So my dad is building a '92 Civic hatch for a drag car, and he's planning on running a HUGE turbo in the bumper. Well I decided to design a custom header for him so that I could get some more experience with AutoCAD (I've been doing it for 4 years, but any experience helps) and this is my first time messing with 3D Modelling. Check it out and let me know what you think :D
Looks great! but I can only go on aesthetics as I have no experience in building headers.
Same here. I'm trying to find the programming where I can flow test it and make changes accordingly. Thanks for the compliment 
Looks like it will flow well. Good job with the modeling. I assume you will be welding where the cuts are shown. I just got my Pacesetter in the mail and you could convince me thats one of theirs.
Oh really! Now that is a comment that I was not expecting. And yes, where you see the lines is where the welds would be.
From my admittedly unqualified examination:
Just trying to be helpful. Take luck and care!
Completely understandable 
1. I did that, because I wanted cylinders 3&4 to run parallel into the collecter. SO in order to do that I had to snake it around a little.
2. The inner diameter of the pipes are 1 5/8", so they are a decent diameter.
3. Yes, I have, they look like they come out far but they are ~8" wide from flange to farthest runner. I also made sure that the runners came away from the flange a couple inches before they start bending so that it's easilly accessible.
Thanks for the questions, you actually made me go back and double check everything lol
instead of going 4 into 1 is there any advantage going 4 into 2 into 1 ?
Play with some pipe cleaners and a rubber band, and you'll see how you can reduce some of the bends, and get the pipe lengths better matched. Remember more bends and sharper bends reduce flow.
For example, sweep #4 less far forward, and don't sweep #1 back so quickly. Cant the collector a little outboard and you can eliminate the double bend on #2.
Reverse your collector shape and double the length (roughly) and it will flow better.
Out of curiousity, did you bring the pipes together that way for rotational flow, or is that incidental?
foxtrapper wrote: Remember more bends and sharper bends reduce flow.
why you should AVOID high rise headers if you possible can!
You might look into anti-reversion pipes
N Sperlo wrote: I just got my Pacesetter in the mail and you could convince me thats one of theirs.
NOT a compliment.
BBsGarage wrote: instead of going 4 into 1 is there any advantage going 4 into 2 into 1 ?
I'm not sure, but if there is, I don't mind going back and changing some stuff around.
Why put the turbo so far from the head?
turboHLS30 wrote:BBsGarage wrote: instead of going 4 into 1 is there any advantage going 4 into 2 into 1 ?I'm not sure, but if there is, I don't mind going back and changing some stuff around.
For a turbo setup, not really. Now, if he's using a divided T4 style flange, then you may need to do some re-thinking of how your pulses are going to arrive. (Just as a general statement. The images are blocked at work for me at the moment.)
foxtrapper wrote: Play with some pipe cleaners and a rubber band, and you'll see how you can reduce some of the bends, and get the pipe lengths better matched. Remember more bends and sharper bends reduce flow. For example, sweep #4 less far forward, and don't sweep #1 back so quickly. Cant the collector a little outboard and you can eliminate the double bend on #2. Reverse your collector shape and double the length (roughly) and it will flow better. Out of curiousity, did you bring the pipes together that way for rotational flow, or is that incidental?
I'll definitely give that a try. I'm trying to figure out how to reroute #2 so that it doesn't have that double bend. The pipes came together like that incidentally.
Osterkraut wrote:N Sperlo wrote: I just got my Pacesetter in the mail and you could convince me thats one of theirs.NOT a compliment.
Oh ok lol
z31maniac wrote: Why put the turbo so far from the head?
Just to clear up any confusion, the manifold is a remote mount turbo manifold. It's made to put the turbo forward facing in the front bumper to create a ram air affect on the turbo.
92CelicaHalfTrac wrote:turboHLS30 wrote:For a turbo setup, not really. Now, if he's using a divided T4 style flange, then you may need to do some re-thinking of how your pulses are going to arrive. (Just as a general statement. The images are blocked at work for me at the moment.)BBsGarage wrote: instead of going 4 into 1 is there any advantage going 4 into 2 into 1 ?I'm not sure, but if there is, I don't mind going back and changing some stuff around.
I don't know about that yet, but now that you mentioned it, I will ask my dad about it.
Stole this from this website, "ALL ROUND RACE PERFORMANCE The best exhaust header design for all round race performance would have 1⅝ inch primary pipes that are 32 inches long. These dimensions provide the best power curve over the widest RPM range and would be ideal for rally cars. An exhaust manifold with longer primary pipes would provide better top-end power but with less pulling power, while an exhaust manifold with shorter primary pipes would provide better low-end torque. On a turbocharged engine, an exhaust manifold with short primary pipes will help with acceleration until boost pressure is reached and the turbocharger spools up. Thus, you should have the exhaust manifold tuned to your specific needs during the design stage."
Osterkraut wrote:N Sperlo wrote: I just got my Pacesetter in the mail and you could convince me thats one of theirs.NOT a compliment.
Should have piped in the conversation then. I believe the complaint was corrosion. I'll be taking care of that today. Believe it or not, I WOULD have appreciated your input.
With a turbo FWD car, I don't think you'd want low end torque, because then you'd have to deal with the torque, boost, and in my dad's case, VTEC. So having the longer primaries would result in more MPH on the top end. Am I right?
turboHLS30 wrote: With a turbo FWD car, I don't think you'd want low end torque, because then you'd have to deal with the torque, boost, and in my dad's case, VTEC. So having the longer primaries would result in more MPH on the top end. Am I right?
Depends how nerdy you want to get about it. As far as i'm concerned unless your dad is chasing records, i'd just make something that flows well and let boost do the rest.
In a FWD drag car, low end power is never going to be a problem, because you're going to have a monster turbo on that little B-series and "torque" in the traditional sense is not really on the menu.
When you're talking primaries, are you still talking about exhaust manifold? Or did you switch to intake?
That is definitely true, but I'd still like to eliminate as much wheel spin as possible. We are kinda sorta chasing records, we're trying to show that a little shop can do the same thing that those big shops are doing. We're still talking about the exhaust when we're talking about primaries. The header will definitely be shortened up, because I don't have THAT much room.
turboHLS30 wrote: That is definitely true, but I'd still like to eliminate as much wheel spin as possible. We are kinda sorta chasing records, we're trying to show that a little shop can do the same thing that those big shops are doing. We're still talking about the exhaust when we're talking about primaries. The header will definitely be shortened up, because I don't have THAT much room.
What's the goal(s)?
9.40-9.0 and ~165mph 
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