Purpose of jpipes
#1
Drifting
Thread Starter
iTrader: (1)
Join Date: Nov 2010
Location: Salt Lake City, UT
Age: 42
Posts: 3,490
Received 852 Likes
on
605 Posts
Purpose of jpipes
I've done some searching on the subject but I wasn't able to find all the answers. First, what is the whole purpose of aftermarket jpipes? It it simply a matter of increased exhaust flow? And if so, how exactly does it accomplish this? From eliminating one of the cats? And if that's the case, will installing a jpipe cause you to fail emissions?
Has anyone seen an MPG increase from an aftermarket jpipe?
Same question goes for CAI's. I know colder air can increase power, and that decreased filter drag can slightly decrease the work an engine has to do. Can anyone vouch for any noticable power or MPG increase on this? It seems like the benefit would be insignificant. I don't want to pay $200ish just to get a little better sound. (2X that for the jpipe)
Sorry for all the noob questions. I've never modded before but wanted to consider a few of these bolt ons if it doesn't end up being too much trouble/expense.
Has anyone seen an MPG increase from an aftermarket jpipe?
Same question goes for CAI's. I know colder air can increase power, and that decreased filter drag can slightly decrease the work an engine has to do. Can anyone vouch for any noticable power or MPG increase on this? It seems like the benefit would be insignificant. I don't want to pay $200ish just to get a little better sound. (2X that for the jpipe)
Sorry for all the noob questions. I've never modded before but wanted to consider a few of these bolt ons if it doesn't end up being too much trouble/expense.
#2
Burning Brakes
It replaces the stock J pipe with one with better flow properties, which in turn give you some more horsepower.
http://www.heeltoeauto.com/ATLP-J-Pi...-pr-63698.html
a pic of how it achieves this
http://www.acuratlparts.com/uploads/...34f020b0a7.jpg
http://www.heeltoeauto.com/ATLP-J-Pi...-pr-63698.html
a pic of how it achieves this
http://www.acuratlparts.com/uploads/...34f020b0a7.jpg
Last edited by ankur914; 01-06-2011 at 04:24 PM.
#5
Race Director
iTrader: (8)
Can't go wrong with either ATLP, XLR8 or RV6.
#6
Banned
How much hp gain would the J32 powered cars get on stock exhaust? If I could I'd buy/install both at the same time but it seems J-pipe yielded more hp gain on stock exhaust vs. adding an exhaust on stock j-pipe. Would this also be true?
#7
Former Sponsor
iTrader: (18)
Enough to feel, but nothing crazy. You can't trust what other people dynod or gained because every car is different (specs, weight etc) and everyone has different mods. Some mods actually hurt the car, if you get an intake, TB it will actually hurt HP. Gains would be tremendous if you did a full exhaust (Pre-cats, j pipe, third cat and cat back). I have a guy that can make pre cats and can make them high flow along with a j pipe with third cat delete with a HFC to replace the third cat and the catback for cheap with high end material that will never crack and is plug and play. I have his stuff and its all magna-flow products, stainless parts/piping with lifetime warrantees on the parts. The HFC are magna-flow and also have a lifetime warrantee.
Trending Topics
#8
Banned
Enough to feel, but nothing crazy. You can't trust what other people dynod or gained because every car is different (specs, weight etc) and everyone has different mods. Some mods actually hurt the car, if you get an intake, TB it will actually hurt HP. Gains would be tremendous if you did a full exhaust (Pre-cats, j pipe, third cat and cat back). I have a guy that can make pre cats and can make them high flow along with a j pipe with third cat delete with a HFC to replace the third cat and the catback for cheap with high end material that will never crack and is plug and play. I have his stuff and its all magna-flow products, stainless parts/piping with lifetime warrantees on the parts. The HFC are magna-flow and also have a lifetime warrantee.
#9
Moderator
iTrader: (1)
again, this is the latest and greatest version.
