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headers v free flow

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Sonic Silver View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Sonic Silver Quote  Post ReplyReply Direct Link To This Post Posted: May/25/2022 at 8:48am
True. LOL. There were several places that sold lifetime batteries back in the 70's. It was only good for the original owner. I'm sure they didn't expect very many folks to keep their cars forever, or if they did, that they would lose their warranty papers. The last couple of batteries that they replaced was a hassle. 

   They had to get the manager (different one each time) and neither had ever heard of a lifetime battery. I showed them the warranty and they made me bring the car in to make sure the car was the same car that the original was bought for. They didn't have a service dept. I had to park the car out front of the store, remove the battery, and bring it to the back of the store and give it to them. The manager wanted to make it hard on me and didn't seem too pleased.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RandyB Quote  Post ReplyReply Direct Link To This Post Posted: May/25/2022 at 10:12am
Had headers on my Corvette for 10+ years only had to replace twice and first time was my fault, forgot to retorque the bolts after the first heat cycle and the second time I replaced them when I had the heads ported.
If you tune your exhaust, you can get great gains with headers, while I agree they are a pain to install, they gains you get on even a slightly modified engine I think are worth it, especially if you tune your whole exhaust system. Putting too big or too little primaries is going to hurt you more than help you.
Randy B
68 Javelin SST 343
73 Charger Rallye 340 triple Blk
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ccowx Quote  Post ReplyReply Direct Link To This Post Posted: May/25/2022 at 10:33am
As has been said above, the issue in many ways is quality rather than the basic fact of headers themselves. I have operated a set of headers for 30+ years on my 70 Javelin 390 and here are some observations:

-The torque curve is noticeably flatter on a car with long tube headers. I have several friends that have been in my car and it has contributed to them giving a set of quality headers a try. 
-The headers available currently are crap and that has been the case since the 60's. Hedmans and Hookers have all the issues mentioned above with sealing beads and flanges that don't fit, headers that are thin and over heat starters, etc, etc. 
-I have a set of NOS Thorley's from back in the day and they are terrible too. I would have to basically recreate the bead on every port to have any chance of sealing and they would warp horribly the minute you started the car. 
-I have a set of thick metal reproduction Thorleys that were done in the mid 80's. They are the original design but made better and with thick metal. $400 in 1988 and the best money I ever spent on the car. Seal great, sound good, perform well, don't overheat the starter, withstand hitting the ground well. 
-Headers are low. My car is at stock height and I have to be a bit cautious going over speed bumps. If that bothers you, don't get headers. 
-The Control Freak or ARH headers are worth the money if you want them and don't mind the clearance issues. Don't waste your time and hobby good will getting standard headers, they are not worth the stress. 

Chris 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Gench Quote  Post ReplyReply Direct Link To This Post Posted: May/25/2022 at 10:56am
Originally posted by Sonic Silver Sonic Silver wrote:

True. LOL. There were several places that sold lifetime batteries back in the 70's. It was only good for the original owner. I'm sure they didn't expect very many folks to keep their cars forever, or if they did, that they would lose their warranty papers. The last couple of batteries that they replaced was a hassle. 

   They had to get the manager (different one each time) and neither had ever heard of a lifetime battery. I showed them the warranty and they made me bring the car in to make sure the car was the same car that the original was bought for. They didn't have a service dept. I had to park the car out front of the store, remove the battery, and bring it to the back of the store and give it to them. The manager wanted to make it hard on me and didn't seem too pleased.

Lifetime warranties hurt them for sure. I worked at a place called Midwest Steel in Madison WI when I was younger, we had the first super shreader in the US I believe. Huge belt would run a car, a bus, didn’t matter, up the belt and fall into swinging hammers in the shape of a bell, 800 lbs each. Needless to say tiny pieces came out the other side. Magnets and tubs of water separated all the material on the way, again on belts, to rail cars. It was a cool but nasty place. Long story longer, a person would inspect each belt to pick missed separations of material. Those guys would have a pile of craftsman tools and coins daily, all chewed up but if it was identifiable and over 50% present, they traded them in. One took a handle in, end was gone, they got a new 3/4” ratchet and didn’t even know if it was a ratchet. 

Common sense should have stopped lifetime, clearly not sustainable, accountants must love guessing that loss quarterly. 

Congrats on keeping the car, battery and receipts. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Sonic Silver Quote  Post ReplyReply Direct Link To This Post Posted: May/25/2022 at 11:14am
Originally posted by Gench Gench wrote:

Originally posted by Sonic Silver Sonic Silver wrote:

True. LOL. There were several places that sold lifetime batteries back in the 70's. It was only good for the original owner. I'm sure they didn't expect very many folks to keep their cars forever, or if they did, that they would lose their warranty papers. The last couple of batteries that they replaced was a hassle. 

   They had to get the manager (different one each time) and neither had ever heard of a lifetime battery. I showed them the warranty and they made me bring the car in to make sure the car was the same car that the original was bought for. They didn't have a service dept. I had to park the car out front of the store, remove the battery, and bring it to the back of the store and give it to them. The manager wanted to make it hard on me and didn't seem too pleased.

