New Open Megaphones

Glenn B.

Lifetime Supporter
I followed Mike from Nederland's (MHNCO) lead and ditched the over-silenced mufflers provided by Superformance from the factory. The engine is 427FE big block, now with 3" tapering to 4" megaphones. I added a set of Dynatech Vortex insert cones in a futile attempt to be socially responsible. Not much effect. They took a little of the edge off the "crackling", but had no appreciable effect on the overall volume.

Dynatech Accessories - Vortex Insert Cones

Here's how she sounds now. Definitely gives the folks at Cars and Coffee the "authentic" GT 40 experience.

[ame=http://www.youtube.com/watch?v=tnxFSvc-QFg]1966 Ford GT at Austin Cars and Coffee - YouTube[/ame]

The car is almost complete. Installing new harnesses this week and still waiting on my Firestone Gold Lines that have been back-ordered for 6 months from Coker Tire.
 
Sound great Glenn.

Has anyone actually done a true back to back on the dyno on these things.
I would be interested.

Not just peak HP, the best is curtain area on the print out to get a full range comparison.

Jim
 

Ron McCall

Supporter
Sound great Glenn.

Has anyone actually done a true back to back on the dyno on these things.
I would be interested.

Not just peak HP, the best is curtain area on the print out to get a full range comparison.

Jim
I bet Ford did! ;-)
 

Mike

Lifetime Supporter
Sounds excellent. I will say there are times I'd like to knock a little edge off of it. Inside the car it is barely louder than with the mufflers but outside... She is loud! I have followed my brother driving it and if your just cruising along it is not bad at all. Idling at stop lights is silly loud and full throttle... don't ask :)

This winter I may try to add something to another set to take the crack out of it. Burns has some interesting baffling that I may try. How much did the cones help? Take any edge off?

I will say the car with megaphones makes everything else sound tame and well actually quite lame :)
 
I bet Ford did! ;-)
My point exactly Ron.
A change in cam will effect a megaphone

I have found megaphones seem to work on higher tuned engines because they become almost 2 stroke like in there tune.

It would be interesting to know if anyone has gone to the trouble of back to back them on what are more street able engines.

I made some for my 40 and it went backwards because it narrowed the band and effected the scavenge, it is not a highly strung eng it liked back pressure.

I was interested to see if anyone has tested what they bolt on ?.

Sorry Glenn if Im hijacking, I see these pipes and have always wondered what other people have found.

Jim
 

Keith

Moderator
I followed Mike from Nederland's (MHNCO) lead and ditched the over-silenced mufflers provided by Superformance from the factory. The engine is 427FE big block, now with 3" tapering to 4" megaphones. I added a set of Dynatech Vortex insert cones in a futile attempt to be socially responsible. Not much effect. They took a little of the edge off the "crackling", but had no appreciable effect on the overall volume.

Fantastic - sounds like it should, bit softer, but it's there. I've asked this question before and received no answer. Taking a stroked Windsor 427 al la Roush, would there be any appreciable difference in sound given the same level of tune?

In other words is the FE a unique sound?
 

Glenn B.

Lifetime Supporter
I had a Roush 427 IR stroker in my Daytona Coupe. Granted, the engines were in much different cars, but the FE seems to have a deeper rumbling tone, but that's probably more in my head than in my ears.

Here's my car with the original SPF mufflers for comparison. Definitely a lame sound for making 611hp.


[ame]http://www.youtube.com/watch?v=vEzqMO87Sjo[/ame]
 

Mike

Lifetime Supporter
LOL Glen I meant the average Corvette/Ferrari/Lambo/ whatever else shows up at cars & coffee. A muffled GT40 is still quite nasty sounding.
 

Keith

Moderator
AS you say difficult to judge but 615hp on mufflers? That ain't shabby at all. Assuming 180 degree header arrangement on megs, I am not sure that, say 6,000 rpm these motors would sound that different. What I am trying to pin down is whether sound is dictated by swept or stroked volume and cam choice rather than pure CC's. I guess my engine guru hero JacMac should chime in now as he will know.

And I'll bet he will be watching this as I write.

If I was in the game now, I would definitely have Jac build me an engine and insist he flew over to adjust the tappets between rounds!!
 

Glenn B.

Lifetime Supporter
If you listen to the Cars and Coffee video again, you will hear a Lamborghini Gallardo Superleggera a few cars away start up right before me. Definitely a limp linguini in comparison.
 

Howard Jones

Supporter
I think total sound pressure (DB) will be ultimately be determined by the amount of power produced. It's one of those physics things.

The cones are supposed to reduce sound levels by 3 Db. On a at the margin sound level that might really prove valuable. Say you are at 105DB at a track and need to get down under 103. But they are not mufflers.

These might just be the ticket for "quite tracks" 95db will do it at most places.

Day Motor Sports - 95 DB RACING MUFFLER - SCH-14272735-78
 

Mike

Lifetime Supporter
Fantastic - sounds like it should, bit softer, but it's there. I've asked this question before and received no answer. Taking a stroked Windsor 427 al la Roush, would there be any appreciable difference in sound given the same level of tune?

In other words is the FE a unique sound?
I don't hear much of any tone difference between Glen's FE and my Stroked Windsor at least as idle.


[ame]http://www.youtube.com/watch?v=Tbp8ZP4yFIE[/ame]
 

Glenn B.

Lifetime Supporter
Someone else posted another video of my car...

After seeing (hearing) this, all I can say is: I'm so damn happy with the results!

[ame=http://www.youtube.com/watch?v=S8aJPMYan2Y]66 Ford GT in Austin #2 - YouTube[/ame]
 
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