Stock Downpipe (Cat) and Front Pipe Question

[CIVICUK]

Just come across this thread and i am about to go back to my stock downpipe (cat) as i have sold my ktuner (no purpose for it anymore) as the prl catted has threw up a CEL code p0139 and i am due for M.O.T soon!

But my question to this is, will i notice a significant reduction in exhaust noise by going stock cat? Also i have the prl frontpipe and im debating wether to take that off too. I am running ark exhaust which is staying on the car along with my prl sri and intercooler ( just helps in hot weather and i like the sound

Cheers!

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[Phy]

Just come across this thread and i am about to go back to my stock downpipe (cat) as i have sold my ktuner (no purpose for it anymore) as the prl catted has threw up a CEL code p0139 and i am due for M.O.T soon!

But my question to this is, will i notice a significant reduction in exhaust noise by going stock cat? Also i have the prl frontpipe and im debating wether to take that off too. I am running ark exhaust which is staying on the car along with my prl sri and intercooler ( just helps in hot weather and i like the sound

Cheers!

While not a direct answer, when I changed my wifes front pipe to the megan racing 2.5" I noticed an increase in sound just from that. Not a lot, but noticeable. She had stock DP and resonator and muffler delete.

 

[ayeitsmikko]

While not a direct answer, when I changed my wifes front pipe to the megan racing 2.5" I noticed an increase in sound just from that. Not a lot, but noticeable. She had stock DP and resonator and muffler delete.

Hmm you got me rethinking of buying an Invidia Front Pipe that's 70mm. I have an Invidia R400 exhaust and the sound note is great. I was hoping a front pipe would make it just a bit louder, but I don't want to get a catted downpipe because of the many users saying that it won't pass SMOG in CA.

Was that front pipe worth it? The Invidia that I'm looking at is about $230, but if it doesn't make that much of a difference, I might just use that money for wheels and tires.

 

[Phy]

Hmm you got me rethinking of buying an Invidia Front Pipe that's 70mm. I have an Invidia R400 exhaust and the sound note is great. I was hoping a front pipe would make it just a bit louder, but I don't want to get a catted downpipe because of the many users saying that it won't pass SMOG in CA.

Was that front pipe worth it? The Invidia that I'm looking at is about $230, but if it doesn't make that much of a difference, I might just use that money for wheels and tires.

The Megan front pipe was 120$, so I think it was worth it even if it wasn't noticeably louder, just for the larger diameter. We added the catless Megan downpipe this weekend and now it's obnoxiously loud, so I'll probably be putting the stock DP back on, maybe someday try for a catted PRL or RV6 and see if it's a livable in between.

 

[Myx]

The Megan front pipe was 120$, so I think it was worth it even if it wasn't noticeably louder, just for the larger diameter. We added the catless Megan downpipe this weekend and now it's obnoxiously loud, so I'll probably be putting the stock DP back on, maybe someday try for a catted PRL or RV6 and see if it's a livable in between.

I may have to give this Megan frontpipe a try. I have had no success with the PRL Front pipe. My 2nd PRL frontpipe still made contact with my intermediate drive shaft. Not expecting some power gain since I have the stock exhaust on. It just irks me going from a 3" downpipe to a 2" frontpipe, regardless of how 'unrestrictive' the 2" stock frontpipe is.

 

[Phy]

I may have to give this Megan frontpipe a try. I have had no success with the PRL Front pipe. My 2nd PRL Frontpipe still made contact with my intermediate drive shaft.

Is PRL frontpipe also 3"? I can imagine that being tight in there.

 

[Myx]

Is PRL frontpipe also 3"? I can imagine that being tight in there.

Yes!
https://prlmotorsports.com/civicxfrontpipe.aspx

 

[CIVICUK]

Well in the end i decided to just go stock frontpipe aswell as the cat, and although ive lost the chance getting more future power or running bigger turbo, i can honestly say that the ark exhaust on stock dp fp is perfect! Theres no loud drone on cold start like when i was prl catted dp/fp so im glad i have made the swap back.

I guess sound means more to me than power, but i supose everyones goals are different

 

[Phy]

If the frontpipe wasn't such a pain in the ass to change I'd switch them out for the sake of experimentation

 

[The_STIG]

Just ran into this... I want better flow, but do not want louder exhaust. (yes, im already at that age)

I personally find the choke point to be the connector between the FP and the exhaust. According to 27WON, the piping is almost 60mm, but that connector reduces down to like50mm... thats the choke point....
I feel like the best gain is a PRL catted DP, with a new connector between FP and stock exhaust that matches the actual piping.

