Looking for a Downpipe

Discussion in 'B58 6-Cyl Engine, Exhaust, Drivetrain, Bolt-Ons' started by twarner776, Sep 4, 2019.

  1. supramk5

    supramk5 Active Member

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    I've had it longer than a month now and no CEL. I also have the rest of the exhaust from AFE and everything is all good.

    Here's a video of the downpipe tune we did with Counterspace Garage:

    We are tuning again today with the rest of the exhaust and intercooler piping. We'll make another video too.
     
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  2. MA617M

    MA617M Well-Known Member

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    Just to confirm - were you on a tune or piggyback?

    Or

    No CEL on stock tune??
     
  3. supramk5

    supramk5 Active Member

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    Tuned with Bootmod3 and no CEL the moment the downpipe was installed
     
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  4. Extreme Power House

    Extreme Power House Well-Known Member
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  5. newbimmerguy

    newbimmerguy New Member

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    8. ETS Extreme Turbo Systems Catless with 4.0" outlet for use with their 4" to dual 3" Y pipe. $445 https://www.extremeturbosystems.com/products/ets-2020-toyota-supra-downpipe?variant=29606559809606

    -I'm really interested in a discussion on whether / when people think that changing to a 4" outlet downpipe will make a difference.

    I saw this thread stating that most all of the catless downpipes are going to be roughly the same in terms of power as they're all dealing with the same inlet, length, and outlet, but that's no longer true with the ETS. ---The stock exhaust, I believe goes from 4.5" at the inlet, down to 3.15" at the outlet, and then through the Y-pipe to dual 3" exhausts to the back.

    That huge bottleneck from 4.5" to 3.15" and then dual 3.0", IMHO, makes no sense; I can only assume BMW / Toyota did this because it would require expensive oval tubing to fit in the available space and they wanted to save $$.

    I'm not clear on whether ETS will sell just their Downpipe with the 4" outlet and their 4" to dual 3.0" Y-pipe to work with the stock exhaust or not, though. (They seem to only offer the 4" inlet Y-pipe with their complete cat-back exhaust system.)

    Anyone know of any other B58 catless DP's doing with the 4" diameter outlet and Y-pipe? Anyone have any estimates on the point at which the stock restriction down to 3.15" will "matter"?


    Adam
     
  6. newbimmerguy

    newbimmerguy New Member

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    For S#7$ and giggles, I ran a traditional exhaust size calculator and it said that a single 3.15" diameter pipe can support 407 BHP, but I think that calculation is based upon assumptions that only apply to NA engines. I think the higher pressures in the exhaust of a turbocharged engine change the math significantly, as seen very obviously by all the B58's running with 3.15" diameter downpipe outlets making far in excess of 407 BHP...


    Adam
     
  7. MA617M

    MA617M Well-Known Member

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    from my moderate experience with 2JZs with singles, going from a 3" to 4" dump pipe has a massive effect on the shape of the power curve at the top-end (doesn't fall over, just keeps climbing)
     
  8. Twisted Tuning

    Twisted Tuning Well-Known Member
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    Just wait on our modular downpipe. You'll be able to pick and chose the size of the downpipe outlet from as big as 4" down to stock exhaust size
     
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  9. Powaup

    Powaup Well-Known Member

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    Have you seen dynos showing power increase without tune? Usually just changing the DP won’t affect power output since the engines configuration wasn’t adjusted (which is where a tune comes in)
     
  10. Extreme Power House

    Extreme Power House Well-Known Member
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    These numbers are with a tune
     
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  11. LS3Twins

    LS3Twins Well-Known Member

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    Actually the 30-35whp was without a tune. I did dyno pulls after every change and that was what it picked up. I was getting it tuned the next day and just ran it on the dyno to see the gains before the tune. I don't recommend running a catless downpipe without a tune but I did want to see what the difference was to document it.
     
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  12. Extreme Power House

    Extreme Power House Well-Known Member
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    Impressive!
     
  13. Twisted Tuning

    Twisted Tuning Well-Known Member
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    Going from a stock setup to a catless setup on a turbo car. Downpipes almost always gain some power with just the swap. its physics.
     
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  14. Extreme Power House

    Extreme Power House Well-Known Member
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    That all depends on what you mean by some power. 35 whp is not some power to me, thats a lot of power from only a downpipe without any ECU tune.
     
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  15. HATED1

    HATED1 Well-Known Member

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    Stupid question time. Will a downpipe without a tune void the warranty on the engine?
     

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