E90Post
 


MINHS Auto Care Center
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > Feedback re: Downpipes please



Reply
 
Thread Tools Search this Thread
      11-27-2007, 09:45 PM   #1
boosted305
Private First Class
 
Drives: 335i Coupe
Join Date: Nov 2007
Location: South Florida

Posts: 115
iTrader: (0)

Feedback re: Downpipes please

Was at Advance Autowerks the other day making some preliminary inquiries.
Was interested in getting some DP's (having been a long time previous turbo owner and a DP was KEY)
I Asked about Downpipes and got a surprising response...

one of the guys there didn't recommend them, said they don't make any power because the turbos are so small and need SOME backpressure....

this is counterintuitive to all that I know about turbos....every turbo I've ever had: the faster you can get the exhaust out the better...of course I've never had 2 turbos sooooo small...never had less than a T04

asked around at a couple of other tuner shops in the area and did get one other similar response...(they might have just heard this from AA also though)

I tried a search and didn't find any posts mentioning anything like this

can I get some feedback from you guys on this?

thanks in advance
boosted305 is offline  
0
Reply With Quote
      11-27-2007, 09:47 PM   #2
jpsimon
Team Zissou
 
jpsimon's Avatar
 
Drives: 2015 STi
Join Date: Dec 2006
Location: CT

Posts: 8,999
iTrader: (4)

didn't riss racing downpipes net a nice 50 wheel torque gain?
__________________
2015 STi / 335xi (solid)
www.datazap.me - fast, free, interactive data log viewing

jpsimon is offline   United_States
0
Reply With Quote
      11-27-2007, 09:49 PM   #3
E90 335i
Banned
 
Drives: 2007 E90 335i
Join Date: Sep 2007
Location: Fort Lauderdale, Florida

Posts: 559
iTrader: (0)

Send a message via AIM to E90 335i
HFC DP by UR will help with the backpressure. To hell with that advice, the gains are proven on the dyno!
E90 335i is offline   United_States
0
Reply With Quote
      11-27-2007, 09:49 PM   #4
boosted305
Private First Class
 
Drives: 335i Coupe
Join Date: Nov 2007
Location: South Florida

Posts: 115
iTrader: (0)

like I mentioned, every post I've seen has said how great they are and I was really interested...that's why I was so surprised with their response...
boosted305 is offline  
0
Reply With Quote
      11-27-2007, 09:56 PM   #5
E90 335i
Banned
 
Drives: 2007 E90 335i
Join Date: Sep 2007
Location: Fort Lauderdale, Florida

Posts: 559
iTrader: (0)

Send a message via AIM to E90 335i
I went in there a few weeks after I got my car and asked some questions. I was startled by their ridiculous hourly charge and the full hour of installation it takes for XEDE. My first time for a similar install was one hour. Now I bet I can do it in thirty minutes, let alone a tech can do it in 20 I bet.

Then I was told the same thing about DP and the backpressure thing. I have no idea who I talked to, but you have got to be kidding me. You don't know anything if you can't read the delta on a dyno. 20-30 whp cannot be an artificial number, even with hood up and fans on full blast. Not happening.

Forget the advice, search the oodles of information on here, and make the decision. They are beneficial and the HFC version will give you the least headaches because you can plug your O2 sensors right in the available bungs...no SES light, no limp modes, no rasp, no rice, nothing. HFC DP FTW....and DP in general...FTW.
E90 335i is offline   United_States
0
Reply With Quote
      11-27-2007, 10:17 PM   #6
jbuds335xi
Second Lieutenant
 
Drives: 335xi Manual, Jet Black, Black
Join Date: Jul 2007
Location: All over

Posts: 248
iTrader: (0)

Quote:
Originally Posted by E90 335i View Post
I went in there a few weeks after I got my car and asked some questions. I was startled by their ridiculous hourly charge and the full hour of installation it takes for XEDE. My first time for a similar install was one hour. Now I bet I can do it in thirty minutes, let alone a tech can do it in 20 I bet.

Then I was told the same thing about DP and the backpressure thing. I have no idea who I talked to, but you have got to be kidding me. You don't know anything if you can't read the delta on a dyno. 20-30 whp cannot be an artificial number, even with hood up and fans on full blast. Not happening.

Forget the advice, search the oodles of information on here, and make the decision. They are beneficial and the HFC version will give you the least headaches because you can plug your O2 sensors right in the available bungs...no SES light, no limp modes, no rasp, no rice, nothing. HFC DP FTW....and DP in general...FTW.
The man's got it right, Dyno's don't lie. Whoever you talked to clearly needs to get himself on e90post before making random recomendations
__________________

Modded.
jbuds335xi is offline  
0
Reply With Quote
      11-27-2007, 10:24 PM   #7
Dan335i
Lieutenant Colonel
 
Dan335i's Avatar
 
Drives: 07 335i coupe 6MT,w/sp. pack.
Join Date: Oct 2007
Location: orange county NY

Posts: 1,788
iTrader: (2)

I dont care what size turbo,s you running.The least amount of back pressure on a turbo car the better the performance.On a street driven NA performance car you need some back pressure.
Dan335i is offline  
0
Reply With Quote
      11-27-2007, 11:19 PM   #8
335iheLLraiseR
اوليسيس
 
335iheLLraiseR's Avatar
 
Drives: e92 335
Join Date: Jun 2007
Location: sfl

Posts: 4,660
iTrader: (8)

Garage List
2007 e92 335  [5.00]
i have also heard of that, i actually started a thread on it and got somewhat of a mixed response.

