E90Post
 


Extreme Power House
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > Guttin Cats on DP's?



Reply
 
Thread Tools Search this Thread
      06-08-2007, 11:19 PM   #1
1badE90
Private First Class
 
Drives: Montego Blue w/ Sports Package
Join Date: May 2007
Location: Arcadia, Ca

Posts: 109
iTrader: (0)

Garage List
2007 335i  [0.00]
Guttin Cats on DP's?

All this talk about dp's on another thread. Has anyone thought about guttin cats. Audi guys used to call this piggie pipes and we made a lot of power on stock pipes. If no one makes a reasonable dp I might do the same. I'll do a dyno b4 and after if I do, do this.
1badE90 is offline   United_States
0
Reply With Quote
      06-09-2007, 05:29 AM   #2
Neema
Major General
 
Neema's Avatar
 
Drives: a few BMWs
Join Date: Dec 2006
Location: SoCal

Posts: 7,186
iTrader: (11)

sounds good. The only thing that keeps me cautious about DP modding is the obvious AFR problems, 02 sensor problems, and CEL issues.
Neema is offline   United_States
0
Reply With Quote
      06-09-2007, 06:27 AM   #3
judec
born to be turbocharged
 
judec's Avatar
 
Drives: Not a bimmer yet
Join Date: May 2007
Location: Slovakia

Posts: 1,347
iTrader: (0)

Send a message via ICQ to judec Send a message via Skype™ to judec
Quote:
Originally Posted by 1badE90 View Post
All this talk about dp's on another thread. Has anyone thought about guttin cats. Audi guys used to call this piggie pipes and we made a lot of power on stock pipes. If no one makes a reasonable dp I might do the same. I'll do a dyno b4 and after if I do, do this.
What?
Be so kind and give some explanation, pics etc.
judec is offline   Slovakia
0
Reply With Quote
      06-09-2007, 05:25 PM   #4
SfValley335i
Colonel
 
Drives: Current:135i Sold:335i sedan
Join Date: Mar 2007
Location: City of Angels

Posts: 2,396
iTrader: (8)

Send a message via AIM to SfValley335i
Quote:
Originally Posted by Boost_Nation View Post
sounds good. The only thing that keeps me cautious about DP modding is the obvious AFR problems, 02 sensor problems, and CEL issues.

thats why you get a tune for it.... every mod you do requires a tune to get the full use(power) out of the mod.
SfValley335i is offline   Afghanistan
0
Reply With Quote
      06-09-2007, 05:48 PM   #5
itsbrokeagain
 
itsbrokeagain's Avatar
 
Drives: E28 535, 1996 Dodge Ram Diesel
Join Date: Mar 2007
Location: Valley Stream, NY

Posts: 15,737
iTrader: (7)

Send a message via AIM to itsbrokeagain
no point in gutting the downpipes. Would cause a restriction as mentioned in the other thread due to the sudden increase in pipe diameter then back down again.

Not to mention why would you break apart a set of downpipes that cost somewhere north of $1500 each?
__________________
AUTOCouture Motoring: Handling reflector installs to turbo upgrades and superchargers, and everything in between
15-01 Pollitt Drive, Fairlawn NJ 201-666-3500

<-Official Vehicle Transport for AUTOCouture
itsbrokeagain is offline   United_States
0
Reply With Quote
      06-09-2007, 06:11 PM   #6
max boost
Lieutenant
 
max boost's Avatar
 
Drives: 07 335i
Join Date: Nov 2006
Location: east side

Posts: 408
iTrader: (1)

Quote:
Originally Posted by itsbrokeagain View Post
no point in gutting the downpipes. Would


Not to mention why would you break apart a set of downpipes that cost somewhere north of $1500 each?


max boost is offline  
0
Reply With Quote
      06-09-2007, 06:45 PM   #7
kujo
Major
 
Drives: BMW
Join Date: May 2006
Location: LA, CA USA

Posts: 1,153
iTrader: (1)

This worked very , very well on B5 S4s.

I came from the audi world and this, with a tune made GOBS of HP.

Piggie Pipes..........
kujo is offline  
0
Reply With Quote
      06-09-2007, 07:21 PM   #8
1badE90
Private First Class
 
Drives: Montego Blue w/ Sports Package
Join Date: May 2007
Location: Arcadia, Ca

Posts: 109
iTrader: (0)

Garage List
2007 335i  [0.00]
Quote:
Originally Posted by itsbrokeagain View Post
no point in gutting the downpipes. Would cause a restriction as mentioned in the other thread due to the sudden increase in pipe diameter then back down again.

