Muffler change on sidepipe

[priobe]

Hello All,

I am looking to change my mufflers on my sidepipe. I have looked into the CHambered mufflers however it seems as if the largest size they make them is 3 " inlet.

Here are the specs

3.5" tube to 4 bodied muffler (Lobak) 3.5 turndown 12 inch long.


I am looking to keep the same size.

The reason for me to change this muffler is because I noticed that I ha 7/8 with augers.

Looking to fee up some power.

What have you done.

[RICK LAKE]

Priobe You need a small amount of back pressure. If not you will burn out the exhaust valves. The ideal number is between 1-2 psi under WOT. 3-5 is OK and will help with drivability. Anything more and you are killing HP and torque. If you are running 500 cubes, you only need the system to handle 250 cubes, a 4 cylinder. I have a race set of pipes and street set that came with the car. I am loosing 34 HP and 6,000 rpms with street pipes but still have my hearing on the left side. Car maken 2,000 HP are running 4" exhaust pipes. Step headers also help make more power. 3" in and out should be good for your car. The muffler design inside needs to be like an old glass pack like a cherry bomb and straight through. Rick L.

[Dwight]

Check this web site. http://www.classicchambered.com/

Dwight

[mickmate]

I changed out the mufflers on a SPF with an FE 427 recently. He had pretty restrictive crushed pipe mufflers prior and can roll a baseball through the ones he has now. He says it's the single biggest performance increase he's done to the car, I also noticed very little volume increase. There's a good article about changing the mufflers in Kit Car a couple of issues back. If you need any further pointers on it ask here. We got the mufflers from http://www.stainless-specialties.com/products2a.htm

[ceslaw]

For what it is worth, I replaced the stock side pipes on my Everett Morrison Gen IV with pipes from Stainless - Specialities. They custom made them to an exact fit based on drawings I prepared. They sound much better - and a bit quiter. Excellent service. The stainless has a mirror like finish. The Genesis 427 SO still has plenty of power. Highly recommend Stainless Specialities.

[priobe]

Thanks mickmate,

I looked in to stainless specialties and they only offer stainless steel mufflers. I am running mild steel.


Dwight,

I think I will be running the classic chambered mufflers since they offer a set in mild steel.

ceslaw,
did you ever have a chance to look at the muffler EM supplied with your replica?

whats is it the lobak version?

[ceslaw]

The EM side pipe are made by EM and are a sort - of Lobak style. The problem was that the"fins" set away from the sides of the pipe by about a half inch. In other words the diamter of the fins is about 3 inches but the side pipe is 4 inches in diameter, so the exhaust sort of just flowed by the fins and thus they had no discernable effect on the noise level that we could detect. I understand that EM is redesigning the pipes.

The good thing about the EM pipes is that they would not likely have much back pressure.

There was not much differene between the EM side pipes and no pipes.

The Stainless Specialities side pipes made a world of differnce. Still loud, but manageable.

[767Jockey]

OK, some dumb questions from a guy with no fabricating skills. I have an old Contemporary with the original pipes. I assume that they are probably terribly restrictive. I'm putting a 482" sideoiler in the car, and projected horsepower is about 625 or so. I'm thinking of doing the pipes over with the classic chambered packed 3" pipes. I don't mind a rumble but I'm not going to be pleased with deafening loud, either. I guess the big 3" core with the packing is a good compromise. Has anyone used these, and what are the sound and performance levels like?

Anyway, the rear hanger bracket on my pipes now is welded on to the turnout pipe just behind the muffler body. The turnout pipes on the classic chambered site are 12" long, mine are 13" long and my mufflers are 20" long at the body. The math here doesn't work. What I figured is to use 22" mufflers, (which should theoretically be just a small amount quieter than the 20" as well) and make the rear turnout 11" long, giving the overall pipe the same length. Does this sound like a plan to you guys? Will it look OK? The potential problem now is that the bracket, if it goes to the same place, is now on the muffler body. I believe that I can mount the bracket on the new turnout, and just re-drill the outer frame sponson for the new location. However, while I get these all welded up, I will need a jig of some sort to have the bracket come off the pipe at the proper angle and location relative to the header, no?

