E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > Tuning & Tech > Driveline, Engine & DME Tuning

Driveline, Engine & DME Tuning
Talk about driveline improvements, NA tuning and DME tuning your E46 BMW here. This includes diffs, intakes, exhausts, chips, software and OBD tuning.

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 08-02-2012, 07:39 AM   #1
Grande D
Registered User
 
Join Date: Dec 2006
Location: PA
Posts: 3,311
My Ride: Whiiiite BMW!
Question So I Hear Our Stock Catalytic Converters are 400CPI... Question

First of all, can anyone verify that this is correct? Are the non-M headers 400cpi?

And this is really reaching, I wouldn't imagine anyone flowbenched the stock cats at any point? I'm looking at race cats.

Third question, 400cpi- does that mean 400cpi per cat? For example Supersprint says their race cat section one is 200cpi, which according to M3forum means there are two 100cpi cats, for a total of 200cpi. Is that how the stock manifold works? Is it two 200 cell cats for a total of 400cpi?

TIA!
__________________
Quote:
Originally Posted by Jaymalls View Post
dont listen to these fuQ faces... just go to a junk yard and get a used complete left rear end. i cracked my left rear control arm on the highway because i was driving w/o shocks... lol! ***Was too busy caking on these bitches instead of taking care my car!***
Grande D is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 08-02-2012, 02:41 PM   #2
jared_wiesner
Registered User
 
Join Date: Aug 2009
Location: Ontario Canada
Posts: 678
My Ride: 1999 328i
Quote:
Originally Posted by zhp43867 View Post
First of all, can anyone verify that this is correct? Are the non-M headers 400cpi?

And this is really reaching, I wouldn't imagine anyone flowbenched the stock cats at any point? I'm looking at race cats.

Third question, 400cpi- does that mean 400cpi per cat? For example Supersprint says their race cat section one is 200cpi, which according to M3forum means there are two 100cpi cats, for a total of 200cpi. Is that how the stock manifold works? Is it two 200 cell cats for a total of 400cpi?

TIA!
I have been wondering the same thing. I would really like to know the answer to this if someone else can chime in.
__________________

Check out my band - The Marked

1999 BMW 328i (Daily Driver) - m54b30 intake manifold, ebay headers, Rebirth Motorsports CAI, Rogue Engineering underive pulleys, Epic Motorsports Remote Dyno Tune, Custom 3 inch exhaust with Burns Merge, Schrick 264/248 Cams
1967 Buick Skylark - 430 Buick Big Block Swap.
jared_wiesner is offline   Reply With Quote
Old 08-06-2012, 09:21 AM   #3
NIVO
Registered User
 
Join Date: Jan 2010
Location: Worcester, Ma
Posts: 339
My Ride: 2004 330Ci ZHP
Send a message via AIM to NIVO
Quote:
Originally Posted by zhp43867 View Post
First of all, can anyone verify that this is correct? Are the non-M headers 400cpi?

And this is really reaching, I wouldn't imagine anyone flowbenched the stock cats at any point? I'm looking at race cats.

Third question, 400cpi- does that mean 400cpi per cat? For example Supersprint says their race cat section one is 200cpi, which according to M3forum means there are two 100cpi cats, for a total of 200cpi. Is that how the stock manifold works? Is it two 200 cell cats for a total of 400cpi?

TIA!

If the car has 400cpi OEM catalytic converters and you go to a higher flowing 100 cell per inch race cat the car might throw a light. I have seen these many times. 200 cell is mostly used when you want good sound absorption but yet still flow better then OEM and not throw a light. I myself have a 200cpi metallic substrate catalytic converter I will be using for my car.

I highly doubt that the factory catalytic converters are 200 cpi each. more like 500-600cpi as companies like Porsche, Ferrari etc use 400cpi cats too. I have replaced a few of those with performance versions and they were not 200cpi even on Porsche turbo model cars!

