Justin517 Posted January 19, 2009 Share Posted January 19, 2009 I tail pipe has been clunking against my reciever hitch and I blew out the ripoff "resonatior repair kit" in a few places on my '03 pathy and am finally going to order the stuff to build custom. I would be doing 2.25" or 2.5" mandrel bent to a dual inlet, single 3" outlet muffler in the stock location with (obvioulsy) a 3" tail pipe out the back... probably to the side like the VG pathys had but with slightlu more downward angle... basically to go over the axle imk going to cut a 3" 180° down the center, add a straight piece in the middle and make the rearward "leg" angled to stick out the side a bit. A few quastions: First- I know the VQ likes to breathe, and I hear the thing "hissing" when I get on it because of the puny diameter stock piping, so I think any improvement will be appreciated by the engine, but do you think I should go with 2.25" or 2.5" the price difference is negligeable and there seems to be a decent amount of room to fit it in there. Second- do you think 3" for after the muffler would be big enough? I could get 4" but each 180° bend is $10 more ($26 vs $16) and I'm not sure if I could get a muffler (atleast not for cheap) witha 4" outlet. I was also considering maybe doing 2.5" dual... not out both sides, they would exit nect to eachother on the passenger side... it would be a bit more expensive but probably sound pretty cool, ahve a larger choice of mufflers, and with an offset muffler I migth not need to do much for the tail pipe, could maybe do straight out the back, or maybe just a small kink here or there. any input is appreciated. Link to comment Share on other sites More sharing options...
ronin152 Posted January 19, 2009 Share Posted January 19, 2009 I have the flowmaster 50 series suv muffler and it sounds awesome. I had the 40 series before and it was way to loud and annoying. I have 2.25 tubing into a 3 in muffler and it looks and sounds great. Link to comment Share on other sites More sharing options...
shift220 Posted January 19, 2009 Share Posted January 19, 2009 I would go with 2.5" for the whole exhaust system. 3" max after the muffler. Anything bigger would just look silly and offer no performance increases. Infact I would run 2.5" for everything. Anything bigger is for looks Link to comment Share on other sites More sharing options...
180sx Posted January 20, 2009 Share Posted January 20, 2009 2.5" for a stock setup is almost on the large side. considering that its only 3 cylinders on each side, 2.25" would be large enough. But, 2.5" is good, and louder! Going 2.5" to a dual inlet, and 3" out is pefectly fine, and probably the most convinient set-up. I am in the process of doing a true dual exhaust system. 2.25" into muffler (havent decided wich one's yet, probably super 40's) and then 2.5" out of the muffler. I think that 3" out is just over kill, and looks kinda silly on something as small as the pathfinder. Just my .02 Jose Link to comment Share on other sites More sharing options...
tekazgtr1984 Posted January 20, 2009 Share Posted January 20, 2009 Yup, I'm planning on the same for my exhaust upgrade. 2.25" out to 2.5" should be all one needs for the VG to sound mean and breathe right. Link to comment Share on other sites More sharing options...
PDCCD Posted January 20, 2009 Share Posted January 20, 2009 wow, i'm suprised 02silverpathy hasn't chimed in on this one, he's done some extensive exhaust research, maybe do a search for his username and check out his exhaust posts. Very informative. Pete Link to comment Share on other sites More sharing options...
silverlion Posted January 21, 2009 Share Posted January 21, 2009 (edited) I agree, 4" is overkill. 2.5 should be ideal for such a small engine. I had 4" on my '69 Chevelle, but I was pushing 630CI and almost 800 hp with a B&M Supercharger. I get a kick out of the wannabe rednecks that buy the Dodge w/ the Cummins and put a 6" stack through the bed behind the cab. Git'er done! Or this... this is cool.... Edited January 21, 2009 by silverlion Link to comment Share on other sites More sharing options...
tekazgtr1984 Posted January 21, 2009 Share Posted January 21, 2009 Bahahaha Now that's some gooooooood taste... Link to comment Share on other sites More sharing options...
laxman0324 Posted January 21, 2009 Share Posted January 21, 2009 Mine started the hissing about 2 weeks after I got it, it turned out it was leaking at the connector right above the axle, I guess I blew out a gasket...I am just gonna cut the mid pipe right before the connecting point and learn to weld putting pipes that are 1/2" bigger on the end... Link to comment Share on other sites More sharing options...