Also, they recommend a transition piece to help the exhaust flow from my 3 1'2" collector into the 3" core. This too will add length. How much does the use of this thing usually add to the pipe assembled length? Right now the collector is welded right to the rounded end of the muffler body. Any ideas on if I need this flow reducer or not, what it looks like and how much longer it makes the assembled pipe? Any idea what I can expect to pay to get this all assembled and welded? How do you make this jig? Pictures, ideas, input of any sort is appreciated.

[Dwight]

Jockey,
we have a couple of muffler shops where the owners race on Friday night, dirt or circle track. If you take you car to them they can do the work. Be careful who you pick because sometime their finish welding is crude. In a race car looks are not as important as it is to us.

Dwight

[RedBarchetta]

Originally Posted by Dwight

Jockey,
we have a couple of muffler shops where the owners race on Friday night, dirt or circle track. If you take you car to them they can do the work. Be careful who you pick because sometime their finish welding is crude. In a race car looks are not as important as it is to us.

Dwight

Better yet, find a local race car chassis fabricator. These guys are incredible welders and usually use TIG for a really nice bead/finish.

[Three Peaks]

Originally Posted by 767Jockey

OK, some dumb questions from a guy with no fabricating skills. I have an old Contemporary with the original pipes. I assume that they are probably terribly restrictive. I'm putting a 482" sideoiler in the car, and projected horsepower is about 625 or so. I'm thinking of doing the pipes over with the classic chambered packed 3" pipes. I don't mind a rumble but I'm not going to be pleased with deafening loud, either. I guess the big 3" core with the packing is a good compromise. Has anyone used these, and what are the sound and performance levels like?

Anyway, the rear hanger bracket on my pipes now is welded on to the turnout pipe just behind the muffler body. The turnout pipes on the classic chambered site are 12" long, mine are 13" long and my mufflers are 20" long at the body. The math here doesn't work. What I figured is to use 22" mufflers, (which should theoretically be just a small amount quieter than the 20" as well) and make the rear turnout 11" long, giving the overall pipe the same length. Does this sound like a plan to you guys? Will it look OK? The potential problem now is that the bracket, if it goes to the same place, is now on the muffler body. I believe that I can mount the bracket on the new turnout, and just re-drill the outer frame sponson for the new location. However, while I get these all welded up, I will need a jig of some sort to have the bracket come off the pipe at the proper angle and location relative to the header, no?

Also, they recommend a transition piece to help the exhaust flow from my 3 1'2" collector into the 3" core. This too will add length. How much does the use of this thing usually add to the pipe assembled length? Right now the collector is welded right to the rounded end of the muffler body. Any ideas on if I need this flow reducer or not, what it looks like and how much longer it makes the assembled pipe? Any idea what I can expect to pay to get this all assembled and welded? How do you make this jig? Pictures, ideas, input of any sort is appreciated.

If you want some really gorgeous sidepipes, send them to Len Ewell in Tigard, Oregon. I've gotten to know him pretty well and his work is gorgeous. He can match just about anything you send him as he makes headers/sidepipes for a number of different cars. I was at his place last week and he was sending a set to India for a Cobra! I believe he also makes sidepipes for Finishline and several Cobra manufacturers here on the West Coast.

I can get you his contact information if you are interested.

Bob

[767Jockey]

Originally Posted by Three Peaks

If you want some really gorgeous sidepipes, send them to Len Ewell in Tigard, Oregon. I've gotten to know him pretty well and his work is gorgeous. He can match just about anything you send him as he makes headers/sidepipes for a number of different cars. I was at his place last week and he was sending a set to India for a Cobra! I believe he also makes sidepipes for Finishline and several Cobra manufacturers here on the West Coast.

I can get you his contact information if you are interested.

Bob

I'd like his contact info please.....thanks!

[Three Peaks]

PM Sent with contact info.

Bob

[Rare Iron]

For those that want to do their own muffler replacements, Cobrapacks work pretty good.

I build & ship them all over the world. Not a single unhappy customer that I know of. Most are 3" cores, 24" bodies, packed. Some like 'em unpacked & brutal.

-Eric

(the 3.5" to 3" reducers get trimmed, welded, & they are completely hidden inside the 3.5" OD collector).

[427 S/O]

I never did understand the muffler/cobra thingy. I had 'augers' inserted in my side pipes, no maintence, ever!. Loud?, when you get on her real hard. No way would I add additional 'something to fix' to the beast. 14000 miles and she still amazes me.