Lifetime warranties hurt them for sure. I worked at a place called Midwest Steel in Madison WI when I was younger, we had the first super shreader in the US I believe. Huge belt would run a car, a bus, didn’t matter, up the belt and fall into swinging hammers in the shape of a bell, 800 lbs each. Needless to say tiny pieces came out the other side. Magnets and tubs of water separated all the material on the way, again on belts, to rail cars. It was a cool but nasty place. Long story longer, a person would inspect each belt to pick missed separations of material. Those guys would have a pile of craftsman tools and coins daily, all chewed up but if it was identifiable and over 50% present, they traded them in. One took a handle in, end was gone, they got a new 3/4” ratchet and didn’t even know if it was a ratchet. 

Common sense should have stopped lifetime, clearly not sustainable, accountants must love guessing that loss quarterly. 

Congrats on keeping the car, battery and receipts. 
It was an easy decision. I knew I was going to keep the car forever, so lifetime battery and mufflers and tailpipes made sense.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote hacksaw1971 Quote  Post ReplyReply Direct Link To This Post Posted: May/27/2022 at 9:35am
been looking into this header/pipe set up for my S/C.....  im sure i can make the jav/amx system work.  going to do the stock stuff  and save the up the 4k to get the whole set up.  i have had alot of work done to the heads and stock intake $$$$$ id hate to choke all that time and money down with what i have now under it.  again  im looking at the whole curve .... not just peak.  i think thats where most get confused.  peak don't mean much on a street car.  we ain't turning 6500 all the time.  if ya are... it ain't no street car .... lol 
 JMO


Edited by hacksaw1971 - May/27/2022 at 9:38am
its the little things that make the biggest difference
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ccowx Quote  Post ReplyReply Direct Link To This Post Posted: May/27/2022 at 9:59am
A thought on pipe diameter. I looked it up and like everything else there is a formula to give an idea of what size pipe you need to support X amount of HP. I recall that dual 2-1/4" will support roughly 425 HP and 2-1/2" will support 500 hp and change. All of this assumes dual exhaust and free flowing mufflers. 2" supports the stock hp, no problem. Once you have hit minimal restriction, there is no benefit to going more, unless you like the look. Most here would be fine with 2-1/4" or 2-1/2" pipes. 

Mufflers are critical too. I gained .4 seconds with a simple muffler change from a chambered to a straight through design. 

Chris 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote SC397 Quote  Post ReplyReply Direct Link To This Post Posted: May/27/2022 at 10:20am
Here is the curves from the 401 with the Free Flow manifolds that we dynoed back in 2012.
Here are my notes from back then:
The exhaust manifolds had more of a torque plateau. It was 400 #/ft at 3600 and stayed there until about 4500. At 4750 it was about 395. At 5000 it was about 385.

For the shortys at 3000 the torque was about 393. At 3500 it was 400. From about 3750 to about 4400 it was about 410 but had a slight dip in the middle. At 4750 it was about 395. At 5000 it was about 380.

For the long tube headers the torque was 420 at 3500, 425 at 4000, 430 at 4250, 400 at 5000.

Keep in mind that this was a 401 with the dual quad Awfulhauser so it was intake limited which is probably why the exhaust didn't make a huge difference.
I will see if I can find the rest of the curves



Edited by SC397 - May/27/2022 at 10:23am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mbwicz Quote  Post ReplyReply Direct Link To This Post Posted: May/27/2022 at 11:01am
Originally posted by ccowx ccowx wrote:

A thought on pipe diameter. I looked it up and like everything else there is a formula to give an idea of what size pipe you need to support X amount of HP. I recall that dual 2-1/4" will support roughly 425 HP and 2-1/2" will support 500 hp and change. All of this assumes dual exhaust and free flowing mufflers. 2" supports the stock hp, no problem. Once you have hit minimal restriction, there is no benefit to going more, unless you like the look. Most here would be fine with 2-1/4" or 2-1/2" pipes. 

Mufflers are critical too. I gained .4 seconds with a simple muffler change from a chambered to a straight through design. 

Chris 

  There is also a school of thought that says you can run one step smaller tail pipes because the exhaust is cooler as it gets further away from the engine.  This can make a difference for going over axles or tight clearance areas.  The ARH exhaust is 3" x-pipe and 2-1/2" tail pipes.
  I think I remember some pretty extensive exhaust testing on a pontiac that confirmed this.

Mike
1970 AMX, one step forward, one step back. Both steps cost time and money.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote hacksaw1971 Quote  Post ReplyReply Direct Link To This Post Posted: May/27/2022 at 5:09pm
Originally posted by mbwicz mbwicz wrote:

Originally posted by ccowx ccowx wrote:

A thought on pipe diameter. I looked it up and like everything else there is a formula to give an idea of what size pipe you need to support X amount of HP. I recall that dual 2-1/4" will support roughly 425 HP and 2-1/2" will support 500 hp and change. All of this assumes dual exhaust and free flowing mufflers. 2" supports the stock hp, no problem. Once you have hit minimal restriction, there is no benefit to going more, unless you like the look. Most here would be fine with 2-1/4" or 2-1/2" pipes. 

Mufflers are critical too. I gained .4 seconds with a simple muffler change from a chambered to a straight through design. 

Chris 

  There is also a school of thought that says you can run one step smaller tail pipes because the exhaust is cooler as it gets further away from the engine.  This can make a difference for going over axles or tight clearance areas.  The ARH exhaust is 3" x-pipe and 2-1/2" tail pipes.
  I think I remember some pretty extensive exhaust testing on a pontiac that confirmed this.

Mike
 i have always stept down one size after the muffler.  ir realy dose work.  and with 2.5 on it now .i can see there is going to be a thing with getting 3in over the rear and out the back. 
its the little things that make the biggest difference
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