I would do 200 cpi metallic substrate spun cats if you can.
__________________

www.E46Turbo330Ci.com
WARNING: This modification is known to the State of California to cause cancer and birth defects or other reproductive harm due to the extreme G forces once turbo kicks in. ~ Nivo
The rest of my signature is reserved for pointless modification bits like: Halos | window Tint | carbon fiber roundels | short shifter
NIVO is offline   Reply With Quote
Old 08-07-2012, 03:12 PM   #4
Grande D
Registered User
 
Join Date: Dec 2006
Location: PA
Posts: 3,311
My Ride: Whiiiite BMW!
Random Tech would be my choice, cost vs performance. I hear HJS might be even better. MBS is a left field alternative. I know 100 would throw a light, I'm just wondering whether 400cpi means 200+200, or 400 and 400.
__________________
Quote:
Originally Posted by Jaymalls View Post
dont listen to these fuQ faces... just go to a junk yard and get a used complete left rear end. i cracked my left rear control arm on the highway because i was driving w/o shocks... lol! ***Was too busy caking on these bitches instead of taking care my car!***
Grande D is offline   Reply With Quote
Old 08-07-2012, 04:14 PM   #5
NIVO
Registered User
 
Join Date: Jan 2010
Location: Worcester, Ma
Posts: 339
My Ride: 2004 330Ci ZHP
Send a message via AIM to NIVO
Quote:
Originally Posted by zhp43867 View Post
Random Tech would be my choice, cost vs performance. I hear HJS might be even better. MBS is a left field alternative. I know 100 would throw a light, I'm just wondering whether 400cpi means 200+200, or 400 and 400.
the M3 is a high output vehicle and other manufacturers use the 400 cpi cats as their high flow but yet emission friendly. I am sure that the factory M3 cats are considered 400cpi each.

A few years back we did testing on Random Tech metallic substrate 200cpi, Mil.Spec 100cpi, Magnaflow spun metallic substrate 300cpi, Eastern Cat metallic substrate 200cpi.

In order of performance:
Mil.Spec - $179 - 434whp
Eastern Cat - $80 -427whp
Random Tech - $255 -421whp
Magnaflow - $190 - 407whp

Since the testing I have used the Eastern cats for daily driving with some performance, I remove them for the track with a Vband set up. Previously I have used Mil.Spec and Random tech. I chose based on testing at the dyno I ran.

I attached a picture of one of the set ups we used during testing. Don't quote me on this but I think it is the Mil.Spec on the picture.
Other pic is of us having fun on the dyno testing this stuff.
Attached Thumbnails
Click image for larger version

Name:	IMAGE_010.jpg
Views:	76
Size:	144.3 KB
ID:	463959   Click image for larger version

Name:	Cat Dyno test.jpg
Views:	59
Size:	76.0 KB
ID:	463960  
__________________

www.E46Turbo330Ci.com
WARNING: This modification is known to the State of California to cause cancer and birth defects or other reproductive harm due to the extreme G forces once turbo kicks in. ~ Nivo
The rest of my signature is reserved for pointless modification bits like: Halos | window Tint | carbon fiber roundels | short shifter
NIVO is offline   Reply With Quote
Old 08-08-2012, 01:47 PM   #6
Grande D
Registered User
 
Join Date: Dec 2006
Location: PA
Posts: 3,311
My Ride: Whiiiite BMW!
Nice! Great info. How about the durability of the Eastern Cat? How does it "handle" the OBD-2 light saga compared to Random Tech and Magnaflow if you know?
__________________
Quote:
Originally Posted by Jaymalls View Post
dont listen to these fuQ faces... just go to a junk yard and get a used complete left rear end. i cracked my left rear control arm on the highway because i was driving w/o shocks... lol! ***Was too busy caking on these bitches instead of taking care my car!***

Last edited by Grande D; 08-08-2012 at 01:48 PM.
Grande D is offline   Reply With Quote
Old 08-08-2012, 02:11 PM   #7
NIVO
Registered User
 
Join Date: Jan 2010
Location: Worcester, Ma
Posts: 339
My Ride: 2004 330Ci ZHP
Send a message via AIM to NIVO
Quote:
Originally Posted by zhp43867 View Post
Nice! Great info. How about the durability of the Eastern Cat? How does it "handle" the OBD-2 light saga compared to Random Tech and Magnaflow if you know?
Well the higher flow through the cat will make the secondary Oxygen sensors thik that there is no cat there thus throwing a light, this is very common with the 100cpi cats. rarely does it happen on 200cpi on up. Using the Mil.Spec 100 cell cat the 4 out of 7 cars I know have passed emissions. I decided to go with the 200cpi myself because in mass they are strict like in Cali.

