Discovery 4 Freeflow exhaust on a Diesel?





Page 1 of 2 1 2 LastLast
Results 1 to 20 of 29
  1. #1
    Join Date
    Mar 2012
    Location
    Fourways
    Age
    36
    Posts
    975
    Thanked: 387

    Default Freeflow exhaust on a Diesel?

    My exhaust has its fair share of dings, scrapes, cat removal and welds from the life the car lives so I am looking at fitting a new exhaust. We have recently discovered a leak on the exhaust which explains why the V6 growl sounded so sexy.

    Is there any benefit of fitting a freeflow exhaust to the 3.0 Diesel?
    Rob,

    D4 SDV6 HSE ARB Bullbar, Compos, BFG 265/65R18s, Big Country drawers, National Luna 52L, Dometic 50L, Spare Wheel Carrier, Roof Rack, Hardshell RTT, FR 50" LED Bar, Lift Rods, Mantec Snorkel, C-TEK Dual batt system, 270 Ostrichwing, Maxtrax, TXG Rock Sliders, IIDtool, shelf

  2. #2
    Join Date
    Nov 2010
    Location
    Sandton
    Age
    46
    Posts
    2,397
    Thanked: 73

    Default Re: Freeflow exhaust on a Diesel?

    Be Carefull !!
    I played around with free flow systems on my D3. Took it to the Dyno afterwards and the power was down by up to 10% on some systems.

    I think Viper Exhausts are the guys to talk to.
    GASMAN

    Land Rover D3 TDV6 HSE 2007 - Goldilocks - Gone
    Land Rover D4 SDV6 HSE 2012 - Voeniks
    Ratel Bullbar
    Ratel Snorkel
    Ratel Rock Sliders
    Ratel Offroad Tow Hitch
    Melville & Moon Seat Covers
    TORQTUNE Map



    ORRA Z 173

  3. #3
    Join Date
    Apr 2019
    Location
    Pretoria
    Age
    21
    Posts
    70
    Thanked: 35

    Default Re: Freeflow exhaust on a Diesel?

    The less back pressure for a turbo diesel lowers egt and the turbo spools earlier , i removed both my silencers from my 300 tdi and my egt was lower as well as low down power improved alot.

  4. #4
    Join Date
    Mar 2008
    Location
    De Wildt
    Age
    56
    Posts
    34,609
    Thanked: 9730

    Default Re: Freeflow exhaust on a Diesel?

    Quote Originally Posted by DETOUR-GP View Post

    Is there any benefit of fitting a freeflow exhaust to the 3.0 Diesel?
    less turbo lag, faster spool up, lower exhaust gas temperatures

    no negatives except extra noise
    2012 Jeep Sahara Unlimited 3.6 V6
    Percivamus

  5. The Following User Says Thank You to jelo For This Useful Post:


  6. #5
    Join Date
    Jul 2008
    Location
    Wellington
    Age
    40
    Posts
    2,084
    Thanked: 436

    Default Re: Freeflow exhaust on a Diesel?

    Its an interesting topic
    A while ago I had a chat with the local Powerflow guys and he was of the opinion a freeflow on a diesel doesnt really make much sense
    You dont gain anything, and with the wrong system in place, could have a drop in power
    Some car, some bike and two legs

  7. #6
    Join Date
    Feb 2015
    Location
    Bloemfontein
    Posts
    282
    Thanked: 69

    Default Re: Freeflow exhaust on a Diesel?

    I am no expert, but any turbo motor, diesel or petrol, will benefit from a more free flowing system.

    There is however a lot of discussion about the size of the exhaust, to fit any form of silencer or not, and the size of these.

    Straight pipe is very loud though, so one silencer is probably the way to go?

    Now for the pro's to comment...
    2016 Ford Everest 3.2Tdci XLT AWD A/T - Mods have begun!
    2010 BMW 320i AT (SWAMBO)

    Always go for the deepest mud, muddy stories make the best memories!

  8. #7
    Join Date
    Mar 2008
    Location
    De Wildt
    Age
    56
    Posts
    34,609
    Thanked: 9730

    Default Re: Freeflow exhaust on a Diesel?

    Quote Originally Posted by hcs View Post
    Its an interesting topic
    A while ago I had a chat with the local Powerflow guys and he was of the opinion a freeflow on a diesel doesnt really make much sense
    You dont gain anything, and with the wrong system in place, could have a drop in power
    the only way you will have a drop in power is if you try and fool the downstream lambda sensor and the catalytic converter sensor if present: the ECU then gets conflicting info on the O2 levels and reverts to a safer map

    but whatever, I'm tired of saying things and getting some hearsay rebuttal
    2012 Jeep Sahara Unlimited 3.6 V6
    Percivamus

  9. The Following 3 Users Say Thank You to jelo For This Useful Post:


  10. #8
    Join Date
    Jul 2008
    Location
    Wellington
    Age
    40
    Posts
    2,084
    Thanked: 436

    Default Re: Freeflow exhaust on a Diesel?

