I have triple carbs on now with K&N filters that are 69mm deep, wondering if it is worth it from a performance stand point to install 25mm or maybe 50mm air horns?

Using 50mm horns only allows 19mm of space between the end of the air filter and the horn but the angular distance would be more.

Has anyone tried horns inside of the air filters?

Chris

I am running air horns under my K&N filters, they fit great....Makes getting the filter on a bit of a bear, but it can be done

Zedyone, how long are they?

As far as performance, Yes it is worth running air horns.

Maybe, maybe not. Dyno it and you'll know for sure! Don't shroud the inlet, or you'll kill performance.

Air horn geometry plays into it as well: http://www.profblairandassociates.com/pdfs/RET_Bellmouth_Sept.pdf

They are the horns that came with my triple webers..

Let me see

I am pretty sure they are these exact horns.

Weber DCOE Air Horn<br><font color="red">52840.012</font>

They say they are 1.5 inches long. That sounds about right, as I have about an inch or more room from the cover of the K&N to the inlet of the horn.

Hell yes they're worth it IMHO. I'm running these with my SU's. Motorsport! Air Horn, 70-72 240Z S.U. Carburetors - The Z Store! Nissan-Datsun 240Z-260Z-280Z-280ZX-300ZX(Z31/Z32)-350Z-370Z Parts

They fit perfect in the K&N's. I noticed an improvement throughout my rpm range and don't think I imagined it. Had them before my first dyno run though. They're worth it just for the sound they make when you're revving it with the hood up.

Oh yeah, certain race mechanics I know object to calling them air horns - they prefer the term velocity stacks.

Edited September 19, 201311 yr by Stanley

These are the air horns I have ordered AIR HORN <br><font color="red">52845.010</font>

I have the carbs running fairly well at the moment but was wondering when I bolt on the new air horns will I have to adjust the balance, idle or change any jets?

Thanks,

Chris

Since you're there when you're putting on the airhorns, I would check balance/sync anyways. Regarding changing jets/idle/etc, I dont think you would have to....Do you have an O2 sensor? The air is supposed to flow more smoothly with the radius in the lip, so maybe a slight increase in mains? Sorry, never tried it without horns.