Who is useing Header extensions?

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mopar65

mopar65

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Well I just order a new set of ceramic coated headers for my Dakota and I am going to have to move my o2 sensor. I see that they make header collectors that have the o2 sensor bung welded on. So I got to looking and see that they also sell header extensions in 12 and 18 inch lengths. I have heard and read that they will add torque and HP. I have never used a set before. So just looking for info to see if anybody on here has used them and did you see a ET improvement etc with them. Also I am unsure which ones to get. I have a 11.1 compression 360 magnum, trick flow heads, comp 580 lift solid lifter cam, indy single plane intake, Holley 800DP, 904 Transmission 8 inch 5600 stall and 4.30 gears. 96 2 wheel drive Dodge Dakota. I hope it doesn't weigh more than 3300 pounds with me in it and ready to race.
 
Have tried them and not Seen anything on the time slip, but your experience might be different.
Most people are going to tell you to run them, with a bit of paint the length of them, then cut them off after running them where the paint is most discolored.
Certainly worth a try
 
It was sure the thing to do in the 1970’s and 80’s. Now I have exhaust back to in front of my rear slicks. I love the sound of Pype’s mufflers plus it helps get the alcohol fumes out of the car.
 
Alcohol fumes play havoc on the eyes if not ventilated properly. Had to work on an alcohol burner in a trailer once, we couldn't wait to get out once it fired up. LMAO
 
My opinion is you need length after the 4 tubes end for scavenging. Sometimes a collector is sufficient, and some headers have about 7" of tube after the 4 pipes end.
 
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IMO only... let's say you have 3" collectors on your headers, and you are running a 3" exhaust back to your muffs or dumps... there will be NOTHING to be gained with header extensions performance-wise. All you are gaining is the O2 bung. Save yourself time and money and just buy the $1.50 O2 bung and weld it in yourself.
 
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B3422w5 said:
wanna sell me your cool can....lol
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That made me lol so I had to go out on my scrap pile and see if it was still there. It was in a bunch of parts I bought and I finally got tired of seeing it.
 
Professor Fate said:
IMO only... let's say you have 3" collectors on your headers, and you are running a 3" exhaust back to your muffs or dumps... there will be NOTHING to be gained with header extensions performance-wise. All you are gaining is the O2 bung. Save yourself time and money and just buy the $1.50 O2 bung and weld it in yourself.
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I dont have a exhaust system right now. Also can you weld on ceramic coated headers?
 
mopar65 said:
I dont have a exhaust system right now. Also can you weld on ceramic coated headers?
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Not without destroying/removing the ceramic coating where you weld. If you're not going to run exhaust pipes, a set of extensions might be your best option. Length will depend on your setup, I've heard of the method B3422w5 mentioned being used with some success, so start there... Just keep the O2s as close to your collectors as you can.
 
We used them back in the day to add low end torque, and yes I tried the paint trick. With new convertor technology I'm not sure if they add much.
 
B3422w5 said:
Have tried them and not Seen anything on the time slip, but your experience might be different.
Most people are going to tell you to run them, with a bit of paint the length of them, then cut them off after running them where the paint is most discolored.
Certainly worth a try
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I didn't think you could weld on the headers with out grinding on them. As much as I paid for them, I would be nuts to grind on them. Lol well after buying the pipe and the collector rings, I only have $19 in the whole thing. I already had the 02 sensor bung.
 
mopar65 said:
I didn't think you could weld on the headers with out grinding on them. As much as I paid for them, I would be nuts to grind on them. Lol well after buying the pipe and the collector rings, I only have $19 in the whole thing. I already had the 02 sensor bung.
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I was talking about the 3 bolt collector extensions
 
Collecter extensions work well on a car with a tight converter or a stick car that has an rpm drop on shifts that is fairly big? The higher the stall in relation to max hp rpm the less collecter length you need.
 
We've used them for years on the Dakota & my Demon. Not much difference in performance, we just used them for the scavenging effect & race type collects don't radiate heat up to the drivers side floorboard.
 
