[5soko]

Was just looking for some owners feedback on quality, and fit of these DP's.

http://www.cp-e.com/products/bmw-335...5i-3-downpipes

I really like the belmouth cast 3" by the turbo even tho it then goes to a 2.5".
But then again i never was a believer that making a DP taper earlier or later to 2.5" helped anything, as long as the first part of the DP is 3" to collect the exhaust gases coming out the turbo directly. Since ALL DP's taper to 2.5"anyways.
Its like blowing into a straw, will compressing with ur fingers closer to the top of the straw rather than closer by the bottom, make a difference of how much air is released

[Zasquatch]

I've got these and absolutly love them. No complaints at all. I had the same viewpoint as you... in my opinion the cast bellmouth made up for the fact that they tapered sooner. The fact that the piping is 2.5" also makes installation alot easier since you have more room to work with. The welds are beautiful, the castings are fantastic, and fitament is spot-on.

[PlutoniumTans]

Originally Posted by 5soko335i

Was just looking for some owners feedback on quality, and fit of these DP's.

http://www.cp-e.com/products/bmw-335...5i-3-downpipes

I really like the belmouth cast 3" by the turbo even tho it then goes to a 2.5".
But then again i never was a believer that making a DP taper earlier or later to 2.5" helped anything, as long as the first part of the DP is 3" to collect the exhaust gases coming out the turbo directly. Since ALL DP's taper to 2.5"anyways.
Its like blowing into a straw, will compressing with ur fingers closer to the top of the straw rather than closer by the bottom, make a difference of how much air is released

Lumi you Serbian speed racer , if you don't mind spending around 600 already better for these http://www.europeanautosource.com/pr...s-n54-variants i'm sure there are vendors who will go bellow the price, it's full 3 inch, fits like a glove, and will have a better resale value

[5soko]

Originally Posted by Zasquatch

I've got these and absolutly love them. No complaints at all. I had the same viewpoint as you... in my opinion the cast bellmouth made up for the fact that they tapered sooner. The fact that the piping is 2.5" also makes installation alot easier since you have more room to work with. The welds are beautiful, the castings are fantastic, and fitament is spot-on.

Thanks alot for the input! Much appreciated.

Originally Posted by PlutoniumTans

Lumi you Serbian speed racer , if you don't mind spending around 600 already better for these http://www.europeanautosource.com/pr...s-n54-variants i'm sure there are vendors who will go bellow the price, it's full 3 inch, fits like a glove, and will have a better resale value

HAHA thanks Mike this exactly was looking for after researching everything else. still wanna hear more about the CP-E from the owners. The MS looks exactly like the AR and AA's, all taper right before the flange to 2.5 and all are 3.0's.. the MS and AA's are def a great value for full 3" Dp's

[PlutoniumTans]

Originally Posted by 5soko335i

Thanks alot for the input! Much appreciated.



HAHA thanks Mike this exactly was looking for after researching everything else. still wanna hear more about the CP-E from the owners. The MS looks exactly like the AR and AA's, all taper right before the flange to 2.5 and all are 3.0's.. the MS and AA's are def a great value for full 3" Dp's

I think aa don't look anywhere near as good as MS, the curves on MS are nice and smooth, the welds are great, and I heard from installer shops the fit better too.

[5soko]

Yea i have been hearing some people are having install trouble with the AA's too..

[tscdennab]

If you will spend the money on downpipes, why not get 3" and settle for 2.5" for even more money ? You may leave power on the table with 2.5". And why spend the money and not maximize your gains ? Macht Schnells are like $150 cheaper, full 3" and fit perfectly.

[Jeff@TopGearSolutions]

I think the CP-E, MS, and AA are all great DP's. Pick your poison!

[5soko]

Originally Posted by tscdennab

If you will spend the money on downpipes, why not get 3" and settle for 2.5" for even more money ? You may leave power on the table with 2.5". And why spend the money and not maximize your gains ? Macht Schnells are like $150 cheaper, full 3" and fit perfectly.

At the moment Mike and Terry are selling the CPE's for 570.. but i mean for me, im not fully convinced that tapering earlier within the DP to 2.5 will make less power than a DP that tapers later in the DP to 2.5, as long as there 3" piping by the exiting of the Turbine gases by the top of the DP im pretty comfortable with that.. JMHO but i love to hear different views.
If it was a full 2.5 DP, then i might not be very comfortable.

[PlutoniumTans]

Originally Posted by 5soko335i

At the moment Mike and Terry are selling the CPE's for 570.. but i mean for me, im not fully convinced that tapering earlier within the DP to 2.5 will make less power than a DP that tapers later in the DP to 2.5, as long as there 3" piping by the exiting of the Turbine gases by the top of the DP im pretty comfortable with that.. JMHO but i love to hear different views.
If it was a full 2.5 DP, then i might not be very comfortable.

There's a reason why people go up in size in piping right ? so if the beginning is 3 and tapering to 1 inch is same thing also ? More flow , better for turbo cars!

[5soko]

Originally Posted by PlutoniumTans

There's a reason why people go up in size in piping right ? so if the beginning is 3 and tapering to 1 inch is same thing also ? More flow , better for turbo cars!

pretty much would be the same, if the rest of the catback is 1 inch...

