E90Post
 


TireRack
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > High Flow Cats. The Deal?



Reply
 
Thread Tools Search this Thread
      07-28-2013, 03:06 PM   #23
jnat
Boosted
 
Drives: 09 335 XI A/T
Join Date: Sep 2012
Location: Jersey

Posts: 133
iTrader: (0)

I really believe downpipes are overkill on this platform at 15-17 PSI and that 350 WHP level.

Last edited by jnat; 07-29-2013 at 06:29 AM.
jnat is offline  
0
Reply With Quote
      07-29-2013, 03:23 AM   #24
Cozy
Major
 
Cozy's Avatar
 
Drives: E82 135i
Join Date: Mar 2011
Location: Surrey, England

Posts: 1,489
iTrader: (0)

Quote:
Originally Posted by jnat View Post
That's what I'm talking about, for a DD, that's the ticket! I really believe downpipes are overkill on this platform at 15-17 PSI.
Perhaps, but why is there so much more to be had from upgrading the downpipes & losing the cats? What you're saying is that we could all just fit an intercooler and then map the car to an FBO tune. Has anyone tried running a Cobb Stage 2+ or equivalent JB4, Vishnu etc map with the stock downpipes? I sure haven't seen it and I wouldn't feel comfortable pushing that amount of flow through the stock downpipes without some sort of tests showing the effect on longevity of parts. There are a lot of tuners offering downpipes for this engine and sure, they are in the business of making money but they don't do their R&D for fun.

You mention in your previous post that you don't think running factory DP's at 350whp is a problem and you are right. However, 350whp is basically a Stage 1 + FMIC tune which does not require downpipes at all.

Last edited by Cozy; 07-29-2013 at 03:36 AM.
Cozy is offline   United Kingdom
0
Reply With Quote
      07-29-2013, 06:05 AM   #25
BuraQ
Colonel
 
BuraQ's Avatar
 
Drives: 11" E92 335is
Join Date: Nov 2010
Location: Florida

Posts: 2,858
iTrader: (0)

Garage List
2011 BMW 335is  [2.88]
Quote:
Originally Posted by Cozy View Post
Perhaps, but why is there so much more to be had from upgrading the downpipes & losing the cats? What you're saying is that we could all just fit an intercooler and then map the car to an FBO tune. Has anyone tried running a Cobb Stage 2+ or equivalent JB4, Vishnu etc map with the stock downpipes? I sure haven't seen it and I wouldn't feel comfortable pushing that amount of flow through the stock downpipes without some sort of tests showing the effect on longevity of parts. There are a lot of tuners offering downpipes for this engine and sure, they are in the business of making money but they don't do their R&D for fun.

You mention in your previous post that you don't think running factory DP's at 350whp is a problem and you are right. However, 350whp is basically a Stage 1 + FMIC tune which does not require downpipes at all.
Btw Cobb recommends highflow catted or cattless downpipes to run with there race maps.

I am surprised you mention JB4, Terry has been supporting lots of vehicles running 19 PSI on an all stock car

As for Vish, well, never seen him condoning such a thing. Perhaps I pay less attention to his tuning, but never heard of him doing this.

Everything about this platform and the community is about the "cheapest" alternative for max power gains so that is why cattless DPs have a larger presence over highflow catted DPs. Balance and efficiency is so much ignored it has no value or merit.

The difference of power gains between cattless and catted (highflow) are only a 5-8 whp difference and for some that is just not worth the sacrifice.
__________________
AP-V3 & Cobb Protuned by PTF: (New Times Coming Soon)
RENNtech Tuning: 11.78 ET @ 116 Mph in 1/4 mile YouTube
Dinan Stage 3: 12.5 ET (Best) 111 Mph (Best) in 1/4 mile
400+ launches, 3 Driveshafts, No DCT Slippage, Flash Only
BuraQ is offline   United_States
0
Reply With Quote
      07-29-2013, 06:39 AM   #26
jnat
Boosted
 
Drives: 09 335 XI A/T
Join Date: Sep 2012
Location: Jersey

Posts: 133
iTrader: (0)