Richie has dynoed the pipe on a stock car and it gained 15hp. RV6 is coming out with acat back with gains of 15 horses as well on a stock car.
BUTT put these two together and it does not make 30hp.
youre going to be removing the 3rd cat. you will still pass emissions. the 3rd cat is in place to reach the ULEV II rating. there are no sensors on the 3rd cat.
#10
^^^Wow...very nicely put!
.....+1
The only thing I would add is when I installed my CAI I noticed about 1mpg better fuel economy and after I added richie's RV6 V3 Jpipe I really didn't notice a change in gas mileage. Then I added an ATLP V2 exhaust and it didn't do much either. I think all these mods are very minimal when it comes to fuel economy. For HP to $$$ ratio, go for the Jpipe.
![Thumbs Up](https://acurazine.com/forums/images/smilies/thumbsup.gif)
The only thing I would add is when I installed my CAI I noticed about 1mpg better fuel economy and after I added richie's RV6 V3 Jpipe I really didn't notice a change in gas mileage. Then I added an ATLP V2 exhaust and it didn't do much either. I think all these mods are very minimal when it comes to fuel economy. For HP to $$$ ratio, go for the Jpipe.
Last edited by 1islandparadise; 01-06-2011 at 07:14 PM.
#11
Moderator
iTrader: (1)
^^^Wow...very nicely put!
.....+1
The only thing I would add is when I installed my CAI I noticed about 1mpg better fuel economy and after I added richie's RV6 V3 Jpipe I really didn't notice a change in gas mileage. Then I added an ATLP V2 exhaust and it didn't do much either. I think all these mods are very minimal when it comes to fuel economy. For HP to $$$ ratio, go for the Jpipe.
![Thumbs Up](https://acurazine.com/forums/images/smilies/thumbsup.gif)
The only thing I would add is when I installed my CAI I noticed about 1mpg better fuel economy and after I added richie's RV6 V3 Jpipe I really didn't notice a change in gas mileage. Then I added an ATLP V2 exhaust and it didn't do much either. I think all these mods are very minimal when it comes to fuel economy. For HP to $$$ ratio, go for the Jpipe.
#12
Team Owner
Less exhaust restriction means more hp, torque, and mpg.
Less intake restriction means more hp and no change in mpg.
There was a guy on here that got some nice gains from PCDs and a J-pipe with stock exhaust. In fact, he got the normal gains that people with a catback get. This leads me to believe that most of the restriction is at the usual place.... the precats up to the first cat. The sound was extremely nice, something I would do and I'm ultra conservative when it comes to the looks and sound of my car. It sounded pretty much stock at idle and like stock only louder at full throttle.
Less intake restriction means more hp and no change in mpg.
There was a guy on here that got some nice gains from PCDs and a J-pipe with stock exhaust. In fact, he got the normal gains that people with a catback get. This leads me to believe that most of the restriction is at the usual place.... the precats up to the first cat. The sound was extremely nice, something I would do and I'm ultra conservative when it comes to the looks and sound of my car. It sounded pretty much stock at idle and like stock only louder at full throttle.
#13
Three Wheelin'
I love the "ive done research and couldn't find anything on....."
This is with every new thread, so nothing aimed at you specifically
Seriously....everything you want answers for has been beating to death to waste the 9 lives of a cat...
So in all honesty..you didn't search, you didn't bother to read.
This is with every new thread, so nothing aimed at you specifically
Seriously....everything you want answers for has been beating to death to waste the 9 lives of a cat...
So in all honesty..you didn't search, you didn't bother to read.
Last edited by Opel; 01-06-2011 at 09:26 PM.
#14
Safety Car
One purpose of a well design J-pipe is to create scavenging (click here- see Post #26). This is the key design concept behind the RV6 V3 Long Tube J-Pipe (click here).