Here is a test from the Evo guys:
Ceramic highflow vs metallic substrate mil.spec, gains 14whp, ceramic is dotted lines


Here is an owner that wanted to go from test pipe to 100cpi cat (mil.Spec)
Lost 5whp and 11wtq. Test pipe is dotted lines
__________________

www.E46Turbo330Ci.com
WARNING: This modification is known to the State of California to cause cancer and birth defects or other reproductive harm due to the extreme G forces once turbo kicks in. ~ Nivo
The rest of my signature is reserved for pointless modification bits like: Halos | window Tint | carbon fiber roundels | short shifter

Last edited by NIVO; 08-08-2012 at 02:12 PM.
NIVO is offline   Reply With Quote
Old 08-08-2012, 02:35 PM   #8
Grande D
Registered User
 
Join Date: Dec 2006
Location: PA
Posts: 3,311
My Ride: Whiiiite BMW!
What about durability? Estimate mileage before failure? Mostly for street use- some track.
__________________
Quote:
Originally Posted by Jaymalls View Post
dont listen to these fuQ faces... just go to a junk yard and get a used complete left rear end. i cracked my left rear control arm on the highway because i was driving w/o shocks... lol! ***Was too busy caking on these bitches instead of taking care my car!***
Grande D is offline   Reply With Quote
Old 08-08-2012, 02:57 PM   #9
NIVO
Registered User
 
Join Date: Jan 2010
Location: Worcester, Ma
Posts: 339
My Ride: 2004 330Ci ZHP
Send a message via AIM to NIVO
Quote:
Originally Posted by zhp43867 View Post
What about durability? Estimate mileage before failure? Mostly for street use- some track.
Well I know that on my Z cars and other cars that I have used spun metallic substrate cats from random tech, mil.spec, eastern catalytic, well they all worked and no issues at all even with rich mixtures. I have a few Evo buddies with over 450whp with the Eastern Cat and no issues. that also goes for the Mil.Spec cat.

Metallic substrate cats flow a bit more the ceramics and can withstand the heat from diesel and turbocharged high EGTs.

for a daily driver it will last longer then OEM ceramic cats. I haven't personally seen any metallic spun high flow cats fail. That is all I will ever use to replace OEM units.
__________________

www.E46Turbo330Ci.com
WARNING: This modification is known to the State of California to cause cancer and birth defects or other reproductive harm due to the extreme G forces once turbo kicks in. ~ Nivo
The rest of my signature is reserved for pointless modification bits like: Halos | window Tint | carbon fiber roundels | short shifter
NIVO is offline   Reply With Quote
Old 08-08-2012, 03:51 PM   #10
aggieE46
Keep it clean
 
aggieE46's Avatar
 
Join Date: Aug 2006
Location: Royse City
Posts: 8,037
My Ride: 03 Evo, 07 Passat
Send a message via AIM to aggieE46
That's some good information.

Quote:
Originally Posted by NIVO View Post
the M3 is a high output vehicle and other manufacturers use the 400 cpi cats as their high flow but yet emission friendly. I am sure that the factory M3 cats are considered 400cpi each.

A few years back we did testing on Random Tech metallic substrate 200cpi, Mil.Spec 100cpi, Magnaflow spun metallic substrate 300cpi, Eastern Cat metallic substrate 200cpi.

In order of performance:
Mil.Spec - $179 - 434whp
Eastern Cat - $80 -427whp
Random Tech - $255 -421whp
Magnaflow - $190 - 407whp

Since the testing I have used the Eastern cats for daily driving with some performance, I remove them for the track with a Vband set up. Previously I have used Mil.Spec and Random tech. I chose based on testing at the dyno I ran.

I attached a picture of one of the set ups we used during testing. Don't quote me on this but I think it is the Mil.Spec on the picture.
Other pic is of us having fun on the dyno testing this stuff.
__________________
aggieE46 is offline   Reply With Quote
Old 08-09-2012, 05:06 PM   #11
aggieE46
Keep it clean
 
aggieE46's Avatar
 
Join Date: Aug 2006
Location: Royse City
Posts: 8,037
My Ride: 03 Evo, 07 Passat
Send a message via AIM to aggieE46
I started up my car today with no catback on. With stock headers and no exhaust it's quieter than my car was with Techniks and headers.
__________________
aggieE46 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

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
Censor is OFF





All times are GMT -5. The time now is 05:34 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
(c) 1999 - 2011 performanceIX Inc - privacy policy - terms of use