OBX headers don't look like equal length
 

OBX headers don't look like equal length headers, do they still flow better than stock?

Anything flows better than stock. I bet even that SSautochrome crap does. Equal length isn't magic for flow, either.

Dynos with obx show same numbers as cattman with basic boltons.

obx, ssautochrome, all the same sh1t. most of the power comes from deleting that awful contraption that we call a y-pipe with its precats and awkward bends.

Any opinion of yours from here on out is null and void.

It isn't. I've dyno'd countless mustang 5.0's back in the day. Never a clear winner either way. It's very mod dependant, and if you run a power adder, it a moot subject.

I run the el cheapo 129.00 dollar headers on my 02. Considerable difference in manifold exit diameter, and fuel trims all went positive. So yeah, even the cheapies make a difference. I youre not going all out N/A, it is well worth the 150 dollar investment.

For the most part he is right. If we were talking about a longitudinally mounted motor then what he is saying is pretty much BS, but for a transverse mounted V6.....Equal length is nice but the huge bends in Y pipe to get them equal length can out weigh the benefits of just having them unequal and taking the shortest path to the tail pipe. Especially when i look at the OBX design tbh if i got them it would be for sound not because they out perform everything else because they dont.

Hi guys I have a question,on my 2003 should I do headers or not(it's my daily)I didn't know how will these cars do with headers and they've been daily too?My cats are gutted already!

Headers are kind of pricey to buy and even more if you have to pay to get them installed. If you got a car in good shape and want to get into performance, sure, but most people on here find the gutted cats already good enough.

Ok thanks Cotozic,yeah the car feels pretty good-but I was just getting the more hp itch��

Jesus Cotozic, 660cc injectors?

back on topic ..
Headers don't seem to be readily available much these days any more.

I DD mine with headers, have since 2004 and 130k ago. Gained about 20 hp with that as the only mod (stock airbox and everything else). Added a GAB and got another 10 or so on top of them. If you could find them, get 'em.

Also, this was covered a helluva long time ago, we refer to them as "equal length" but like crusher said, with this transversely mounted V6, never going to get true equal length long tubes like they need to be.

They do outperform everything else... But nvm what do I know? Only the science behind exhaust agrees with me, and pretty much every manufacturer almost goes out of their way to make an equal length (in terms of exhaust pulses, merging two banks) exhaust (except for some really chitty motors) so I'm most likely wrong.

The aftermarket OBXs have a Y pipe but, not having built in pre cats is probably where the flows come from.

I do NOT necessarily subscribe to the theory that just because it's after market it flow better, there are some cars out there that have decent headers but, i think the smoking gun here is deletion of the pre cats.

Equal length headers aren't so much about flow but, equalized exhaust pressure/pulse and whosa-ma-whats-its and stuff like, that i haven't read about in 2 or 3 years. There is a lot more to an exhaust than just raw flow. Especially if you want to delete the resonator and NOT have droning. (having your cake and eating it to)

However that plays both ways specially with the comments regarding transverse engine setups vs space.


Does ANYONE know how much a ***** it is to install an OBX system with out dropping the engine or is it not possible?

I was thinking of dropping the engine to do the exhaust trans and timing chain all at once.

for whats it's worth i'm looking at doing OBE header kit with a full cat delete/punch and a resonator delete, basically straight pipe with a muffler and then get the ECU reprogramed. Getting the ECU reprogramed will be a whole new thing of research.

You are talking about matching exhaust pulses which is all fine and dandy but exhaust gas velocity is most important. And making the exhaust take more bends and angles, especially the sharp 90 bend in the OBX design. Well now we are just increasing back pressure. Isn't that what we are trying to reduce with equal length headers? And here is what does it. Even when testing equal vs unequal the results are around 1-2hp difference going either way. I just saw a mustang down with unequal length shorty headers making MORE power than the equal length shorties. In any case most of the exhaust pros say it is the collector and the size of primaries that really make the difference not them being equal vs unequal.

That said if we were talking about a car that revved to the moon and back(+9000rpm), you want equal length. A bolt on VQ on the other hand? Just....it doesn't matter as long as you are getting rid of that ugly contraption called a y-pipe.

so the OBXes might just be a pile of crap then or not?

It is possible but just be prepared for some difficult bolts. the hardest part of header install is getting the heat shield off the stock manifold. My trick was once unbolted(which unbolting it is another PITA) angle it down, remove all wires or anything that can get damaged easily. Take my jack handle and a 5lbs mallet and beat the b1tch till it fell to the ground.

The only hard part with the OBX design was on the 4th gens and their crossmembers needing to be notched to fit the header, im not sure if that applies to the 5th gen as well but it could.

Not really, they are better than anything else we have off the shelf outside of Cattman and hotshot stuff. the best thing it seems to do these days is to buy the altima OBX headers then have a custom y-pipe built for them. Personally i just bought the ebay shorties and y-pipe and called it a day. i could careless about it because for the maybe 5hp everybody else will gain over me i will have a much easier time installing sh1t.

Here is what it has come down to these days. Due to the lack of a market in the maxima world nobody really makes headers for these cars so anything that you buy brand new is going to need some modification to fit. The ebay route is usually the best and cheapest, then finding a local exhuast shop to fab something up for you for around $150 will get you the best performance, you will then be able to choose what size piping you want to run. IIRC the VQ looses power with a 3" y-pipe, so a 2.5 or 2.75. then into a 3" catback for 3.5 guys maybe even 3.0s.

