[No_curebimmer]

Mini review for my newly installed c-PE catless downpipes & the BMS dual cones intake on my 335is...these are the only mods on my car (yet)

I had a fellow forum member help me install these downpipes over the weekend (many thanks e90TiAg335i super knowledgeable, works fast and professional, highly recommend him for local N. Florida work).

SOUND: I echo what other forum members witnessed, the change in sound is amazing, it really sounds like a different car, the start up in the morning is quite a few decibels louder, overall lower 'baritone' sound during WOT and 'normal driving', more back fires/popping sounds on deceleration, I really love it! However, there is a small issue: I get a rasp around 5-6k rpms, I read other reviews (335i only) and they had no rasp at all - anything I can do about it (like get resonators)? Would other downpipes mated with my PE exhaust make a different sound, less raspy?

POWER: well here I didn't see nor feel what everyone says about downpipes (c-PE or other brands, they are still pipes) and "wow, my car feels and pulls so much stronger!". I'm going to check with my mechanic (e90TiAg335i) this weekend to see if he can help me troubleshoot it, but in no way am I really impressed with the power. As a matter of fact, can I say, it even feels slower...? Example: I'm looking for a parking space my work garage this morning, car is in manual & sport and 1st gear, feathering the gas pedal, there is no acceleration anywhere between 850 to 2000 rpm levels, I just hear the exhaust and the intake, but the car doesn't 'jerk/lurk' forward like it used to do. I hear the exhaust and the intake noises are there a good second or so before the car actually moves, but simply the car does not seem as responsive as it used to be. It's as if I put the car in neutral and just rev the engine...

Am I imagining things here? I know I'm supposed to get about 15-20 hp increase, but the way the car feels now it doesn't seem it gained any. This does not make any sense: I eliminated the cats, a freer flowing exhaust should give less turbo back pressure, increase the responsiveness of the engine, tied that in with the intakes giving in more air,

Physics don't lie, so what could it be?

Thanks for any input, insights, etc...

[Dr. G]

People who say they don't have rasp are delusional LOL, I've heard 8 of these setups in person now (including my own) plus at least another 5 people I've spoken through via PM and all have the same issue with the IS exhaust or PE + Downpipes.

Throw in some small vibrant resonators into the midpipes somewhere if you don't mind welding the OEM mids. I'm thinking of doing the same thing if there's room.


As for the power, I feel you man. People remove 10 pounds of weight from the car and go OMG pulls so hard up top! I think people are just looking to feel something so they feel it. It's hard to notice gains, but when you go back to stock you can VERY CERTAINLY feel the losses. Are you tuned?

[bigdaddycane]

You need a tune to bring out the full effect of the DPs...I'd be surprised if your still disappointed after adding a tune to your setup.

[RaihaX]

+1 to resonators

[CPWINCH]

Originally Posted by bigdaddycane

You need a tune to bring out the full effect of the DPs...I'd be surprised if your still disappointed after adding a tune to your setup.

+1 no real benefit of dp without a tune. obviously some gain but not like with a tune. get a tune! what are you waiting for

[No_curebimmer]

Originally Posted by bigdaddycane

You need a tune to bring out the full effect of the DPs...I'd be surprised if your still disappointed after adding a tune to your setup.

Thanks for everyine who chimed in!

Well since I'm not tuned, I didn't expect 'night-and-day' power gains with DPs like one would with a tune...

However, shouldn't the car "feel" more responsive not just sound better? Exhaust management is key for a turbo. So how would you explain the 'dead power zone' around 1500rpm, like I'm standing still? Is that a side effect of the DPs? I haven't read that anywhere...

Also what resosantors would you recommend for the "raspyness"?

[No_curebimmer]

Originally Posted by CPWINCH

+1 no real benefit of dp without a tune. obviously some gain but not like with a tune. get a tune! what are you waiting for

I know I know...I'm shopping/looking for COBB!

[No_curebimmer]

Originally Posted by bigdaddycane

You need a tune to bring out the full effect of the DPs...I'd be surprised if your still disappointed after adding a tune to your setup.

So I take it others who installed DPs without having a tune first were disappointed as well?

[RaihaX]

Originally Posted by No_curebimmer

Also what resosantors would you recommend for the "raspyness"?

Vibrant #1792 seems popular.

[AU335i]

just heard my friend with a 335is and CP-E catless DP's tonight... it sounds amazing... people saying it's raspy are too damn sensitive imo... definitely wouldn't say it was "raspy" during his flyby.

[Dr. G]

I don't know about sensitive, I like a TINY bit of raspy, the setups I heard were the most raspiest e92's I have ever seen in my life.
They sounded horrifying, all you heard was rasp, sounded much much much much worse than with stock downpipes. I currently have the stock downpipes back on and am trying to see if I can squeeze some small resonators into the mids so I can put the DP's back on.

[barton2002]

Sorry for hijacking ur thread but just a quick question.

I bought Cpe catless dp too but for my 335i, with stock exhaust, not IS. so i wont get any rasp, right? This is what I saw from everyone's review but this just worries me abit since I am about to install mine.