180sx Posted January 21, 2009 Share Posted January 21, 2009 I agree, 4" is overkill. 2.5 should be ideal for such a small engine. I had 4" on my '69 Chevelle, but I was pushing 630CI and almost 800 hp with a B&M Supercharger. I get a kick out of the wannabe rednecks that buy the Dodge w/ the Cummins and put a 6" stack through the bed behind the cab. Git'er done! Or this... this is cool.... Well, the 6" stack to you may look rediculous ( wich it is) but size is not why. Those cummins are turbo, and there is no such thing as "too big" exhaust for turbos. just be reasonable. Considering turbos make any where from 20 to 40psi of back pressure in the manifold, you just don't want to add any after the turbo, you know? quick question, not to TJ or anything, but i read that we have 4 cats. well, when i was under my truck today taking measurements and what not, i noticed i only have 2, and they are the ones on the manifolds. then its dual into a 2 inlet muffler, and single into another muffler, and than out the side. and thats it. just wondering if any one elses is like this. i've never seen the underside of another pathy, and ive had mine for only over a year... Link to comment Share on other sites More sharing options...
Alkorahil Posted January 21, 2009 Share Posted January 21, 2009 (edited) More than 3" and you will mess with the backpressure on the engine. It actually needs a little to fucntion properly. Edited January 21, 2009 by Alkorahil Link to comment Share on other sites More sharing options...
180sx Posted January 21, 2009 Share Posted January 21, 2009 Its not actually back pressure an engine needs, its the exhaust scavaging that the venturi effect creates in an exhaust system that the engine needs. back pressure just happens to be there as a result. And this is for non boosted applications. Boost is a diferent story, since there is already pressure pushing the exhaust out. And the Turbo itself cause a high level of back pressure in the exhaust manifold, like i said, about 20-40 psi depending, so you want as little presure after the turbo as possible. Link to comment Share on other sites More sharing options...
02silverpathy Posted January 21, 2009 Share Posted January 21, 2009 (edited) wow, i'm suprised 02silverpathy hasn't chimed in on this one, he's done some extensive exhaust research, maybe do a search for his username and check out his exhaust posts. Very informative. Pete Ta-Da! I only wish I was as cool as the dark knight! I had 2 exhaust systems on my 02 so far! I had from the 2 resonators back replaced with 2.25 piping (not mandrel bent) all the way back to a Magnaflow that had the "X" pipe inside it. This was the longest Magnaflow available (26" long maybe?). This was a dual in dual out set up. After the larger piping and super free flowing muffler (oh and nearly $400 in parts and labor) the truck lost Torque something terrible. I ripped that exhaust off the same day in favor of the OEM tacked back on! I enjoyed the OE until the rear resonator rusted off at the flange, which happens a lot, then I had an Aero Turbine muffler put on and the OE pipe made to fit infron and in back with the resonator delete. My current exhaust looks like hell, but is GREAT ! The Aero exhaust is the 2525xl....it has a resonator in it right in front of the aero foil that is actually the muffler. I have a video up on youtube.....however the music in the background is cruddy and I think that the exhaust has even changed its tone since then so I need to add a new vid soon. and that's my $.02 USD. Edited January 21, 2009 by 02silverpathy Link to comment Share on other sites More sharing options...
Justin517 Posted January 21, 2009 Author Share Posted January 21, 2009 More than 3" and you will mess with the backpressure on the engine. It actually needs a little to fucntion properly. I wasnt going to do dual 3", that would just be the tail-pipe after the muffler. Link to comment Share on other sites More sharing options...
Justin517 Posted January 21, 2009 Author Share Posted January 21, 2009 Ta-Da! I only wish I was as cool as the dark knight! I had 2 exhaust systems on my 02 so far! I had from the 2 resonators back replaced with 2.25 piping (not mandrel bent) all the way back to a Magnaflow that had the "X" pipe inside it. This was the longest Magnaflow available (26" long maybe?). This was a dual in dual out set up. After the larger piping and super free flowing muffler (oh and nearly $400 in parts and labor) the truck lost Torque something terrible. I ripped that exhaust off the same day in favor of the OEM tacked back on! I enjoyed the OE until the rear resonator rusted off at the flange, which happens a lot, then I had an Aero Turbine muffler put on and the OE pipe made to fit infron and in back with the resonator delete. My current exhaust looks like hell, but is GREAT ! The Aero exhaust is the 2525xl....it has a resonator in it right in front of the aero foil that is actually the muffler. I have a video up on youtube.....however the music in the background is cruddy and I think that the exhaust has even changed its tone since then so I need to add a new vid soon. and that's my $.02 USD. REALLY? thats pretty suprising. What kind of torque loss are we talking about here?? How was the top end with the 2.25" on there? and also I would imagine that it would improve gas mileage a bit with the larger exhaust, increased pumping efficency. I am really suprised it lost that much torque, maybe 2" would be a good compromise? I mean, looking at the aftermarket exhausts for the 350Z/Maxima/3.5 altima, they all seem to use decently sized piping, and while I know those vehicles weigh a bit less, they also dont have 4.68:1 axle ratios so torque loss I imagine would be an issue... How badly were the bends "pinched" on your system? a press-bent 2.25" pipe can have as small a cross section as a 1.75" pipe, especially in a 90° bend, which will hurt performance... both horsepower and torque. Link to comment Share on other sites More sharing options...
