PaceSetter header questions?

[rednightrain]

I was on their website and they give specs of their ('99) headers:

Tubing diameter: 1.5"
Collector diameter: 2.5"

My questions are.... What are these specs, what do they mean, and what might the stock header specs be?

[speedy-v6-camaro]

I believe that stock the 99 V6 has manifolds...not headers.

[rednightrain]

What's the difference?

[satellite98]

I think advantage is a better and more direct flow.

Some say its easier to work on the engine and changed the plugs with the headers, too. I hope so, my blazer is still a pain to reach a couple of the plugs. :(

[onoiocoko]

headers kinda look like tubes and like he said are a more direct smoother flow. i think the tubing diameter is how wide the tubing is where it connects to the motor. where each port lets the exaust into it. and the collector is where the tubes come together. manifolds are sorta like a big rectangle on each side, with three openings for the cylinder's to let the exaust go through, then one on the bottem to release it. its just hollow though. i dont think i explained it good. but there both basically part of the exaust that the gas goes through first so flow is real important here.

im not tryin to make it sound like u dont know anything, just trying to cover what i can.

[ May 17, 2003: Message edited by: onoiocoko ]</p>

[Dominic]

Manifolds are inexpensive to make, theyre not tuned, they just direct the exhaust to the piping. Theyre far too short and usually cause a great deal of backpressure.

Headers are usually equal length, so that each cyl performs identically, and they tend to have a much larger and smoother collector to allow gases to blend together easier and create a bessel vacuum on the other two cyls before they open their exhaust valves.

The pipe diameter and length of a header determines the powerband of the engine. Too small a pipe results in backpressure, too large a pipe kills the flow, long pipe inmproves low rpm power at the loss of high end power, short pipe improves high end power at the expense of some low end power.

Without knowing the lengths of the tubes, theyre useless for calculation. But the size of all that seems fine to me! Our exhaust valves are 1.52", so the header pipe size is fine, any larger would be wasteful probably. And our stock collectors are only 2.25", so this 2.5" collector is beneficial in that its much more free flowing.

I like it.

[ May 17, 2003: Message edited by: Dominic ]</p>

[Bliggida]

I'd would rather like to have seen the collectors at a full 3" so a full 3" exhaust can be bolted up without tapering.

But, you can always have someone cut the collector flange off, and weld in place a 3" collector flange.

[shortdog273]

I didn't know their collectors are only 2.5". [img]graemlins/crybaby.gif[/img]

[strobhen]

Read up on why its BAD for pipes to be too large (reduced gas velocity) and you will find that their size isn't bad at all.

Nothing wrong w/ a 2.5" collector

The primaries are probably too short though. Longtubes are where the real gains are (our primaries should be around 36 inches long)