01 headers, y-pipe, exhaust options and ?s

[sweed88]

i have an 01 maxima se. i was looking into getting an exhaust for it but every exhaust i find has a small collector. either 2" or 2.5". that seems like a pretty small exhaust for a 3.0l v6. i would think that a 3.0l should have atleast a 3 inch exhaust to flow freely while still keeping good low end. are there any exhausts out there with a 3" collector? also what are the best headers and y-pipe for it? i read a forum which i now cannot find that said warp speed and cattman i think were cheap and not worth the money. also are there any good performance sites for this car. seems to be hard to find many parts for this year.

[MTZI30]

I wouldnt go higher then 2.5", i would think 3 would be way too big and youd lose too much back pressure.

[allensteiner]

2.5" is all you need, it's not a big v8, most turbos have a 2.5" inlet. you should check out the exhaust thread to see what most ppl are running...but that requires a search which you might not be familiar with so here you go: zerothread/234925

for parts check out the ads on the site, the advertisers' marketplace, jwt, injen, stillen, intense etc

[sweed88]

well i was thinking most after market exhausts for 2.0 4 cylinder cars are 2 1/4 to 2 1/2. so lets just say you want a 2 inch on the 2.0 4 cyl. thats an inch for every liter of displacement. therefore 3.0 liter if you do a small aftermarket exhaust should be aleast 3" while still maintaining great bottom end. for an exhaust you don't want back pressure. many people confuse this. the reason for not going to big on an n.a. car exhaust is beacuse of back pulses of exhaust gassesexiting the exhaust ports. the back pulses cause the exhaust gasses to bounce off the walls of the exhaust pipe. if the pipe is to big they bounce to much dont' flow and reduces the velocity of the exhaust. if the pipe is to small it simply becomes restrictive. if its the right size it will cause the gasses to move with alot of velocity decreasing back pressure and boosting power.the size also affects where you will notice the gains. thats why im thinking 3'' seems to be a good size. has anyone used a 3'' on an 01 maxima? how big is the stock exhaust?

[sweed88]

what is the most someone has gottan out of 3.0l na with the 2.5" y pipe?

[maxhopper]

Y-pipes generally add approximately 9hp. This is mostly due to the fact that the y-pipe eliminates the pre cats.

[allensteiner]

the diameter is not such a simple math. semi tractors run exhaust as small as 5" and it's on a 14L engine. i believe the stock max is 2" but i haven't measured mine so not sure. one thing is that going with a 3" exhaust tubing the headers would have to have an increased diameter and that would cause the exhaust gases to cool down too much before exiting which in turn would make the whole system inefficient.

[sweed88]

y would the headers have to have an increased size. arent the common headers found for this care made with 1 and 5/8 tubing for each cylinder? and if it did cool the exhaust gasses down to the point where it slowed the velocity of the exhaust gasses then simply wrapping the headers and y pipe would significantly raise the temp aswell as keeping the heat away from the engine bay and intake.you can't really compare a 12L turbo desiel to a 3.0l gas na. most of the bigger tractor trailers running engines 12L and up have twin 4 or 5inch pipes. has anyone ever had a 3'' exhaust on a maxima NA?

[allensteiner]

y would the headers have to have an increased size. arent the common headers found for this care made with 1 and 5/8 tubing for each cylinder? and if it did cool the exhaust gasses down to the point where it slowed the velocity of the exhaust gasses then simply wrapping the headers and y pipe would significantly raise the temp aswell as keeping the heat away from the engine bay and intake.you can't really compare a 12L turbo desiel to a 3.0l gas na. most of the bigger tractor trailers running engines 12L and up have twin 4 or 5inch pipes. has anyone ever had a 3'' exhaust on a maxima NA?

you're partially right on the semi tractors, it's a straight engine though so stock they run a single exhaust but that depends also on many things ie single or twin turbo etc.

back to the max most guys i've seen under boost run a 2.5" exhaust, haven't seen anyone with a 3"...but they might be out there. also the flange on the stock headers or y pipe is not a 3" diameter - that's what i meant when i said bigger. seems that you're pretty stuck on running 3" so i'd say go for it and maybe you'll get bigger power gains than from an aftermarket 2.5", don't know though because i haven't seen one that did and dyno'd their car.

header wrap is proven to destroy headers over time and as for engine bay heat...i think the designers calculated that into the overall design. as a comparison i have an 05 bonneville na with a lot of room in the engine bay - a lot cooler than the max, larger diameter intake and exhaust, more tq and hp than the max and bigger displacement and the max still pulls a lot stronger and faster. i think that aftermarket exhaust companies went with a 2.5" exhaust for a reason and i would hope that their design is based on research and dyno testing. you should give one of them a call and ask why not 3"?
Modified by allensteiner at 7:16 PM 7/30/2008

[allensteiner]

one more thing before i go to work...the tb is 60 or 62mm which is about 2.5" - maybe that's why 2.5" exhaust?

[sweed88]

good point about the throttle body size. yea i know the wrap decreases the life of the headers. maybe ceramic coat them. since were on the subject which headers and y pipe are the best out there? most of them look pretty similar are there any dyno tests the proove on system to make more power over the other?

thanks for all the information and help. i appreciate it.

[allensteiner]

i bet they're all the same except for the price and name but maybe someone has dyno sheets to prove that cattman y pipe is better than a half priced ebay pipe. i'd say go the cheapest route and have a muffler shop make you the catback and order the headers and y pipe off the internet.

if you look into jwt or vq35 cams and jwt ecu, 00vi or mevi you'll see that these will give you gains you'll feel while driving, exhaust and intake produce gains but they're too small to notice - except for the sound but that's all in the head, not on pavement

[kzoosho]

270whp is the most on a 2.5 inch y pipe. N/A you dont need more than that or you will lose low end. In an N/A app you do want back pressure for scavaging purposes . Im running 3 inch but i am also boosted. My supercharged car is running 2.5 as there is no need for anything larger.

[ae01maxine]

Not sure about 3.0s but this 3.5 gain from a 3" exhaust and its a N/A

http://forums.maxima.org/dyno-....html

[kzoosho]

O he has a 3 inch catback not 3 inch y. so trully he doesnt have 3 inch.

[ae01maxine]

Yes , but he was also asking about doing 3" Exhaust . I just notice Cattman is having a August sell with only a couple of 3" Exhaust available . just an FYI