Exhaust Manifold

mezomaster · Post by **mezomaster** » Tue Mar 06, 2007 5:27 pm

Hi everybody, i have 2004 1.6L Nubira, and i had removed the cat and exhaust filter and changed the back muffler into a leganza one, but it kept making bad noise when i accelerate because the exhaust flow is so rough for only one muffle along the way, so finally i removed it and now i got Jasma-5Zigen and the bad noise is no longer happening and the sound is goood now, but i wanted to change the pipes along the car into a bigger pipes because there are alot of welds in it,so i wanted to know is the best size for the pipes is 2" or 2.5" because i dont want to lose tourqe if i put a very big pipes, and also i wanted to know is there a certain shapes or sizes or lengths for the pipes if i decided to make a header, i mean should all the pipes which comes out of each cylider should be equal length or there is another way of making a header, and also how big should be the pipes size which i use for the header? i will make sure to post pics soon for every process i take in the car, to know your openions.
Thanks everybody and i would be glade if u gave me the best information to get the best results

logikal · Post by **logikal** » Tue Mar 06, 2007 6:12 pm

As for the diameter of your exhaust, that all depends on what your palns are for the car. If you plane on turboing the car I would go with a 2.5" from the headers. If keeping NA, then 2.25" is enough as long as you dont plan on creating a super high powered motor. As for the exhaust manifold, you can learn a lot of information form this site:

http://clubs.hemmings.com/clubsites/tex ... xhaust.htm

Good luck on the exhaust!

mezomaster · Post by **mezomaster** » Thu Mar 08, 2007 8:24 am

but u sure that 2.25 inches pipes wont lose any torque???

i dont think i will turbocharge the car soon tho

kinkyllama · Post by **kinkyllama** » Thu Mar 08, 2007 6:03 pm

mezomaster wrote:but u sure that 2.25 inches pipes wont lose any torque??? i dont think i will turbocharge the car soon tho

In my opinion I'd go smaller. 2.25 seams about right for my 2.0l motor..so I'd say 2" foryou.

mezomaster · Post by **mezomaster** » Thu May 24, 2007 8:33 pm

so anyone had made any custom headers for the stock 1.6L engine? i am going to do that very soon in the next couple of days and i wanna know the diameters anybody used for the 4 pipes in the headers for the 1.6L engine, would it lose power or torque if i go with large pipes? i will put some sport filter with 2" in and out with the rear jasma muffler which is 2.25" in diameter and the pipes along the way is 2" too

mezomaster · Post by **mezomaster** » Thu May 24, 2007 8:35 pm

also i am a bit worried that the header may cause extra heat near to the fans and the plastic parts

gse_turbo · Post by **gse_turbo** » Thu May 24, 2007 8:55 pm

for a 1.6 i wouldn't go past 1.5" primaries to a 2.5" collector. and thats really important for an all motor application cause you need back pressure for more power and tourque.

garrett

mezomaster · Post by **mezomaster** » Fri May 25, 2007 2:51 pm

THX man, but if i used a 2.5" collector, does it mean that the rest of the pipe diameter along the way must be 2.5" also? or i can decrease the diameter gradually in 15 or 20 cm untill i reach 2" diameter to go on for the rest of the pipe?

mezomaster · Post by **mezomaster** » Fri May 25, 2007 4:30 pm

and for the collector, is there a best order for the primary pipes to go in the collector, or i just can put them at any order, and should the lenght of the primary pipes be equal untill they come to the collector or it doesnt matter? i am worried about the turbulance in flow. and of course the O2 sensor doesnt matter if its located in the collector or in the pipe after the collector, doesnt it? Thx for feeding me back with the suitable info.

gse_turbo · Post by **gse_turbo** » Fri May 25, 2007 4:53 pm

if you build a turbo header or a shorty header i will matter but if you build a long tube header then you will be better off.

if you see most headers in a 4-1 or even a 4-2-1 set up, then #1/#4 and #2/#3 are the same lengths. if you mix up this order there will be turbulance.

i would recommend a 4-2-1 with a 2" collector if that's the exhaulst size you're running. i think you'll have great reuslts.

you can put the O2 just about anywhere, that i suggest is building that header, puting it in place and then find the best spot for clearence, heat and accessablity.

hope it goes well,
garrett

gse_turbo · Post by **gse_turbo** » Fri May 25, 2007 4:54 pm

do you have the flange lined up?

garrett

mezomaster · Post by **mezomaster** » Sat May 26, 2007 12:56 am

No, and thanks alot for this info, i will let u know once i got that work done, and by the way im not turboing it yet, its just a header for a stock 1.6 engine,

mezomaster · Post by **mezomaster** » Sat May 26, 2007 1:03 am

you know? u made me think again about it, i think i will make it be 4-2-1, i like the idea very much although im still a bit worried about loosing any torque or power but i think i just have to try now and see the reaults, i know that the final collector after the 4-2 pipes will be too small to be 2" but i think there is nothing to do about it if i want to reach the maximum torque and power

mezomaster · Post by **mezomaster** » Sat May 26, 2007 1:08 am

by the way, what about the intake manifold too?? can i custom make anything about it to have more power? i know its 1.6L only and i know its not a V8 engine, but why dont i try to reach the maximum power from this stock engine by doing different things? what do i need to care about when i try to make a custom intake manifold? anyone made this before?? and for the throttle body, do i need to custom it too to make the inlet opening wider? and if i do, how can i install the sensors from the stock throttle into the custom one?? i know i am asking alot, but thats me, i like to make sure about everything cuz i hate when it doesnt work after alot of effort LOL. THANKS GUYS, specially GSE TURBO...lol

gse_turbo · Post by **gse_turbo** » Sat May 26, 2007 4:52 pm

THANKS FOR THE KNOD!!

i think someone has done one before but not sure who.

there are two types of intake manifolds that you could design after. and the most common (and my least favorite) is the 'log' style.
http://cgi.ebay.com/ebaymotors/OBX-AIR- ... 3384QQrdZ1
it's a good manifold if you plan to stay all motor because the log fills with air and the motor sucks that air into the primaries and into the motor.
this is not a good design what you are forcing the air into tha motor.
in my opinion you should always with force indution in mind. the the clear option is using an equal length turbo header style so the you're forcing the same amount of air to each cylinder.
http://cgi.ebay.com/ebaymotors/ws/eBayI ... 8918&index
if you we'er to buy or build something like this just make sure where the primaries come together is smooth.

the T/B is up to you. you could build with the leganza T/B in mind or you could build for the most popular application like honda so that you have a lot of options for size.

if you have one made buy a good tig welder then they should be able to add all the fittings needed for injector, sensors and vaccuum.

hope this is what you were wanting to get.

garrett