#17
Drifting
Thread Starter
iTrader: (1)
Join Date: Nov 2010
Location: Salt Lake City, UT
Age: 42
Posts: 3,490
Received 852 Likes
on
605 Posts
One purpose of a well design J-pipe is to create scavenging (click here- see Post #26). This is the key design concept behind the RV6 V3 Long Tube J-Pipe (click here).
Less exhaust restriction means more hp, torque, and mpg.
Less intake restriction means more hp and no change in mpg.
There was a guy on here that got some nice gains from PCDs and a J-pipe with stock exhaust. In fact, he got the normal gains that people with a catback get. This leads me to believe that most of the restriction is at the usual place.... the precats up to the first cat. The sound was extremely nice, something I would do and I'm ultra conservative when it comes to the looks and sound of my car. It sounded pretty much stock at idle and like stock only louder at full throttle.
Less intake restriction means more hp and no change in mpg.
There was a guy on here that got some nice gains from PCDs and a J-pipe with stock exhaust. In fact, he got the normal gains that people with a catback get. This leads me to believe that most of the restriction is at the usual place.... the precats up to the first cat. The sound was extremely nice, something I would do and I'm ultra conservative when it comes to the looks and sound of my car. It sounded pretty much stock at idle and like stock only louder at full throttle.
I love the "ive done research and couldn't find anything on....."
This is with every new thread, so nothing aimed at you specifically
Seriously....everything you want answers for has been beating to death to waste the 9 lives of a cat...
So in all honesty..you didn't search, you didn't bother to read.
This is with every new thread, so nothing aimed at you specifically
Seriously....everything you want answers for has been beating to death to waste the 9 lives of a cat...
So in all honesty..you didn't search, you didn't bother to read.
#18
BANNED
iTrader: (33)
no worries losiglow, looks like you made your decision. i fully understand your need to pose this question. it is a big purchase and you just wanted to make sure you got some up to date opinions on which one to go with and why.
^with that said...here is your jpipe, now go buy it!![Too Cool](https://acurazine.com/forums/images/smilies/toocool.gif)
http://rv6-performance.com/index.php...mart&Itemid=62
^with that said...here is your jpipe, now go buy it!
![Too Cool](https://acurazine.com/forums/images/smilies/toocool.gif)
http://rv6-performance.com/index.php...mart&Itemid=62
#20
Former Sponsor
iTrader: (1)
![Agree](https://acurazine.com/forums/images/smilies/agree.gif)
Also make sure you consider each of the j-pipe designs. Each j-pipe on the market uses a different grade steel and a different design.
XLR8 J-pipe - T304 SS (Domestic) with equal length runners and 2.5" collector
ATLP J-pipe - 439 SS with 2.5" collector
RV6 J-pipe - 304 SS (Overseas) with 2.5" exit (eliminates 3rd cat)
#21
Intermediate
iTrader: (4)
Join Date: Dec 2010
Age: 37
Posts: 35
Likes: 0
Received 0 Likes
on
0 Posts
![Agree](https://acurazine.com/forums/images/smilies/agree.gif)
Also make sure you consider each of the j-pipe designs. Each j-pipe on the market uses a different grade steel and a different design.
XLR8 J-pipe - T304 SS (Domestic) with equal length runners and 2.5" collector
ATLP J-pipe - 439 SS with 2.5" collector
RV6 J-pipe - 304 SS (Overseas) with 2.5" exit (eliminates 3rd cat)
Already have XLR8 cat back and ATLP race pipe, is there any reason to take off the race pipe and go RV6 v3 or just do your XLR8 J-Pipe and add it to whats already there?
#22
Safety Car
k i haven't read your post(s), but just to simply answer your question. the j-pipe comes down from pre-cats (which come directly off the exhaust manifolds in the front and back, off the block). the part that connect the pre-catalytic converts to the rest of the exhaust system (cat back), is the j-pipe. If you look @ the stock j-pipe, you'll see quite a bit of restriction (mainly from small size).
