:::RHMT::: Real Home Made Turbo

General Category => Hybrid/Tech => Topic started by: PhilStubbs on November 29, 2009, 02:19:02 PM

Title: Header design questions
Post by: PhilStubbs on November 29, 2009, 02:19:02 PM
so, i did some googleing and havent come up with much. i just dropped an LS into my DD eg coupe and i want to try to make it a nice solid DD with some good torque. being a turbo guy i would normally just use a small turbo and call it a day, but simplicity is key here. i want to make a header to promote low end torque and midrange power. i figure the headers i could buy that are reasonably priced are junk and the ones that are expensive are going to be designed for top end power.

so far what i have gathered from my searching is a 4-2-1 design with small tubes, maybe 1.25" and a 2.25" collector. anyone have any input?

i figure a 2.5" short ram intake with a stock LS intake manifold will be good for the intake side. judging by v8 intakes, little to no plenum is best for low end power so an after market manifold with short runners seems like a horrible idea

discuss
Title: Re: Header design questions
Post by: turbob16hatch on November 29, 2009, 03:15:54 PM
stock ls header 4-2-1 cast manifold/header. thats the cheapest and truely best way to go.

I don't know if you have seen ls ports but a 1.25" runner is smaller then the head ports even a 1.5" runner would be smaller. the smallest i would run if designing a header for a ls engine would be 1.65" runners all the way to the collector. But then again i wouldn't do that EVER.

but really just stick with the oem unit it works.

Oh and on the intake manifold, the runner length will play a bigger part in where the powerband comes in then the plenum. i'm pretty sure the plenum is sized to keep from choking an engine at high rpm. so bigger would help up top but hurt down low. Now what i just said is extremely basic as i have not studied intake manifold design to be an expert on the sudject.
Title: Re: Header design questions
Post by: PhilStubbs on November 29, 2009, 06:21:26 PM
I have a spare LS head. I guess I should have measured the ports before even thinking about it. I guess my biggest concern is knowing what works best for my rpm goals.

I think the stock intake will be perfect for my plans. I have done some reading on intake design, just never really cared about headers cause I turbo everything
Title: Re: Header design questions
Post by: turbob16hatch on November 29, 2009, 06:28:46 PM
There is a reason why i don't make n/a headers. If you don't know what your doing you can lose power.
Title: Re: Header design questions
Post by: PhilStubbs on November 29, 2009, 10:02:39 PM
Yea, I know what you mean.  I'm not so concerned with getting it right the first time though. It's something I want to learn. Lots of local guys with weird swaps have asked me to make them headers and luckily none of them have actually come forward with the cash yet since I don't really understand the concept enough.
Title: Re: Header design questions
Post by: onlyflash944 on November 29, 2009, 10:55:25 PM
http://www.amazon.com/Introduction-Internal-Combustion-Engines-Richard/dp/0768004950 (http://www.amazon.com/Introduction-Internal-Combustion-Engines-Richard/dp/0768004950)


TONS of useful information an theory.  has plenty of stuff about exhausts
Title: Re: Header design questions
Post by: Robb on November 29, 2009, 11:23:36 PM
Good writeup JD did on PGMFI.  You gotta be logged in to see it.  It will get you thinking.
 
http://forum.pgmfi.org/viewtopic.php?f=46&t=5148 (http://forum.pgmfi.org/viewtopic.php?f=46&t=5148)
Title: Re: Header design questions
Post by: turbob16hatch on November 30, 2009, 01:01:52 AM
well i don't have an account over there. So copy paste that shit. or have jd do it.
Title: Re: Header design questions
Post by: 88dx on November 30, 2009, 03:52:10 AM
well i don't have an account over there. So copy paste that shit. or have jd do it.
or spend a second and sign up, tons of good info on that site  :yes:
Title: Re: Header design questions
Post by: turbob16hatch on November 30, 2009, 03:54:48 AM
It won't let me for some reason. idk it's stupid
Title: Re: Header design questions
Post by: chris on November 30, 2009, 04:14:42 AM
I need to start going over to pgmfi more often
Title: Re: Header design questions
Post by: PhilStubbs on November 30, 2009, 08:28:49 AM
how could someone into hondas not be a member on that site? i have been there since 04

thanks for the links. i will check them out