BTW, did you mean Active Autowerks?
__________________
Quote:
Originally Posted by lawdude View Post
Anyone who can transition seamlessly from defending one vendor and bashing another vendor to bashing the one he formally defended and defending the one he formally bashed has a instant credibility problem.
<---Sign up Now for Bonus Storage! Up to 10gb!
335iheLLraiseR is offline   United_States
0
Reply With Quote
      11-27-2007, 11:30 PM   #9
FuelTuner
New Member
 
Drives: 07 E90 335i Alpine White/Lemon
Join Date: Nov 2007
Location: Edmonton Alberta Canada

Posts: 24
iTrader: (0)

Love my UR Downpipes.. and yes they certainly did make a difference. Go for it .. you"ll love them...
__________________
EFI University Certified Tuner
AEM EMS Training
Unichip Authorized Tuner
AA R7 / UR HFC Downpipes, BMC Filter
FuelTuner is offline  
0
Reply With Quote
      11-27-2007, 11:41 PM   #10
boosted305
Private First Class
 
Drives: 335i Coupe
Join Date: Nov 2007
Location: South Florida

Posts: 115
iTrader: (0)

Quote:
Originally Posted by 335iheLLraiseR View Post
i have also heard of that, i actually started a thread on it and got somewhat of a mixed response.

BTW, did you mean Active Autowerks?

whoops, yeah Active is what I meant!

thanks for the responses guys....
boosted305 is offline  
0
Reply With Quote
      11-28-2007, 01:08 AM   #11
Adam@Riss Racing
Banned
 
Drives: 2006 Interlagos Blue BMW M5
Join Date: Jul 2007
Location: Irvine, CA

Posts: 1,310
iTrader: (1)

Garage List
Send a message via AIM to Adam@Riss Racing
Quote:
Originally Posted by boosted305 View Post
Was at Advance Autowerks the other day making some preliminary inquiries.
Was interested in getting some DP's (having been a long time previous turbo owner and a DP was KEY)
I Asked about Downpipes and got a surprising response...

one of the guys there didn't recommend them, said they don't make any power because the turbos are so small and need SOME backpressure....

this is counterintuitive to all that I know about turbos....every turbo I've ever had: the faster you can get the exhaust out the better...of course I've never had 2 turbos sooooo small...never had less than a T04

asked around at a couple of other tuner shops in the area and did get one other similar response...(they might have just heard this from AA also though)

I tried a search and didn't find any posts mentioning anything like this

can I get some feedback from you guys on this?

thanks in advance
Less back pressure the better on turbo cars. Dp's make power.
Adam@Riss Racing is offline   United_States
0
Reply With Quote
      11-28-2007, 04:20 AM   #12
rambino
Rape Your Car!
 
rambino's Avatar
 
Drives: 335ci
Join Date: Jun 2007
Location: Miami

Posts: 410
iTrader: (2)

Active can be a little snobbish at times, they do like money and charge a lot , when i had my M3, there , i spent over 2000 on just flashing my ecu a few times and then had to pay $100 when i needed a 5 min update after the dealer reset my ecu, not to mention the silly $200 just to turn off my upgraded thermostat light.. like many companies, they only like to sell and talk about there products (which makes sense), but on the downside, if they dont have a downpipe out, then they probably wont suggest it till they do...

Dont get me wrong they do a great job and have excellent products but ive learned to be careful about what they charge and tell me.
rambino is offline  
0
Reply With Quote
      11-28-2007, 10:03 AM   #13
Nyulak
Captain
 
Nyulak's Avatar
 
Drives: 2009 BMW 535xi
Join Date: Feb 2007
Location: SheffVill, OH

Posts: 950
iTrader: (4)

Garage List
2009 BMW 535xi  [0.00]
FI applications utilize smaller valve-event overlaps, which benefit from no back pressure. A quick diesel upgrade is simply changing to really large exhaust to dro as much back pressure as possible. For hot cams with high-lift and large overlaps, back pressure helps at low RPMs to keep the car from turning off, since the intake air will vent to the exhaust port to quickly for low cylinder speeds. If you have variable valve overlap, you can program the ECU to keep the overlap duration relatively small for low RPMs and increase with RPMs. This will keep the engine happy and produce a lot of power. In this case, you could easily reduce back pressure.

In the end, a properly tuned car will benefit from the least amount of back pressure. Notice any dragsters running exhaust restrictors to increase back pressure?
Nyulak is offline   United_States
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 08:54 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