maxispeed

So theres a hole in my exhaust by my muffler which is getting fumes into my car when i have the heat on. I need to get it fixed but instead of just fixing it and have a stock exhaust, I figured I'd put that money towards an aftermarket exhaust. I read something here on the org about exhausts and it stated that 2.5 is the smallest to use when turboed (something I plan to do). I was wondering if i got the 2.5 on w/o a turbo would it kill my torque. I know in the article i read, it stated that the whole back pressure thing is a myth, but Ive talked to other people and they said it is needed. So should I go with 2.25 or 2.5?

95Maxed

I slapped on my 2.5 inch catback and i felt a small increase in power. It shouldnt kill torque

ChrisMan287

iTrader: (34)

Go with 2.5 " since I haven't seen any 2.25" aftermarket catbacks. I recall them being made back in the day though by OBX.

schmellyfart

iTrader: (46)

My old Pacesetter exhaust is 2.25".

aic96max

iTrader: (12)

spend once, go 3" (:

97 4thgen

I don't mean the thread jack but I have similar problem but my hole is in front of my cats and after the cats is gone I want ss exhause but I hear the car runs best with all 3 cats on without a turbo and I'm planing on going all motor what's your idea on that

kel456

go buy aluminized steel oem direct fit replacement exhaust and be done with it. after the cat will run you around 150 or maybe 175 with free shipping without special muffler tip of course plus nuts and gaskets. once you start with the ss stuff it's going to cost you. WS ypipe without the pre cats will give a slight increase in hp on dyno but everyday driving does not matter much because to take advantage of that hp is around 4k rpm. ypipe oem direct fit with 2 pre cats replacement will run round 350 plus 2 nuts and 3 gaskets with pipe hanging pole to the rubber is attached. it only comes in aluminized steel. if noise is a concern then stick with oem direct fit replacement. 3" is for turbo it doesn't do anything if there is no blower installed. save that money for more part replacement to come for our old 4th gen max.

aic96max

iTrader: (12)

why pay 350 for an aluminized oem y pipe?? pshhh i got a custom made 3
inch ss made for less than that, and i didnt need to turn one nut!!!

if oem quite is what you want. id say get a ss y pipe they are cheap on here like waspeed, seen them for less than 100 bucks, hell i have one that has a slight mod that i would sell for 50 bucks lol and then get an ebay ss catback , but trash the muffler bc its too loud and get a real greddy and then it will be more toned down. if oem is what you want then yeah, stick to oem but know the sluminized stuff will rust out again.

and if performance is what you want, then no, 3 inch is not just for the turbo or sc guys, you will see gains even na. guaranteed. get others opinions, but its all upto what you want. oem no noise, or performance. if you do go with a 3 inch, put a resonator and a big 22 inch muffler.

JSMax

iTrader: (13)

Slight increase in power with a warpspeed ypipe? Under 4000 rpm sure. But over that it is awesome and more than makes up for the lack I the lower end. Op spend once and do it right. Cattman I believe has a intrest thread on 3" someplace on here

deezo

iTrader: (3)

Go 3" and lose power unless you're boosted.


To the OP, if you go aftermarket, just get a 2.5".

maxispeed

So I should just go with the 3in or 2.5? If i do go 3in what should i put onto it so it doesnt sound ricey? i dont feel like disrupting conversations 1mile away haha. And while were talking exhaust, after the cat-back is there any headers you guys suggest?

deezo

iTrader: (3)

Do NOT buy a 3" exhaust on your NA car. If you're going to boost it, then it's ok. Go with the 2.5 being that you're going to spend the same or more for the stock 2.25" catback.

98nismomax

iTrader: (5)

2.5 will work just fine and when you start boosting your car then get the 3 inch.

schmellyfart

iTrader: (46)

I felt gains all through the powerband with my 3" exhaust. The Wizard and Aackshun have also reported feeling gains. All cars N/A.

96MaXiclean

iTrader: (6)

2.5

deezo

iTrader: (3)

Butt Dynos don't prove anything.


We've been thru this argument before.

95Maxed

Huh? How can a dyno not prove an increase in performance?

wirelessdude04

iTrader: (24)

go with 2 1/2 for N/A 3 inch on N/A might be too crazy

deezo

iTrader: (3)

I said "Butt" Dynos.

mista0406

iTrader: (22)

Go 3" let that bish breathe!!!!!

95Maxed

meaning a mustang dyno or dynojet?

aackshun

iTrader: (3)

Really now? Making bold statements such as that means you have solid dyno proof showing where the 3" losses are, if so, I'd like to see it, then I'll shutup and say I do not know what I'm talking about.

