Downpipe questions, help me decide???

topspin · 08-28-2010, 08:10 PM

I’m interested in purchasing a set of downpipes.

I have stock exhaust, DCI and PROcede V4 on a 2008 335i with 6AT. I’ll be getting the CP-E FMIC + OC soon via the group buy that just ended.

I've read that to get big gains you need should go catless but, I need to be able to pass emissions tests which they did the last two years by connecting to the OBDII port.

With catless will I have emissions problems?
With catless will I have any problems with secondary cats getting damaged from less restrictive exhaust flow plus running higher boost allowed by a tune?
Are there significant advantages to thermal wraps or coatings like additional power or lower temperatures felt near the floor board?
I saw where Mr. 5 showed that 3 inch downpipes yielded additional power when compared to 2.5 inch in his car. Finally, is there any consensus as to whether 3 inch is generally better everything else held equal?

OK I’ll stop there for risk of asking too many questions to start a thread.

Syndicategt · 08-28-2010, 08:13 PM

Depending on how strict your state is, you should be fine with just having secondary cats on and still be able to pass emissions.

Might want to ask in you regional forums.

topspin · 08-28-2010, 08:26 PM

Quote:

Originally Posted by Syndicategt

Depending on how strict your state is, you should be fine with just having secondary cats on and still be able to pass emissions.

So emissions standards are defined by state... I'm in Chattanooga, TN.

Maybe someone from Tennessee can comment on their testing experience while catless?

cn555ic · 08-28-2010, 09:32 PM

If there is no visual inspection you should be fine, plus Procede V4 has 02 sims built in so either way you will pass...Many people have secondary cats in place and are fine and doesn't get damaged...Coating is supposedly better to retain heat which I had done with my Dps...I dont feel any excessive heat at all...3 inch compared to 2.5 inch is marginal in performance although Mr 5. did show gains, but like I stated its marginal IMO..

Forcefed3 · 08-29-2010, 10:09 AM

Quote:

Originally Posted by cn555ic

If there is no visual inspection you should be fine, plus Procede V4 has 02 sims built in so either way you will pass...Many people have secondary cats in place and are fine and doesn't get damaged...Coating is supposedly better to retain heat which I had done with my Dps...I dont feel any excessive heat at all...3 inch compared to 2.5 inch is marginal in performance although Mr 5. did show gains, but like I stated its marginal IMO..

What kind of DP's did you get? AR?

cn555ic · 08-29-2010, 10:16 AM

AR dps with thermal coating. Bought them directly fro
AR Designs. Had to wait a little longer for delivery because of coating but IMO even though other DPs for significantly less works, I had piece of mind when installing them that I would not run into any issue of fitment....If you already did a DP install with ramps, you all know how difficult it is and then to find out that there are fitment issues and you can't get the car back up and running, it beyond frustrating to the point that I would probably had exploded and the stress would have been to the roof....I bought that AR knowing that they have never had an issue with fitment....I paid a little more but for safe of mind and also fitment had to be SPOT on with a E93 chasis which is alot more difficult to install because the space is smaller...

topspin · 08-29-2010, 08:40 PM

It seems to be well known on the forums (although I'm just learning this) that downpipes are a PITA to install and perhaps the most difficult of all the mods. So now I'm wondering about installation and fitment.

Does anyone have estimates on how long it would take a mechanic to install downpipes?

Does anyone have an installation guide or know of any DYI guides?

Thanks in advance.

cn555ic · 08-29-2010, 08:41 PM

Quote:

Originally Posted by topspin

It seems to be well known on the forums (although I'm just learning this) that downpipes are a PITA to install and perhaps the most difficult of all the mods. So now I'm wondering about installation and fitment.

Does anyone have estimates on how long it would take a mechanic to install downpipes?

Does anyone have an installation guide or know of any DYI guides?

Thanks in advance.

For a mechanic using a lift, it should take about 2 hours.

forza1976 · 08-29-2010, 10:04 PM

AR Design DP's ONLY!

ar design · 08-30-2010, 09:49 AM

Quote:

Originally Posted by cn555ic

For a mechanic using a lift, it should take about 2 hours.