Think of it as the exmaple i gave before, if u blow into a straw (no homo) and compress it a lil with ur finger at the top of the straw compared to if u are compressing it by the bottom of the straw, will the amount of air coming out the straw differ? einstein status hahah or i might be over thinking this.

[Bodie217]

As long as the outlet is 2.5", it doesn't matter if it's a full 3" DP or if its a 3" bellmouth tapering to 2.5"... It's just slick marketing lingo to make you buy their product.

[Topless///M]

One plus for the CP-Es is they seem thicker, a little more insulated like stock.

Most probably won't care, but when I had my ARs installed, I did hear more exhaust flow noise through the firewall and footwell area (not rubbing or leaks, but airflow noise) probably because they're not as thick and insulated as the stock ones. Some will probably think I'm crazy, but it's the same noise you hear when you put aftermarket headers on a car with thinwall primaries coming from a thick cast iron exhaust manifold. Wasn't that noticeable, but you could tell the difference. I didn't care much, but it's worth noting and my brother knew what I meant.

CP-Es seem to be made of thicker material....at least I know the cast belmouth is, not sure on the pipe.

[5soko]

Originally Posted by HomeRun217

As long as the outlet is 2.5", it doesn't matter if it's a full 3" DP or if its a 3" bellmouth tapering to 2.5"... It's just slick marketing lingo to make you buy their product.

Yea i always thought the same honestly. Even tho evberyone will refer to Mr.5 dyno comparison of 2.5 vs 3inch dp's, i dont really see how but i have yet to see anymore data.

Originally Posted by Topless///M

One plus for the CP-Es is they seem thicker, a little more insulated like stock.

Most probably won't care, but when I had my ARs installed, I did hear more exhaust flow noise through the firewall and footwell area (not rubbing or leaks, but airflow noise) probably because they're not as thick and insulated as the stock ones. Some will probably think I'm crazy, but it's the same noise you hear when you put aftermarket headers on a car with thinwall primaries coming from a thick cast iron exhaust manifold. Wasn't that noticeable, but you could tell the difference. I didn't care much, but it's worth noting and my brother knew what I meant.

CP-Es seem to be made of thicker material....at least I know the cast belmouth is, not sure on the pipe.

Interesting, thanks.

[Zasquatch]

Originally Posted by 5soko335i

Yea i always thought the same honestly. Even tho evberyone will refer to Mr.5 dyno comparison of 2.5 vs 3inch dp's, i dont really see how but i have yet to see anymore data.

Not to mention the amount of R&D cp-e puts into their products is incredible. I got their FMIC after reading their white paper detailing their design and testing and the balance between dP and dT. I highly doubt they just chose their downpipe design willy nilly and ignored the fact that competitors used longer sections of 3" piping. I gaurantee those bellmouths are CAD modeled and flow tested/optimized...

[ar design]

Originally Posted by Topless///M

One plus for the CP-Es is they seem thicker, a little more insulated like stock.

Most probably won't care, but when I had my ARs installed, I did hear more exhaust flow noise through the firewall and footwell area (not rubbing or leaks, but airflow noise) probably because they're not as thick and insulated as the stock ones. Some will probably think I'm crazy, but it's the same noise you hear when you put aftermarket headers on a car with thinwall primaries coming from a thick cast iron exhaust manifold. Wasn't that noticeable, but you could tell the difference. I didn't care much, but it's worth noting and my brother knew what I meant.

CP-Es seem to be made of thicker material....at least I know the cast belmouth is, not sure on the pipe.

We use .065 wall tubing, same as cp-e.

[geterdone]

Essentially if the DPs have 3" bellmouths and taper at least 1/3rd of the DP's length and are well designed, i.e. bends, then essentially a 3.0" to 2.5" would perform better based on physical flow modeling; since the rest of the exhaust is 2.5". I wish I could draw this out, but bigger isn't always better in some scenarios. Hence this is why I am probably going to go with the CPE's over the RLand's, since the RLand's are 2.5 all away down. Also please don't show me Mr.5's dyno results or thread, there is a huge difference when it comes down to having 3" bellmouths; in which case were not used on that test. Thanks

[E92ML]

How many xi guys are using CP-E downpipes?

[TOS_335i]

I'm in the process of installing my new CP-E dps right now! They are really nice pieces. Clean welds, and except for the bellmouth, they are a single piece. Can't really beat that for flow... I can't comment on the fitment, because I haven't gotten that far yet... I guess I'll find out soon enough.

BTW... I'm i not xi...

[Rotary Rasp]

I have VRSF but I have the admit, I think the CP-E are probably the best design. I also think the price is reasonable given the casting of the bell housing and one piece design.

[BMWeber]

Ive tried a few different DPs and CP-E are my favorite great fit easy installation and they are very rugged.

[klipseracer]

Originally Posted by 5soko335i

Since ALL DP's taper to 2.5"anyways.

Not true. 3" all the way through the midpipes, vbands both ends of the DP. No taper until the end of the midpipe, and only because it mated to stock exhaust.