[Tigers] Air cleaner & horsepower

[Buck Trippel]

On a chassis dyno our 289 race motor used to deliver about 370 RW HP.

We tested it both with and with out an air cleaner. We actually saw a few 
more HP with the air cleaner installed. Mind you this was not a stock Tiger 
housing. It was similar to what Jere previously reported. A 9" round 
X-Stream top and the biggest paper element that would fit under the hood 
scoop. (appx 2  inches tall)

Afterwards, when we looked at the detailed dyno reports we could see that 
the runs with the air cleaner installed showed less variation in the 
mixture. The air cleaner seemed to "smooth" the fuel ratio trace. I think 
there is something to be said for the X-Stream top which allows a more 
linear flow into the venturi.

bt

----- Original Message ----- 
From: "Thomas Witt" <atwittsend at verizon.net>
To: <tigers at autox.team.net>
Sent: Thursday, July 05, 2012 3:30 PM
Subject: Re: [Tigers] Air cleaner & horsepower


> While air is fluid, it is also turbulent. And, as you stated it can move 
> backwards in relationship to a forward moving car.  For air to turn a 
> sharp corner over the choke housing potentially reduces its ability to 
> flow smoothly through the venturi's.  Also most of this discussion related 
> to the air cleaner height measured from the mounting base for the filter 
> housing. As Theo was getting at the choke housing rises at least an inch 
> or so on most carburetors. With a 2" filter and a lid on top this 
> effectively makes for about an inch of air passage over a relatively sharp 
> edged choke housing.
>
> From my understanding a venturi stack with a length long enough to 
> straighten the air before entering the carburetor would be ideal. Even the 
> filter base can matter.  I recall test done in the '70's where running the 
> car without a filter still had a few HP gain simply by retaining the base 
> and removing a degree of turbulence.
> Tom
>
>
>> Theo,
>>
>> I'm not an engineer, just a guy that has been playing with cars, race
>> cars, motorcycles, boats and airplanes for 35 years.
>>
>> An internal combustion engine is nothing more than an air pump, it
>> sucks air, as much as it can, therefore, I do not get the "can't turn
>> a corner" comment.
>>
>> Air is about the most fluid thing there is, it even goes backwards on
>> a 200 mph race car going forwards because of poor aero design.
>>
>> Have you seen the air flow models for an F1 car, air can be made to do
>> about anything you want it to do.
>>
>> Air filters are judged by 1) surface area and 2) restriction quality.
>>
>> My suggestion more than triples the effective surface area of any 2"
>> round air filter and by using a K&N type oil cloth element, the
>> restriction is also much less.
>>
>> So please educate me, I open to learn.
>>
>> Michael
>>
>>
>>
>> On Thu, Jul 5, 2012 at 12:01 PM, Smit, Theo <Theo.Smit at dynastream.com> 
>> wrote:
>>> That looks trick but how tall is the center part? If it's only two 
>>> inches or
>> so, then you don't really gain any flow capability over the stock 
>> assembly.
>> The main problem with a four-barrel and medium to high rise manifold is 
>> that
>> you can't get the air to turn the corner and get into the carb, 
>> especially if
>> the carb has a choke tower.
>>>
>>> Theo
>>>
>>>> -----Original Message-----
>>>> From: tigers-bounces at autox.team.net [mailto:tigers-
>>>> bounces at autox.team.net] On Behalf Of michael at michaelshortt.com
>>>> Sent: July 5, 2012 9:29 AM
>>>> To: Dave Munroe
>>>> Cc: tigers at autox.team.net
>>>> Subject: Re: [Tigers] Air cleaner & horsepower
>>>>
>>>> If some of you are serious about gaining HP over the stock look ( and
>>>> you can always keep a stock housing in the trunk for car shows ),
>>>> I strongly recommend using a pair of K& N conical air filters with a
>>>> relocation kit like this one.
>>>>
>>>> http://www.summitracing.com/parts/SPE-771/?rtype=10
>>>>
>>>>
>>>> Michael Shortt
>>>>
>>>
>>>
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>>>
>>
>>
>>
>> --
>>
>>
>>
>>
>>
>>
>>
>> Michael L. Shortt
>> Savannah, Georgia
>> www.michaelshortt.com
>> michael at michaelshortt.com
>> 912-232-9390
>>
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