Would appreciate some advice before I get going.
When I purchased my 74 it had a modified 79 350 with approx 400hp, so the previous owner said.
Any way It has Hooker Comp Headers with 3" collectors and drops down to 2" stock exhaust.
As you can imagine there is plenty of back pressure.
I purchased Patriot Tight Tuck headers with 2 1/2" collectors and plan on hooking them up to a set of Patriot side pipes.
The headers would tie into the 2" pipes on the sidepipes then exit into the 3" muffler section of the sidepipes and then out.
The question is, am I going to get a similar back pressure problem or is the 3" section of the sidepipes going to eliminate the back pressure.

Schoon

 

I would think that the 2' pipes would define the restrictiondetermining your back pressure.

 

I thought that's what you would say.
Looks like I am better off running 2 1/2" all the way.
Guess I will send the sidepipes back.
Probably to loud anyway!

 

You won't have as much restriction because the 2" portion will be quite a bit shorter. Is there anyway you could take the pipes to a good muffler shop and have the 2" section replaced with 2 1/2"? At any rate the sidepipes will be significantly less restrictive than a complete system. Plus they are infinitely sexier! I would guess with all the contortions in the full system(each bend is a restriction no matter the diameter) It would be just about a toss-up.
Ron

 

I'm with partsman for modifying the feedpipe on the sidepipe kit. The length of the narrow pipe isn't relevant though, as it is a choke point. You want width for flow. If you do have choke points (cats, mufflers that restrict a bit, smaller diameter pipes, etc.), you want them as far away from the engine as possible. Having *volume* before the choke point helps to smooth out the bursts of exhaust and gives a more "mellow" sound, and a more even exhaust pressure. I have JEGS headers to a 3" collector and 2.5" pipes the whole way back. Made a huge difference. A good exhaust shop can probably replace the feedpipe with a custom piece for under $100

bill.

 

Depends on how they are baffled.

 

Hey Guys,
I think I am going to go with Starship on this one.
My3" collectors going into 2" pipe is like blowing through a straw.
Also like Wrwalke's Idea,before I send the sidepipes back I will talk to a muffler shop and see if they can increase the " feed to 2 1/2" for a reasonable price.

 

IMHO,.....

Stay away from the 'chain shops'. [:'(]

Find yourself a local guy.
He'll do a better job and appreciate the work.
He will want you back sometime, and to tell all your friends.
More pride in his work. [sm=icon_rock.gif]

 

Whatever you decide on, if you want it to last and be a lot cooler, get it coated w/ Jet Hot. Especially the headers.

 

Tight Tuck headers are coater and I plan on using SS pipe and fittings until I reach the sidepipes. The sidepipes are cheap enough to toss every couple of years if the rust out on me.
I really want to go with the pipes but if my car is going to run like crap I need to re-think the set up.

Schoon