custom exhaust pipes for a peugot 505turbo.

meatwad969 · #1 10-22-2009, 01:02 AM

PLEASE CUT ME SOME SLACK, I AM A CAR NOOB AND MY FRIEND IS SLOWLY LEARNING ME.

now that thats out of the way, my british friend has a 1985 peugot 505turbo in his yard thats missing an engine.

he has a spare zdjl pug engine, and the turbo and intercooler to go along with it. he wants a manual 7tranny(his words, he hasnt explained what a 7 is yet... god i feel ****ing retarded)

he knows exactly what hes doing when it comes to these, hes built a total of 3 pugs so far, but this one is going to be mine, and is next in line to be built.

my question here is: the cast exhaust pipes that mount directly to the engine block. they are all curvy and twisty. i imagine its to cause some sort of backpressure so the engine doesnt breathe too quickly and ceases because there ends up being a lack of air. i know im 99.9% wrong, and feel free to inform me, i would be much obliged.

he wants to custom make(weld) STRAIGHT pipes, and everyone ive asked about this in person kinda looks skeptical and says "id like to see it run for the 2 minutes its going to"

im almost certified in arc welding, so he wants me to weld them. thats no problem. the problem is, i dont want them on my future car if theyre not going to work properly. what the hell should i do? he has the pipes that come stock, and the pipes that need to be welded.

so i come to the auto forum seeking help.

atomicbadgerman · #2 10-22-2009, 01:05 AM

Just straight pipes, no collectors or anything? Why not just run open headers...

http://www.thirdgen.org/techboard/ex...-you-ever.html

read, comprehend. That writeup will tell you just about anything and everything you need to know to fully understand how an exhaust system works.

mossdabomb · #3 10-22-2009, 01:07 AM

ok from what I understand hes going to build you a custom turbo manifold and you're going to weld it?

Is that correct?

meatwad969 · #4 10-22-2009, 01:10 AM

Quote:

Originally Posted by mossdabomb

ok from what I understand hes going to build you a custom turbo manifold and you're going to weld it?

Is that correct?

just about, yes. hes going to be right there when the welding is taking place, so its all kinda him.

ccgprep · #5 10-22-2009, 01:29 AM

straight pipes

meatwad969 · #6 10-22-2009, 01:32 AM

Quote:

Originally Posted by ccgprep

straight pipes

pros/cons? assuming everything is the correct diameter and length, ARE there any cons?( i read the write up and understand it for the most part)

Hammi · #7 10-22-2009, 02:00 AM

So he wants to do straight pipes from the head to the turbo? No curves?

Dake · #8 10-22-2009, 02:04 AM

The con is that it will be loud, possibly illegal in your area.

Everything else is a pro.

meatwad969 · #9 10-22-2009, 02:11 AM

Quote:

Originally Posted by Hammi

So he wants to do straight pipes from the head to the turbo? No curves?

i believe so

Quote:

Originally Posted by Dake

The con is that it will be loud, possibly illegal in your area.

Everything else is a pro.

and a muffler would defeat the whole purpose, wudnt it?

Hammi · #10 10-22-2009, 02:16 AM

if you're doing straight pipes from the head to the turbo that's stupid because it will flow the best with the pipes each leaving the head at 90* to the head and then entering the turbo at 90* to the hot side flange.

If he's talking about straight pipes after the turbo, then Dake is right on.

Dake · #11 10-23-2009, 01:30 AM

Quote:

Originally Posted by meatwad969

and a muffler would defeat the whole purpose, wudnt it?

Depends on the muffler, but It's more or less the same story. A muffler that flows well will *typically* be louder than one that does not flow well.

That said, if you are driving this car on the streets, get a muffler.

meatwad969 · #12 10-23-2009, 01:51 AM

Quote:

Originally Posted by Hammi

if you're doing straight pipes from the head to the turbo that's stupid because it will flow the best with the pipes each leaving the head at 90* to the head and then entering the turbo at 90* to the hot side flange.

If he's talking about straight pipes after the turbo, then Dake is right on.

i saw the headers (again) today, and he's talking about equal lenth pipes(either straight or not) going through the turbo. the actual exhaust pipe after the turbo he said will come later, hes going to purchase an aftermarket one rather than bother with making somethign that big...

thanks for all the help guys. i guess we'll just see how this plays out lol