Exhaust Set-ups and pics

it has to be 300mm behind the most rearward opening window and also has to align with bodywork, so you can dump it before the diff in a ute as long as its poking out the side, on a sedan/wagon has to exit behind the rear wheel to the side or rear. plus having it dumped under the car makes cruising enoying as the car vibrates and resonates the noise which is ok for show car but not your daily

 

To let it breath

carbie what carbie sir

 

Yea, but thats like shooting a sparrow with a shotgun.

Not saying thats bad.....

 

U aint going to put a restrictive exhaust system on a 500hp + engine r u

carbie what carbie sir

 

The majority of 253 and 308's are running twin 2 1/2" because they sound good. Nothing to do with flow.

What you quoted above though is correct. The best exhaust is no exhaust. The sole purpose of an exhaust is to quieten the car, nothing else.

Have you thought about a pressure wave termination box? The engine sees that as the end of the collector and as a result, whatever you fit after that is irrelevant. Typically, the formula for working out how big the box needs to be is 8 x the capacity of 1 cylinder, so on a V8, typically the capacity of the engine. There are quite a few good articles on the net explaining how they work. I will be fitting one to my Rangie when the new engine goes in. More of a try it and see sort of thing.

 

It's basically just a muffler that is empty inside. Twin in and out. It is capacity in cubes/litres however you want to say it. For a 355 cui engine, roughly 5.8L, you would need a box that is 23cm wide, 10cm high and 25 cm long. This box has a capacity of 5.75L.

It's purpose, as it's name implies, is to terminate the pressure waves coming out of the headers. The engine sees it as the end of the collectors as that is where the pressure wave exits. It hits the box and dissipates as a pressure wave, but the exhaust gas that is already inside the box gets pushed out without affecting back pressure at all. With a normal style exhaust, you need the correct size to keep velocity up, with a PWTB, you don't. The only thing you need to do is make sure the exiting pipe is as big or bigger than the inlets. The exhaust after the PWTB is only there to direct the gases where you want them. It will still be loud without any sort of muffling, so you will still need mufflers in the pipes after the box.

 

just dynoed a carb 304 stroked to 6L YT heads single plane mani 750 demon and big hydraulic cam max power through dual 2,5 to single 3" 257rwkw @6000rpm needs solid cam and better exhaust and some 4 into 1 headers triY's sound **** LOL

 

Hey mate, sorry for late reply, I've been in sydney for 3nights.
I am still deciding on rear exhaust setup for mine. single pipe to the tail will be lighter, but twin pipe will take up less height.

Thickness: I thought twin 2.25" would be too small, but maybe twin 2.5" would be too big. twin 2.5" with 2mm walls gives me a slightly smaller internal than what twin 2.5" with 1.6mm walls would. Plus I'm pretty sure my exhaust man had a really good reason behind it also, I can't remember what it was though. It could be strength, or less drone, or less reverberation.

 

Interesting thread.
After I re-powered my VX Clubby from a 5.7 LS1 to a crate 6L LS2, I decided to go with Di Filipo system. Have been stoked with the performance and sound. It sounds nice and sleepy till you nail it.

Before the headers were HPC coated.



Headers done.

 

Here are some pics of a VH I saw at the Speedshow in auckland over the weekend. Dont know the size.





Whats the purpose of the joiner pipe that links the left exhaust to the right exhaust?

I was thinking of twin pipes through twin resonators into a single joiner with a three chamber baffleless mufler then over the diff and out (possible nother resonator to aid quieting the exhaust)

Q

 

Without wanting to sound like a know all.
That joiner pipe is very important. It's called a balance pipe. It helps equal the pressure between both banks of 4 cylinders. Without it it sounds and performs like ****. I learnt the hard way finding this out.
Nice system!

 

the dyno operator was impressed but high comp and on pump gas with full exhaust thats all she wrote.its made 560hp on an engine dyno open headered on race fuel but it had nearly 10 degrees more advance with good fuel

 

Yes and no. It is called a balance pipe, but it's more to do with the Helmholtz effect. It takes away the raspy note. It does balance the pressure in a sense, but not the way you may think. The firing order of the V8 is not sequential, two cylinders on each side fire after one another, 8 and 4, 3 and 1. This sends uneven pressure waves down each side, so a balance pipe is added up the front dissipate the two pulses that are close to each other on each bank.

You are correct in saying it affects performance without one, but only in the low to mid range, high revs it makes no difference.

Not that I'm aware of. I can custom make a set, but I need the car.

 

I quoted a set of 4-1's on a VN 5.0L about 6 months ago, $1200.

Chevs do a similar thing though, 8 and 4, 5 and 7. Ford Cleveland has 3 sets of same side firing, 1-3, 2-6, 4-8. The Hemi V8's were the same as Chev.

It's what gives them their lumpy sound. It's what also makes a set of 4-1 "tuned" length headers not so "tuned" length. True tuned length sequential pulse headers are a cross over style that put sequential pulses left-right-left-right. Not practical on a street car though. They also sound like ****.

 

the 2 best sounding V8's I have had were fords but i think it had more to do with exhaust shape.
first one was a 302windsor with a single turbo, so 1 bank went straight into the turbo and the other ran around the front then into the turbo then a 3.5in single system which sounded like a WRX on steroids
second was a hot 351 clevo with big 4-1's the the left side went 90deg into the right pipe then into a single flowmaster, the sound was very pulsy (if thats a word) and i loved it