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Everything posted by Tungsten

  1. Did some searching around and found this: http://www.nissanpathfinders.net/forum/topic/35773-what-to-expect-out-of-a-vg33-and-vg34/ That's pretty much it for power gains! Also the only guys that have had some reasonable gains with the Thorley short tubes and high flow exhaust alone are those who run the supercharged VG33ER. I am suspecting that this is due to an increase in the size of the down pipes rather than actually scavenging better.
  2. Just a FYI those washers are super cheap brand new from Nissan. People destroy them all the time because that bottom sprocket can seize on sometimes and the best way to get it off is to destroy the washer behind it.
  3. I agree that Doug Thorley makes fine headers. However, Nissan knew what they were doing in the 1980's because they actually won races. Their exhaust manifold design for the VG30E/i was also re-used on the VG33E and that should say something. The manifolds are not the problem but the rest of the exhaust can be a little restricted. It doesn't matter if you have short tube headers, long tube headers, or exhaust manifolds. The difference between them will be very small just due to the fact that you are running stock cams with stock heads (that have casting flashes in them) and there is a muffler and a catalytic converter in the way. Suppose you have a "high flow" exhaust setup. The difference between short tubes and long tubes may be like 5-7 hp all else being equal. The difference between short tubes and manifolds if you are lucky (and Nissan didn't design the most efficient manifold possible) will be like 2 hp. Actually removing the restrictions down-stream is more important. If you were to compare the exhausts just opened up after the Y-pipe (and not road legal) you would see a bigger jump between long tubes and short tubes and manifold. Still, you won't feel it in anything over second gear because of the garbage truck style gearing these trucks have. I am basing these assumptions on countless hours of research and experimenting and obtaining information from actual high performance engine builders. This isn't something I'm just pulling out of nowhere. If you spend some time on this, you will see what I mean. If you want to do it the cheapest and best way possible, save your money and skip the headers. Look for any exhaust leaks and broken hangers and fix them. Consider taking the heat shields off the manifolds and then taking off the gap guards from the inner fenders. This puts a lot less heat and stress on the studs and makes them last longer. Get either a Gibson cat-back exhaust or a Borla cat-back exhaust or even just make one yourself with a Flowmaster 60 Delta Flow muffler. Then get a Magnaflow high flow Direct-Fit bolt on CARB compliant catalytic converter. Put those on and enjoy the small added throttle response. The only drawback is it will be slightly louder than factory. Maybe except for Gibson which is really quiet for an aftermarket muffler. This will help scavenge exhaust better from the factory manifolds because you are helping with the main restrictions downstream. If you have to use crush bent tube, which I'm not a fan of, make sure the tube diameter is bigger to accomodate for the crush bends. Mandrel bent/CNC bent pipe is always the best way to go. Now if you want more power, consider either swapping to a VG33E or building a VG34E which is a VG33E that's bored and uses some parts bin stuff. If you go the VG34E route, then you can build a larger diameter exhaust and look into getting a set (or making a set) of long tube headers.
  4. Geo Metro was basically a Suzuki Swift Nothing swift about it...
  5. Honoring a recall could also be their way of saying hey come to us again for your next car
  6. Well it's a Jeep thing. Cushy interior but Chrysler parts really show outside and mechanically. I was going to get one with the I6 and backed out. Good luck.
  7. That's a good theory but they don't only break on Pathfinders. The ultimate fix is to drill them out to 10mm.
  8. VG34E build. Looks exactly like factory but has the performace of a VQ35DE. Best of both worlds.
  9. The whole point of that was to show that just popping on an exhaust system from manufacturer X may not guarantee any results. There is a lot of ground to cover when changing out a system. Everything from noise levels to emissions to heat output and what you can do about those things. Short tube headers perform identical to exhaust manifolds because more modern exhaust manifolds are designed to also function as performance headers at low rpm. If there is any gain going from manifolds to short tubes, it will be very marginal. You may see a little bit more just replacing old exhaust components with slightly bigger better quality ones. Similar to a cat-back but with a few more parts. See link: http://www.carcraft.com/techarticles/ls1_engine_header_test/evaluation_dyno_numbers.html
  10. LSX is a great engine but at that point it's not really a Nissan anymore. It depends on how you feel about mixing brands.
  11. Coming back to this I forgot to mention that the pipe diameter going off the heads (primary tubes) also matters. The general rule of thumb is that the more power your engine makes, the larger the primary tubes should be. If the tubes are too small, the engine has to work harder to push the gasses out. If the tubes are too big then the scavenging effect starts to fade with lower rpms. They usually range from 1.500" to 2.125". Another thing that makes a difference is the shape and length of the collector. Finally, coating matters. The coating of the primary tubes should ideally be ceramic. This makes a tiny positive difference in power but a huge difference in underhood tempereture and heat soak.
  12. My current setup (also in my profile) is like this (and it does pass inspection here but not CA legal due to wrong cat): Doug Thorley Headers (short tube) 2.5" 304 SS piping 49-state Magnaflow cat Flowmaster 50 DF muffler I agree, those extra components are required for the truck to be road legal in most states. Obviously you don't want to be driving around blowing out people's ear drums. Perfect scavenging is possible on any engine no matter the size. It's really just a concept of physics. The more equal length and longer the pipes are before they meet at the collector, the better horsepower you get. Gain results may vary depending on other factors like boost. The muffler and catalytic converter cause turbulence and back-pressure inside the exhaust system and negate the scavenging effect somewhat but not entirely. That's just the reality. The quieter it gets, the more back pressure inside the system there is. It's not that big of a deal (if any at all) at low rpms but it becomes a drain once you're getting closer to the fun rpm. The exhaust isn't the only factor here. There are also different cam profiles that are used on a daily vs a race vehicle and different compression ratios. The factory cam profiles and maybe even the factory head is the real choke point of the engine, not so much the exhaust. You might see like a 15 hp gain on a N/A motor with stock cams just running open long tubes. There are plenty of unequal length vs. equal length dyno charts online. For example on Subarus, the equal length headers remove the signature boxer sound but give more performance. With all those things being said, good luck finding a high performance exhaust header for a Nissan truck. You can make one yourself but you will need a tube bender and a welder and a lot of time and dedication. I hope this answers all of the questions. There is a lot of confusing information out there.
  13. Headers and exhaust seem to be a common thing to go after and this question has been asked multiple times. If you're having power issues, even if the maintenance has been done, it is really easy to overlook the most simple things. Any rubber component on the engine will dry rot over time and cause a vacuum leak. Older engines use a lot more vacuum hoses than newer ones. Simply replacing all the rubber hoses can return lost power. Other than screwing with the function of various devices controlled by vacuum, another reason is if any of those get split open or crack, you will have unmetered air going past the MAF sensor and this results in a lean condition because the computer doesn't spray enough fuel. Also, check the most obvious one of all, the flex pipe between the air intake and the throttle body. I replaced mine recently because it split open and gained quite a bit of power back. Keep in mind that sometimes those cracks are not very easy to see. Squeeze it and feel it around to make sure there are no cracks. What you really want is not even the DT short tube headers but equal length headers that ensure perfect exhaust scavenging at the collector. Unequal length short tube headers are just prettied up manifolds. Also, having extra components on the exhaust like muffler and catalytic converter are somewhat of a negation on the headers already. For these reasons, there isn't much of a gain changing out the exhaust with a slightly bigger aftermarket system but it does sound nice and look pretty under the hood. The gains are comparable to a regular cat back system. My favorite part about changing the exhaust though is that I was able to replace all of the exhaust piping from the engine to the tail pipe with stainless steel tubes. No more rust there!
  14. It's the weather, it always gets worse... It just sucks when stuff like this hits populated areas but eventually people will learn to build more resilient structures like most of east Asia is already doing.
  15. THIS The tire pressure you run depends on the design of the tire. For a 31" on a Pathfinder, you should not need to run more than 33 PSI on an All Terrain tire because of a reinforced sidewall. On the contrary, highway tires benefit from higher pressure because they have softer sidewalls. You can run highway tires as high as 40 PSI. You can always air down off-road but I can't say how much because I never ran into a situation that required lowering tire pressure. Also, the recommended tire pressure of 26 PSI is for the tires that were included with the truck. They were not that great. The pressure was reduced for a soft ride but if you don't keep it at 26 PSI all the time, it will get dangerously low. You lose pressure in the tire when the temperature drops. You always want a little overhead to account for that.
  16. By the way, there is always that wires getting broken in the harness from pulling when changing air filter theory. Wiggling the wires might help to clear up the problem. I had that problem before when I took my fix harness off and what I did eventually was cut off the old factory harness a little more down the line and splice the new fix connector harness on. I left the ground connected on but I seemed to have no problems if the extra ground was not connected. Many theories exist for this problem. lol Ok done post spamming. Where is that edit button when you need it?
  17. It could also be some sort of an internal ECU ground and for some reason it doesn't work sometimes so the harness just gives it an extra ground.
  18. There is no ground wire without this. It goes to a 0 volt source on the ECU. I'm not sure why or how. Maybe there is a built in tuner of some sort on the ECU that tweaks the reference ground?
  19. Damn it... All the pictures disappeared. Here is the wiring diagram: H
  20. Haha! I did make the exhaust! There is very little clearance for an aftermarket system let alone a stock one. The funny thing about thicker stainless steel material is it has a unique rattle sound. It does not sound anything like regular thin aluminized steel pipe rattle. Instead it sounds like a very muffled rattle. Almost like a woodpecker is stuck down there. I'm pretty sure it's hitting on some bracket down there by the Y-pipe. You are correct on the thermal expansion of the pipe B. When the pipe is cold it has just enough clearance but as it expands it will touch something down there if the motor moves a little too much. Also, I checked the transmission and engine mounts just in case and they checked out fine. No I did not trade my truck for a blue oval but I did buy one. More on that later...
  21. Forgot to mention but I also changed the hubs to manuals. I wanted to do it anyway and thought maybe the autos went bad or something. They didn't but I do love the manual hubs now.
  22. The worm one is standard Nissan and it doesn't hold a lot of pressure because it's only the return line. The feed line does have a proper clamp. I have a theory that Nissan does this to label the hoses so the return and feed lines never get installed backwards.
  23. Yes, almost. It was a combination of things. New U-joints and brake lines definitely helped. Now to find out why the engine makes the exhaust touch...
  24. I think I found it. Looks like the damn exhaust crossover is hitting on the frame again or possibly the mid-pipe where it gets close to the transmission bracket. I think I'm going to check the transmission mount again. It just happens every so often and it sounds like something is grinding but it's really just the pipe buzzing when the engine starts shaking around under load enough. I did have a tapping sound from the drive-train earlier too but that seems to have completely disappeared with new brake flex hoses. Now I did have some issues with the shifting and engine acting funny earlier but it rarely ever happens and I think it's just the knock sensor being triggered when the noise gets a little too loud. It wasn't happening before so I think it's just a mount getting a little loose.

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