fortysixandtwo

Quote:
Originally Posted by Matthew951
Would this have to do with the air cooling off? Expanding a little when it cools down? If thats the theory behind it. It would make perfect sense, but it you go to big, to fast, wouldnt it hurt the performance also?

Do you mean the exhaust tubing is expanded because the exhaust gasses are cooling? Gasses will contract as they cool. The theory is that the cooler denser gas is more difficult to move, so the tubing diamiter is increased to maintain a closer to equal back pressure.

aeronautica86

yeah you're right, I'm a dumba$$ - this is what happens when a philosophy major tries to figure out physics....

Swedish Meatball

Please post more pictures of your custom exhausts people! I'm going to try to put together an exhaust this winter so I need all the tips and tricks I can possible get! Doesn't anyone have a complete list of bends that are used or something?

Ahmet

The coupler on your exhaust does not appear to be a factory part.

Aside from that, it's also not stainless, I would say this pretty much rules out that it's "factory". It's not unusual for aftermarket parts to be stamped with a factory, or "factory like" part #. What you want to look for is a symbol indicating the originality of that part, by the #, if you care about that.
Ahmet

Ahmet

If you want to give me that part #, I can run it in the system and see what it's identified as, I imagine it'd be interesting.
Ahmet

daniel951

that pic of that exhaust is exactly how i have mine. Took it a exhaust shop and had them make all of that for around 80 bucks not including the muffler

Duke

If you're doing a step-up diameter exhaust, put the wg tie-in just at, or after, one of the step-ups.

That way you reduce the somewhat major bottleneck when the wg exhaust pulses collide with the ones from the turbo.

Skunk Workz

Hot gas expanding when cooling ?? Edit: ...just read all the threads....

awilson40

Must be one of those 'alternate universe physics' things you hear about on Star Trek

Eyal 951

hahaha, thats what I thought, didnt want to post incase i was wrong.

jwlester

LOL...I think ya'll had a bunch of people scratching their heads. I started thinking I was crazy and went to pull out my fluid dynamics books from college.

I dont know how much it would help on our cars but I"m told by some of my engineering buddies that ended up in NASCAR that they do this to increase torque and that it is quite successful. I believe when they do it is more gradually done than stepped. Promising theoretically though. Anyone have any numbers to tell the difference between this and a straight 3inch or 4inch?

Kool

How do you know where to put the steps?

shortyboy

well,i did some research and found out that i could make the 951 exhaust with 5-45 degree mandrel bent pipes as you can see in the picture,i think we can get away with only using 45 degree bends.i checked out SFRs and Lindseys exhaust systems and they also used some begree between 45 and 90.the green lines in the picture is to give you an idea on how im going to route the pipes.im going to get some 3" exhaust piping and 5-45 degree mandrel bends from summit racing,i wont be using a cat or muffler,ill be keeping the rear section of my exhaust system a secret for now,lets just say its going to be real different.from summits prices its $22 for each 45 degree bend,i can get a 3" exhaust piping from a friend for like $30 and i have another friend that'll let me borrow his welding equipment(i forgot what type it was).it might be a few weeks till i actually start it because of the holiday season but when i start ill be sure to keep all of you updated with alot of pictures and write ups.thanx

*ps-should i use exhaust clamps or v-band flanges?im thinking v-band would be an easier route since i wont have to take the pipes in to a shop to get em flared for a slip fit.

MR951

V-bands are kinda pricey. If you're on a budget just go w/ the exhaust clamps.

As far as getting 'em flared, after you have everything cut to size take them to Midas w/ a case of soda/beer and they'll do it for you . I've gone to the one on Dillingham and also the one on Beretania and they hooked me up.

Laust Pedersen

I saw on another thread that you were soliciting pictures of exhaust systems, so here is my modular system. The catalytic converter is a $70 general purpose unit, which can easily be substituted with a test pipe (also shown) when going on the track since V-clamps are used. There are so many mufflers on the market with different looks, different sound, slightly different flow and some very cheap, so a V-clamp was installed in front of the muffler, so I in the future can easily swap out mufflers.
I bought the car with the basic stainless system, without knowing exactly what it was. Is that a Lindsey system?

Laust