Can someone EXPLAIN TO ME though, how the J-pipe adds up more whp? It's better free flowing, which makes sense, but added onto a stock exhaust system, doesn't that create bottlenecking? Doesn't that just shift the hp/tq curve further up the rpm band?
Can someone EXPLAIN TO ME though, how the J-pipe adds up more whp? It's better free flowing, which makes sense, but added onto a stock exhaust system, doesn't that create bottlenecking? Doesn't that just shift the hp/tq curve further up the rpm band?
#23
Intermediate
iTrader: (4)
Join Date: Dec 2010
Age: 37
Posts: 35
Likes: 0
Received 0 Likes
on
0 Posts
k i haven't read your post(s), but just to simply answer your question. the j-pipe comes down from pre-cats (which come directly off the exhaust manifolds in the front and back, off the block). the part that connect the pre-catalytic converts to the rest of the exhaust system (cat back), is the j-pipe. If you look @ the stock j-pipe, you'll see quite a bit of restriction (mainly from small size).
Can someone EXPLAIN TO ME though, how the J-pipe adds up more whp? It's better free flowing, which makes sense, but added onto a stock exhaust system, doesn't that create bottlenecking? Doesn't that just shift the hp/tq curve further up the rpm band?
Can someone EXPLAIN TO ME though, how the J-pipe adds up more whp? It's better free flowing, which makes sense, but added onto a stock exhaust system, doesn't that create bottlenecking? Doesn't that just shift the hp/tq curve further up the rpm band?
![](http://i288.photobucket.com/albums/ll191/shortyjtc/14sep8_b02.gif)
#24
Team Owner
k i haven't read your post(s), but just to simply answer your question. the j-pipe comes down from pre-cats (which come directly off the exhaust manifolds in the front and back, off the block). the part that connect the pre-catalytic converts to the rest of the exhaust system (cat back), is the j-pipe. If you look @ the stock j-pipe, you'll see quite a bit of restriction (mainly from small size).
Can someone EXPLAIN TO ME though, how the J-pipe adds up more whp? It's better free flowing, which makes sense, but added onto a stock exhaust system, doesn't that create bottlenecking? Doesn't that just shift the hp/tq curve further up the rpm band?
Can someone EXPLAIN TO ME though, how the J-pipe adds up more whp? It's better free flowing, which makes sense, but added onto a stock exhaust system, doesn't that create bottlenecking? Doesn't that just shift the hp/tq curve further up the rpm band?
#25
2014 Jeep SRT
![Tongue](https://acurazine.com/forums/images/smilies/tongue.gif)
Albeit the j-pipe does have some benefit, the return-on-investment might turn you away.
#26
Former Sponsor
iTrader: (1)
Excelerate - Would your XLR8 J-pipe paired with an ATLP race pipe (already on the car) be almost identical to the RV6 v3 pipe that deletes the cat?
Already have XLR8 cat back and ATLP race pipe, is there any reason to take off the race pipe and go RV6 v3 or just do your XLR8 J-Pipe and add it to whats already there?
Already have XLR8 cat back and ATLP race pipe, is there any reason to take off the race pipe and go RV6 v3 or just do your XLR8 J-Pipe and add it to whats already there?
#27
Three Wheelin'
ok ok, no inconvenience
I apologize I came across the way I did
Goodluck with your decisions...these guys know this stuff to a great extent, so anything you decide based on their advice, will be the right decision.
I apologize I came across the way I did
Goodluck with your decisions...these guys know this stuff to a great extent, so anything you decide based on their advice, will be the right decision.
#30
Keep'n it clean- Orlando
Less exhaust restriction means more hp, torque, and mpg.
Less intake restriction means more hp and no change in mpg.
There was a guy on here that got some nice gains from PCDs and a J-pipe with stock exhaust. In fact, he got the normal gains that people with a catback get. This leads me to believe that most of the restriction is at the usual place.... the precats up to the first cat. The sound was extremely nice, something I would do and I'm ultra conservative when it comes to the looks and sound of my car. It sounded pretty much stock at idle and like stock only louder at full throttle.
