David Visard on exhaust and mufflers

I watched this and it gives some guidance to flow so you don't lose hp.

Same exact info as he covered in this book 11 years ago. Even the pics and graphs are the same.

We all need a reminder after some time about info we have read he just dragged it out too long in the video to get to the point.

He really needs to have a script to keep him on track instead of just winging it.

Nobody sells that expansion box. I bet he has an ironclad patent on that after Walker got him on the Super Turbo muffler.

The expansion box or boxes is the least of the problem.

Would a Hooker Aerochamber muffler work (the center inlet, center outlet version)?

The design looks good, but does it have enough volume?
And does the perforated opening affect the "open air" signal that the chamber mimics?
Me thinks not. The drawing looks pretty simple, a little math to figure the dimensions and an afternoon with
a welder and Bob's your uncle.

All I can tell you is those Aerochamber mufflers are nice! They sound good and make good power. Right in the ballpark of a straight through Dynomax Ultraflow and WAYYYY better than the super restrictive Dynomax Super Turbo.

The expansion box is a piece of cake. For a 526 c.i. stroker I calculated a box 4" high x 10" wide by 14" long per side. Then into the muffler. Trouble is the expansion box eats up all the stock muffler location.

I had those on my dad's chevelle. Very nice low mellow tone. I use Hooker Max flow's on my Barracuda. No real testing, but they are quit til ya hammer on it, then just the sound of badass muscle.

Just some pics from the video to help.

2

My brother has aero chambers on his car, and it runs very close to the same times so he just leaves them on when he races. Not worth the effort to remove them after driving the car to the track.

that was an interesting video by mr visard for sure ! thank you for posting !

When it comes to a street car, many things are more trouble than they're worth. You build a 550 hp motor but the mufflers you use kill 25 hp. Will you really ever notice that ?!?! And was your combo optimal to begin with, with parts that are designed to work together or did you opt for something like a tunnel ram just because you liked the looks.

Truthfully, building the optimum system such as Mr Vizards's would be a real pain in the ass and expensive. Assuming everything is carefully chosen right down to the headers, you now have to optimize the collector tubes to the custom expansion box(es). Then find mufflers that flow the necessary CFM. Then there's the issue of fitting all this under the car. Well congratulations. Now someone with a bigger cam comes along and kicks your ass.

Its nice to see all this research but applying its is quite another matter.

So with all that negativity do you know if it would fit on anyones car?The example in the pic with full exh is a 600hp Vette.I am just making conversation.Here is an exhaust pipe calculator if you want to use it. exh calc

Old stuff my 1973 Bultaco had one cylinder 1-3/4 header and then the expansion chamber (tapered up to 4-1/2) then outlet pipe was maybe 1-1/8

They did a muffler Dyno shootout in a local magazine many years ago, the Hooker Aero Chamber was the best for both power and torque. This was probably 25 years ago

There was a straight through Magnaflow muffler that was quite popular as well, do they still exist?

Come on,you know better than this.
Lets ignore that 25 hp loss,and while we are at it lets leave that stock aircleaner on their,and yeah i know we dont need that roller cam either that gives us alitle more power,and surely we dont need those few hp we get from that aftermarket intakemanifold and,that big old holley is not worth the trouble either so lets keep that that stock carter 600cfm thingy,and why would anyone care to put headers on their car,its just a few hp anyway so lets keep those old manifolds,they tend to fit better anyway,and why on earth would anyone botter to actualy put the effort into get that timingcurve right?

Yeah at this point you are pretty much back to a stock engine,just because we didnt bother for those last 25 hp in a bunch of places....

Interesting vid,I also have the hooker aerochamber mufflers.

Don't know if any of you caught the muffler test on a new episode of Engine Masters(it was just on this past week). They ran straight pipes then tested a hooker muffler(don't remember witch one) but it made more power than just straight pipes and all the other mufflers tested! The muffles had a 4 inch in/out design.

according to your chart 2.5 inch dual exhaust makes 463 hp hows david dudek running 9s in his cuda

Up to 500 hp, newer mustang GTs have a great big resonater that may be a nice choice for some projects. It has a LOT of volume and 2.5. Inch dual in/out pipes. No drone, and with great mufflers in the trunk area and you will have a very low hp loss system and be able to hear your stereo at speed!

It was the Hooker Maximum Flow muffler.

I have radio delete.

I'm currently using max flows. Kinda quit til ya nail it, then very loud. Using them in a 3.5" extension 18" then into 4" pipe and into 4" max flow. They are heavy mufflers thou.

All this discussion about expensive mufflers and complicated systems seems like a bit of a waste of time to me. Why not just put electric cut-outs on and forget it? Pick any system that fits, is affordable, sounds like you want and go with it. No lost ponies. And if you attend cruises or car shows or the like, the cut-outs are a ton of fun. Fun and functional, what's not to like? I have had electric cut-outs on my cars for over 20 years and feel that they are an important part of the combo.

I had a set of the old Magnaflow 14 inch oval by 7 inch tall 3.0 inch side inlet straight through to a center outlet mufflers with 3.0 inch pipes from the BB Hooker 1 7/8 primary pipes headers with 3.5 inch collectors, the muffs were mounted behind the rear end. It was fairly quiet at part throttle and got louder at WOT
That combination was .02 ET and .2 MPH slower hooked when up than removed on my old pump gas Duster, 7.01 at 95.2 MPH in the 1/8 mile versus with them removed 6.99 ET at 95.4 MPH, I'm sure that the weight had something to do with those results, not the back pressure form the pipes and muffs