    Quote Originally Posted by jelo View Post
    the only way you will have a drop in power is if you try and fool the downstream lambda sensor and the catalytic converter sensor if present: the ECU then gets conflicting info on the O2 levels and reverts to a safer map

    but whatever, I'm tired of saying things and getting some hearsay rebuttal
    Hearsay.. aint that about 99% of the posts on this forum anyway?
    Some car, some bike and two legs

  11. The Following User Says Thank You to hcs For This Useful Post:


  12. #9
    Join Date
    Jun 2015
    Location
    Pretoria East
    Posts
    548
    Thanked: 490

    Default Re: Freeflow exhaust on a Diesel?

    Quote Originally Posted by hcs View Post
    Its an interesting topic
    A while ago I had a chat with the local Powerflow guys and he was of the opinion a freeflow on a diesel doesnt really make much sense
    You dont gain anything, and with the wrong system in place, could have a drop in power
    I would stay clear from this chap at Powerflow (unless he was maybe referring to non-turbo diesels). On my 79 V8 Cruiser the De Graaf 76mm freeflow had a significant improvement in power delivery. A turbo diesel gain enough power in my opinion to warrant the expense.

    A vehicle still under warrantee is another subject as the manufacturer may not honor claims afterwards.
    Dirk Theron
    Land Cruiser FJ
    Hilux 2.8 GD-6 Auto 4x4
    BL865 Ratel4
    Life’s a journey, enjoy the ride

  13. #10
    Join Date
    Mar 2016
    Location
    Cape Town
    Age
    28
    Posts
    2,720
    Thanked: 1814

    Default Re: Freeflow exhaust on a Diesel?

    The best exhaust on a diesel, is no exhaust
    Always think: Could this be sarcasm?

  14. The Following 2 Users Say Thank You to Oppies3800 For This Useful Post:


  15. #11
    Join Date
    Mar 2008
    Location
    De Wildt
    Age
    56
    Posts
    34,609
    Thanked: 9730

    Default Re: Freeflow exhaust on a Diesel?

    Quote Originally Posted by DCTheron View Post
    I would stay clear from this chap at Powerflow (unless he was maybe referring to non-turbo diesels).
    indeed

    No turbo diesel exhaust needs to have a tuned length header or be tuned for scavenging. It needs as big an exhaust and downpipe possible (without being silly) to get as much of the exhaust gases away from the impeller as fast as possible.

    Now there MIGHT and I say again, there MIGHT be extreme conditions of gas/fluid dynamics where you COULD get the gas velocity to be PERFECT using a tuned extraction system downstream of the turbo, but without extensive modelling systems, I doubt you'd get more than a 5% improvement over a plain old freeflow pipe.
    2012 Jeep Sahara Unlimited 3.6 V6
    Percivamus

  16. #12
    Join Date
    Jul 2008
    Location
    Wellington
    Age
    40
    Posts
    2,084
    Thanked: 436

    Default Re: Freeflow exhaust on a Diesel?

    Quote Originally Posted by DCTheron View Post
    I would stay clear from this chap at Powerflow (unless he was maybe referring to non-turbo diesels). On my 79 V8 Cruiser the De Graaf 76mm freeflow had a significant improvement in power delivery. A turbo diesel gain enough power in my opinion to warrant the expense.

    A vehicle still under warrantee is another subject as the manufacturer may not honor claims afterwards.
    Roddy knows his stuff so I would trust him. Keep in mind, this was on my old 2.5 Ranger that I inquired about at the time. We ended up just replacing the stock exhaust
    Some car, some bike and two legs

  17. #13
    Join Date
    Feb 2015
    Location
    Bloemfontein
    Posts
    282
    Thanked: 69

    Default Re: Freeflow exhaust on a Diesel?

    JBC Performance exhausts in Bloem builds amazing exhausts.

    Maybe give Johan a call? They have a page on facebook.

    They do a lot of diesel Cruisers and Rangers
    2016 Ford Everest 3.2Tdci XLT AWD A/T - Mods have begun!
    2010 BMW 320i AT (SWAMBO)

    Always go for the deepest mud, muddy stories make the best memories!

  18. #14
    Join Date
    Dec 2011
    Location
    Pretoria
    Age
    43
    Posts
    984
    Thanked: 911

    Default Re: Freeflow exhaust on a Diesel?