Till then your points are just as valid as butt dynos.

If you want to split dyno cost 50/50 I will find a 2.5" system in houston and have some FACTUAL evidence so these myths can stop creeping around.

Now if you had included an... "IMO or an "I think" in those statements, then fine that's your opinion, but PLEASE do not state your opinion as actual facts, which is how they sound above.

My opinion is go 3", the exhaust is relatively high flowing on these cars (intake is a diff story), and backpressure is ALWAYS, ALWAYS bad, if someone says backpressure then I quickly stop listening to what they have to say and nod my head like i am still paying attention. What they really mean is Exhaust Velocity, you want exhaust to escape the block as hot and quickly as possible, so does that mean slap on a 4" exhaust for more power? Hellllll no, you still want to have the gas travel a high velocity, but not trap it, it's all about finding a perfect balance.

Also IMO, the gains from the smaller aftermarket exhaust are just mainly from smoother piping design, and not those silly crush bends the stock system has.

I know my 190/210 is not SAE, but go find any 2.5" bolt on untuned dyno for a 3.0 over 200 ft/lbs please, I'll even count 00VI/MEVI's too.

VisciousMo

iTrader: (4)

What about a ebay 3inch vs cattman 2.5 inch aackshun. Or the megan 3 inch, I know a local N/A with one

JSMax

iTrader: (13)

His car is boosted.
sorry your wrong.

aic96max

iTrader: (12)

y do people who dont even have 3 inch catbacks, probably never had, even arguing this point ????????? if the most power power is what you want, 3 inch all the way. dont spend countless money on sh8t you will want to upgrade later on, buy once. all the dek na cars out near where im at, 3.0 and 3.5 have seen gains from 3 inch na.

schmellyfart

iTrader: (46)

No need to apologize.
http://forums.maxima.org/7842616-post369.html
http://forums.maxima.org/7803502-post278.html
He has yet to report back as far as gains on the boosted max:
http://forums.maxima.org/7906854-post413.html





I could not agree with you more.

azdevils013

iTrader: (5)

mista0406

iTrader: (22)

definitely some great words of exhaust size wisdom in this thread.

deezo

iTrader: (3)

If you think you gained power by adding a 3" exhaust to your car then so be it. And just because you invested in a 3" exhaust without research the effects of it mated to our VQ's is on you. You don't have to believe what I'm saying here and the fact of the matter is there are many threads on this topic from several years ago so I don't need to prove anything. I've even been in exhaust shops who have also said the same.

Every part of the stock exhaust is free flowing except the Y pipe. I felt the gains from the Y pipe which is 2.5" mated to my stock 2.25 catback. When I went up to the 2.5 catback, there were no gains to be felt. 2.5 is the highest one should go on an NA Max. 3" is for boosted Maximas.

It's funny that I've been on the org since 2000, yet you don't think this has been talked about and laid to rest?

ChrisMan287

iTrader: (34)

Have you seen his dyno thread?

deezo

iTrader: (3)

I mean by a driver adding something to his car and like spark plugs or a 3" exhaust and thinking the car is fast by just driving it. In order to know if you've gained power, you need to put the car on a dyno of some sort and not judge it by the seat of their pants.

deezo

iTrader: (3)

No.

ChrisMan287

iTrader: (34)

Dynojet-173whp/185wtq
Current Modifications:
Bomz SRI
Warpspeed Y-Pipe
?Brand? High Flow Cat
RT UDP
G35 Coupe Rims on Michellin Sport PS2s (235/45/17)
Amsoil 10w30
93 Octane
http://forums.maxima.org/dyno-discus...no-thread.html

Dynojet-190whp/210wtq
Final List:
Bomz SRI
OBX 3.5 Equal Length Headers
Magnaflow high flow cat (2.5 ID)
Cattman 3" Catback
Unorthodox Racing UDP
Amsoil 10w30XL
Napa 80w Gear Oil
G35 Coupe Rims (7.5")
Hankook Optimo's 225/50/17
190,5xx miles on the original motor.
http://forums.maxima.org/7854364-post86.html

There's no way he picked up 17whp and 25wtq from those OBX headers alone..

deezo

iTrader: (3)

Did he do a test with the Y and the 3" catback? I just read thru the thread and didn't see that he did. Maybe most of the gain is from the headers. Back in the day, we didn't have them.

aic96max

iTrader: (12)

+1 i would have to aggree. vq's definitely like to breath

ChrisMan287

iTrader: (34)

I don't think he dyno'd with the Warpspeed y-pipe and 3" catback but I'm not exactly sure. I mean I can definitely see the gains with those headers but not that much of a gain, it just doesn't add up.

aackshun

iTrader: (3)

Deezo, you've been on the org since it's youth, great glad you find reasons to come back and share the expeirience, my interest has changed over the years and landed me here and I have not really looked back to the days when I was first interested in the world of automobiles and modifications.