I did last set in under 2 hrs on jackstands.....

Bimmer This · 08-30-2010, 10:05 AM

Quote:

Originally Posted by ar design

I did last set in under 2 hrs on jackstands.....

That's because your mechanic skills are unbeatable!

Kevin@AKMotorwerk · 08-30-2010, 10:06 AM

do yourself and your car a huge favor and use ar design dp's, not only are they perfect, they have much better resale value!!!!!

Bimmer This · 08-30-2010, 10:11 AM

Quote:

Originally Posted by Kevin@AKMotorwerk

do yourself and your car a huge favor and use ar design dp's, not only are they perfect, they have much better resale value!!!!!

And world class customer support!

ar design · 08-30-2010, 10:50 AM

Quote:

Originally Posted by Bimmer This

That's because your mechanic skills are unbeatable!

Coming from V himself..... what more can be said?

Quote:

Originally Posted by Bimmer This

And world class customer support!

I heard the owner is a real jerk.....

Bimmer This · 08-30-2010, 11:12 AM

Quote:

Originally Posted by ar design

Coming from V himself..... what more can be said?

I heard the owner is a real jerk.....

You must be talking to the wrong owner. The one know is a "softy" teddy bear.

ar design · 08-30-2010, 11:42 AM

Quote:

Originally Posted by Bimmer This

You must be talking to the wrong owner. The one know is a "softy" teddy bear.

Type-R Yo! · 08-30-2010, 11:51 AM

Just order AR design catless dps.

topspin · 08-30-2010, 01:03 PM

Quote:

Originally Posted by ar design

I did last set in under 2 hrs on jackstands.....

Does AR have an installation guide? If so I may just get your pipes through the group buy and try the installation myself.

Bimmer This · 08-30-2010, 01:08 PM

Quote:

Originally Posted by topspin

Does AR have an installation guide? If so I may just get your pipes through the group buy and try the installation myself.

DP's are pretty straight forward. Just don't get the O2's mixed up.

topspin · 09-03-2010, 01:35 AM

I ordered the AR catless downpipes with ceramic coating as part of the Lutz Performance group buy that closed earlier this week. The cost was $650 (downpipes) + $159 (ceramic coating) + $30 (shipping) for a total of $839.

Thanks to all who contributed to helping me decide.

08-28-2010, 08:10 PM	#1
topspin Private First Class 4 Rep 177 Posts Drives: 2008 BMW 335i Join Date: Jun 2010 Location: Chattanooga, TN iTrader: (1)	Downpipe questions, help me decide??? I’m interested in purchasing a set of downpipes. I have stock exhaust, DCI and PROcede V4 on a 2008 335i with 6AT. I’ll be getting the CP-E FMIC + OC soon via the group buy that just ended. I've read that to get big gains you need should go catless but, I need to be able to pass emissions tests which they did the last two years by connecting to the OBDII port. With catless will I have emissions problems? With catless will I have any problems with secondary cats getting damaged from less restrictive exhaust flow plus running higher boost allowed by a tune? Are there significant advantages to thermal wraps or coatings like additional power or lower temperatures felt near the floor board? I saw where Mr. 5 showed that 3 inch downpipes yielded additional power when compared to 2.5 inch in his car. Finally, is there any consensus as to whether 3 inch is generally better everything else held equal? OK I’ll stop there for risk of asking too many questions to start a thread.
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08-28-2010, 08:13 PM	#2
Syndicategt Brigadier General 164 Rep 3,730 Posts Drives: 335i Join Date: Sep 2009 Location: Nor Cal iTrader: (11)	Depending on how strict your state is, you should be fine with just having secondary cats on and still be able to pass emissions. Might want to ask in you regional forums. __________________ 2008 BMW 335i e90 - Sold - Rob Beck Turbos / PROcede V5 / Aquamist HFS-4 / AR Downpipes / AE Exhaust / ER Comp FMIC / ER CP / TiAL BOV / Custom Intake / RPI Scoops / Quaife LSD / Swift-Koni Coilovers / DSS HS / Morr VS8.2 Sig Black / Michelin PSS / P3 Boost Guage / M3 body / M3 steering wheel / Adam's Rotors / Hawk HPS / SS lines / Last edited by Syndicategt; 08-28-2010 at 08:35 PM..
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08-28-2010, 09:32 PM	#4
cn555ic 460 Rep 18,331 Posts Drives: 335i Join Date: Jun 2007 Location: US iTrader: (6)	If there is no visual inspection you should be fine, plus Procede V4 has 02 sims built in so either way you will pass...Many people have secondary cats in place and are fine and doesn't get damaged...Coating is supposedly better to retain heat which I had done with my Dps...I dont feel any excessive heat at all...3 inch compared to 2.5 inch is marginal in performance although Mr 5. did show gains, but like I stated its marginal IMO..
	Appreciate 0 Quote