I'm not even looking at it from a money stand point. I'm just thinking about what we have on our platform and what others have on theirs. I'm also taking into consideration years (like most of you) of research, reading and modding. Speaking of vendors, tuners, there are several that think on this platform with using two downpipes (three cylinders per) we are fine up to 400 WHP. At some power level, I'm in total agreement that you need to upgrade but if you look at our stock downpipes, there actually designed very well in comparison to some stock downpipes on other makes. The gains in our case are from loosing the kitties, not the downpipe design. Lastly, as referenced above, the gains are minimal and not much 'bang for buck'. My point is very arguable, just food for thought!
jnat is offline  
0
Reply With Quote
      07-29-2013, 06:47 AM   #27
Cozy
Major
 
Cozy's Avatar
 
Drives: E82 135i
Join Date: Mar 2011
Location: Surrey, England

Posts: 1,489
iTrader: (0)

As far as I know ALL tuners recommend that you use high flow downpipes (catted or not) with an FBO tune. If 5-8whp is all we can get between catless aftermarket and stock catted downpipes then why do we all bother?

I have never seen a tuner say that you can use an FBO tune with stock downpipes. If that was the case I'd be very happy and I'd go right outside now and change my tune from Cobb Stage 1+ to Stage 2+ and save a heap of cash.
Cozy is offline   United Kingdom
0
Reply With Quote
      07-29-2013, 09:20 AM   #28
BuraQ
Colonel
 
BuraQ's Avatar
 
Drives: 11" E92 335is
Join Date: Nov 2010
Location: Florida

Posts: 2,858
iTrader: (0)

Garage List
2011 BMW 335is  [2.88]
Quote:
Originally Posted by Cozy View Post
As far as I know ALL tuners recommend that you use high flow downpipes (catted or not) with an FBO tune. If 5-8whp is all we can get between catless aftermarket and stock catted downpipes then why do we all bother?

I have never seen a tuner say that you can use an FBO tune with stock downpipes. If that was the case I'd be very happy and I'd go right outside now and change my tune from Cobb Stage 1+ to Stage 2+ and save a heap of cash.
I agree but then there are some that do the contrary as they are suppose to lead by example.

Its because it is a cheaper solution. If catted DPs were less than $100 more than a cattless DPs then people would buy them more. However there is an average $400+ difference between the two.

I can show you worse, a tuner condoning a completely stock car running PSI that is suppose to be ran on a FBO car; however common sense says its wrong period
__________________
AP-V3 & Cobb Protuned by PTF: (New Times Coming Soon)
RENNtech Tuning: 11.78 ET @ 116 Mph in 1/4 mile YouTube
Dinan Stage 3: 12.5 ET (Best) 111 Mph (Best) in 1/4 mile
400+ launches, 3 Driveshafts, No DCT Slippage, Flash Only
BuraQ is offline   United_States
0
Reply With Quote
      07-29-2013, 03:39 PM   #29
jnat
Boosted
 
Drives: 09 335 XI A/T
Join Date: Sep 2012
Location: Jersey

Posts: 133
iTrader: (0)

Then why do we all bother is exactly my point! On other platforms, if you look at dyno plots, the difference between the stock pipe and any aftermarket is 35-50 WHP (with tune). On ours, the difference is up to 8 WHP, doesn't that raise a eyebrow or two? My read on that is our stock downpipes are not bottlenecks, they're fairly efficient and flow well. Again, at higher power levels, they're needed but not at DD power levels or what we all refer to as FBO. It's another personal preference. If I saw an incredible difference in dyno plots, I'd do it, but I don't. I'm going to stay away from the 'every tuner recommends' statements because it's not my point. I like to look at the results and again, IMHO the results say that at 350-400 WHP, our stock downpipes especially since we have two work well.
jnat is offline  
0
Reply With Quote
      07-29-2013, 03:45 PM   #30
shadow191
Captain
 
Drives: '07 E92 335i / '07 Infiniti FX
Join Date: Dec 2012
Location: GA

Posts: 818
iTrader: (3)

Difference between catless and high flow catted downpipes is 5-8 whp. Difference between OEM and catless is much higher.

