Hooker Aero Chambers?? 2.5" or 3" Pipe?May 18 2017 at 3:38 PM
|Trever (Login treverd)|
71' F-100 - 445FE - 3.50 9" - C6 - Shorty Sanderson FF427 Headers (1.75" Primaries) - Built For Low End Torque - 9.5 CR
Thinking about 2.5" Mandrel Bent with a X-Pipe. Or should it be 3"?
I have been doing some research on mufflers.
Trying to find a muffler that is mellow at idle and cruising (no drone). But has some volume at WOT.
I haven't found many bad review on the Hooker Aero Chambers. Is there something better you would suggest?
Long tube headers and 3" pipes. No reason not to.
|May 18 2017, 5:50 PM |
I also have read many many good things about Hooker Aerochambers, though I've never used them myself.
|May 18 2017, 6:02 PM |
I've also heard the Hooker Aerochambers on a car and they sound good. I would stay with 2 1/2" pipe, no need for 3" on that.
Shorty Headers Unfortunately
|May 18 2017, 6:13 PM |
Unfortunately the Sanderson FF427 headers are shorty style. 1.75" Primaries and 3" collector. They are one of the only decent built headers that hug the block and don't require to notch the firewall.
Given the RPM range of the engine I was hoping that the 2.5" pipes would be enough. I don't think 3" would hurt anything but I believe that it would increase the noise potential.
3" pipes will be louder and slightly heavier.
|May 18 2017, 6:17 PM |
Okay, If you're really going to keep it to 5000 rpm max, then I could maybe see using 2-1/2" pipes.
Are you sure you can't find long tube headers that fit to your satisfaction? A truck engine bay is pretty big and open.
Okay, I have to push you as far as I can on exhaust......
|May 18 2017, 6:48 PM |
Can you run 3" pipes after the collector on your shorty headers as far back as you can?
Then neck it down to 2-1/2" mufflers and tailpipes?
I don't have empirical evidence to back this up, but I think keeping the pipe diameter constant after the collector as long as possible is beneficial. I think it is important to not reduce pipe diameter until after the cross-over pipe at the minimum. Are you going to use an H-Pipe or an X-Pipe?
edit: I re-read and saw you are intending to use an x-pipe. Can you keep the pipe diameter at 3" until after the x-pipe?
|This message has been edited by Paul_Lovett on May 18, 2017 7:02 PM|
RE: mellow at idle and cruising (no drone). But has some volume at WOT.
|May 18 2017, 7:14 PM |
What you describe is how the Aero Chambers sound on my mustang with 2.5" pipes all the way from front to back with no X pipe(I still run it now and then even though the fenders are off). I believe the drone effect might be dependent on some natural resonant frequency of the car body, not just the mufflers; but mine do not seem to drone.
My Mustang would be irritant to the neighbors as it is, if I operated it often. I would expect that 3" pipes and mufflers would be quite a bit louder, maybe double(??) which might be just perfect.
I would like to try 3" pipes on my pickup truck, just because they could fit. But my kids who are more sensible than most, think that would become obnoxious.
3" pipes definitely louder
|May 18 2017, 7:33 PM |
I read somewhere all else equal 2.5 to 3" is around a 10db increase.
I've never actually measured with a decibel meter to verify but I have gone from 3" on a 390 x pipe in a 68 galaxie to 2.5 with an x and the same mufflers and it made it much more user friendly.
Headers were different, hooked full length with the 3" and FPA shortys with the 2.5".
Didn't notice any performance difference but it was a mild ~300hp build.
I have the sanderson shorties to 3" w/ 2.5" h pipe near the bell housing, 3" run back
|May 18 2017, 9:00 PM |
3" dynomax offset straight through box mufflers, then 2.5 out the back of the car. I feel it works well for my application, 428 with a hot 'stock' CJ cam in a 64 galaxie, to 5800 RPM max. Not too loud, very soft on cruise which i like, no boom or flowie echo to burst your head, but a bit of rumble at idle and some good bark on top when the 2x4 opens up.
Helps cut the noise with the downsizing, but because it is after the large column of air spring inside the dual three inch pipes and mufflers, back pressure is still low.
|This message has been edited by TorinoBP88 on May 18, 2017 9:02 PM|
I get drone right around 2000 RPM, which is cruising speed.
|May 18 2017, 11:17 PM |
I've got the 2.5" Aerochambers with x-pipe. They sound pretty good otherwise, a bit loud.
