How should I setup my exhaust with these headers?

[ISAslot]

My head pipe is rusting through... so I thought I may as well put some headers on. I've always wanted to.
Here's a link to them:
http://www.jegs.com/i/Hooker-Headers/520/6130-3/10002/-1

The collector tube size is 3" should I stay with that size or go down to 2.5" for the rest of the exhaust?

What kind of muffler would you recommend? I currently have some turbo mufflers. They sound... okay I guess. I like a mean idle sound. Not crazy about loud cruising though.

The stock exhaust has an H pipe. Should I try duplicate, or do a X pipe?

 

[franksta]

For a dual exhaust 2.5" is fine, you'll regret a huge 3" for duals. I like Magnaflow mufflers but it's dependent on the rest of your setup. Those headers are for FE Ford motors which I've got no experience with. What's the rest of your motor specs?

 

[cbrsurfr]

That's expensive for headers. Drop down to the comp headers instead of the super comp? Comp for my 351C from hooker is $473.

 

[ctk1981]

Another vote for 2.5". Those headers are the ceramic coated super comp which is why it has a high price. The standard super comp is about ~500.

For mufflers I'm a fan of http://www.classicchambered.com/.

 

[ISAslot]

For a dual exhaust 2.5" is fine, you'll regret a huge 3" for duals. I like Magnaflow mufflers but it's dependent on the rest of your setup. Those headers are for FE Ford motors which I've got no experience with. What's the rest of your motor specs?

Stock 390 Z code 4bbl

That's expensive for headers. Drop down to the comp headers instead of the super comp? Comp for my 351C from hooker is $473.

I'd like to... though these are the only ones that appear to fit without customization.

Another vote for 2.5". Those headers are the ceramic coated super comp which is why it has a high price. The standard super comp is about ~500.

For mufflers I'm a fan of http://www.classicchambered.com/.

Thanks, I'll check those out.

 

[ISAslot]

I did come across a forum post where someone recommended a different set of headers over the super comps. About the same cost if I include the reducers. Only issues are the they have a 3 week backorder and only come in chrome or grey. I prefer black. Decisions, decisions.

 

[phucheneh]

I don't think any muscle-era stuff had a crossover pipe from the factory. H is better than nothing, X is better than H.

Muffler choice will probably have a lot more impact on backpressure than the difference between 2.5" and 3" pipes. The latter could even be harmful to performance, because the wide-open pipe will reduce scavenging (which, IIRC, is one of the main points of having a crossover).

Chambered mufflers tend to drone more and not perform as well when compared to a quality 'straight through' design. E.g. Flowmasters vs Dynomax Ultra-Flo's. I really, really like the latter. Very quiet idle and cruise.

YMMV and I am not a fluid dynamics expert.

 

[ISAslot]

Do you know if an x pipe can just be added, or if calculations are necessary for optimal location? I mean, there would be little point if tossing one in would have no effect, or worst possibility hurting performance.

 

[phucheneh]

I think you really have three options:

1) Read Hot Rod, Car Craft, and the like. Do what their articles say is best. It's the closest thing you'll get to widely-published unbiased empirical testing.

2) Become an engineer, or otherwise find one to do some figuring for you. Even then, you're probably going to be dealing mostly in the theoretical, as to truly know what is optimal for your car, you're going to need to know things like the volume of air flowing into your engine, the volume (and velocity) of the air exiting the cylinders, ect. Rates of heat exchange, gas expansion...all kinds of shit that, unless you're a professional racing team, is probably going to be beyond your abilities.

3) Just copy other people. Use what you can easily procure and accept that maybe you'll waste a tiny amount of power by not having every component be engineered to death.

Frankly, I'd pick number 3. Get an X-pipe made to mate to the engine and headers that you're using. I think the general idea is to put the crossover as far forward as reasonably possible. Or maybe that's just because putting it anywhere else is difficult because the trans crossmember will get in the way if you move it any further back.

One thing of note is that it is generally a lot easier to fit an H-pipe, since you can easily cut and weld on the center portion to get the width exactly right. An X-pipe really needs to be direct fit, unless you're fabbing your own exhaust from scratch and can make the right bends to mate to your header collectors without issue.

I can't find any direct fit X-pipes for 390's.

http://www.summitracing.com/parts/jba-6655sh/overview/make/ford

There's an H; note how they made the center to build in some adjustability.

 

[phucheneh]

Oh wait, here ya go...I'm so used to late models and their finicky exhaust fitments. I forgot that there ARE easily fitted universal X-pipe kits.

http://www.summitracing.com/parts/sum-642125/overview/

Just cut the 45* sections to the necessary lengths to get your desired overall width. Lightly clamp everything in place, including your reducers at the header end, and take it to someone who can weld it up nice. Much, much easier to get good welds with the pieces off the vehicle.

 

[ISAslot]

Ended up getting them from FPA.
http://www.fordpowertrain.com/fpaindex/headers2.htm

Got them in July. I still haven't installed them yet as I've been finishing other projects. I've got to say they make nice sculpture. They're currently sitting on my dining room table.

 

[AMCRambler]

Oooo pretty

 

[Zargon]

nice

 

[olds]

Ended up getting them from FPA.
http://www.fordpowertrain.com/fpaindex/headers2.htm

Got them in July. I still haven't installed them yet as I've been finishing other projects. I've got to say they make nice sculpture. They're currently sitting on my dining room table.

You know how I know you are single?

 

[inachu]

For which car is this for?

 

[thedarkwolf]

Missed this post when you originally made it but I had a 67 galaxie with a 390 and ran the same FPA headers . Think I ran 2.25 duals but i has been a long time.

 

[ISAslot]

For which car is this for?

Here she is a few yrs ago before the paint started to go. 68 Ford XL

 

[ISAslot]

Oh wait, here ya go...I'm so used to late models and their finicky exhaust fitments. I forgot that there ARE easily fitted universal X-pipe kits.

http://www.summitracing.com/parts/sum-642125/overview/

Just cut the 45* sections to the necessary lengths to get your desired overall width. Lightly clamp everything in place, including your reducers at the header end, and take it to someone who can weld it up nice. Much, much easier to get good welds with the pieces off the vehicle.

These look good. I may get by using my current setup for a while. Once i trim the pipes for the headers/collectors it should get rid of the section that has holes in it.

You know how I know you are single?

:hmm: :awe:

Missed this post when you originally made it but I had a 67 galaxie with a 390 and ran the same FPA headers . Think I ran 2.25 duals but i has been a long time.

Nice, 67-68 are my fave Galaxies. Were the collectors 2.25 as well?

 

[thedarkwolf]

It has been almost 15 years since I sold it. I really can't remember.

 

[ISAslot]

Well, this sucks

Last bolt snapped. Looks like I'm taking the heads off. Maybe I should put on an aluminum intake while I'm at it. :hmm: