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Thread: BF xr6t boost issues

  1. #1

    BF xr6t boost issues

    Hey guys

    Im having an issue with a BF xr6t which we have done a turbo back exhaust, larger intercooler, 1150cc injectors etc.

    We have had the wastegate bore machined with larger flapper, and a turbosmart actuator. Had issues on the dyno with overboost close to 20psi.
    Turned off closed loop boost control and lowered wastegate duty as low as possible, but found still overboosting.

    Bypassed complete boost control system, running the wastegate just off spring pressure which was 12psi, found still overboosting.
    Tried a 7psi spring to see if removing boost earlier would help found still going over spring pressure.

    Removed Actuator and bench tested off turbo, and found it opens at 7psi.

    So this leads me to believe that i have an issue with my internal wastegate bore size being to small or a restriction on my actuator rod or flapper arm,
    which is causing it to open late or not open enough.

    Currently stripping it down to see what i can find. Has anybody had similar issues?

    What should be the optimum internal bore size after machining?

    What angle should the flapper roughly be at when wastegate is fully open? i see it can only open so far due to fouling on flapper pivot.

    Thanks in advance

  2. #2
    Tuner
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    You should get on to the Ford xr6 Turbo forum and start reading about overboosting.
    There is also a good thread on fapper mods and waste gate porting which is what you need to do to fix the problem
    You are having. Flapper port should be a D shape not bored round so the flap doesn't get caught up in certain positions.
    Your main problem is the port leading into the flapper hole it needs blending on the short turn radius and may also
    Need channeling prior to the short turn.
    From what I found, different brand turbos require different amounts of porting.

  3. #3
    Thanks for the reply

    I tested the system this morning, the only obvious thing I can see is there is a noticeable difference in travel between the factory wastegate and the turbosmart wastegate.

    The factory wastegate has 20mm of travel from 0 - 10 psi (double spring pressure) while the turbosmart wastegate has only 10mm of travel from 0 - 15psi, which leaves the
    flapper only half open.

    I need to put 20psi+ pressure into it to get it completely open

  4. #4
    Tuner
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    Hi, how did you go with this did you get it sorted out ?

  5. #5
    Getting a 11.8 psi garrett actuator, and have spent time reshaping and channelling the wastegate port.

    Hope to have the turbo back in in the next couple of days. Will keep you posted.

  6. #6
    Potential Tuner
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    Quote Originally Posted by Eperformance View Post
    Getting a 11.8 psi garrett actuator, and have spent time reshaping and channelling the wastegate port.

    Hope to have the turbo back in in the next couple of days. Will keep you posted.
    Did reshaping and channelling the wastegate port solve the overboosting or was it more due to the actuator travel? Or both?

  7. #7
    I think main issue was the port, as the garrett actuator still had limited travel. which i guess will always be the case when going up in spring rate.
    I managed to control the boost to where i wanted it, but would really struggle to run less then 14psi.

  8. #8
    Advanced Tuner
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    Correct mate, it's not so much the actual port size, it's the short side radius that needs the most attention.
    Ford BF Turbo Ute,Stock head/cams, In house built bottom end,Atomic Springs, Forged Rods,Cosworth Pistons,Atomic Billet oil pump gears,ARP Head/mainstuds,Process West Stage 3 Cooler Kit- Plazmaman plenum,Precision Int.Gate 6466,Manta twin 3" exhaust,ID1000s Plazmaman surge with Holley 12-1800 pump, Home Built ZF6H26, On United Pump E85 499rwkw 10.5@135mph https://www.youtube.com/watch?v=dgZupPhrMss
    Latest mods, FG intake manifold conversion and ID1300s-500rwkw, Yet to see the 1/4Mile

  9. #9
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    Correct Mic, but some turbos especially ones with a larger wheel like some of the Mamba ones also need channelling leading up to the port as well.
    Btw congrats on being a daddy.

  10. #10
    Advanced Tuner
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    Thanks mate, Hopefully I'll be back at the track soon. Finally have some motivation/free time to finish retuning it. Couple highway pulls is all it needs.
    Ford BF Turbo Ute,Stock head/cams, In house built bottom end,Atomic Springs, Forged Rods,Cosworth Pistons,Atomic Billet oil pump gears,ARP Head/mainstuds,Process West Stage 3 Cooler Kit- Plazmaman plenum,Precision Int.Gate 6466,Manta twin 3" exhaust,ID1000s Plazmaman surge with Holley 12-1800 pump, Home Built ZF6H26, On United Pump E85 499rwkw 10.5@135mph https://www.youtube.com/watch?v=dgZupPhrMss
    Latest mods, FG intake manifold conversion and ID1300s-500rwkw, Yet to see the 1/4Mile