[goatwgn]

I know it has been discussed before, but I thought I would weigh in on this subject. I know every combination is different, and my old air filter setup worked fine, but I ran across one of these filter lids very cheap and figured I would just see what it did. On my car, it seemed to actually create a slight bog or hesitation for a split second on hard acceleration. Weird that something as simple as this air cleaner lid would cause something like that, but it has happened to others who have used it. My car is a '66 Tempest Custom wagon with a 9.3 to 1 455, 068 cam, TH 400 with Gear Vendors and 3.42 axle. A '71 GM 1 intake and a Q jet with divorced choke. Ram Air pan fitted to open hood scoop for cooler air. Just figured I would report my experience to anyone thinking about using it.

[dragracerx2813]

I have one. But my car runs better without it. I did think about blocking of my regular filter with tape or something. Then try the running with just the lid .

[Steve C.]

During much testing over the years it is suggested a carburetor with a smooth inlet contour for the airflow works well with it, like the Holley "HP" series. A carb design WITHOUT a smooth contour, example one with a choke tower and a Q-jet carb design, can affect the testing results. I've been told the entrance on a Holley 'HP' series carb with it's smooth contour is a completely different ballgame. It reduces intake turbulence.

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[Formulajones]

Yep, it worked well on dad's 69 GTO when he was running the factory ram air setup on it with a 950HP carb underneath.

I've never tried it on a carb that has all the choke provisions.

[leeklm]

I have read on this forum of the qjet not liking the filter top. I ran one with a holley hp carb on a 3x14 filter element and always had better ET with back to back testing at the track. One difference could have been the cold air filter box I ran on the street, which had two 4" intake ports. Possible that air box was restrictive at full throttle....


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[TCSGTO]

https://www.speed-talk.com/forum/dow...8423&mode=view

If you saw the Engine Masters episode this makes sense. It looks funky but I have to try it. The mini velocity stacks can be found at Speedway motors.

[TCSGTO]

Mini velocity stack. Lost nothing on a 520 HP Chevy over no filter on the dyno.

[Formulajones]

Link doesn't work for me.

Many years ago they used to make a formed top that slipped onto the airhorn of the carb, either holley or q-jet, and fit around the choke housings to smooth the incoming air flow.

Not sure if that's what you are talking about. I had one years ago and never got to try it. When the HP carbs got more prevalent that sort of faded away.

[Formulajones]

Oh I see the pic now.

Yeah velocity stacks like that always seem to make more power.

Used to see them all the time on tunnel rams on the street. Not only do they look bitchin' they friggin work.

[TCSGTO]

I have one of those K&N lids so if there is enough room I’m going to test it on one of those mini stacks. Running a L88 base with a 14x4” tall filter now. Seems to work but air flowing straight down the carb throat works better that across the top.
https://www.ebay.com/itm/26479944960...5ca76dc7da35e5

[dragracerx2813]

I run a flat base with a 14x5 filter and a 1/2 spacer between the carb and base. The car is about a 1/10 quicker than running no filter.

[Formulajones]

I've had the GM style drop bases actually make more power on the dyno than the aftermarket drop bases. But they all seem to do even better without a drop base at all and more of a gentle entry. Unfortunately that almost never fits under a stock hood unless you really shorten the filter. Then the lid being too close to the air horn starts to become a hindrance.

[dragracerx2813]

Originally Posted by Formulajones

I've had the GM style drop bases actually make more power on the dyno than the aftermarket drop bases. But they all seem to do even better without a drop base at all and more of a gentle entry. Unfortunately that almost never fits under a stock hood unless you really shorten the filter. Then the lid being too close to the air horn starts to become a hindrance.

Hood clearance is always the limiting factor. The half inch spacer I use is a problem on most flat hoods.

[amcmike]

Looks like the wife's going to be missing a salad bowl soon...

https://www.dailymotion.com/video/x693421

[78w72]

Originally Posted by Formulajones

Link doesn't work for me.

Many years ago they used to make a formed top that slipped onto the airhorn of the carb, either holley or q-jet, and fit around the choke housings to smooth the incoming air flow.

Not sure if that's what you are talking about. I had one years ago and never got to try it. When the HP carbs got more prevalent that sort of faded away.

i think that is the k&n "stub stack"... black plastic thing that fit over the top of the carb to smooth the air flow. k&n says it increases cfm by almost 30 & worth 10hp.

i have one of them from a long time ago, was wondering if people still used them, i dont need it so will probably try & sell it.

https://www.knfilters.com/racing/stubstacks.htm

[Formulajones]

Originally Posted by 78w72

i think that is the k&n "stub stack"... black plastic thing that fit over the top of the carb to smooth the air flow. k&n says it increases cfm by almost 30 & worth 10hp.

i have one of them from a long time ago, was wondering if people still used them, i dont need it so will probably try & sell it.

https://www.knfilters.com/racing/stubstacks.htm

Yep, I had one somewhere.

I wanted to try it with different base and lid configurations to see how it affected things, especially with the filtered top that this thread is about.

[Steve C.]

Regarding the stub stack.........

If you are looking for me (Joe Sherman Racing) I DO NOT see anything good in them at all. When I tested one on my flow bench, the gain in airflow was only 5 CFM, they were claiming up to 40 cfm increase. On the dyno. It made NO difference at all. ZERO. Where did you see an article that I used the stub stak ??Let me tell everybody something else. You know the K & N trick lid with the whole top surface like a big filter. They used to advertise this alot. It ALWAYS LOOSES 5,6 or 7 HP over any other regular chrome lid. Notice they don't advertise these any more??

JOE SHERMAN RACING

https://www.speed-talk.com/forum/viewtopic.php?t=6333

Finding 14 hp in the Right Air Cleaner Assembly

https://www.motortrend.com/how-to/air-cleaner-assembly/

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[TCSGTO]

[QUOTE=Steve C.;6306189]Regarding the stub stack.........

If you are looking for me (Joe Sherman Racing) I DO NOT see anything good in them at all. When I tested one on my flow bench, the gain in airflow was only 5 CFM, they were claiming up to 40 cfm increase. On the dyno. It made NO difference at all. ZERO. Where did you see an article that I used the stub stak ??Let me tell everybody something else. You know the K & N trick lid with the whole top surface like a big filter. They used to advertise this alot. It ALWAYS LOOSES 5,6 or 7 HP over any other regular chrome lid. Notice they don't advertise these any more??

JOE SHERMAN RACING

Dave Vizard was the one claiming the 40cfm gain. I believe he was involved in it’s development and was getting royalties from K&N sales. He hawked them pretty hard in magazines back in the day until everyone found out they didn’t work.

[Steve C.]

The K&N X-Stream filter top has been discussed for years. I've always wanted to test with and without it. I had the opportinity on a chassis dyno but ran out of time to do so. For tuning with the installation of my direct port fuel injection set up we put my car on a chassis dyno. At the end of the session for interest we tested and found my air cleaner assembly cost 17 HP at peak power rpm. 608 HP to the wheels with and 591 HP without. However because of my hood scoop arrangement and the Victor intake I cannot run a large air cleaner, its a K&N 9-inch diameter filter with a X-Stream filter top.


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[Steve C.]

The Stub Stack was included with the air cleaner testing I linked above. Not by itself, but included to aid the following.....

"We learned that paying attention to air cleaner design and especially to how air enters the carburetor can pay huge horsepower benefits as power numbers continue to climb."


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