Page 1 of 2 12 LastLast
Results 1 to 25 of 44

Thread: straight pipes

              
  1. #1
    Join Date
    Aug 2010
    Location
    over there
    Posts
    288
    Rep Points
    481.1
    Mentioned
    14 Post(s)
    Rep Power
    5


    Reputation: Yes | No

    straight pipes

    My car has vrsf downpipes and stock exhaust with no muffler today i deleted the last cats so my car is now straight piped on the butt dyno it feels like it gained about 15hp and more tq. Next plan is to go to full 3 inch dual straight pipes
    Turbo lag is the on ramp to the highway which is power.

  2. #ADS

  3. #2
    Join Date
    Mar 2010
    Posts
    961
    Rep Points
    1,137.3
    Mentioned
    44 Post(s)
    Rep Power
    12


    Reputation: Yes | No
    Must sound like total crap. I am sorry but although you gained some power, I heard this setup and it rasp city and on cold startups it sound like something is broken!

  4. #3
    Join Date
    Feb 2012
    Location
    south florida
    Posts
    1,964
    Rep Points
    2,314.1
    Mentioned
    91 Post(s)
    Rep Power
    24


    Reputation: Yes | No
    Click here to enlarge Originally Posted by WDBi Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    My car has vrsf downpipes and stock exhaust with no muffler today i deleted the last cats so my car is now straight piped on the butt dyno it feels like it gained about 15hp and more tq. Next plan is to go to full 3 inch dual straight pipes
    i like your style

  5. #4
    Join Date
    Aug 2010
    Location
    over there
    Posts
    288
    Rep Points
    481.1
    Mentioned
    14 Post(s)
    Rep Power
    5


    Reputation: Yes | No

    Click here to enlarge Originally Posted by Cn555ic Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    Must sound like total crap. I am sorry but although you gained some power, I heard this setup and it rasp city and on cold startups it sound like something is broken!
    Honestly it does. Do i care... not really. Actually not at all. I have no in cabin drone and thats the only thing i care about noise wise. I look at exhausts as a performance mod not a sound mod. I am looking to further upgrade my exhaust is a month or 2 to a full true dual 3inch turbo back exhaust straight piped. Im not doing it to draw attention or to be loud im doing it go fast and 15hp and maybe a bit more tq is worth the "total crap" of a exhaust note.

    But to each their own i guess.
    Turbo lag is the on ramp to the highway which is power.

  6. #5
    Join Date
    Jul 2010
    Location
    Encino,CA
    Posts
    6,724
    Rep Points
    4,027.6
    Mentioned
    103 Post(s)
    Rep Power
    41


    Reputation: Yes | No
    I got the same set up with my cobalt ss. 3" catless dp stock resonator muffler delete straight pipes. Sounds mean and raspy but I love the back fire. Click here to enlarge
    Click here to enlarge

  7. #6
    Join Date
    Sep 2012
    Location
    Brisbane, Australia
    Posts
    2,624
    Rep Points
    787.5
    Mentioned
    43 Post(s)
    Rep Power
    8


    Reputation: Yes | No
    why not just add 2-4 resonators

    no restriction

    no rasp

    win win

    Click here to enlarge Originally Posted by WDBi Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    Honestly it does. Do i care... not really. Actually not at all. I have no in cabin drone and thats the only thing i care about noise wise. I look at exhausts as a performance mod not a sound mod. I am looking to further upgrade my exhaust is a month or 2 to a full true dual 3inch turbo back exhaust straight piped. Im not doing it to draw attention or to be loud im doing it go fast and 15hp and maybe a bit more tq is worth the "total crap" of a exhaust note.
    Click here to enlarge Originally Posted by WDBi Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote

    But to each their own i guess.

    twin 3" is way overkill, all the way back

    unless you want 1000whp or so?

    it will drone for sure, too

    you'll also lose a bit of torque, as much as you'll gain hp.

