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Forum namePerformance/Engine
Topic subjectheaders hp question
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=64811
64811, headers hp question
Posted by oRACLe063, Dec-16-03 10:01 AM
i know this has been discussed before a long time ago ... but didnt the greddy headers only make .5 hp for our cars? the only real bottleneck in our stock system was the intake part of it from what i remember ... annyone have any imput on this
64812, RE: headers hp question
Posted by daniel992gnt, Dec-16-03 10:04 AM
i got that pacestter header and it made a good enough differece to me. and looks better than that heat shield
64814, RE: headers hp question
Posted by DR1665, Dec-16-03 10:08 AM
LOL.

I think pretty much any header will give us about the same gains man. I'm pretty sure I remember hearing that the intake manifold was our bottle neck. If you have i/h/e, then it's the only thing really left to deal with really. Why you asking?
64850, RE: headers hp question
Posted by smileysae, Dec-16-03 04:56 PM
If that is the problem, do they make an aftermarket one that will help this? This may be a stupid question, but I'm new to the page and was planning on putting an exhaust and header on. But if they make an intake manifold that will work I might just save up and buy one of those too. Like I said, may be a dumb question, but I'm new to the page, take it easy on me :shrug
64873, RE: headers hp question
Posted by Michael_97RS, Dec-17-03 04:10 AM
AAAAAAAAAHHHHHHHHH!!! Okay, here we go again...

A properly designed header will always help your engine!

Exhaust gases move into your ehaust system in puses as you move through the power stroes of the engine. A properly designed header will have equal legnth runners. This will make the xhaust pulses hit the exhust piping at different times. A stock manifold or poorly designed header will have the exhaust pulses running into each other, interupting flow. When the pulses hit the exhaust in series, they actually pull the next exhaust pulse along quicker, this is the scavanging effect, that improves power throughout the power band, with longer runners designed in you get a nice low end gain this way. There are other things of course to concider such as primary length, diameter and collector design, also material/coatings.

Anyway, while the stupid dyno chart may have only showed one or two horse power. No one has talked about the power curve. Which I'd bet shows improvement throughout the rpm range. Study Thermodynamics and Fluid Dynamics for a good understanding of why exhaust gases do what they do.



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64880, RE: headers hp question
Posted by JWoodley, Dec-17-03 05:47 AM
An increase is an increase. You'll enjoy what it gives you. The powerband is alot smoother, plus it looks great under the hood. :thumbsup
64882, RE: headers hp question
Posted by oRACLe063, Dec-17-03 07:04 AM
i was arguing with someone on the effects of the header. i am a firm beliver in having things run more efficently. i just cant see spending 500 dollars such minimal gains. i wont go obx or pacesetter ... i would want the greddy header. and mike i remember that import tuner with the 2gnt on the dyno i still have it and if memory served correctly it was almost a carbon copy of stock save the 4000 rpm gain. but of course thats import tuner
64923, RE: headers hp question
Posted by Kahn, Dec-18-03 01:36 AM
Well -- being one of the 2gnts that had one (thanks to Stan)... You won't see any SUPER DUPER gains.. Oracle - I am pretty familiar with your car... I would think that with the already large exhaust you aren't truly putting down enough power to need a header. I think you would be better off investing that money in the modern performance throttle body.

If you are expecting that you will put the header in and be thrown back in your seat or all of the sudden at certain RPMs you will get a surge in power... it aint gonna happen.

Too bad my car got scrapped (or some insurance adjusters kid has it) with all my mods, ported head, headers, underdrive pulley, lowering springs and shocks..etc... Oh well.. got my GTI instead -- and there is a HUGE surge of power -- oh about 3000 rpms... comes with a high pitched whistle :-)

64934, RE: headers hp question
Posted by Amish_Eclipse, Dec-18-03 09:12 AM
alright here's a small spin on this. what about a motor with higher compression pistons? would a header benefit that motor a little more with the exhaust gases being hotter and wanting to expand more wouldn't it be better to upgrade the flow of the exh. manifold?
64939, RE: headers hp question
Posted by Michael_97RS, Dec-18-03 10:33 AM
Certainly.



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