[No_curebimmer]

Originally Posted by RaihaX

Vibrant #1792 seems popular.

Thanks - I'll look into that...

[No_curebimmer]

Originally Posted by barton2002

Sorry for hijacking ur thread but just a quick question.

I bought Cpe catless dp too but for my 335i, with stock exhaust, not IS. so i wont get any rasp, right? This is what I saw from everyone's review but this just worries me abit since I am about to install mine.

Speaking solely from my particular experience, the sound is dramatically improved and the overall sound improvement far outweighs the small raspyness around 5,500 rpms...but I wouldn't let just that deter me from the install.

My main concern is the loss of responsiveness I received once I put these bad boys in...no one else experienced this? Again, I am NOT tuned...

All the reviews I read (exception is the one above Dr G) rave about huge sound and power improvements.

[bigdaddycane]

So I take it others who installed DPs without having a tune first were disappointed as well?

not sure mainly because most people who mod N54's do a tune prior to DPs; due to price and typical mod order.

Originally Posted by barton2002

Sorry for hijacking ur thread but just a quick question.

I bought Cpe catless dp too but for my 335i, with stock exhaust, not IS. so i wont get any rasp, right? This is what I saw from everyone's review but this just worries me abit since I am about to install mine.

You shouldn't. I just installed the CP-e c@tless DPs and the exhaust sounds really good. No rasp that I can tell and just slightly deeper tone all around. That is if you keep the secondary cats and resonators. Taking either of those off can cause rasp with DPs installed.

BTW, the fitment of the CP-e DPs is spot on....plenty of room and perfect fitment.

[barton2002]

Originally Posted by bigdaddycane

not sure mainly because most people who mod N54's do a tune prior to DPs; due to price and typical mod order.



You shouldn't. I just installed the CP-e c@tless DPs and the exhaust sounds really good. No rasp that I can tell and just slightly deeper tone all around. That is if you keep the secondary cats and resonators. Taking either of those off can cause rasp with DPs installed.

BTW, the fitment of the CP-e DPs is spot on....plenty of room and perfect fitment.

Hey thanks for your confirmation bro, cant wait!!

[BQTuning]

Originally Posted by Dr. G

People who say they don't have rasp are delusional LOL, I've heard 8 of these setups in person now (including my own) plus at least another 5 people I've spoken through via PM and all have the same issue with the IS exhaust or PE + Downpipes........

Another reason why I am going with the CP-E Highflow Catted Downpipes. Coming soon !

[bryce]

catted downpipes are a waste of time and money, in my opinion. the gains are restricted, even though there are "high flow cats."

if you're going to get downpipes, and you don't want too much rasp, look into ar design resonated downpipes. no restriction like cats, but they really cut down on rasp and make the exhaust sound stealthy

[BQTuning]

Originally Posted by bryce

catted downpipes are a waste of time and money, in my opinion. the gains are restricted, even though there are "high flow cats."

if you're going to get downpipes, and you don't want too much rasp, look into ar design resonated downpipes. no restriction like cats, but they really cut down on rasp and make the exhaust sound stealthy

You and others make it sound like its a significant whp difference. Verified by CPE and AR themselves, regardless who you want to get it, there is roughly a 5hp "average" difference between the catted highflow and the cattless DPs

How much are you going to pay to add resonators ? Is the greedy 5 hp worth it ? Common man....like the waste of money statement this is a waste of time, and time is money.

This will benefit lots of people who live in emissions enforced states. It makes all sense to spend the money now rather than have to spend more money later in make corrections

[bigdaddycane]

People who say they don't have rasp are delusional LOL, I've heard 8 of these setups in person now (including my own) plus at least another 5 people I've spoken through via PM and all have the same issue with the IS exhaust or PE + Downpipes.

Even with the secondary cats and oem resonators in place?

[bryce]

Originally Posted by BuraQ

You and others make it sound like its a significant whp difference. Verified by CPE and AR themselves, regardless who you want to get it, there is roughly a 5hp "average" difference between the catted highflow and the cattless DPs

How much are you going to pay to add resonators ? Is the greedy 5 hp worth it ? Common man....like the waste of money statement this is a waste of time, and time is money.

This will benefit lots of people who live in emissions enforced states. It makes all sense to spend the money now rather than have to spend more money later in make corrections

please provide dyno results directly comparing the same car with catted and catless downpipes. it's more than 5whp

[bryce]

by the way, you won't likely pass emissions inspection with catted downpipes. you might do it the first year, but every member with catted downpipes has said after a little while (6 months to a year), they not longer pass inspection, get a CEL, etc.

so, i don't really see the point in catted downpipes.

a) you won't pass emissions
b) catless downpipes aren't THAT much louder
c) you pay more for the catted versions, that are more restrictive
d) cats fail, especially on the CP-e versions. i've read numerous for sale threads where the user had to send the downpipes back to CP-e for them to re-install new cats



please enlighten me as to why you think catted downpipes are worth it. if it's only based on the sound, GTFO and go buy a quiet civic hybrid