR's, 750DP, T2, full exhaust

My webpage http://lnlpd.com/home
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Old 03-05-2021, 10:44 AM
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This is the finished product.

whats the epoxy around the vent hole for? shouldn't the hole be over the vent on the carb & not turned to the rear?

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