Not your normal header question.

Ok some my (95) stock header is cracked and I want to replace it but I'm not really impressed with what's available for a decent price. I'll eventually do a stroker engine but for now it'll remain as is. So the question I have is for those of you that have put aftermarket headers on (real true headers) how has your low end power been? Has it improved or stayed the same. I'm looking for driveability mainly for rocks and not looking for it to be a race truck as this thing will be getting heavier as the build goes on. The reason I think I'll build my own header with a longer primary tubes and even lengths (or even flow style if i can't package the lengths). I've talked with our cam gurus here at work and the std 6~3~1 system that is used is effective so I don't plan on changing that, just from years of testing (V8 race engines) I don't see the store bought headers as being the best they can be. I know a lot of different considerations go into a product so I'm not blaming them just saying if I'm going to spend money why not do it myself for just the cost of materials as my time is sort of free.
Thanks,
Mike

A header alone isn't going to give you much. What people consider "noticeable" is often just a placebo effect.

You can combine items to give real world results, such as a cat-back exhaust, 62mm throttle body, and header to gain anywhere from 25-40 HP (Banks testing shows), but alone, changes are minimal.

25-40 hp haha...

The stock header is a pretty real header.. but there are dyno results to show 5-10 HP gains with a quality (Banks, Borla) header+exhaust on a low miles jeep.

I would say there is some low end power to be noticed if you do a good intake, good header, and 2.5" exhaust all the way out including a new downpipe.. but just doing the header itself you won't notice any difference.

Ok thanks for the replies keep them coming. To answer some of the points already made. The PO already bored out the TB. I do plan on doing a complete 2.5" exhaust with a high flow cat. I'm not sure I'd call the stock system a real header, having primary tubes coming together at almost a 90deg intersection isn't very good for power. Also I've been thinking about making a new intake manifold with equal length runners into a common plenum with the TB on the end. I have a basic idea of how I want it to to look, I just have to take sone measurements and sit down and think about it. I'd cut a stock manifold after the injector bosses and weld on from there. All my experience has been with Ford V8's and a little bit on GM's e800 back 20 years ago with my dad's drag car. The biggest hurdle is since I don't have a dyno or extra money I can't test so I'll just have to go with what i think will work. It'd be nice if I could talk with someone who has done some header work.

DynoGuy said:

Also I've been thinking about making a new intake manifold with equal length runners into a common plenum with the TB on the end. I have a basic idea of how I want it to to look, I just have to take sone measurements and sit down and think about it. I'd cut a stock manifold after the injector bosses and weld on from there. All my experience has been with Ford V8's and a little bit on GM's e800 back 20 years ago with my dad's drag car. The biggest hurdle is since I don't have a dyno or extra money I can't test so I'll just have to go with what i think will work. It'd be nice if I could talk with someone who has done some header work.

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Are you looking to try and improve flow of a 99+ intake manifold? Those are equal length runners.

David Bricker / SYR

Performance parts can make the powertrain more efficient, giving you more ponies at the wheels relative to stock, but the only way to make more base power is to increase the size of the combustion chamber. There's no replacement for displacement.

thatxjguy said:

\
You can combine items to give real world results, such as a cat-back exhaust, 62mm throttle body, and header to gain anywhere from 25-40 HP (Banks testing shows), but alone, changes are minimal.

Click to expand...

what are they putting in the water in Florida

David_Bricker said:

Are you looking to try and improve flow of a 99+ intake manifold? Those are equal length runners.

David Bricker / SYR

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Well mines a 95 so it has the crappy intake so 99+ intake would be better and is on my radar. The OEM has many considerations when they produce a powertrain system(emissions, driveability, production costs etc) and I'd trade some upper rpm performance for more off idle torque. So the lengths may not be optimum for what I'd like to see but I haven't seen/held a 99+ one.

DynoGuy said:

Ok thanks for the replies keep them coming. To answer some of the points already made. The PO already bored out the TB. I do plan on doing a complete 2.5" exhaust with a high flow cat. I'm not sure I'd call the stock system a real header, having primary tubes coming together at almost a 90deg intersection isn't very good for power. Also I've been thinking about making a new intake manifold with equal length runners into a common plenum with the TB on the end. I have a basic idea of how I want it to to look, I just have to take sone measurements and sit down and think about it. I'd cut a stock manifold after the injector bosses and weld on from there. All my experience has been with Ford V8's and a little bit on GM's e800 back 20 years ago with my dad's drag car. The biggest hurdle is since I don't have a dyno or extra money I can't test so I'll just have to go with what i think will work. It'd be nice if I could talk with someone who has done some header work.

Click to expand...

Well.. I don't really know all that much about performance improvements, but based on what I read here, you should probably spend a couple of weeks reading on Stroker Forums before you spin your wheels too long.

Even if you don't plan on stroking your motor, theres a lot of good information there you should start with.

http://www.jeepstrokers.com/forum/

cal said:

Well.. I don't really know all that much about performance improvements, but based on what I read here, you should probably spend a couple of weeks reading on Stroker Forums before you spin your wheels too long.

Even if you don't plan on stroking your motor, theres a lot of good information there you should start with.

http://www.jeepstrokers.com/forum/

Click to expand...

Not sure how to take the spinning wheels comment, but thanks on the link to jeepstrokers forum. I'll check them out and join the conversation there also.