 

[Hondanickx]

Decided to bring this thread back from the dead. This video is a little old also, but still answers the question of whether or not a front pipe will yield any gains, with a dyno test.

Weird... if you look at his downpipe install video and dyno then he only gains 5hp and 7Ft/lbs.His front pipe install gained more torque then that...but almost no hp...

 

[Myx]

Weird... if you look at his downpipe install video and dyno then he only gains 5hp and 7Ft/lbs.His front pipe install gained more torque then that...but almost no hp...

Weird you just posted this as I was just looking at all three of Edge Autosports videos with the AFE Downpipe, Front Pipe (They call it a rear downpipe) and exhaust. They gained horsepower/torque on all 3 products. Based on what I JUST saw (Literally within the last hour), I plan on going with an AFE frontpipe as I already have a PRL Downpipe and custom 3" Injen Exhaust.

BTW...in a nutshell, here's what they made (I wrote notes).
AFE exhaust: 6whp (This was installed first with stock downpipe and frontpipe). HERE
AFE downpipe: 5whp (On lowend. Topend, they were experiencing hp loss due to hot intake temps/ignition timing being pulled. HERE
AFE frontpipe (Or Rear Downpipe they called it): 10whp. HERE

All of their testing that was done on the very same car have convinced me about the exhaust results, despite all that has been said about changing anything on the exhaust doesn't give anyone hp/torque. Even my own experience had me having the same trap speeds with the stock exhaust. I have a lot more testing to do.

Also, the lowend torque gains are a HUGE plus for me. Always looking to spool up the turbo quickly. Not necessarily looking for more lowend torque (CVT) but quicker spool up is always a plus.

BTW: I just updated my first post with the links I provided above. Makes for easier finding for later.

 

[varge]

Take note of their final before (bone stock exhaust) after (full aFe) and the final delta is 11whp
I'm taking that with a grain of salt as their ktuner custom tune netted a 17whp gain (191 stock vs 207 tuned vs 218 full aFe) when we all know that Si's can be pushed so much further and are making even more more power on OTS tunes.
Details on their blog posts here :
https://blog.edgeautosport.com/proj...boback-exhaust-setup-on-our-10th-gen-civic-si

And a reminder that my base EUDM is on the 250whp range with bone stock exhaust (stock cat even)

 

[KingOfBrussels]

Keep in mind Edge Autosport is in Colorado. The altitude produces some funky numbers. That's why they had to do a custom tune. The fact that they're making even roughly similar numbers to sea level is an accomplishment. Don't pay so much attention to the absolute power levels they're achieving, look at the relative gains for each item. They have some great videos but they should be mentioning that altitude in every dyno video.

 

[Hondanickx]

Weird you just posted this as I was just looking at all three of Edge Autosports videos with the AFE Downpipe, Front Pipe (They call it a rear downpipe) and exhaust. They gained horsepower/torque on all 3 products. Based on what I JUST saw (Literally within the last hour), I plan on going with an AFE frontpipe as I already have a PRL Downpipe and custom 3" Injen Exhaust.

BTW...in a nutshell, here's what they made (I wrote notes).
AFE exhaust: 6whp (This was installed first with stock downpipe and frontpipe). HERE
AFE downpipe: 5whp (On lowend. Topend, they were experiencing hp loss due to hot intake temps/ignition timing being pulled. HERE
AFE frontpipe (Or Rear Downpipe they called it): 10whp. HERE

All of their testing that was done on the very same car have convinced me about the exhaust results, despite all that has been said about changing anything on the exhaust doesn't give anyone hp/torque. Even my own experience had me having the same trap speeds with the stock exhaust. I have a lot more testing to do.

Also, the lowend torque gains are a HUGE plus for me. Always looking to spool up the turbo quickly. Not necessarily looking for more lowend torque (CVT) but quicker spool up is always a plus.

BTW: I just updated my first post with the links I provided above. Makes for easier finding for later.

The 10whp gain with the front pipe was due too their previous dyno pulling timing Because of heatsoak.
So they said there was no hp gain.
I was also watching their videos ?,i didn't saw the exhaust video yet.

Also this is tested on a SI which allready has a bigger stock exhaust then a regular Civic or eudm Civic.

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