Quote:
Originally Posted by jnat View Post
Then why do we all bother is exactly my point! On other platforms, if you look at dyno plots, the difference between the stock pipe and any aftermarket is 35-50 WHP (with tune). On ours, the difference is up to 8 WHP, doesn't that raise a eyebrow or two? My read on that is our stock downpipes are not bottlenecks, they're fairly efficient and flow well. Again, at higher power levels, they're needed but not at DD power levels or what we all refer to as FBO. It's another personal preference. If I saw an incredible difference in dyno plots, I'd do it, but I don't. I'm going to stay away from the 'every tuner recommends' statements because it's not my point. I like to look at the results and again, IMHO the results say that at 350-400 WHP, our stock downpipes especially since we have two work well.
shadow191 is offline  
0
Reply With Quote
      07-29-2013, 03:54 PM   #31
marcvtec
Lieutenant Colonel
 
Drives: 335i
Join Date: Oct 2006
Location: toronto

Posts: 1,785
iTrader: (0)

The way I see it is cat less helps turbo longevity.
So I'd rather pay 800 bucks to help the turbos spool better and gain more power
__________________
COBB Powered, Spec2+, Wavetrac, DCI, Forge DV's, AR catless DP's, AA FMIC, M3 links & Sways, 19' BBS LM's wrapped in PSS, Zimmerman cross drilled rotors, hawk carbon pads, M3 Spoiler, AC roof Spoiler, Aero Lip, Vorsteiner Diffuser, m3 sides, Tinted, And One Happy BMW Driver.
marcvtec is offline  
0
Reply With Quote
      07-29-2013, 04:02 PM   #32
jnat
Boosted
 
Drives: 09 335 XI A/T
Join Date: Sep 2012
Location: Jersey

Posts: 133
iTrader: (0)

This is directly off the Cobb web site on an N54.
06-15-2012 11:02 am 328 hp 388 ft/lb Stage 1 Agr. Baseline
07-11-2012 06:00 pm 339 hp 400 ft/lb Stage 2 Agr Baseline
Stage one is a tune plus FMIC and Stage two adds kittiless downpipes/DCI.
I don't see it and again, it's personal preference.
Also, real world feed back from members.
1)Yea I didn't feel much of a difference going from stage 1+ to stage 2 + the boost is just a little higher up top but there is no point to really rev that high on stock snails
2)I briefly ran the OTS Stage 2+ Sport map when I first installed my downpipes and was still running straight 91 octane pump gas. I was actually a little disappointed. I thought going from Stage 1+ to Stage 2+ would be a substantial jump. If anything, I thought Stage 2 felt slower.

Last edited by jnat; 07-29-2013 at 05:13 PM.
jnat is offline  
0
Reply With Quote
      07-29-2013, 04:06 PM   #33
Cozy
Major
 
Cozy's Avatar
 
Drives: E82 135i
Join Date: Mar 2011
Location: Surrey, England

Posts: 1,489
iTrader: (0)

Quote:
Originally Posted by jnat View Post
This is directly off the Cobb web site on an N54.
06-15-2012 11:02 am 328 hp 388 ft/lb Stage 1 Agr. Baseline
07-11-2012 06:00 pm 339 hp 400 ft/lb Stage 2 Agr Baseline
Stage one is a tune plus FMIC and Stage two adds kittiless downpipes/DCI.
I don't see it and again, it's personal preference.
Do you have a tune? Are you able to or have you dyno'd on an FBO tune with your stock DP's? I'd be interested to see your logs or a dyno plot.
Cozy is offline   United Kingdom
0
Reply With Quote
      07-29-2013, 04:18 PM   #34
jnat
Boosted
 
Drives: 09 335 XI A/T
Join Date: Sep 2012
Location: Jersey

Posts: 133
iTrader: (0)

My set up is very basic, just a JB4/G5-DCI-secondary kittyless-E25-30. My next very soon mod is an upgraded FMIC and an OCC. I'm leaning towards the Wagner FMIC I like that step up design. I'm really not interested in a dyno at this point as I'm personally not chasing a number. If I had dyno'd prior to any mods for a baseline then maybe it would make sense but I did not. I'm just looking to add useable power to my DD and add (like the OCC) preventative measures where possible. Walnut blasting is on my to do list also 45k miles (a little off topic).
jnat 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 05:33 AM.




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