Not to mention why would you break apart a set of downpipes that cost somewhere north of $1500 each?
Do some research first. I came from the audi tuning world. Guttin the cats on DP's would give the car an increase in HP. Do a search on Audiworld.com
and there are endless dyno charts on piggie pipes.
1badE90 is offline   United_States
0
Reply With Quote
      06-09-2007, 07:23 PM   #9
1badE90
Private First Class
 
Drives: Montego Blue w/ Sports Package
Join Date: May 2007
Location: Arcadia, Ca

Posts: 109
iTrader: (0)

Garage List
2007 335i  [0.00]
Quote:
Originally Posted by Boost_Nation View Post
sounds good. The only thing that keeps me cautious about DP modding is the obvious AFR problems, 02 sensor problems, and CEL issues.

From what i am told that A. this car uses wideband B. the o2's are b4 the cats and c. custom maps from vishnu would solve CEL and AFR issues.
1badE90 is offline   United_States
0
Reply With Quote
      06-09-2007, 09:01 PM   #10
itsbrokeagain
 
itsbrokeagain's Avatar
 
Drives: E28 535, 1996 Dodge Ram Diesel
Join Date: Mar 2007
Location: Valley Stream, NY

Posts: 15,737
iTrader: (7)

Send a message via AIM to itsbrokeagain
Quote:
Originally Posted by 1badE90 View Post
Do some research first. I came from the audi tuning world. Guttin the cats on DP's would give the car an increase in HP. Do a search on Audiworld.com
and there are endless dyno charts on piggie pipes.

Oh I know they would give an increase in power. You are removing a restriction in the pipe. But you would get MORE hp if you just had a smooth flowing, straight pipe.

IMO I still wouldn't do it.
__________________
AUTOCouture Motoring: Handling reflector installs to turbo upgrades and superchargers, and everything in between
15-01 Pollitt Drive, Fairlawn NJ 201-666-3500

<-Official Vehicle Transport for AUTOCouture
itsbrokeagain is offline   United_States
0
Reply With Quote
      06-09-2007, 09:39 PM   #11
PSI Power
Twin Turbo Goodness
 
PSI Power's Avatar
 
Drives: '07 335i E90
Join Date: Jan 2007
Location: Northern Virginia

Posts: 614
iTrader: (2)

Yes Piggie Pipes worked very well on the older S4.
I bought aftermarket downpipes for my S4, cost me $1600 plus installation. I did not think the added performance to my stock turbos was worth the 1600. I would have probably had done piggie pipes if my timing was better.

For the S4, upgraded turbos required larger downpipes but getting larger downpipes on the stock turbos was not worth it for me. It did add better top end performance but nothing that blew me away.
__________________
ED Date: May 7, 2007
Montego Blue / Black Leather / Aluminum Trim / 6Spd
Prem, Sport, Navi, CW, CA, PDC, and Lots of Fun!

MODS: A little bit of this, A little bit of that
PSI Power is offline   United_States
0
Reply With Quote
      06-10-2007, 10:43 AM   #12
zenmaster
Lieutenant Colonel
 
Drives: '13 AH3
Join Date: Mar 2007
Location: Atlanta

Posts: 1,610
iTrader: (1)

Quote:
Originally Posted by itsbrokeagain View Post
Oh I know they would give an increase in power. You are removing a restriction in the pipe. But you would get MORE hp if you just had a smooth flowing, straight pipe.

IMO I still wouldn't do it.
It's common sense you'd get more HP from smoother flowing pipes. I wouldn't gut the cats on a new car, but on an older car, sure - if it yielded decent gains .

Downpipe mod might return the largest gain after the ECU mod. The turbos will spool up faster, so you get more power available at lower RPMs and throughout the power band. The backpressure on turbo'd engines can be alliviated with better flowing exhaust, and there really no limit to power returns (unlike a NA engine). It sucks that there is not enough room provided to do a 3" exhaust on these cars.
zenmaster is offline   United_States
0
Reply With Quote
      06-10-2007, 11:35 AM   #13
My E90
Captain
 
Drives: '13 E92 M3 6MT SSII
Join Date: May 2007
Location: South Floorida

Posts: 755
iTrader: (2)

Quote:
Originally Posted by judec View Post
What?
Be so kind and give some explanation, pics etc.
Piggie Pipes - a common name for downpipes off of an Audi B5 S4 (2000-2002) that have had the contents of the pre-cat removed.