I would go Hooker Maxflow, Magnaflow, Borla ProXS, or Jones
|May 19 2017, 4:03 AM |
I'd also go 3 inch if your headers are 3 inch, no benefit of necking them down. BTW I did the same thing on my F100 when it was a low HP 390 to prep for the 445 and it was a noticeable gain in the whole RPM range
2.5 mandrel bent will be fine, but if you are building an exhaust, intermediate and tail pipes do not change the torque of an engine if too large, but they can let it hang in a bit longer.
The reason I like the mufflers I listed is because they are absorption mufflers, they tend to bark wide open, but they don't bounce sound waves into each other changing them to mechanical and heat energy. The reflective mufflers do that and at some point have to resonate, every vehicle is different, but the FE strokers tend to drone where you don't want them to. Additionally, an absorption muffler tends to make more power
The Stainless Jones are a deal now and a real nice piece. Here is what I have, I forget the length I used, but I think 22
Here is mine, 3 inch mandrel bent, X-pipe, 445 idling
and just for reference, here is a set of Borla ProXS on my 489 Mustang with 3 inch exhaust and an H pipe. I really like the Borla, but they are 3 times more expensive for no benefit over the Jones. All the mufflers I listed in the title are about the same
Hope this helps
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 445 cid FE, headers, RPM intake, 1000 HP series Holley, 4 speed
Also, get the biggest longest muffler you can if you want it to be quieter.
|May 19 2017, 5:02 AM |
You can get the benefits of a 3" exhaust and then buy a super long 3" muffler to keep it quieter.
No loss I power from a quality muffler if it's bigger/longer. Just less noise. Slightly more weight I suppose, but not much.
That's probably the best way to have your cake and eat it, too. The good news is you have a truck and that makes it easier to package all this stuff. If you had a '68-'70 Mustang it'd be much harder or likely impossible, to make an ideal exhaust system.
Re: Hooker Aero Chambers?? 2.5" or 3" Pipe?
|May 19 2017, 12:18 PM |
Different strokes for different folks.
My 63.5 with a 390 stroker, I welded up mandrel bent 2.5 inch exhaust.
Easy to fit, easy to install, and I think at street rpms under 5,000 I don't think I'm losing anything.
I have cutouts at the headers for track usage should I so choose.
For mufflers I bought the cheapest ones I could find. Summmit turbo mufflers. I think they were $18 each.
have an idle and accelerating video.
|May 19 2017, 4:24 PM |
If it is a truck with a gas tank inboard of the frame put a single exhaust on it. 3 1/2" is fine for the 390 but for a 428 and more RPM use 4". Big truck mufflers are cheap and available with a variety of lengths and decibel dampening. Check the Donaldson catalog. The routing is easier, weighs less than duals and I think it makes more power too. My ramp truck with a 428 and single 4" and my 302 Ranger with single 3" both ran quicker ET trough the whole system and the Ranger even had two 2 1/2" cats before it merged into single.
Large single advantage
|May 21 2017, 8:02 PM |
4" pipe has 12.566 square inches of cross sectional area (big is better) and 12.5 inches of circumference metal in contact with the gas (slowing it down; lesser is better)
Two 2.5" pipes has 9.817 square inches of cross sectional area (not as good) and 15.7 total inches of circumference metal in contact with the gas (slowing it down; more than the above)
So you can see the single 4" pipe has 28% volume advantage, with only 79.6% of the metal dragging on the passing gasses.
But dual's sound cool!
|This message has been edited by Garyford on May 21, 2017 8:12 PM|
Well, I would of said...
|May 19 2017, 5:08 PM |
Hooker Aero Chambers for sure cuz I have run them for 15yrs. They sound great but you do get some drone. One of my Aero Chambers just blew out and I was just getting ready to order some ones but Ross has me thinking about the Max Flow or the Jones. I chose the Aero Chambers cuz of the flow test I saw on them. The only muffler that outflows them is the Maxflow but I went with the Aero Chambers cuz they are a deflection muffler and the maxflo were an absorption muffler and I thought they might burn out quicker and be too loud. Ross?
3" Crush Bent = 2.5" Mandrel Bent?
|May 20 2017, 9:37 AM |
This shop only does crush bends in house. Looks like I will be going with 3".
I know crush bends can really hurt airflow, especially in tight bends.