  8. #7
    Join Date
    Aug 2012
    Location
    Florida
    Posts
    118
    Rep Points
    153.7
    Mentioned
    4 Post(s)
    Rep Power
    2


    Reputation: Yes | No
    There is no way that you have no in cabin drone with catless downpipes and straight pipes all the way back.
    Daily: 2007 Montego Blue E92 335i - Stock
    Weekend: 2008 Graffiti CBR 600RR - Two Brothers | CBR Heaven | Shogun | Motovation | Power Commander | Honda Racing


  9. #8
    Join Date
    Aug 2010
    Location
    over there
    Posts
    288
    Rep Points
    481.1
    Mentioned
    14 Post(s)
    Rep Power
    5


    Reputation: Yes | No

    I will post videos tomorrow there is no drone. and when it comes to turbo cars you want no back flow what so ever and since i have 3 inch downpipes off the turbos going any smaller than that will cause flow restrictions. Also i know it may sound crazy overkill but resonators are extra weight and weight is the biggest enemy when it comes to cars. When you remove weight everything gets better braking, acceleration, turning, fuel economy. And even though resonators are just a couple of pounds every pound counts especially in races.
    Turbo lag is the on ramp to the highway which is power.

  10. #9
    Join Date
    Jul 2012
    Location
    Boston, MA
    Posts
    1,178
    Rep Points
    628.5
    Mentioned
    25 Post(s)
    Rep Power
    7


    Reputation: Yes | No
    Click here to enlarge Originally Posted by WDBi Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    I will post videos tomorrow there is no drone. and when it comes to turbo cars you want no back flow what so ever and since i have 3 inch downpipes off the turbos going any smaller than that will cause flow restrictions. Also i know it may sound crazy overkill but resonators are extra weight and weight is the biggest enemy when it comes to cars. When you remove weight everything gets better braking, acceleration, turning, fuel economy. And even though resonators are just a couple of pounds every pound counts especially in races.
    Don't your downpipes taper right away to 2.5''? No one makes a true 3'' DP. Once guy had them customer made...

  11. #10
    Join Date
    Mar 2012
    Posts
    468
    Rep Points
    1,031.5
    Mentioned
    5 Post(s)
    Rep Power
    11


    Reputation: Yes | No
    Click here to enlarge Originally Posted by Torgus Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    Don't your downpipes taper right away to 2.5''? No one makes a true 3'' DP. Once guy had them customer made...
    This is true, unless he modified the downpipes as well.

  12. #11
    Join Date
    Sep 2011
    Location
    SoCal (OC/Riverside)
    Posts
    414
    Rep Points
    258.8
    Mentioned
    7 Post(s)
    Rep Power
    3


    Reputation: Yes | No
    Click here to enlarge Originally Posted by Torgus Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    Don't your downpipes taper right away to 2.5''? No one makes a true 3'' DP. Once guy had them customer made...
    He has VSRF downpipes so yeah they taper to 2.5" too...So no real point in going to 3" > 2.5" > 3" unless your looking to lose a little low end torque

    Click here to enlarge Originally Posted by EDM92 Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    There is no way that you have no in cabin drone with catless downpipes and straight pipes all the way back.
    One of my buddies had catless downpipes and secondary cats deleted...Similar to what @WDBi has...It didnt really drone but it really had this weird rasp in the low RPMs and it was kind of annoying to drive...You have to change your driving style to work around it...Car was E92 manual
    PERFORMANCE: Cobb AP \ JB4 \ DCI \ AR Downpipes \ CX FMIC \ ER Chargepipe \ Synapse BOV \ KW V2 \ Muffler Delete \ CDV \ ZHP Shifter \ Cyba Scoops
    FUN: LC Lemans 19" \ M3 Front \ Mtech Rear \ JL 10W6 \ ModMyNav \ V1 Hardwired \ LUX H8 \ Gloss Black Trim \ Cyba Quads \ Cyba Mtech Diffuser

  13. #12
    Join Date
    Sep 2012
    Location
    Pittsburgh
    Posts
    1,259
    Rep Points
    1,382.6
    Mentioned
    35 Post(s)
    Rep Power
    14


    Reputation: Yes | No
    I understand exhaust scavenging, exhaust tubing diameter and exhaust gas velocity as it applies to torque on an NA engine. However, I was under the impression a larger exhaust was always better up to the point of practicality on an FI engine. Am I mistaken? Does exhaust gas scavenging have an appreciable affect on low end torque in an FI platform?

  14. #13
    Join Date
    May 2012
    Location
    Jacksonville, FL
    Posts
    2,639
    Rep Points
    2,218.7
    Mentioned
    73 Post(s)
    Rep Power
    23


    Reputation: Yes | No
    Click here to enlarge Originally Posted by rooringhusky Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    He has VSRF downpipes so yeah they taper to 2.5" too...So no real point in going to 3" > 2.5" > 3" unless your looking to lose a little low end torque



    One of my buddies had catless downpipes and secondary cats deleted...Similar to what @WDBi has...It didnt really drone but it really had this weird rasp in the low RPMs and it was kind of annoying to drive...You have to change your driving style to work around it...Car was E92 manual
    That rasp you speak of is what makes me want to burn my BMW PE. I'm manual also, i wonder if its worse on manuals because of the driving style.
    2007 BMW 335i 6MT / Alpine Weiss
    Click here to enlarge

  15. #14
    Join Date
    Jul 2012
    Location
    Boston, MA
    Posts
    1,178
    Rep Points
    628.5
    Mentioned
    25 Post(s)
    Rep Power
    7


    Reputation: Yes | No
    I really wish a company like VSFR would make true 3'' DPs mated to 3'' or larger mandrel bent exhaust. They could even make the DPs slightly shorter and sell adapters. So if you are going to a 2.5'' stock exhaust you use their 2 flange'd 3'' adapter that goes from 3'' to 2.5'' so it can mate with the stock exhaust. If not using the stock exhaust and VSFR's aftermarket 3''-4'' than no adapter needed and it bolts right up. Who knows about the performance gain I imagine it would be decent especially with stage 2/RB turbos.

    OP if you really want more performance have a few true 3'' DPs made. I am sure if you sold 3-4 it would pay for yours on your car. Win win for everyone. Just an idea.

    Are you going to upload some video for us?

  16. #15
    Join Date
    Sep 2011
    Location
    SoCal (OC/Riverside)
    Posts
    414
    Rep Points
    258.8
    Mentioned
    7 Post(s)
    Rep Power
    3


    Reputation: Yes | No
    Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    That rasp you speak of is what makes me want to burn my BMW PE. I'm manual also, i wonder if its worse on manuals because of the driving style.
    Not sure if it is worse with manuals vs automatic....bc I've only heard a manual with that setup...Personally ive always felt the manuals are slightly more raspy by nature..(just an opinion though and I personally have a 6MT)

    Oh and most importantly!! If your gonna burn the PE send it to me instead to hack open haha...just joking but either way have to looked into adding a resonator? Don't kno if it'll fix the problem but just a possible suggestion
    PERFORMANCE: Cobb AP \ JB4 \ DCI \ AR Downpipes \ CX FMIC \ ER Chargepipe \ Synapse BOV \ KW V2 \ Muffler Delete \ CDV \ ZHP Shifter \ Cyba Scoops
    FUN: LC Lemans 19" \ M3 Front \ Mtech Rear \ JL 10W6 \ ModMyNav \ V1 Hardwired \ LUX H8 \ Gloss Black Trim \ Cyba Quads \ Cyba Mtech Diffuser

  17. #16
    Join Date
    Sep 2012
    Location
    Brisbane, Australia
    Posts
    2,624
    Rep Points
    787.5
    Mentioned
    43 Post(s)
    Rep Power
    8


    Reputation: Yes | No
    Click here to enlarge Originally Posted by Torgus Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    Don't your downpipes taper right away to 2.5''? No one makes a true 3'' DP. Once guy had them customer made...
    im pretty sure there are SOME fully proper 3" DP's no?
    not that it matters because 5" of exhaust is STILL OVERKILL (i know it's not e same as having single 5" pipe, probably closer to a 4" in terms of total surface area.

