Why get headers?

[ClawSS]

not trolling, just looking for great insight:

Why get headers? If the stock manifolds support up to 700+ on a turbo car and getting exhaust OUT of the engine in a turbo car is the MOST important of all power adders...how come turbo owners are fine with using stock manifolds, but S/C owners and N/A guys must have headers?

Seems counter productive from a power and $$$ point of view that if the one power adder (turbo) that would benefit from smoother exhaust flow delivery doesn't need them, what the heck do the others need them for. They flow fine enough for turbos, they would flow plenty fine enough for the others. I think it is actually the tune that is helping cars run better...not the pipes.

Dropping the cats on the otherhand...That helps! No argument.

What if you tune BEFORE headers...then put them on. What are the gains? Please don't respond with "I gained this much from headers and a tune"...I am not asking that.

Ted, Ryan, Shawn....other tuners...what say you?

[Spartan01]

Your engine is a big air pump essentially.
The more air in and out the better and more powerfully it runs.
Headers are (usually) lighter, and flow more efficiently than the stock manifolds, they also (in most opinions) look better, additionally the opne design allows for enhanced cooling.

As for gains with a tune, that depends on the tune. You will see better results from a good tune after headers are installed than a similar tune before headers.

With a turbo, you are taking wasted exhaust energy and using that to drive an impeller that sucks in much more air. Most turbos will hook up to the stock manifold instead of aftermarket headers.

[ClawSS]

Yes, I agree, but if you make gains from an impeller driven by "inefficient" flow, then how inefficient is it. I see that you are talking 15% flow increase for hundreds of dollars.

You will see better results from a good tune after headers are installed than a similar tune before headers.

Why? I bet you won't see $1000 worth...5hp, 10 maybe? This is where I would like to see some numbers. I bet manifold tunes, if the tuner is really trying to get HP and not trying to sell headers, would rival those post header tunes.

Most turbos will hook up to the stock manifold instead of aftermarket headers.

Irrelevant to the conversation.

[Rcfiddy1]

Headers made correctly will have same length tubes allowing for better gas evacuation and lower back pressure resulting in more power. They can also be cooled better and free up room in the engine compartment and looks 1000% better.
For forced Induction the more air in, the more air needs to go out so efficiency is important here. Turbos work off exhaust gas and I don't know much about using headers with them. I would think that you want to be able to spin them up as fast as possible so you would want them close to the exhaust ports as possible otherwise you get lag in power delivery. Most exhaust manifolds are short, meaning distance from exhaust port to cat so hooking up a turbo seems easy on stock manifolds and allows turbos to sit as close to ports as possible. Superchargers don need care what length pipes you have other than how fast you can get exhaust out.

[62nalide]

Depends who you wanna do things, I had a front mount turbo on my truck with a custom log and stock manifold on the driver's side then swapped to a shorty and gained 43rwhp by swapping 1 header. Its all on your budget and what you want.

[ClawSS]

Heat...maybe something there, but this about power made before heat soaking.
Looks, irrelevant...

Was you truck an LS motor? Did your "log" follow the same design as the L99/LS3?

I think that returns on investment for headers is overblown based on the stock design of the LS exhaust manifold. At some point you reach critical flow and theoretical scavenging, but not until way up in the HP range. They are practically tubular exhaust manifolds now, right?

[ClawSS]

Moderators: This is an NA thread that is only using FI as a tool to explain exhaust efficiency...please do not move to an FI group...

Turbos work off exhaust gas and I don't know much about using headers with them.

You would think that working off exhaust gas, you would want the best flow, yet many on the forum are advising that unless you are over 1400 hp, why bother with adding shorties...
turbo+headers

I say, if they (manifolds) can support monster FI HP like that, WTF do I need them on a NA car without a huffer.

Help me understand the works and not tell me to throw away money on heat and looks!

Don't regurgitate what you heard about headers. I want comparisons to the LS stock manifold! That design is an efficient air mover for normal builds...who has proven it isn't?

This is your HP issue!

[GONIF]

All I can tell you is on a NA engine headers make more power . If you still doubt this ,after researching this nothing anyone can tell you will change your mind .

[Destructo09]

It's been proven that you will gain about 20 RWHP just by running high flow cats on the stock manifolds. So, I think your point is valid, however you will net probably another 10-20 from the headers themselves. So, I think you probably are correct in that just the headers probably get you a huge amount of HP.

My car dyno'd at 393 with longtubes, high flow cats, and CAI. So, lets assume it would have dyno'd at 360 completely stock, that means I only gained 33 HP from longtubes and cats and a CAI pre tune. I supposed you could say the CAI MAYBE accounts for 5-10HP and the removal of the stock cats 15-20, so, the headers alone probably did not provide that much power alone.

However, tune all this properly and you wind up with my 421 RWHP. The Tune, headers and cats cost me about 1k, so it cost me about a grand to gain 51 RWHP. That's a pretty good return I think.

I'm not sure if anybody here has tuned a LS3 with highflow cats and stock manifolds, I would be interested to see those numbers.

I think your point is probably valid over-all, but who doesn't love the sound of long tubes? It was worth the money to me!

[Destructo09]

Also, a bit of searching turned up this post, second post the guy claims 392 RWHP with just high flow cats and stock manifolds with no tune. Thats pretty much exactly my 393 pre-tune with longtubes. Different dyno however and he provided no stats on whether that was SAE corrected or not.

Edit: Forgot the link: http://www.camaro5.com/forums/showthread.php?t=171658

[ClawSS]

ok, Destructo...you got me on sound...but crunch this with your guesstimates ("free" tune included)

CAI cai = $400
Solo high flows = $575
ARH Headers = $1200

5-10 ($400) + 15-20 ($575) = 20 to 30 subtracted out of 51 = 21 to 31 rwhp for 1200+ if big name headers...if tuned properly.

$1600 (CAI + headers)...$975 (CAI + high flows)...$550 (CAI plus $150 deletes that will stink but will be tuned for O2)...same theoretical HP gained on 1/3 price.

From ARH.....notice that they do not mention tuning BEFORE headers which means essentially a high flow cat install, just headers WITHOUT a tune.

[Destructo09]

I certainly don't dispute that as far as dollar per HP goes, headers aren't a great value. I'm just trying to add into the convo here and trying to be somewhat scientific lol. I'm honestly curious myself.

I went and found that users post after he got tuned: http://www.camaro5.com/forums/showthread.php?t=171491

402 RWHP after a tune, so he's still a good 15 HP lower than what most long tube guys wind up with after a tune.

However, this honestly concludes what your trying to say which. Are headers worth it if you spend 1200 bucks on them and only gain 15HP? I think it really just boils down to a personal question and if you have the money to burn, why not? Is it the best decision who knows, but when it comes down to modifying cars it's very rarely a financially sound decision.

[ClawSS]

If I was a top fuel dragster, $100 / hp might be cheap.

[Destructo09]

So, just don't buy headers then? lol