Is it still The Beast for East, or has someone else taken over?

Any pictures and specifications would be great.

if you do 3" all the way you wont go wrong in any aspect stock or uprated tubs

I see the 3inch down pipes and 3inch decat are off the self but cant seen to find a 3inch cat back system

when we car talking 3 inch we are talking a dual system ? not a single 3 inch from the cat back

when we car talking 3 inch we are talking a dual system ? not a single 3 inch from the cat back

 

yes you want a full 3" elbows down pipes and catback

http://www.z1motorsports.com/product_info.php?cPath=6_19&products_id=6723

 

dan here you go

Not it liter the thread but I was of the understanding the cat back isn't that important, by the time it's reached that it's cooled down and condensed a bit. So many chose to run 3" front pipes with 2.5" rears, obviously a 3" full system is a bit loud esp in a world of lower and lower track day decibel allowances. You obviously gain more from a full 3" system but not a lot, happy to be corrected but that's how I understood it.

Not it liter the thread but I was of the understanding the cat back isn't that important, by the time it's reached that it's cooled down and condensed a bit. So many chose to run 3" front pipes with 2.5" rears, obviously a 3" full system is a bit loud esp in a world of lower and lower track day decibel allowances. You obviously gain more from a full 3" system but not a lot, happy to be corrected but that's how I understood it.

its the opposite way round the gases expand as they cool down and require more room the further down the exhaust they go so in therory you need the exhaust a larger diameter the further down the car it goes other wise it expands and has no where to go and creates back pressure choking your turbo and causing less power and slower spool

Oh so if you heat wrap an exhaust it holds the heat in, the gasses cool less and they leave the exhaust faster?

 

Why do gasses expand as they cool? Sounds counter intuitive.

Yeah, very much so. That defies psychics doesn't it?

I've had a quick read up, gasses cool and become more dense and slow down, if the pipe expands they will also slow down. We forget tuning is a proper science after the first round of swapping stuff and get serious. There is also talk about quick exhaust gas using it's momentum away from the closing exhaust valve causing a pocket of low pressure, this low pressure helps draw the next packet of exhaust gas out of the chamber.

Oh so if you heat wrap an exhaust it holds the heat in, the gasses cool less and they leave the exhaust faster?

 

Why do gasses expand as they cool? Sounds counter intuitive.

you are correct thats why they spool faster when manifolds and turbos are wrapped exhaust also hence heat wrap exsists

 

think about a pond as exhaust gases are techincaly a liquid form with fuel and so in them when it freezes the water becomes ice and expands same principal applies here as they cool down they expand

in non turbo tuning this applies in turbos the want no back pressure so you want them to exit as soon as possible

Interesting stuff, weird how things work sometimes. 3" systems do sound awesome in any event.

I am going to start a new thread, meet me over there guys :-)

Interesting stuff, weird how things work sometimes. 3" systems do sound awesome in any event.

a 3" exhaust dosent have to be noisey its only the size of the silencer around it that dictates the db level

How come Bob is in 2nd and 3rd place? Are these his 2 separate cars? If not and its just the one, then surely it should just be 2nd place with the more up to date number. Otherwise 1 person could take up the whole top 10 every time they get a new mod and have another mapping session lol

Maybe a mod could move this stuff to a new thread, so we can discuss this interesting topic without making a mess :D

Bob has a run with and without nitrous. Think is said it here or in another similar thread that 3" cat back makes 10-20hp at the top end of 700+ car based on testing in the US, the real benefit is the downpipes and earlier part of the decat

Crikey, top 5.... didnt realise that!

 

Will be interesting to see how close the next round of mods will get me to Bobs Non Nitro numbers.

I've had a quick read up, gasses cool and become more dense and slow down, if the pipe expands they will also slow down. We forget tuning is a proper science after the first round of swapping stuff and get serious. There is also talk about quick exhaust gas using it's momentum away from the closing exhaust valve causing a pocket of low pressure, this low pressure helps draw the next packet of exhaust gas out of the chamber.

 

That's why sometimes you get boost spikes on cold days. Cooler air is more dense so your car intakes are increased. This is how I blew a turbo on one of my old cars.

Yeah I know, Silverline had said that gas expands as it cools "like water expands when it freezes". I was unsure about that so gave it a google. Fascinating stuff :) The conversation went over to a thread called exhaust tuning, me bolt and silverline had a good long chat.