Before and after American racing 1 7/8 headers

[65sohc]

Edit: Added a video & Graph

So i recently had my car dynoed, only power mods were the Air raid CAI and tune (i dunno if you count GT500 axlebacks as a power mod). It dynoed 375/356 on an AWD mustang dyno, then (within 24 hours) the shop installed American Racing 1 7/8th headers with a catless X pipe, and ran it again. Final numbers were 403/375, all i can say is wow what a difference. i went with the GT500 axlebacks because i knew id be doing headers down the road, and I'm glad i did. its still fairly tame under 3000 rpm, and just screams above that. Couldn't be happier, looking under the car they don't seem to be any lower than the factory exhaust was. I haven't noticed a decrease in tq anywhere, just more power throughout.

I was going to wait until i have the graphs to post this but i figure at least i could put the numbers out there and add the sheet later. The headers weren't cheap, but IMO worth every penny, the way it screams makes me all tingly inside. I don't think i have turned on the radio since i picked the car up. The best part was it was all done while i was away in Disney World, so i got off a plane, got dropped off at the shop, and got to enjoy my new headers...needless to say knowing it was done and ready i couldn't wait to get home to hear it in person...lol. I have a video on facebook but im not sure how to get it on here.

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AFR looks a little funky. There is probably more left in the tune.

 

[RC-5.0]

hopefully this thread puts to rest the "do headers make power" or are they worth it questions. basically if you have the coin they are definitely worth it.

well the question of "worth it" is a different story. When people talk about "bang for the buck" it's not a great value, especially if you're like me and had a shop install it. Im a little older and have the funds, so for me I don't mind the extra coin. Almost the sound alone was worth it for me :rolling:
RC

 

[toomnymods]

What i'd like to see is a dyno comparison between the ARH race catted x pipe and ARH race catted H pipe and the comparison between the ARH o/r x and ARH o/r H pipe..
has anyone found any one mustang that has does all 4 in a comparison video?

 

[Monster5.0]

I picked up the same HP with cat deletes on my 2011 GT back a few years ago. I have been saying this since that LTs are not worth it on our cars unless you are on boost. NA, you have great flowing heads/manifolds and the cats are the restriction. Drop the cats, pickup good HP. I was shown a dyno sheet from another person's car by my dyno operator. That car had same mods except he had headers. My car made the same peak numbers, but made more tq throughout the curve. Headers are a waste of cash for street cars that will stay NA.

 

[ExTurbo]

I picked up the same HP with cat deletes on my 2011 GT back a few years ago. I have been saying this since that LTs are not worth it on our cars unless you are on boost. NA, you have great flowing heads/manifolds and the cats are the restriction. Drop the cats, pickup good HP. I was shown a dyno sheet from another person's car by my dyno operator. That car had same mods except he had headers. My car made the same peak numbers, but made more tq throughout the curve. Headers are a waste of cash for street cars that will stay NA.

i dunno i like having lots of tq...agree to disagree i guess :shrug:

also 20 different cars with the same mods will all make different power, just my observation

 

[Monster5.0]

i dunno i like having lots of tq...agree to disagree i guess :shrug:

also 20 different cars with the same mods will all make different power, just my observation

No I said my car made more tq throughout the curve than the car with headers. My car only had the cat deletes. You missed the point. Less back pressure will effect your tq curve. And on an NA motor, you are not able to take advantage of that extra low back pressure and free flowing exhaust the LTs will give you. Basically, the stock manifolds made more power with the cat deletes than the other guys car with the LTs and no cats.

 

[USNjocson]

No I said my car made more tq throughout the curve than the car with headers. My car only had the cat deletes. You missed the point. Less back pressure will effect your tq curve. And on an NA motor, you are not able to take advantage of that extra low back pressure and free flowing exhaust the LTs will give you. Basically, the stock manifolds made more power with the cat deletes than the other guys car with the LTs and no cats.

Now did your car and the other car race on the street, 1/4 miles or just dyno race?

 

[11_Ingot5.0]

I've been on the fence about header for a while. I currently have off road hpipe from lethal and would like to buy headers but get high flow cats since I could get an inspection without swap everything back to stock or find a place willing to pass me. How restrictive will long tubes with high flow cats on an xpipe?or am I better off keeping. The off-road hpipe?

 

[ExTurbo]

No I said my car made more tq throughout the curve than the car with headers. My car only had the cat deletes. You missed the point. Less back pressure will effect your tq curve. And on an NA motor, you are not able to take advantage of that extra low back pressure and free flowing exhaust the LTs will give you. Basically, the stock manifolds made more power with the cat deletes than the other guys car with the LTs and no cats.

Im not doubting what you are claiming, like i sad every car is different....i could put the same mods on my car as another car and im sure id get different HP and tq figures. were both cars dynoed on the same day? both cars have the same tuner? both cars have the same quality gasoline? How new was everyones air filter? what size wheels and tires were you guys running? Im just pointing out that every car is different.

i highly doubt if i swapped the headers out for stock manifolds and an off road X pipe id make more power and torque. i understand how backpressure works, and im fairly confident that there is enough of a restriction to provide enough back pressure in the system even with headers. I cant seem to find any threads where someone added headers and lost power and tq, if you can id love to read about it.

 

[Justin81]

Im not doubting what you are claiming, like i sad every car is different....i could put the same mods on my car as another car and im sure id get different HP and tq figures. were both cars dynoed on the same day? both cars have the same tuner? both cars have the same quality gasoline? How new was everyones air filter? what size wheels and tires were you guys running? Im just pointing out that every car is different.

i highly doubt if i swapped the headers out for stock manifolds and an off road X pipe id make more power and torque. i understand how backpressure works, and im fairly confident that there is enough of a restriction to provide enough back pressure in the system even with headers. I cant seem to find any threads where someone added headers and lost power and tq, if you can id love to read about it.

This post is spot on. Who cares if your buddies car didn't make any power with headers. That sounds like his problem. The OP made some damn good power with his.