Webber air horn for 32/36 DGV.....no numbers anywhere?......

[Allan31]

I was poking around the www looking for some kind of finite chart or somebody's numbers they got from dyno research on these horns and seems there is nothing. Nothing that I could find anyway.





Has nobody done any dyno with these on and off to show results?

A friend of mine offered a convincing argument by saying if they did do any good, everyone at the run-offs would have them on.

Any thoughts?

[Garey Guzman]

Your friend is correct.

(That's not to say that they weren't on everyone's car many years ago!)

[mark elder]

On the dyno and on the rollers, the horns helped as bit but with the body work on, there was less power. Turned out that the with the length of the horns, it was too close to the rear cover for these to be an effect.

[Bernard Bradpiece]

Mark,
Was that on a vintage Ford with the body at the level of the carburetor top and the airhorn exposed, or a modern Ford where the body enclosed the carb and air is fed in through the body?

BB

[EricP]

Mark,
Was that on a vintage Ford with the body at the level of the carburetor top and the airhorn exposed, or a modern Ford where the body enclosed the carb and air is fed in through the body?

BB

Inquiring minds want to know... My car has them... hadn't considered they may not be good...

[EricP]

https://www.apexspeed.com/forums/sho...weber+air+horn

Sounds like the answer might be "depends" as is often the case... Installed poorly with inadequate airflow space, could be bad. BUT, the idea is good. One post in another thread indicated jetting had to be changed for the horn but then top end was improved on the dyno. I'd like to see a direct comparison but that would take some doing to get a proper comparison.

[BorkRacing]

Velocity stacks can serve 2 purposes.

The first is to allow an area for the reversing air and fuel mixture a place to collect and not be dissipated into the air and lost (or worse catch fire from a backfire). This reversion occurs when the flowing mass of air and fuel suddenly hits a closed intake valve and heads back out again. This is more important in non-plenum situations seen in Weber DCOE systems and less so in V-8 motors with large central plenums below the carburator- they have a place for the reversing air/fuel to go. Our situation is more towards a plenum with the DGV and Ford intake and that being so we don't need a long velocity stack to contain the air/fuel mixture. So in this instance it neither helps nor hinders.

The second use of velocity stacks is to smooth the flow of air into the carb venturi, to make it more efficient and thus flow more air and make more power. The problem with our motors is that the carb and the venturi size limits the volume of air that can enter. Making a more efficient system to flow more doesn't help. So again in this instance it neither helps nor hinders again. This may be why you don't see engine builders who NOW use dyno data reccomend velocity stacks.

As an aside, running velocity stacks open vs with a mesh filter on them may cause an actual loss of air flow. This may hinder your production of power.

Hope this helps.

[BeerBudgetRacing]

https://www.apexspeed.com/forums/sho...weber+air+horn

Sounds like the answer might be "depends" as is often the case... Installed poorly with inadequate airflow space, could be bad. BUT, the idea is good. One post in another thread indicated jetting had to be changed for the horn but then top end was improved on the dyno. I'd like to see a direct comparison but that would take some doing to get a proper comparison.

As linked in that post
https://www.piercemanifolds.com/product_p/52848.015.htm

I like smooth edges. I could tell you it added power but I have no evidence.
I installed it for the same reason we make smooth bends rather than abrupt turns.

[Keith Robinson]

I was poking around the www looking for some kind of finite chart or somebody's numbers they got from dyno research on these horns and seems there is nothing. Nothing that I could find anyway.





Has nobody done any dyno with these on and off to show results?

A friend of mine offered a convincing argument by saying if they did do any good, everyone at the run-offs would have them on.

Any thoughts?

Most of the leading cars at the runoff had no use for these; they were fuel injected Hondas !!

[DanW]

I asked Jay Ivey last September at his Open House. He said it was 1HP on the dyno.

[BorkRacing]

I asked Jay Ivey last September at his Open House. He said it was 1HP on the dyno.

Then why doesn't he put one on all of his motors?

Where was the 1 HP, peak? at 6800?

Just curious....

[provamo]

i have seen this work on a dyno .......................marginal gain

but it looks cool as hell

if you ever finish behind a car using one, you will be motivated to purchase same

[DanW]

Then why doesn't he put one on all of his motors?

Where was the 1 HP, peak? at 6800?

Just curious....

I didn't pursue the discussion further. 1HP is well within the calibration tolerance of the dyno. I decided to invest the cost in driver coaching/simulator time instead, much better payout in seconds per lap.

Regards,
Dan