    Click here to enlarge Originally Posted by ajm8127 Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    I understand exhaust scavenging, exhaust tubing diameter and exhaust gas velocity as it applies to torque on an NA engine. However, I was under the impression a larger exhaust was always better up to the point of practicality on an FI engine. Am I mistaken? Does exhaust gas scavenging have an appreciable affect on low end torque in an FI platform?
    not really kinda.. low end off boost yes, you'll notice.. but after that nope lol, FI pushing air in pretty much pushes the exhaust gases out under pressure, scavenging on an FI setup is a moot point.

  18. #17
    Join Date
    May 2012
    Location
    Jacksonville, FL
    Posts
    2,639
    Rep Points
    2,218.7
    Mentioned
    73 Post(s)
    Rep Power
    23


    Reputation: Yes | No
    Click here to enlarge Originally Posted by rooringhusky Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    Not sure if it is worse with manuals vs automatic....bc I've only heard a manual with that setup...Personally ive always felt the manuals are slightly more raspy by nature..(just an opinion though and I personally have a 6MT)

    Oh and most importantly!! If your gonna burn the PE send it to me instead to hack open haha...just joking but either way have to looked into adding a resonator? Don't kno if it'll fix the problem but just a possible suggestion
    Ive got the vibrant resonators welded in place of the mid cats. It helped quite a bit but its still less than desirable.
    2007 BMW 335i 6MT / Alpine Weiss
    Click here to enlarge

  19. #18
    Join Date
    Aug 2012
    Location
    TLH/SoFla/NorCal
    Posts
    1,151
    Rep Points
    1,301.1
    Mentioned
    30 Post(s)
    Rep Power
    14


    Reputation: Yes | No
    Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    Ive got the vibrant resonators welded in place of the mid cats. It helped quite a bit but its still less than desirable.
    AR Resonated Downpipes Click here to enlarge

  20. #19
    Join Date
    May 2012
    Location
    Jacksonville, FL
    Posts
    2,639
    Rep Points
    2,218.7
    Mentioned
    73 Post(s)
    Rep Power
    23


    Reputation: Yes | No
    Click here to enlarge Originally Posted by E90Company Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    AR Resonated Downpipes Click here to enlarge
    Just can't justify the price but might have to go down that road. Someone stole my rear tow hook cover off my car today so I might use this as a reason to buy the m sport rear instead Click here to enlarge
    2007 BMW 335i 6MT / Alpine Weiss
    Click here to enlarge

  21. #20
    Join Date
    Aug 2010
    Location
    over there
    Posts
    288
    Rep Points
    481.1
    Mentioned
    14 Post(s)
    Rep Power
    5


    Reputation: Yes | No

    Yeah my car has the same rasp at right around 2k but if your accelerate past 2k quickly it doesnt happen and when you are cruising under 2k it doesnt happen. Also for people worried about me going 3 inch after 2.5 inch off the end of my downpipes im not. Im having the downpipes cut just before the downsize which is about an inch and a half before the flange so im only cutting out a minute bit of the down pipes the shop will then weld on a vband attachment and build the exhaust back from there. It will be a true 3 inch dual turbo back exhaust.

    It may even be done in titatanium! Click here to enlarge
    Turbo lag is the on ramp to the highway which is power.

