exactly. id like to go into this with the most knowledge possible about exhausts. from what I gather thus far, my collector size will be the same diameter as the primaries as I will not require the larger collectors our engines or any cross plane crank engine requires to reduce restriction. that said, I also believe I could base the primary diameter off what our engines typically perform well on 1 3/4".... no to decide on primary length which I think I will need to base off what I can do with cylinders 1,2,3,4.... 5,6,7,8, are far enough back where with the proper bends I can get them equal length to the first 4.

what ive also gathered, there is no need at all for an x or h pipe which makes things not necessarily easier all in all but is a relief in the entire thought.

 

The fact that almost everyone that has posted says you shouldn't should be enough...

But its your money, i guess.

The only reason I can imagine why you should build 180 degree headers...

I can't come up with a single good reason, other than as a exercise to say you did, or impress a couple guys on the internet.

You are talking about dumping $4,000 on an exhaust that might be worth 10 hp more than a couple hundred $ headers, and on top of that you are spending a ton of time hacking a car up to fit it...

Drop half of that money on a turbo and you can gain 300 to 700 hp, instead of 10 or 20.
Blow the other half on coke and hookers.

You'll end up with a faster car, better stories, and way more impressed guys on the internet

 

you clearly didn't read the entire thread. a turbo is the most stupid idea for the build of my car. it is going to be a well balanced road course car. turbos up front add weight up front, and turbos will not be smooth power.

you must only be commenting here to test out your typing skills because anything you've said is null and void to the point of the thread.

you can go lay down now.

 

Alright, alright, alright! Sorry guys. Just tryin to help.

So you want 180 headers 'cause they sound sweet. Reason enough. It's better than truck manifolds. (Those match the air flow demand at a steady state, in theory.)

So, what cylinders are you gonna pair in order to get the flat plane sound?
How are you gonna merge the tubes?
Stainless?

The 7K rpm on stock heads, with FLAT torque was a tough goal to hack.

 

"Don't build what you can buy" means don't make a 6-speed manual transmission capable of handling 430 foot pounds if Tremec already makes one. Don't build a 430hp pushrod v8 from billet if you can buy a cast one from GM.

As for 180 headers, the original poster is on the right track by using the tube length from a good 1.75" header. He might want to step to 2" and then to the collector diameter of the mass produced header, probably 3". The rest is fitment and fabrication. The only other way to scavenge is to have normal headers X or Y together as close to the collectors as possible. Look at ARH C6 headers, and how they sound.

 

Where are you coming up with $4000 for some pre-bent exhaust pieces? All of the "cost" would be in the time/labor, but I for one don't factor that in since it is fabricating something i would enjoy doing.

OP I'm really anxious to see how you plan out the pipe routing.

 

Maybe I could have, but I graduated with a Mechanical Engineering degree and have come across "engineers" that I would not hand them a hammer in fear they will put it through their own head. (Not saying MIKE1444 is one of them)

Some people have a lot of book/software smarts but can't apply it to the real world and their world ends when something doesn't work the way they think it should. Other engineers are a good blend of both real world and virtual situations. I like to think I am one of those.

I saw the comments in here as:
-OP wants to try something different and "outside the box" to fabricate
-Some come in here and tell him don't do it because some software said so and or you should buy something off the shelf.

The older I get the more I come to realize that being an "engineer" is based on fundamentals of problem solving utilizing technology and experience to find a solution. The engineering school helps you with understanding the WHY's of physics/dynamics but by no means is the end-all be-all answer. You need to make it in order to prove it.

 

doesn't have to be a hammer, they can do equal damage with a pencil eraser.

+1 well put.

Pre-bent tube would make fab easier, and is a good balance between buying and making.

 

1764
8253

probably use a collector size around the primary size, maybe a bit bigger. 1 3/4-2"
4 into one obliviously and step up to a 2.25 or 2.5. duals.

 

3" collector is too large for this exhaust setup. If using equal length, the need for that large of a collector is pointless, the 180 degree intervals eliminate the jamming effect acquired by the cross plane crank firing order

hes getting $4k from earlier in the thread, I had and exhaust shop quote it. then I followed that with I'm not going that route I'm gonna need to get creative.

I would like to lift the tunnel and merge everything above the bell housing if I stay with the 10 bolt out back(have a guy keeping an eye out for a c5 or c6 irs transaxle and torque tube in case I feel like getting really wild but that's not this topic...).

with no rear seats anymore, I'm lifting the floors and running the exhaust out the sides in front of the rear wheels(like an srt10 viper)

see I'm not an engineer but I have a huge interest in the physics part of it. need to learn a lot more but all of intrigues me and I would like to apply what I can learn to the **** I already now and hopefully pull something out that's wild and efficient.

+2

and yes pre-bent is the route I will end up going.


I'm a ways away from doing this so ive been mainly taking measurements and drawing up plans to do this. when the car is done, I'm assuming ill have $20k into the build without a doubt but I'm also trying to build something that NO ONE has and something that LOOKS, SOUNDS, and PERFORMS better than any bird ever did from the factory.

thanks everyone who supports the madness, everyone who is rolling their eyes at the build and wants to drop negative input and not helpful thoughts, troll somewhere else. you think I don't know I'm F*****G NUTS? Einstein was nuts but no one gives him **** now.

 

Hey, engineers or not, we're gearheads, we're never happy to leave the car alone.

 

that sir, is 100% correct!

 

If this is something you really want, we could all pen something out and you compare the results, along with what a shop quotes you.

That way, we learn from each other depending on who scaled what from where. You never know. If a shop says you need 8" long primaries and all of us end up with lengths between 28 and 36. What would you worry less about spending money on?

 

if you would like to draw something up, youre more than welcome and its a huge help. again, ive never took any physics classes so all my knowledge I'm basing my theories off of are self taught from research in the area. I'm open to answer any questions you may need.

 

when i had my lexus ISF i bought headers that were equal length, I guess the idea behind it was to match exhaust pressure pulses evenly. the engine space in isf's are minimal.

 

Those are not 180 degree (crossover) headers.

Does the ISF have a cross plane crank...?

 

'
I definitely saw something typed here that isn't null and void.

More info on the coke and hookers please.

 

OP,

**** or get off the pot. It's obvious you're not gonna get a decent amount of help here. So step up, start the project and start posting pics of progress. At this point everyone is just babbling about.

 

no thanks.

I have a few things that go in-sync with this or need to be done before this based on the layout of my car in its current state and what else will get done to it.

ive gotten a bit of positive feed-back from a few individuals about this and my mind is made up, it is getting done and I will post pics with progress but the thread may be getting put into another direction first before I can continue on with this.

I'm currently on the lookout for a series of parts that play into this role greatly.

as that comes together you will start to see the progress pics leading into this.

for anyone interested in this when the build takes off, stay subscribed but this thread is going dormant for the time being.

anyone who has helped thank you.

to the others that are only subscribed so they can be an ******* or counter everything said, stay subscribed as well, you guys are amusing and i'll love to see what you have to say upon completion of my bastard project

 

Well, you just made your bed.


I give this project a 20% chance of actually getting finished and documented on here with in the next 12 months.