Less intake restriction means more hp and no change in mpg.
There was a guy on here that got some nice gains from PCDs and a J-pipe with stock exhaust. In fact, he got the normal gains that people with a catback get. This leads me to believe that most of the restriction is at the usual place.... the precats up to the first cat. The sound was extremely nice, something I would do and I'm ultra conservative when it comes to the looks and sound of my car. It sounded pretty much stock at idle and like stock only louder at full throttle.
On the integra type R, a previous car I had it was mostly left stock as it really wasnt the MAIN restriction.....
I know there are gains to be had for the TL by adding an exhaust I am just not into the sound, I think I will experiment with the mods and a stock cat back to see the difference in the same mods with people who have a cat back.
hmmmmmmm
![Too Cool](https://acurazine.com/forums/images/smilies/toocool.gif)
additionally and forgive me if this is a stupid theory.....
But what do you think the improvements with lack of sound ( if any ) would be by changing all the stock "piping" only to 2.5 and having it welding back onto the stock resonator and mufflers?
![Roll Eyes](https://acurazine.com/forums/images/smilies/rolleyes.gif)
Last edited by Steven Bell; 01-07-2011 at 10:23 PM. Reason: Threads merged.
#31
Banned
Id be curious to know or theorize up to how much horsepower the stock cat back can actually handle/allow additional power to be added without having to be changed.
On the integra type R, a previous car I had it was mostly left stock as it really wasnt the MAIN restriction.....
I know there are gains to be had for the TL by adding an exhaust I am just not into the sound, I think I will experiment with the mods and a stock cat back to see the difference in the same mods with people who have a cat back.
hmmmmmmm![Too Cool](https://acurazine.com/forums/images/smilies/toocool.gif)
additionally and forgive me if this is a stupid theory.....
But what do you think the improvements with lack of sound ( if any ) would be by changing all the stock "piping" only to 2.5 and having it welding back onto the stock resonator and mufflers?
We agree on this point, were flowing air, and stock amounts at that, I really dont see how the smaller piping would really be that MUCH of a restriction, again I could see some, but not enough to categorize it as "bottle necking" since we are speaking of N/A cars.... Turbo and supercharge I am sure the above would be accurate. Your thoughts?
15 whp proven on a dyno chart is pretty good, Im surprised you would say that would turn someone away... Id gladly take that additional power and will be soon....![Roll Eyes](https://acurazine.com/forums/images/smilies/rolleyes.gif)
On the integra type R, a previous car I had it was mostly left stock as it really wasnt the MAIN restriction.....
I know there are gains to be had for the TL by adding an exhaust I am just not into the sound, I think I will experiment with the mods and a stock cat back to see the difference in the same mods with people who have a cat back.
hmmmmmmm
![Too Cool](https://acurazine.com/forums/images/smilies/toocool.gif)
additionally and forgive me if this is a stupid theory.....
But what do you think the improvements with lack of sound ( if any ) would be by changing all the stock "piping" only to 2.5 and having it welding back onto the stock resonator and mufflers?
We agree on this point, were flowing air, and stock amounts at that, I really dont see how the smaller piping would really be that MUCH of a restriction, again I could see some, but not enough to categorize it as "bottle necking" since we are speaking of N/A cars.... Turbo and supercharge I am sure the above would be accurate. Your thoughts?
15 whp proven on a dyno chart is pretty good, Im surprised you would say that would turn someone away... Id gladly take that additional power and will be soon....
![Roll Eyes](https://acurazine.com/forums/images/smilies/rolleyes.gif)
http://www.youtube.com/watch?v=PotBHLf3pQw
#32
Suzuka Master
iTrader: (2)
The cat-back oem piping itself on modern cars is pretty efficient. On the TL, you'll see a couple horsepower by losing the mid muffler and resonator and another five or so by upgrading the cans.