Now, cattman has only been making 3" catbacks for a few years now and my searches yield almost nothing about a 3" catback on a VQ30... Matter in fact, I remember the EXACT same talks going on for N/A VQ35 guys until a guy put that myth to rest via dynos. Now, if my assumption is correct, me and schmellyfart are the first to have a 3" catback on a N/A VQ30DE, me being the first to have it on a USIM setup.

Deezo, this is where your expiereince here comes into play... I've ran a few googles with no real luck, and as it seems my above assumption is correct, do you remember any one else trying this out on a N/A VQ30DE?????

Anyways, I hope we moved off of that the 3" is too big claim. I mean if you think that then great, I and a few others are just saying otherwise, of course not everyone is going to agree but what everyone must realize is that neither of us have actual hard evidence to support either our claims, the best we can do is state our reasoning and leave the OP to decide.

With just a I/Y/3" I did see immediate gains across the board, the initial throttle response was amazing just leaving the driveway, after some WOT runs and mixed driving, the car really found it's stride and that USIM'd 3rd gear bog that we all know so well was not so evident, that is the biggest butt dyno claim I want to make on that setup. I did attempt to dyno w/ this setup but there was a dyno error.

After the header install though, different car all around, midrange (as noted on the dyno) is really... really... fun!

I could go on and on about the many changes in driving habits and butt dyno recordings but I'm sure my thoughts on the matter are very clear.

To sum it up.

I think that a N/A VQ30DE (USIM/MEVI/00VI/WHATEVER) will benefit with a 3" catback

deezo

iTrader: (3)

I don't recall seeing anyone on the org dynoing the 3" exhaust NA but to be honest, I think we've all come to the conclusion that 3" exhaust don't add more gains than a 2.5" exhaust by other car enthusiasts who have tried it and gained nothing. I've seen people with the GM LS series engines say the same about this topic as well.

I'm not knocking you for trying but my and other recommendations are coming from that time when we really didn't have much to go on here. People were looking for huge gains without spending a lot of money. Anytime we did something to these cars, we always felt gains because we wanted to. Same thing when the MEVI(which I called mine a JPVI because it came straight from Japan instead of the Middle East), people thought it felt more powerful but wen the dynos came, we learn about the mid-range loss and the huge gains over stock in the high RPM ranges.

Hell, it's better for the members anyway if someone comes along and proves us wrong about some things, It give them hope and there is nothing wrong with that at all.

sparks03max

iTrader: (7)

Because you don't recall a 3" vs 2.5" NA dyno on the org doesn't mean it didn't happen. I can direct you to the threads pertaining to said dyno done by merlyn on a I/H/E untuned 3.5 of an aftermarket 2.5" vs a 3".
http://forums.maxima.org/dyno-discus...ft-lbs-10.html
http://forums.maxima.org/6241702-post29.html
http://forums.maxima.org/6249980-post34.html

Also, I gained roughly 1.5 MPH and .15 1/10ths in the 1/8th mile going from a 2.5" to a 3" setup. (best ET and trap from 8.42 and 84.10 to 8.24 and 85.42 at the same track with a worse DA on the faster runs and nearly identical '60 foots)

Now with that evidence shown, there has not been any dyno proof that I know of that the 3.0 will also see such gains. However, I do believe a full bolton and tuned 3.0 (especially with mevi or 00vi) would potentially see benefits.

When it comes to the GM LS series engines, I highly doubt it took them much deliberation to decide that a single 3" will make more power for them than a single 2.5" (the debate i'd find more likely is 3" vs 3.5"). Now when it comes to duals, it may be the case that on the more mild builds a dual 2.5" would turn out better than a dual 3", but in either case there is no reason to compare their results with ours aside from general concepts as there are many factors involved.

maxispeed

@aackshun, what is a USIM?

And I appreciate everybodys input on this topic, it has helped me alot. I believe I will go with the 3" exhaust. Now comes the next question, what kind of muffler should I get because I'll be damned if I drive around ricing it up.

And as for headers, y pipe, and intake. should the intake be 2.5 and the rest be 3? or 2.5 everything except the catback? I have read somethings on here about guys haveing a large intake and it robbing them of power.

And while we are talking about 00VI and MEVI, is it a huge deal to do the swap or should I just save the money?