02silverpathy Posted January 21, 2009 Share Posted January 21, 2009 (edited) I didn't think that they were bent too badly at all...remember I went true dual all the way back as well! I had this set up installed thinking the same thing that you are---350z bla bla bla. It really comes down to pure HP. The truck doesn't make but 240 BHP and presses 260 ft/lbs...this leads to about the 2" exhaust you are mentioning. The loss with the larger set up was bad....tons of working climbing a hill right outside the shop--oh yeah and tons of noise! I did feel like there was more HP (through acceleration) in the higher RPM's but it just didn't justify the low end poo that I was left with. If I had the money to go again, I would probably get 1.75" mandrel to the muffler and then 2" or more after the muffler as the 2 combine into one. The OE pipes are like 1.5 to the muffler and nearly 2" after the muffler, albeit crush-bent. Now, my VG33E 98 loved the larger exhaust...I ran a Flowmaster SUV muffler with 2.25" to the muffler and 3" after and all was awesome!! I noticed only a slight drop in TQ, then again it wasn't a TQ monster anyway. You are correct that the 350 is lighter but lacks the great gears we have available, but we lack a 6 spd manual option!! Yes yes I still want that, I just need other things first, like a house and college for my daughter (whom is 7!!). Edited January 21, 2009 by 02silverpathy Link to comment Share on other sites More sharing options...
PDCCD Posted January 22, 2009 Share Posted January 22, 2009 (edited) I didn't think that they were bent too badly at all...remember I went true dual all the way back as well! I had this set up installed thinking the same thing that you are---350z bla bla bla. It really comes down to pure HP. The truck doesn't make but 240 BHP and presses 260 ft/lbs...this leads to about the 2" exhaust you are mentioning. The loss with the larger set up was bad....tons of working climbing a hill right outside the shop--oh yeah and tons of noise! I did feel like there was more HP (through acceleration) in the higher RPM's but it just didn't justify the low end poo that I was left with. If I had the money to go again, I would probably get 1.75" mandrel to the muffler and then 2" or more after the muffler as the 2 combine into one. The OE pipes are like 1.5 to the muffler and nearly 2" after the muffler, albeit crush-bent. Now, my VG33E 98 loved the larger exhaust...I ran a Flowmaster SUV muffler with 2.25" to the muffler and 3" after and all was awesome!! I noticed only a slight drop in TQ, then again it wasn't a TQ monster anyway. You are correct that the 350 is lighter but lacks the great gears we have available, but we lack a 6 spd manual option!! Yes yes I still want that, I just need other things first, like a house and college for my daughter (whom is 7!!). There you are! Good to see you chime in. makes me want to get going and do the damn exhaust on my truck, but i too am trying to buy a house. Pete Edited January 22, 2009 by PDCCD Link to comment Share on other sites More sharing options...
ronin152 Posted January 22, 2009 Share Posted January 22, 2009 (edited) I agree with silverpathy. I had 2.25 pipes not mandrel bent into a flowmaster 50 series suv muffler with 2.25 back to the 3 in tip. I felt the exact same torque loss as him. When I first had the pathy (3.5L) I always felt like I was spinning tire and that you had to ease into the pedal. After the exhaust I had the same trouble climbing hills and exactly what he said. If I were you honestly I would not get an exhaust. I would just buy factory replacement. I have seen OEM exhaust resonator back on ebay for like 200??? with a warranty. How many revs does the engine sit at when doing 60? With a lift and roofrack and stock tires my truck to do 60 takes about 2200-2300 RPM. What is normal revs for 60 on a flat highway? Edited January 22, 2009 by ronin152 Link to comment Share on other sites More sharing options...
ronin152 Posted January 22, 2009 Share Posted January 22, 2009 (edited) http://cgi.ebay.com/ebaymotors/96-00-Nissa...sQ5fAccessories Edited January 22, 2009 by ronin152 Link to comment Share on other sites More sharing options...
ronin152 Posted January 22, 2009 Share Posted January 22, 2009 Yeah I would deffinatly completely recommend not going custom. I spent over $600 on a custom exhaust and 2 months of time figuring out what the problem was. I felt the same torque loss and told the shop. They said they did everything right. So then I had them redo it with a different muffler. Still same thing. Just get stock. Custom is a waste of money and does nothing for the pathy. Link to comment Share on other sites More sharing options...
