Bcak pressure and beating a dead horse!

[cobra427mnsi]

Hi guys,

I did the muffler conversion. Arizona muffler's 30" long by 2 1/2" id. Thanks for all the advice DV, Petek and Jack21. Also, thanks for the photos Petek.
Just got the mufflers back from being ceramic coated. I ground the welds smooth before coating. It was alot of work but I like the look of the results. I will try to post some pics later.
What a difference over the stock sidepipes ( in power and sound)
They sound much deeper. I was surprised that at speed (120 kilometres per hour here in Canada) the car was quieter. I could here the stereo without turning it up full.
I have a stock FE406 running through a C6 auto ( reverse shifting manual valve body) with 273:1 gears in the back. I have 265 75R 15" tires on the back. I was thinking of going to 355:1 gears, but I may not now. With the muffler upgrade, the tires break loose shifting from 1st to 2nd. They used to chirp when I shifted, but now they break loose. Scared the heck out of me.
If I make the gear change, (I've already got the gears sitting on a shelf in the garage), I will have to convince my wife that I need that wheel and sticky tire upgrade discussed in another thread. What the heck its only money.

Paul

[Don]

In redoing the side exhaust system using the Arizona Exhaust mufflers, I also placed the Car Chemistry disc inserts directly into the header collectors. This is in addition to the Arizona Exhaust mufflers. Different objective of reducing the db as much as possible without too much, but some, restriction being added. Sound is very mellow at normal driving speeds. The inserts, are available in either two or three disc style in 1/2" increments from 2" to 4 1/2". The factory CR header collector uses a 3" insert.

Summit Racing sells the Car Chemistry disc inserts, page 192 on the latest catalog. Lucien informs me that he has received similar requests for a low db muffler, but without the reverse baffles.

Car Chemistry has a web site, maybe someone with a physics background could further explain the principle of sound control employed by the disc insert technology. The two disc inserts, I used a three disc, without a muffler are advertised as meeting the NHRA noise requirements.

No doubt that the use of the disc inserts did add back in some restriction.but the primary objective of reduced db level with a minimal amount of additional restiction/back pressure was obtained, I think.

Car Chemistry
POB 950
1060 B. Enterprises DR
Midlothian TX 76065

972-775-8124

www.carchemistry.com

[John Wais]

Don:
Why did you go with the Lucian rather than the Kustom Metal Werks you have up for sale??
John W.

[Don]

John:

For a variety of reasons I needed a system that was as quiet as possible, which was a complete change in direction and accepted there had to be compromises in performance etc.

Had used "mufflers" from AZ Exhaust, but they were completely open chamber, basically a shell which is exactly what I had requested. In discussing with Lucien, he constructed a muffler to meet my needs and I proceeded to modify the existing system for a 2nd time.

From a posting from DV a few years back, had used his concept of replacing the factory Classics Roadsters set-up.

The system from Kustom Metal Werks is extremely high quality work and did not want to cut it apart. A plus for anyone interested in the KMW side exhaust, no waiting or unknowns as to future delivery, believe everyone will attest to the George's quality. Hope I answered your question.

[Jack21]

Think folks are beginning to see that what impresses the guys on cruise nights, and what your ears can live with on a daily basis are opposed objectives. Practicality has to set in sooner or later.

Looked at the Car Chemistry disk inserts. They might work. But the inserts were $50 apiece, and another quieter muffler was only $30 apiece.

Used Page Mufflers (also in AZ) glasspacks. Just back from the coating shop, as we speak, am reinstalling the 2 1/2" core x 30" with heatshields. Fairly mellow when idling and cruising, and flow extermely well. Am removing the 2 1/4" core x 36" to have coated and use in colder weather when top and sidecurtains are on. These are extremely mellow, and can carry on a conversation in the car (or listen to the sterio) while cruising.

[Don]

The mufflers made by Arizona Exhaust with a case length of 30", diameter of 4" ,ends 5"with ID 3" were $32 each. Quote from Lucien " Core is perforated to produce a vortex along the walls which helps to difuse sound. The smaller the pipe, the more restriction you get ,the fibre glass muffles the higher frequencies "

JC Whitney has in their catalogue a muffler, part number 22UY2853U, with the same specs, cost of $36.95 each

Prefer to do business with Lucien at Arizona Exhaust when he answers the phone himself ,provides great service and excellent quality.

[Steve Dickey]

ERA 535 and/or TURK,
Did you guys find a source for the 3 1/2" flanges and elbows and have you have you tried out your new mufflers???? Cripes, I haven't even got my car together yet and I'm finding new modifications to new parts I haven't even used yet. I'm hoping to hear about huge horspower gains from those big blocks.
Take care, Steve D***ey

[ERA535]

Steve-

We did not go with flanges, using stainless steel clamps instead.

As to the 3.5 inch elbows, they are available through Tognotti's Auto World in Sacramento or SPD exhausts in Rancho Cordova, CA.

The elbows are actually 3.5 inch "U" pipes that are cut as needed.

The stainless clamps and flanges are not cheap - figure about $170 per car for those and about $45 for the "U" pipes and straight pipes.

We will let you know what we think about them I'm sure!

Pat

[Steve Dickey]

Pat,
Thanks for the reply. Keep us informed,inquiring minds want to know.
Say "Hi" to Turk for me, Steve D***ey