In B5 S4 forums (mainly AudiWorld), the S4 is referred to as a pig because of the weight of the car. The Audi guys have a pretty good sense of humor and came up with the term piggie pipes for stock downpipes that had the first set of cats (pre-cats) gutted. They were cheap to buy ($300 from Vast Performance or FREE if you DIY) compared to the custom pipes that were going for $1,200+. On a chipped car and even upgraded to a K04, the measurable difference the extra $1,000 made was not really that much. Endless posts were created on this topic on Audiworld.

The actual pre-cat on the S4 are easier to get to compared to ones on a 335 so it was a much simpler procedure.... remove pipes, gut pre-cats using your favorite tools and put it back on. All that was left to do was relocate the second O2 sensor to the rear of the main cat. No check engine light and about 15whp & torque with faster turbo spool times.

Is it better to have a smooth pipe, yes. But you can't beat $300 (or $free) for similar power. I think this option will come around once tuner-built downpipes start to hit the market.

Hollowed out B5 S4 downpipe:



The inside of the Cat:



Anyways... just my $.02
__________________
'13 M3 E92 SSII | 6MT | ZCP | ZPP | EPS | NAV | MPE | ED & PCD
My E90 is offline   United_States
0
Reply With Quote
      06-10-2007, 11:54 AM   #14
bnj
Banned
 
Drives: e92 335i
Join Date: Nov 2006
Location: Helsinki

Posts: 1,137
iTrader: (0)

Quote:
Originally Posted by zenmaster View Post
It's common sense you'd get more HP from smoother flowing pipes. I wouldn't gut the cats on a new car, but on an older car, sure - if it yielded decent gains .

Downpipe mod might return the largest gain after the ECU mod. The turbos will spool up faster, so you get more power available at lower RPMs and throughout the power band. The backpressure on turbo'd engines can be alliviated with better flowing exhaust, and there really no limit to power returns (unlike a NA engine). It sucks that there is not enough room provided to do a 3" exhaust on these cars.
If 2x2.5" is a restriction for you and you would need 2x3", you are going to have serious power. 600hp? Beyond?
bnj is offline  
0
Reply With Quote
      06-10-2007, 12:42 PM   #15
zenmaster
Lieutenant Colonel
 
Drives: '13 AH3
Join Date: Mar 2007
Location: Atlanta

Posts: 1,610
iTrader: (1)

Quote:
Originally Posted by bnj View Post
If 2x2.5" is a restriction for you and you would need 2x3", you are going to have serious power. 600hp? Beyond?
The thing is, on a turbo'd engine, you should always be able to make use of better flow, regardless of peak power you might want to achieve. 3" should make more power than 2.5", and the power band will probably widen. (Of course larger turbos get even better gains from larger diameter pipes.)
This guy is going to offer one of the first turbo kits for the 335i. Only thing I wonder about is why make all this torque when you know you are going to destroy your stock transmission. Even Alpina, with their hugely expensive B3 edition (the price difference in a stock 335i and B3 335i is over $30,000), limited torque output because installing an upgraded transmission was not an option - probably too costly.
zenmaster is offline   United_States
0
Reply With Quote
      06-10-2007, 02:32 PM   #16
1badE90
Private First Class
 
Drives: Montego Blue w/ Sports Package
Join Date: May 2007
Location: Arcadia, Ca

Posts: 109
iTrader: (0)

Garage List
2007 335i  [0.00]
Quote:
Originally Posted by PSI Power View Post
Yes Piggie Pipes worked very well on the older S4.
I bought aftermarket downpipes for my S4, cost me $1600 plus installation. I did not think the added performance to my stock turbos was worth the 1600. I would have probably had done piggie pipes if my timing was better.

For the S4, upgraded turbos required larger downpipes but getting larger downpipes on the stock turbos was not worth it for me. It did add better top end performance but nothing that blew me away.
Thats why I suggested gutting the cats. Why pay for DP's twice. Eventually when they come out I will do a larger turbo upgrade. But for the mean time why not?
1badE90 is offline   United_States
0
Reply With Quote
      06-10-2007, 06:04 PM   #17
judec
born to be turbocharged
 
judec's Avatar
 
Drives: Not a bimmer yet
Join Date: May 2007
Location: Slovakia

Posts: 1,347
iTrader: (0)

Send a message via ICQ to judec Send a message via Skype™ to judec
Cool

Quote:
Originally Posted by My E90 View Post
Piggie Pipes - a common name for downpipes off of an Audi B5 S4 (2000-2002) that have had the contents of the pre-cat removed.