I'm running a 3.0. I'm the odd man out, can't seem to find any silicone radiator hoses or all aluminum rads. Are you saying i should ditch the ebay OBX y pipe cause i i think i can get some Manzos for cheap withOUT the y pipe.

I have 3.0 headers on my 3.5 :gotme:

:soapbox: HEATHEN!!! YOU MUST BE BURNED AT THE STAKE FOR YOUR BLASPHEMOUS WITCHCRAFT!!!! :soapbox:





:nervous: or something like that.....

my understanding is the OBX eBay headers come with 2" y pipe? no?

does that mean ditch the eBay Y pipe that comes with them? cause i can get a set of Manzos for like $100 shipped sans Y pipe.

I have the ones that appear to be equal length on my 5.7 swap. Don't worry, they make plenty of power with that wimpy diameter. I can keep up with my friend's 3KGT VR4 that's about maxed out on stock turbos.

I still need 4" intake, injectors and tune.

So guys what does this obx headers requires to be installed and run in our 5,5 gens(as far as modding stuff,retunes etc)and I am sorry if this has been covered before!
Thanks guys.

I have cattman headers ypipe so I may have had a little easier then you on an install. If I were you and I'm installing the headers, I would remove cross member it's an easy enough job. While you're at it check the mounts replace as needed. Next remove radiator and fans. It would be a good time for a rad flush. You may think I'm crazy but with that stuff out of your way the header removal and install is much easier. With that stuff out of your way you have plenty of room and your knuckles will appreciate it.

Now if you're really going to yank the motor to do all the other stuff then obviously that would be the time to do it. Question is are you really going to yank the motor?

You don't need to pull the engine, but believe me, it's a pain in the ***. When you do them, make sure you set aside a couple days. I honestly took about 15 or so hours of hands on time to do it. In the process, you'll most likely have to do some trimming. I had to trim quite a bit off my rear motor mount bracket. Also, either have a breaker bar or good quality air tools. I used the handle from the end of my jack as a breaker and pushed with my legs as hard as I could just to remove the bolts on the rear precat. And as far as the rear manifold goes, you can't see anything back there, so you'll want some sort of mirror to use and you'll just have to go by feel. There are a lot of useful threads on this forum on the subject as well.

My cats are gutted and I was just looking at this thread about this obx headers and that's why I've been wondering my self and thinking should I do this to my car or not,and also I keep reading on some members somethings about +2 degrees timing or something-what's all that is about(some sort of aftermarket retune/reflash)?

i think in 15 hours we could yank and reinstall the motor, would make a timing chain kit easier especially with 170K miles on the clock. also probably gonna get an i35 with LSD trans and shift kit if i can keep costs down below $800 for the trans and kit, i'd be like new car with new struts i just got.

Sam, it's about combination of little and big mods that add up.

Chains and guides should never wear out on this gen. I guess if the oil is never changed, then the guides could wear :laugh:

All of the one's I've seen looked brand new (including one of mine at 181K).

So does I35 has a Lsd Trans and they will fit our cars without mods?Or is it just some of the I35 cars that came with Lsd,I know the motors are the same but I don't know about the trany if is the same as the Maximas

Yeah I'm learning a lot about these cars,thanks for the awesome members on the forum!

I wouldnt bother with pulling the motor out just to do headers.

My chain stretched so it is possible for the chain to wear. But a VQ35, yea that chain is not going to need servicing unless you really fcuk up.

Says the one who doesn't even have headers and asking if you need to pull the motor to install them.

It's not just the i35 that has lsd. My maxima se came with it and I got a maxima tranny out of junkyard that had it as well. So don't just look for a i35. The infinity trannys at least where I'm located seem to be more expensive than nissan trannys.

Mattx thanks for the info and I do apologize if I do sound like a pain from times to time but o don't know this cars-and how can you identify the tranny if is the Lsd or not(other then having a running car and you go and do a mad burnout lol)

That's what this site is for, to help fellow maxima owners out. You don't have to apologize. When you find a tranny an easy way to tell is by looking in the hole for the cv shafts. If you can see right through it it's a regular tranny if you see a small bar in the center it's lsd. It's very noticeable you just have to look in it that's all.

One other thing I'm not sure what else you would need to do to convert a non lsd to lsd. I think you might need a different tcm and maybe other stuff as well.

wtf timing chain stretched??? bro..... come one bro...

Cool once again thanks Mattx and I wanna do Lsd swap in my maxima but first I need to get it straight about the swap does it just go in and or does it needs anything else in order to function correctly!I will continue to do my search on the Lsd!And yes the forum has some amazing people-I've get my every question answered by one of the seniors in here!!!!!
Thanks guys.

I think you were looking for this


https://cimg2.ibsrv.net/gimg/maxima....bf503117d7.png

I've never heard of unlimited life timing chains. I also don't know how well my car was serviced before my owner ship. i can only assume there is an inspection port to check the stretch with some sort of spec to compare to for measurement/gauge wear.

Who knows about all aluminum rads on 5th gens? :P