    Quote Originally Posted by DCTheron View Post
    I would stay clear from this chap at Powerflow (unless he was maybe referring to non-turbo diesels). On my 79 V8 Cruiser the De Graaf 76mm freeflow had a significant improvement in power delivery. A turbo diesel gain enough power in my opinion to warrant the expense.

    A vehicle still under warrantee is another subject as the manufacturer may not honor claims afterwards.
    I haven't heard of a turbo diesel that did NOT benefit from a freeflow. As said by others, just be careful to add enough of a silencer so you don't spoil the vehicle with a too noisy exhaust.

  19. #15
    Join Date
    Mar 2012
    Location
    Fourways
    Age
    36
    Posts
    975
    Thanked: 387

    Default Re: Freeflow exhaust on a Diesel?

    Thanks for the comments gents, seems like the general consensus is that the car will benefit from the freeflow.

    I will look at doing it and will post my findings in this thread for others who may be considering doing the same
    Rob,

    D4 SDV6 HSE ARB Bullbar, Compos, BFG 265/65R18s, Big Country drawers, National Luna 52L, Dometic 50L, Spare Wheel Carrier, Roof Rack, Hardshell RTT, FR 50" LED Bar, Lift Rods, Mantec Snorkel, C-TEK Dual batt system, 270 Ostrichwing, Maxtrax, TXG Rock Sliders, IIDtool, shelf

  20. #16
    Join Date
    Mar 2008
    Location
    De Wildt
    Age
    56
    Posts
    34,609
    Thanked: 9730

    Default Re: Freeflow exhaust on a Diesel?

    Quote Originally Posted by DETOUR-GP View Post
    Thanks for the comments gents, seems like the general consensus is that the car will benefit from the freeflow.

    I will look at doing it and will post my findings in this thread for others who may be considering doing the same
    as mentioned, be careful of all sensors, that's where modern cars need the most attention
    2012 Jeep Sahara Unlimited 3.6 V6
    Percivamus

  21. The Following User Says Thank You to jelo For This Useful Post:


  22. #17
    Join Date
    Nov 2006
    Location
    Stellenbosch
    Age
    64
    Posts
    3,684
    Thanked: 408

    Default Re: Freeflow exhaust on a Diesel?

    I can add to what hcs said, I also dealt with Roddy at Powerflow Bellville, also wrt a 2.5 Ranger and I received the same reply.
    On his recommendation we settled for a pipe one size down from max (63mm?) and a small straight through silencer at the back to make everything fit.
    Must say leaving the workshop didnt blow back my hair.
    The tuning at KSD however was a different story.
    Looks like its time for a second opinion/upgrade because every bit helps.
    Last edited by Damdan; 2019/04/30 at 10:05 AM.
    If you live each day as if it was your last, someday you'll most certainly be right. SJ

  23. #18
    Join Date
    Aug 2007
    Location
    Carletonville
    Age
    53
    Posts
    6,527
    Thanked: 598

    Default Re: Freeflow exhaust on a Diesel?

    Quote Originally Posted by Oppies3800 View Post
    The best exhaust on a diesel, is no exhaust
    This is what I have been told over and over. Besides the noise, no reason for an exhaust on a TD. Mine is hardly 1 meter long from turbo to tip. I dump on the passanger side, so I can't hear it, or my wife for that matter. Win, win.
    David/Hillbilly - 1997 SFA Nissan Sani 2,7 TD - 5" lift on 33" tires - Dual Transfer with 4.1 gears

    http://www.youtube.com/user/davidabcab



  24. #19
    Join Date
    Jan 2011
    Location
    Cape Town
    Age
    40
    Posts
    621
    Thanked: 37

    Default Re: Freeflow exhaust on a Diesel?

    On my previous Fortuner I also installed the 76mm De Graaff system and only real difference was a slight reduction in spooling time and a reduction in EGT. Fuel consumption and max power stayed the same (already had the chip in). KSD commented that you will have to adjust the tune to make use of the lower EGTs but my goal was not more power, just lower EGTs so I did go for the "Stage 2" tune.
    2017 Toyota Fortuner 2.8 GD6 4x4 iMT
    2016 Hyundai Tucson 1.6 T-GDi
    2019 Bush Lapa Miskruier BL1861

  25. #20
    Join Date
    Oct 2011
    Location
    Centurion
    Age
    46
    Posts
    1,177
    Thanked: 269

    Default Re: Freeflow exhaust on a Diesel?

    Start wih a freeflow with no boxes in, if the noise is a problem you can add a box or two later.
    Neil

Page 1 of 2 1 2 LastLast

Bookmarks

Posting Permissions

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