#33
Keep'n it clean- Orlando
This was my exact thinking too. I'd so appreciate if you did this and record sound of the exhaust too. ITR friends of mine would only swap intake and headers and leave exhaust stock. It sounded great too. But i have base 08 tech and want to do j-pipe with free flow cat, I heard one on youtube and it sounded awful but he ran a str8 pipe and pre-muffler removed which i plan not to do. Here it is...
http://www.youtube.com/watch?v=PotBHLf3pQw
http://www.youtube.com/watch?v=PotBHLf3pQw
If I could find a cheap stock S exhaust I would experiment with the piping size...
Dont forget by doing the RV6 v3 Jpipe it eliminates the 3rd cat, so thats what you should look at getting.
So what I am going do, is throw the rv6 Jpipe v3 on, and remove ONLY my stock Mid Muffler, and see what type of sound that gives me. I think it will be clean and slightly more tone then stock. Here is exactly what I am looking for, no ricer sound just an aggressive clean tone.
Stock for comparison:
http://www.youtube.com/watch?v=8xNll_FugZU&feature=fvw
This kid removed his 3rd cat ( which is what the J-pipe will do) and his mid muffler, so I predict my sound to be close to this, if not identical.
http://www.youtube.com/watch?v=su_1gi3A4ho
I was interested in the pre-cat deletes, however I need to do more research as there is A LOT of back and fourth about losing torque and that is the last thing I want.... so I guess Ill have to do more reading ....
![what](https://acurazine.com/forums/images/smilies/what.gif)
Last edited by OntheJob; 01-08-2011 at 12:14 AM.
#34
Keep'n it clean- Orlando
![Thumbs Up](https://acurazine.com/forums/images/smilies/thumbsup.gif)
#35
Former Sponsor
iTrader: (1)
Or j-pipe does hang lower than the others but it only hangs slightly lower than the subframe. However, we feel that this design is optimal for exhaust flow. Our j-pipe has been installed on many lowered vehicles. It only becomes an issue if someone is lowered more than 2" usually.
#36
Chapter Leader (San Antonio)
iTrader: (3)
RV6 V3 is the best jpipe you can buy for the TL. Regardless of what other vendors say regarding the steel used, no one has ever had a problem. Let alone Richie has one of, if not the best, customer service and he is always seeking to improve. Also exhaust scavenging is vital in the HP increases of the J pipe. Just like the Labree J pipe, even with the ATLP/XLR8 jpipe with a 3rd cat delete would not be equivalent to the RV6 (not by much but enough for you to take the RV6 route). I've driven TLs with all 3 J pipes and the RV6 is superior.
#37
Intermediate
iTrader: (4)
Join Date: Dec 2010
Age: 37
Posts: 35
Likes: 0
Received 0 Likes
on
0 Posts
Or j-pipe does hang lower than the others but it only hangs slightly lower than the subframe. However, we feel that this design is optimal for exhaust flow. Our j-pipe has been installed on many lowered vehicles. It only becomes an issue if someone is lowered more than 2" usually.
![Wish](https://acurazine.com/forums/images/smilies/wish.gif)
#38
Banned
I'm gonna keep the mid-muffler after hearing your posted video. It's a tad raspy for me. I think the mid-muffler will smooth out the sound. I want "sleeper" status with a little more sound than stock.
#39
Walk the walk
Any thought making the j-pipe out of carbon steel rather than 300-400 series CRES. Thinking in use this part get so hot that condensation corrosion is really not an issue. Then it will look more stealth and be less costly. Maybe a 10% savings because suspect labor and design are the dominate cost drivers
#40
Keep'n it clean- Orlando
![ugh](https://acurazine.com/forums/images/smilies/ugh.gif)
Anyhow I will experiment with the setup post videos, good news is the mid mufler could always be added back on..
![Thumbs Up](https://acurazine.com/forums/images/smilies/thumbsup.gif)