  22. #21
    Join Date
    Jul 2012
    Location
    Boston, MA
    Posts
    1,178
    Rep Points
    628.5
    Mentioned
    25 Post(s)
    Rep Power
    7


    Reputation: Yes | No
    Click here to enlarge Originally Posted by WDBi Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    Yeah my car has the same rasp at right around 2k but if your accelerate past 2k quickly it doesnt happen and when you are cruising under 2k it doesnt happen. Also for people worried about me going 3 inch after 2.5 inch off the end of my downpipes im not. Im having the downpipes cut just before the downsize which is about an inch and a half before the flange so im only cutting out a minute bit of the down pipes the shop will then weld on a vband attachment and build the exhaust back from there. It will be a true 3 inch dual turbo back exhaust.

    It may even be done in titatanium! Click here to enlarge

    Please do before and after dynos! Sounds awesome. Titanium is pricey...

  23. #22
    Join Date
    Nov 2010
    Location
    DC/MD/NOVA
    Posts
    211
    Rep Points
    316.1
    Mentioned
    5 Post(s)
    Rep Power
    4


    Reputation: Yes | No
    Where are the sound clips? =)

  24. #23
    Join Date
    Aug 2010
    Location
    over there
    Posts
    288
    Rep Points
    481.1
    Mentioned
    14 Post(s)
    Rep Power
    5


    Reputation: Yes | No

    sound clips will come when i find a mic that doesnt get overwhelmed lol
    Turbo lag is the on ramp to the highway which is power.

  25. #24
    Join Date
    Aug 2010
    Location
    over there
    Posts
    288
    Rep Points
    481.1
    Mentioned
    14 Post(s)
    Rep Power
    5


    Reputation: Yes | No

    Click here to enlarge Originally Posted by Torgus Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    Please do before and after dynos! Sounds awesome. Titanium is pricey...

    yeah titanium is quite a bit but the thing that really makes it expensive is the actual increase in cost of labor. When welding titanium inert gas must be pumped into the pipe as well as a special little dome over the welder must be made so that the inert gas can be cooled before entering the oxygenated environment. If you dont take these precautions your titanium pipe will go up in flames.
    Turbo lag is the on ramp to the highway which is power.

  26. #25
    Join Date
    Jun 2012
    Location
    NJ
    Posts
    4,064
    Rep Points
    1,780.8
    Mentioned
    97 Post(s)
    Rep Power
    18


    Reputation: Yes | No
    Click here to enlarge Originally Posted by Flinchy Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    im pretty sure there are SOME fully proper 3" DP's no?

    not really kinda.. low end off boost yes, you'll notice.. but after that nope lol, FI pushing air in pretty much pushes the exhaust gases out under pressure, scavenging on an FI setup is a moot point.
    No vendor makes a full 3" DP for the N54. AR, MS, VRSF, CP-e all make a 3" top that tapers down to 2.5" for the OEM midpipe connection. Akrapovic's DP is 2.75" and tapers to 2.5" (they saw no performance gains with that additional .25", but their R&D goes out the window when you start pushing over 500 WHP.

    Click here to enlarge Originally Posted by WDBi Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    It will be a true 3 inch dual turbo back exhaust.
    It may even be done in titatanium! Click here to enlarge
    If you're running the OEM Turbos, this is completely worthless IMO. Like other people have stated, by going 3" all the way back you'll lose "good" back pressure that creates TQ. The only purpose to going full 3" would be on a single turbo upgrade or the RB/Vargas TT upgrades that start pushing over 500 WHP. Unless you're building a purpose built race car (we're talking stripped interior, roll cage, not street legal), this is a unnecessary mod. If you're really that desperate to gain some extra power, invest in some Upgraded Turbos, Meth, Race Gas OR E85.
    COBB AP ProTune by Bren of ///Bren Tuning
    Akrapovic DP | Helix FMIC | Alpina TCM Flash | Walbro 450LPH Fuel Pump


    "The moment money becomes your motivation, you are immediately not as good as someone who is motivated by passion and internal will." -A. Senna

Page 1 of 2 12 LastLast

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •