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Discussion Starter #1
just curious how many peoplewith SU carbs are running the velocity stacks on them. i never even knew that they came with them inside the stock air cleaners. obviously the previous owner of my car tossed em when they installed the K&N air filters.

i am assuming they should be run for optimum performance but i know alot of people that dont for whatever reasons.
 

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It's a tuning thing. They help to straighten out the airflow as it enters the carb to the engine. Longer ones help to give greater low end torque and shorter ones help with top end but sacrifice low end. I have a set from MSA they are the billet aluminum ones, very nice though but a little pricey. THey can be used in conjunction with the K&N units. They sit right in the middle of the filter and draw air evenly all around. Hope this helps!

Dave
 

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Discussion Starter #3
thanks Dave.

i can see where it would straighten out the flow, but figured just with 2 carbs it wouldnt be that big a deal.

there are pricey though.
 

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Ignorant people replace the stock AF housing thinking 2 K&N's have to make more power, the comercial said it does. Then they hear the noise and of course it sounds like more power!

My advice is to find an original AF housing.
 

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Discussion Starter #5
steve,

i have done testing on K&N filters against fram in a fume hood and fram flows better in almost every scenerio. i have always talked people out of getting K&N, and if i could find small round filters the same size as the K&N ones i have now id have switched it by now(im looking for 6x3 round ones)

i have been looking for a stock air box. i found a company that makes plastic air boxes that might stay cooler, but they are very expensive.

id love to find an airbox WITHOUT the air flapper of course...know of any for sale?
 

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Agree!

read my post below on this very subject.

Ignorant is a good way to discribe those who chuck the stock air cleaner.

I mean, it's DYNO-Proven!
 

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The deal with the "snorkle" is it's drawing air basically from the front of the car via a hole in the radiator support. I suppose you could remove the "flapper", not sure how much of a restriction it is? I also doubt very seriously that the metal the AF box is made of transfers much heat. If it was aluminum it might, but steel isn't going to pass than much heat to the air going through this box. It's the same as those aluminum fuel rails vs the steel ones.
 

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My 240 came with the dual K&N filters when I bought it. I had a stock backing plate with the airhorns but not the rest of the box, so I cut out the air horns and bolted them on with the K&Ns. Butt dyno says it was worth it. Also, my 240 used to take exactly 4 seconds of cranking to fire on a cold start. Now it takes exactly 2. I guess the improved airflow over the needle orifice pulls the fuel up better during cranking. I should probably re-check my air/fuel mixture now.

Cutting out the air horns was more trouble than it was worth - buying some from TWM would have been a good option. I did it because I had it sitting there and wanted to experiment. If I did it again I think I would just go with a stock air box.
 

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Discussion Starter #10
with my choke pulled halfway my engine fires in less than a second and goes right to 1500 rpm's. that on a 40 degree morning.
 

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Wow, less than a second. You must have it dialed spot-on. Better not get any air horns, your car might start before you turn the key LOL!
 

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Discussion Starter #12
The previous owner said the choke never worked and i could see why. it was even close to being adjusted from Z Therapy. Now i just bump the starter and it starts.

most people dont have a clue how to get their dual carbs running right especially in cold weather.
 

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EEEEERNT!

"Cutting out the air horns was more trouble than it was worth - buying some from TWM would have been a good option."

Nope, they do not return the HP that the stock horns do, believe it or don't...

But hey, they cost more, loose horsepower, and are something you can point to on the car to all your friends as "rad race-only pieces for the street"....sound's like marketing to me! Where do I get mine?
 

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Second?

My 260 fires on the second or third COMPRESSION EVENT, if you are cranking more than half a second, you need to apply the choke.
If you ARE applying the choke, and it does not IMMEDIATELY fire on a cold morning, you have something DRASTICALLY wrong...
 

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Re: Second?

Tell me more! I do apply the choke, so is something BIG DRASTICALLY wrong as in "You are scoring your cylinders from too much dry cranking" or is it small drastically wrong as in "Tony's car fires faster than yours, nyah nyah!"

The nozzles pull down an even amount, but not their full travel. The lever cracks open the throttle plates enough so that with full choke the car idles around 2500 rpm. I am running a stock '82 F54/P79 combo with no mechanical fuel pump but an electric with regulation set to 4 psi at the fuel rail. ZTherapy carbs with SM needles. GM ignition module.

Any advice welcome.
 
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