08-29-2010, 10:16 AM	#6
cn555ic 460 Rep 18,331 Posts Drives: 335i Join Date: Jun 2007 Location: US iTrader: (6)	AR dps with thermal coating. Bought them directly fro AR Designs. Had to wait a little longer for delivery because of coating but IMO even though other DPs for significantly less works, I had piece of mind when installing them that I would not run into any issue of fitment....If you already did a DP install with ramps, you all know how difficult it is and then to find out that there are fitment issues and you can't get the car back up and running, it beyond frustrating to the point that I would probably had exploded and the stress would have been to the roof....I bought that AR knowing that they have never had an issue with fitment....I paid a little more but for safe of mind and also fitment had to be SPOT on with a E93 chasis which is alot more difficult to install because the space is smaller... Last edited by cn555ic; 08-29-2010 at 12:11 PM..
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08-29-2010, 08:40 PM	#7
topspin Private First Class 4 Rep 177 Posts Drives: 2008 BMW 335i Join Date: Jun 2010 Location: Chattanooga, TN iTrader: (1)	Installation? It seems to be well known on the forums (although I'm just learning this) that downpipes are a PITA to install and perhaps the most difficult of all the mods. So now I'm wondering about installation and fitment. Does anyone have estimates on how long it would take a mechanic to install downpipes? Does anyone have an installation guide or know of any DYI guides? Thanks in advance.
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08-29-2010, 10:04 PM	#9
forza1976 Major General 3507 Rep 6,625 Posts Drives: BMW Join Date: Aug 2007 Location: 49456 iTrader: (13) Garage List 2022 BMW M3X [9.50]	AR Design DP's ONLY!
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08-30-2010, 10:06 AM	#12
Kevin@AKMotorwerk General 290 Rep 28,154 Posts Drives: THE GUY YOU LOVE TO HATE Join Date: Mar 2009 Location: hillsborough, nj iTrader: (1)	do yourself and your car a huge favor and use ar design dp's, not only are they perfect, they have much better resale value!!!!!
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08-30-2010, 11:51 AM	#17
Type-R Yo! Private 2 Rep 75 Posts Drives: 2009 335i 6MT M-Sport Join Date: Aug 2009 Location: Greenville, SC iTrader: (0)	Just order AR design catless dps. __________________ 2001 Phoenix Yellow Integra Type-R (Track Car "Road Course") 2008 Black 911 GT2 (New Track Car "Road Course") 2009 Le Mans Blue E90 335i 6MT M-sport (Built date: 7-09) (Daily Driver) "SOLD" 2012 Palladium Silver Metallic ML350 BlueTec
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09-03-2010, 01:35 AM	#20
topspin Private First Class 4 Rep 177 Posts Drives: 2008 BMW 335i Join Date: Jun 2010 Location: Chattanooga, TN iTrader: (1)	I ordered the AR catless downpipes with ceramic coating as part of the Lutz Performance group buy that closed earlier this week. The cost was $650 (downpipes) + $159 (ceramic coating) + $30 (shipping) for a total of $839. Thanks to all who contributed to helping me decide. __________________ 2008 E90 335i \| PROcede Rev 2.5 \| PWM Meth \| CP-E FMIC + OC \| AR catless ceramic DP \| BMS DCI \| Wavetrac LSD \| MORR MonoForged VS8.2 \| Michelin PSS
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