In B5 S4 forums (mainly AudiWorld), the S4 is referred to as a pig because of the weight of the car. The Audi guys have a pretty good sense of humor and came up with the term piggie pipes for stock downpipes that had the first set of cats (pre-cats) gutted. They were cheap to buy ($300 from Vast Performance or FREE if you DIY) compared to the custom pipes that were going for $1,200+. On a chipped car and even upgraded to a K04, the measurable difference the extra $1,000 made was not really that much. Endless posts were created on this topic on Audiworld...
Thank you for explanation, it's clear to me now.

Quote:
Originally Posted by bnj View Post
If 2x2.5" is a restriction for you and you would need 2x3", you are going to have serious power. 600hp? Beyond?
BS. Bigger is better with turbo car, but fitting 3" pipes into the 335i is PITA.

2x2.5" is similar in volume to 1x3.5", while I've seen 600HP cars with 3" JT exhaust (actually including cat, I guess) and it works and makes ferraris cry on the highway, so everyone telling me 2x2.5" isn't enuff should stop smoking that weed and do the math.
judec is offline   Slovakia
0
Reply With Quote
      06-10-2007, 06:19 PM   #18
zenmaster
Lieutenant Colonel
 
Drives: '13 AH3
Join Date: Mar 2007
Location: Atlanta

Posts: 1,610
iTrader: (1)

Quote:
Originally Posted by judec View Post
2x2.5" is similar in volume to 1x3.5",
But isn't it one pipe for 3 cylinders? I don't know.
zenmaster is offline   United_States
0
Reply With Quote
      06-10-2007, 06:21 PM   #19
judec
born to be turbocharged
 
judec's Avatar
 
Drives: Not a bimmer yet
Join Date: May 2007
Location: Slovakia

Posts: 1,347
iTrader: (0)

Send a message via ICQ to judec Send a message via Skype™ to judec
yes, it is. double pipe 2.5" are almost equal single pipe 3.5" (actually a lilbit bigger). It was posted as an example, what's important is the final output of 600+HP on a single 3". it was 4 cylinders, 2.3liter connected to that one. Now in this one we have 3 cylinders 1.5 litre... 2.5" is not the best possible, but simply enuff.
judec is offline   Slovakia
0
Reply With Quote
      06-11-2007, 10:20 AM   #20
bnj
Banned
 
Drives: e92 335i
Join Date: Nov 2006
Location: Helsinki

Posts: 1,137
iTrader: (0)

Quote:
Originally Posted by judec View Post
BS. Bigger is better with turbo car, but fitting 3" pipes into the 335i is PITA.

2x2.5" is similar in volume to 1x3.5", while I've seen 600HP cars with 3" JT exhaust (actually including cat, I guess) and it works and makes ferraris cry on the highway, so everyone telling me 2x2.5" isn't enuff should stop smoking that weed and do the math.
Perhaps I don't get what you mean with "BS". Does it mean "I agree"? After "BS" you typed the same stuff that I said with slightly different terms.
bnj is offline  
0
Reply With Quote
      06-11-2007, 11:07 AM   #21
judec
born to be turbocharged
 
judec's Avatar
 
Drives: Not a bimmer yet
Join Date: May 2007
Location: Slovakia

Posts: 1,347
iTrader: (0)

Send a message via ICQ to judec Send a message via Skype™ to judec
BS = BullShit. It was meant as a decent comment on "2x2.5" is a restriction". It's volume is actually bigger like a single 3" used widely on lets say 500-600HP applications and until U reach that output I bet my trousers U'll find a whole lot of more real restrictions like a double 2.5" full exhaust (like turbos, IC, injectors, fuelpump...)
judec is offline   Slovakia
0
Reply With Quote
      06-11-2007, 11:42 AM   #22
bnj
Banned
 
Drives: e92 335i
Join Date: Nov 2006
Location: Helsinki

Posts: 1,137
iTrader: (0)

Quote:
Originally Posted by judec View Post
BS = BullShit. It was meant as a decent comment on "2x2.5" is a restriction". It's volume is actually bigger like a single 3" used widely on lets say 500-600HP applications and until U reach that output I bet my trousers U'll find a whole lot of more real restrictions like a double 2.5" full exhaust (like turbos, IC, injectors, fuelpump...)
I said that IF HE THINKS 2 x 2.5 IS RESTRICTION, he must be having > 600 horses.
bnj is offline  
0
Reply With Quote
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 06:43 PM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST