New exhaust and missing low end torque
12-09-2006, 09:57 PM
#1
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New exhaust and missing low end torque
I just got the car back today after a complete exhaust system replacement. Went with ws y-pipe, hi-flow cat (2.5" out), 2.5" b-pipe and OEM muffler. I'm really disappointed with the lack of low-end torque now... so to those that have done exhaust work, has anyone else noticed this? I'm going to take it back and likely get them to put on an OEM 2" b-pipe instead... but before I do, I wanted to get some feedback on whether this would restore some of the low-end torque. Since I mostly drive in the lower RPM range, I want that low-end torque.
12-09-2006, 10:28 PM
#2
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dude i say u take ur hi flow cat down to a 2.25 in that might give u back some low end torque. cuz i had on my last maxima i owned and the one before dat one as well the same exhaust system which consisted of stock y pipe no cat and 2.5 in pipping from where the cat was all the way back to the end where i had a hayame dtx muffler on it had alot of torque after doing all of that
12-09-2006, 10:37 PM
#3
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Unless you have an extremely efficient forced induction setup, I would strongly suggest you retain the same exhaust length and same exhaust diameter as designed by Nissan engineers. The length and diameter of your exhaust is tuned so that each exhaust pulse aids the flow of the next.
12-10-2006, 07:18 AM
#5
^^ bingo
for low end you need some backpressure.
I ran the stock y-pipe with a 2.5" straight out for a while (2 years) it did lack low end, so I just spun the engine a bit more.
can't truly comment on just the y-pipe yet. I only drove it one day and that was in the snow and needing an alignment
for low end you need some backpressure.
I ran the stock y-pipe with a 2.5" straight out for a while (2 years) it did lack low end, so I just spun the engine a bit more.
can't truly comment on just the y-pipe yet. I only drove it one day and that was in the snow and needing an alignment
12-10-2006, 07:39 AM
#6
Originally Posted by internetautomar
for low end you need some backpressure.
A bigger exhaust diameter will provide less obstruction to exhaust flow, but it can also reduce the momentum of the exhaust stream by permitting the exhaust gas to expand and cool, which slows it down. What size is optimal will depend mostly on how big your engine is and in what RPM range you want the power. Many people get away with 2.5" aftermarket exhaust parts in cases where the stock parts are so restrictive and have such poor bends (e.g. the 4th gen Y-pipe) that just having them be smooth yields an overall gain, even though the extra diameter isn't necessarily the best thing. But a full 2.5" exhaust is definitely on the big side for a NA 3.0L engine, especially if you do most of your driving in the low RPM range. That's why you probably want to step down from what you have now.
The ideal setup for you would be something like stock diameter, but with smoother bends for less turbulence.
12-10-2006, 09:24 AM
#7
wsp sells 2 Y-pipes 2" and 2.5" dont they?
i dont have to worry about emissions here sooo i can take my cat out.
before your thread i was going to do a 2.5" wsp, testpipe, and then custom 2.5" b-pipe, with maybe a 40 series flowmaster (it sounds kewl
)
but now that someone did the "FULL" 2.5" exhaust manifold back, im reconsidering.
probably do 2" wsp Y-pipe, test pipe, 2"stainless B-pipe, then probably the 40 series flowmaster
and the reson for the flowmaster: (i klnow they are for V8's)
friend can give me one for free and it sounds nice on his MX6 4cyl why not on a 3.0L V6?
i dont have to worry about emissions here sooo i can take my cat out.
before your thread i was going to do a 2.5" wsp, testpipe, and then custom 2.5" b-pipe, with maybe a 40 series flowmaster (it sounds kewl
)but now that someone did the "FULL" 2.5" exhaust manifold back, im reconsidering.
probably do 2" wsp Y-pipe, test pipe, 2"stainless B-pipe, then probably the 40 series flowmaster
and the reson for the flowmaster: (i klnow they are for V8's)
friend can give me one for free and it sounds nice on his MX6 4cyl why not on a 3.0L V6?
12-10-2006, 11:45 AM
#9
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Originally Posted by internetautomar
^^ bingo
for low end you need some backpressure.
I ran the stock y-pipe with a 2.5" straight out for a while (2 years) it did lack low end, so I just spun the engine a bit more.
can't truly comment on just the y-pipe yet. I only drove it one day and that was in the snow and needing an alignment
for low end you need some backpressure.
I ran the stock y-pipe with a 2.5" straight out for a while (2 years) it did lack low end, so I just spun the engine a bit more.
can't truly comment on just the y-pipe yet. I only drove it one day and that was in the snow and needing an alignment
12-10-2006, 11:59 AM
#10
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Originally Posted by xx-Marshall-xx
wsp sells 2 Y-pipes 2" and 2.5" dont they?
i dont have to worry about emissions here sooo i can take my cat out.
before your thread i was going to do a 2.5" wsp, testpipe, and then custom 2.5" b-pipe, with maybe a 40 series flowmaster (it sounds kewl )
but now that someone did the "FULL" 2.5" exhaust manifold back, im reconsidering.
i dont have to worry about emissions here sooo i can take my cat out.
before your thread i was going to do a 2.5" wsp, testpipe, and then custom 2.5" b-pipe, with maybe a 40 series flowmaster (it sounds kewl
)but now that someone did the "FULL" 2.5" exhaust manifold back, im reconsidering.
I think there's a lot of misinformation in the market, with everyone claiming huge horsepower increases etc. Since the y and bigger exhaust opens up the hi-end, it may be good on some engines and not so much on others. For example, since the VE has VTC, it already has a lot of hi-end power over the VG for example, so I think in this case, you're only gonna see a marginal increase in hi-end power, at the cost of a big loss in low end torque. Going full 2.5" is a significant loss of low-end torque, so it depends on how you like to drive. I am really disappointed, and I think I'm going back to the original setup. I went against my gut feeling on this one, and am quite disappointed how this mod turned out. Lesson learned.
12-11-2006, 07:39 AM
#12
I had the same problem. I had 2.25 piping with a 2.5 cat with dual exhaust setup (2 aftermarket cans). The car lost alot of torque so I decided instead of redoing the whole piping to put 2 stock cans with with nice tips back on. Notice a big difference. I then had a electronice cut-out install a little after the cat for those times when I want to bypass the cans.
I'm very happy with this setup. There is no droning or bees can sound. There is a suttle groan which can be only heard from the outside and about 5 feet away most. With the cutout fully opened the car is god awfully loud inside out and unbearable unless going over 70 MPH.
I'm very happy with this setup. There is no droning or bees can sound. There is a suttle groan which can be only heard from the outside and about 5 feet away most. With the cutout fully opened the car is god awfully loud inside out and unbearable unless going over 70 MPH.
12-11-2006, 08:47 AM
#14
Cripes.... IT'S NOT BACKPRESSURE THAT YOU NEED. BACKPRESSURE IS BAD. If backpressure were the thing to have, why aren't you all telling him to weld a flap onto his muffler to cut off some of the flow?
You want your exhaust system to keep the exhaust stream hot and under high pressure. That makes it move faster, which means it has more momentum, which means it scavenges exhaust gas from the cylinders, which helps power production. Backpressure does exactly the OPPOSITE of that and HURTS power.
The ideal exhaust for low-end torque on this motor would have a diameter around 1.75 to 2 inches, but with a minimum of bends and no pinched sections. That would REDUCE backpressure over the stock setup.
You want your exhaust system to keep the exhaust stream hot and under high pressure. That makes it move faster, which means it has more momentum, which means it scavenges exhaust gas from the cylinders, which helps power production. Backpressure does exactly the OPPOSITE of that and HURTS power.
The ideal exhaust for low-end torque on this motor would have a diameter around 1.75 to 2 inches, but with a minimum of bends and no pinched sections. That would REDUCE backpressure over the stock setup.
12-11-2006, 10:43 AM
#15
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Originally Posted by d00df00d
Cripes.... IT'S NOT BACKPRESSURE THAT YOU NEED. BACKPRESSURE IS BAD. If backpressure were the thing to have, why aren't you all telling him to weld a flap onto his muffler to cut off some of the flow?
You want your exhaust system to keep the exhaust stream hot and under high pressure. That makes it move faster, which means it has more momentum, which means it scavenges exhaust gas from the cylinders, which helps power production. Backpressure does exactly the OPPOSITE of that and HURTS power.
The ideal exhaust for low-end torque on this motor would have a diameter around 1.75 to 2 inches, but with a minimum of bends and no pinched sections. That would REDUCE backpressure over the stock setup.
You want your exhaust system to keep the exhaust stream hot and under high pressure. That makes it move faster, which means it has more momentum, which means it scavenges exhaust gas from the cylinders, which helps power production. Backpressure does exactly the OPPOSITE of that and HURTS power.
The ideal exhaust for low-end torque on this motor would have a diameter around 1.75 to 2 inches, but with a minimum of bends and no pinched sections. That would REDUCE backpressure over the stock setup.
if im not mistaken the factory pipping is already at 2 inches so why would you tell him to take it down to a 1.75" pipping
12-11-2006, 10:54 AM
#17
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yup if im not mistaken the stock pipe on our cars are 2 inch pipping ive owned three maxima se's 2 93's and a 91 se and i beleave all the pipping on all three cars are 2 inchs. as for the lose of power i dont know what you all are doing wrong cuz with the exhaust setup i run i actually feel a gain. but then again im also using a ve motor and not the lower powered vg. VE = !90 at crank VG = 162 at the crank.the setup ive ran with in the past was 2.5 inch no cat with hayamae dual tip muffler inlet on the muffler is 2.25 and outlets on the tips are 3 inches each titled upward.
12-11-2006, 11:16 AM
#19
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Originally Posted by elusivemax93
yup if im not mistaken the stock pipe on our cars are 2 inch pipping ive owned three maxima se's 2 93's and a 91 se and i beleave all the pipping on all three cars are 2 inchs. as for the lose of power i dont know what you all are doing wrong cuz with the exhaust setup i run i actually feel a gain. but then again im also using a ve motor and not the lower powered vg. VE = !90 at crank VG = 162 at the crank.the setup ive ran with in the past was 2.5 inch no cat with hayamae dual tip muffler inlet on the muffler is 2.25 and outlets on the tips are 3 inches each titled upward.
Anyway, I'm definitely going back to 2" b-pipe, my only debate right now is if I want to put the stock y back on. The reason being is that the stock y has equal length pipe from each manifold going to the collector, which may be designed "better" for low end torque because of the exhaust pulse timing and thus greater scavenging effect. The aftermarket y's have unequal length pipe to the collector.
12-11-2006, 12:23 PM
#21
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okay so have we concluded that the problem was due to the oversized B pipe??
or is the hi flow cat still a culprit? since im getting a full exhaust setup from WSP should the smaller 2-1/4" B be okay?? i still need to know all this junk before i order....that is IF they ever email me back... 2 weeks and counting
or is the hi flow cat still a culprit? since im getting a full exhaust setup from WSP should the smaller 2-1/4" B be okay?? i still need to know all this junk before i order....that is IF they ever email me back... 2 weeks and counting
12-11-2006, 12:36 PM
#23
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Originally Posted by d00df00d
Cripes.... IT'S NOT BACKPRESSURE THAT YOU NEED. BACKPRESSURE IS BAD. If backpressure were the thing to have, why aren't you all telling him to weld a flap onto his muffler to cut off some of the flow?
You want your exhaust system to keep the exhaust stream hot and under high pressure. That makes it move faster, which means it has more momentum, which means it scavenges exhaust gas from the cylinders, which helps power production. Backpressure does exactly the OPPOSITE of that and HURTS power.
The ideal exhaust for low-end torque on this motor would have a diameter around 1.75 to 2 inches, but with a minimum of bends and no pinched sections. That would REDUCE backpressure over the stock setup.
You want your exhaust system to keep the exhaust stream hot and under high pressure. That makes it move faster, which means it has more momentum, which means it scavenges exhaust gas from the cylinders, which helps power production. Backpressure does exactly the OPPOSITE of that and HURTS power.
The ideal exhaust for low-end torque on this motor would have a diameter around 1.75 to 2 inches, but with a minimum of bends and no pinched sections. That would REDUCE backpressure over the stock setup.
backpressure = more low end
less back pressure = more top end
12-11-2006, 12:41 PM
#24
What is all the complaining about?
First off, the VE isn't designed for low end torque, it was designed for the upper end. If you want low end torque, get a VG. Most people that have driven both will tell you that a VG feels stronger in low rpms.
The aftermarket exhaust systems are set up to increase hp and decrease 1/4 mile times (go faster). This is especially true with a VE.
If you aren't happy with more hp, better mpg and a car that is faster when pushed, go back to stock.
First off, the VE isn't designed for low end torque, it was designed for the upper end. If you want low end torque, get a VG. Most people that have driven both will tell you that a VG feels stronger in low rpms.
The aftermarket exhaust systems are set up to increase hp and decrease 1/4 mile times (go faster). This is especially true with a VE.
If you aren't happy with more hp, better mpg and a car that is faster when pushed, go back to stock.
12-11-2006, 04:47 PM
#26
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Originally Posted by Hollywood!
okay so have we concluded that the problem was due to the oversized B pipe??
or is the hi flow cat still a culprit? since im getting a full exhaust setup from WSP should the smaller 2-1/4" B be okay?? i still need to know all this junk before i order....that is IF they ever email me back... 2 weeks and counting
or is the hi flow cat still a culprit? since im getting a full exhaust setup from WSP should the smaller 2-1/4" B be okay?? i still need to know all this junk before i order....that is IF they ever email me back... 2 weeks and counting
12-11-2006, 05:33 PM
#27
I too lost a bit of low end torque. The Lightened flywheel and UDP also compound that problem. BUT, I can in 2nd gear at 15-20PMH floor it and squeak the tires. These are sticky KDW's.... The car could not do that before and I attribute it to being able to hit the high HP RPM quickly. i.e. The low end torque sucking exhaust and lightened components move around the torque and HP curves to enable that to happen.
12-11-2006, 06:08 PM
#29
Originally Posted by Hollywood!
To please d00df00d... ITS NOT BACKPRESSURE FOR THE DEAR SWEET LOVE OF GOD
, haha, the dancing guy was supposed to indicate sarcasm, guess that plan fell through...________
Lesbian Threesome
Last edited by Pearl93VE; 04-18-2011 at 12:58 AM.
12-11-2006, 08:16 PM
#31
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Originally Posted by 94maxshima
I know, I was just being an as*hole , haha, the dancing guy was supposed to indicate sarcasm, guess that plan fell through...
, haha, the dancing guy was supposed to indicate sarcasm, guess that plan fell through...sarcasm > me
and i might just take you up on that deal (to mszilves) i was holding off anyways until i get a shipping estimate from them. so ive got nothing but oodles of time. ill be sure to monitor this thread.
12-11-2006, 08:45 PM
#32
Originally Posted by internetautomar
^^ bingo
for low end you need some backpressure.
I ran the stock y-pipe with a 2.5" straight out for a while (2 years) it did lack low end, so I just spun the engine a bit more.
can't truly comment on just the y-pipe yet. I only drove it one day and that was in the snow and needing an alignment
for low end you need some backpressure.
I ran the stock y-pipe with a 2.5" straight out for a while (2 years) it did lack low end, so I just spun the engine a bit more.
can't truly comment on just the y-pipe yet. I only drove it one day and that was in the snow and needing an alignment
Not back pressure, velocity. mmm kay?
Slowmaro owners 
12-11-2006, 09:00 PM
#34
Originally Posted by MrGone
Are you sure you lost powah and are not confusing the "lack of low end gains"?
You could just be making mad horsey powah up high. Like nitrous without the bottle.
You could just be making mad horsey powah up high. Like nitrous without the bottle.
I never felt a loss of low end with my full 2.5" wsp exhaust... I actually prefer 2.5" over the 2.25" I currently have.
12-11-2006, 09:40 PM
#35
when I did my setup I had the pleasure of testing both out. I know the guy who owned the shop that bent out my system, and it turned out that he actually had a 2.25 and a 2.5 system already bent up from some previous customer. For some reason they never ended up getting the exhaust and he had them laying around. (don't ask me, i have no idea) Well, I had a wsp 2.5" y-pipe already, and a choice of catco converters he had in boxes, and the Greddy exhaust, which is 2.25 in diameter suprisingly. So, I tried the 2.5 y-pipe, the 2.5 converter, a 2.5 b-pipe, and the Greddy muffler. I really didn't like it...and experienced the same lack of low end torque you all describe. I then tried the 2.25 y-pipe he had laying around, a 2.25 converter, and a 2.25 b-pipe with the 2.25 Greddy....but didn't really like the sound. (It's suprising the difference!!!) So we tried a few different combos over the course of 2 weeks, and I finaly settled on the 2.25 y-pipe, 2.5 cat, 2.5 b-pipe, and 2.25 Greddy. It sounds just as good as the 2.5 full exhaust, and I get the responsiveness of the 2.25 because of the y-pipe he had. I ended up giving him the 2.5 in exchange for the 2.25. They were both stainless steel and virtually the same in bend quality and weld quality. long story short.....I'm a happy man!!
Cliffs: 2.25 y-pipe, 2.5 cat, 2.5 b-pipe, 2.25 muffler Tried and Tested FTW!!!
Cliffs: 2.25 y-pipe, 2.5 cat, 2.5 b-pipe, 2.25 muffler Tried and Tested FTW!!!
12-12-2006, 10:05 PM
#36
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Ok, got a 2" b-pipe put on today, and it's definitely better! So far, I'm impressed with the power, though it still feels like some of the low end is missing. I'm gonna drive it around a bit (some hills etc. that I know what it used to feel like) and see if I'm happy enough with it, otherwise I'll change back to the stock y.
12-13-2006, 03:27 PM
#39
Originally Posted by traxtar944
well don't go to the stock y, thats the worst option!
the WSP y-pipe caused a noticeable low end loss on my VE A/T.
of course I had been driving a malibu while it was down and that had some major bottom end to it. (220lb ft @ 3200 rpm, 200 hp @ 5400 rpm). better ergonomics and more bottom end, but not as much fun.