Unfortunately, the only true way to know what, if any benefit there is or could be to header extensions is to dyno the engine or the whole vehicle to test various length extensions.

Once the actual length is found to make best power, you need to put on a box and then construct the rest of the exhaust. This box is mimicking an open exhaust to produce the cancellation wave back to the exhaust port to help draw in more of the intake charge.

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Since scavenging and backpressure can have an affect on flow in & out of the combustion chamber, chances are that to get the most out of it, jetting may have to be adjusted to optimize the benefit. Because converter performance doesn't show up on the dyno, track testing would be the best.

i.e.: When I switched from open TTI headers with collectors to a 3" X-pipe system, which stopped at the rear axle with straight through DynoMax mufflers, my particular combo ran better with jetting 2 #'s leaner than before. I saw a slight performance boost which was easier to see because the extra 60 lbs added by the exhaust system was removed from elsewhere in the car. Comparisons were at the same weight with lots of logged runs over the previous years. (Your results may vary.)
 
Locomotion said:
Since scavenging and backpressure can have an affect on flow in & out of the combustion chamber, chances are that to get the most out of it, jetting may have to be adjusted to optimize the benefit. Because converter performance doesn't show up on the dyno, track testing would be the best.

i.e.: When I switched from open TTI headers with collectors to a 3" X-pipe system, which stopped at the rear axle with straight through DynoMax mufflers, my particular combo ran better with jetting 2 #'s leaner than before. I saw a slight performance boost which was easier to see because the extra 60 lbs added by the exhaust system was removed from elsewhere in the car. Comparisons were at the same weight with lots of logged runs over the previous years. (Your results may vary.)
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good seeing you post Myron
I see Orlando and Bradenton are opening up.
Thats great
 
I used a program called" Pipe Max" to determine my collector length.
As was said above it's measured from the inside of the header where all the pipes merge. I ended up with a 12 inch extension on the header.
Did it help.......Yes a few hundred on the 60 foot, but that was when i had my 3000 stall. now i have a 4200 stall.
Agree, the more stall you have, aka the closer you are to your torque peek, the less it will show up in a 60 foot or et.

Remember that your o2 sensor will not read correct at idle. you will need several more feet of pipe past the sensor, to get it to read correctly at idle
 
Also back pressure is never a good idea.......if back pressure help your ride, it is because you hit the tuned length that the eng wants.
And if it slowed.....you probably need to jet it a little. This i have done when i was running a full exhaust and would un bolt at the collector, at the track.

With pipe max it said, that i hit the tuned length at 16.7 inch and then next one was at something like 58 inch and the 3d length one was longer than my car:D

Remember, this is like losing 10 pound off of your car........not going to see much difference in et. But it you can find 10 more placed to remove 10 pound Now, you have improved your ET by a tenth. The colector is just 10 pound............
 
In lieu of a dyno, desktop programs, or other tools that one would have to fork out cash to then take the time to test etc I’d think defaulting to the Direct Connection/Mopar Performance recommendations of extension length would be a good ballpark start....and maybe all that is needed for most. Stick 12”s on and roll, or split hairs and go mad......oops to late!!!.:eek:.:realcrazy:
 
mopar65 said:
Well I just order a new set of ceramic coated headers for my Dakota and I am going to have to move my o2 sensor. I see that they make header collectors that have the o2 sensor bung welded on. So I got to looking and see that they also sell header extensions in 12 and 18 inch lengths. I have heard and read that they will add torque and HP. I have never used a set before. So just looking for info to see if anybody on here has used them and did you see a ET improvement etc with them. Also I am unsure which ones to get. I have a 11.1 compression 360 magnum, trick flow heads, comp 580 lift solid lifter cam, indy single plane intake, Holley 800DP, 904 Transmission 8 inch 5600 stall and 4.30 gears. 96 2 wheel drive Dodge Dakota. I hope it doesn't weigh more than 3300 pounds with me in it and ready to race.
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Since you posted up in the 11 second sticky, (Congrats) I figured I’d bit this thread up again to see what you did for your exhaust. Pictures possible?
 
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