Justin517 Posted January 22, 2009 Author Share Posted January 22, 2009 I didn't think that they were bent too badly at all...remember I went true dual all the way back as well! I had this set up installed thinking the same thing that you are---350z bla bla bla. It really comes down to pure HP. The truck doesn't make but 240 BHP and presses 260 ft/lbs...this leads to about the 2" exhaust you are mentioning. The loss with the larger set up was bad....tons of working climbing a hill right outside the shop--oh yeah and tons of noise! I did feel like there was more HP (through acceleration) in the higher RPM's but it just didn't justify the low end poo that I was left with. If I had the money to go again, I would probably get 1.75" mandrel to the muffler and then 2" or more after the muffler as the 2 combine into one. The OE pipes are like 1.5 to the muffler and nearly 2" after the muffler, albeit crush-bent. Now, my VG33E 98 loved the larger exhaust...I ran a Flowmaster SUV muffler with 2.25" to the muffler and 3" after and all was awesome!! I noticed only a slight drop in TQ, then again it wasn't a TQ monster anyway. You are correct that the 350 is lighter but lacks the great gears we have available, but we lack a 6 spd manual option!! Yes yes I still want that, I just need other things first, like a house and college for my daughter (whom is 7!!). Well it looks like I'll be keeping stock, or atleast mostly stock, i wonder how it would react just replacing the muffler with a dual in single out, higher flowing unit... that would keep the puny dual pipes which are likely what is making the torque, but will give the truck a bit more of a grumble and maybe more top end also, without killing the torque too much... or maybe I'll just get 2 of these, they will provide decent back-pressure to the exhaust: stock turbo for 1.8T like I had on my audi, it was able to spike to 22 psi and held 13 by redline (its tiny) on 1.8L so it should be able to make 6 psi on 3.5L (1.75L each) pretty easily,a nd hold it to red-line, and they would spool so damn quick I'd get monster torque quite quickly... use a small ebay water/air intercooler I have a blown K03 turbo, I'll have to get the thing up on my buddies lift and see what kind of room I have. I'd need an IPT valve body first though me thinks. then there is the question of tuning... bigger injectors/rising rate FPR? SAFC? Wonder if Jim wolf can get me a base tune? sorry... I no longer have a fast turbo'd vehicle and its really bothering me, I dont want to buy another vehicle right now, but I keep thinking of ways to modify the one I have... Link to comment Share on other sites More sharing options...
tekazgtr1984 Posted January 22, 2009 Share Posted January 22, 2009 You're going to boost a VQ35? Link to comment Share on other sites More sharing options...
Justin517 Posted January 22, 2009 Author Share Posted January 22, 2009 You're going to boost a VQ35? Right now its just sort of a pipe dream but I'm really thinking about it. I <3 boost. I know the VQ is 10:1 which is pretty high, but I would only be running 6psi or so,a nd it would be intercooled... so it should be pretty safe... should be...lol. you can also get forged turbo pistons and Brian Crower or Eagle Rods for $$1100-$1200, then you'd have 8.5:1 compression and able to run as much boost as you ahve fueling for, but thats a slippery slope because then you have to upgrade the fuel pump and the transmission would be suspect... and who the hell wants a 550+ horsepower pathfinder anyway... sounds like a deathtrap to me. But yeah Ive thought about an eaton M90 supercharger too, fab up a piece that would go between the lower intake manifold and the blower... maybe even work in a water to air intercooler sandwiched in there... btu that would require hood modification and the belt drive seems like it would be pretty involved, plus it would always be robbing MPGs... witha turbo you can dial back the boost, or just stay out of it while cruising and get the same MPG as stock, or close anyway. I was also thinking about maybe a single turbo, like a big A/R (.82 or so) 60-1 T3 which may simplify things, but the question is where do I fit it? the airbox would be gone and I could re-locate the battery too, so maybe that'd work... so as you can see if I decide to go ahead with it, I have alot of variables to to nail down. Link to comment Share on other sites More sharing options...
tekazgtr1984 Posted January 22, 2009 Share Posted January 22, 2009 I'm exploring a supercharger upgrade for my '98 and there are several factors to consider. Luckily, the VG33E came supercharged on the '02-'04 Xterra so OEM hardware modification is a possibility. I've also been exploring an all-out swap, simply dropping a VG33ER into my rig to makes things easier (It would also make beefing up the R50 VG33E a lot easier.) Hood modification is a must unless you consider a subframe drop. My plan is to install the SFD but not install the engine mounts to raise it up, therefore giving me additional clearance without cutting up the hood. For this to work, I will need to lower the transmission, which may benefit the drivetrain in the end as this won't put the driveshaft at such an angle. An exhaust system will be necessary so I'm planning a 2.25" with 2.5" out. Link to comment Share on other sites More sharing options...
laxman0324 Posted January 22, 2009 Share Posted January 22, 2009 And the transmission and tcase would need to be modified for it to work... Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now