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  1. #1
    Ken62465's Avatar
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    Safe limit to mill out of R&D grate?

    Grates been milled once and currently sitting at 9mm thick where it mounts to X rideplate 3 bolt step. Grate is hanging down 2.25mm still. Am I ok to mill this additional amount out? Not sure what one might think the max thickness that plate to mount should be?


  2. #2
    Logic says, if you're only needing to machine the back end, then provided the front leading edge remains tight you should be ok.

    All the force appears to be loaded on the leading front to mid of the grate, so the back is mainly dealing with a shearing force.

    When they fail they usually lift from the front edge and try to peal backwards.

    I personally don't think it's a problem on the back, on the front I'd be careful.

    Just a logical approach.

  3. #3
    Ken62465's Avatar
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    It was my thought that while the leading edge might take the brunt of force that whole plate is held in place by the 3 mount bolts to rideplate on the X style so thinning that plate further raised concern to me about how far is ok to mill it down.

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    Seems so many posts I've turned up on these R&D grates all talk of how much the plate hangs down below the rideplate. Makes me wonder why the plate is so thick to begin with? Is the point of yield in question and R&D engineered it that way based on yield strength of material used? I then measured the thickness of the plate where the grate mounts on the rideplate and it's 8.15mm. Without knowing grades of material I couldn't determine the yield strength but then again without knowing the applied force calculating any such capacity would be useless. Unless anyone has any figures I might be able to run some numbers.

  4. #4
    Most people only mill down the front mounting plate, as that usually hangs very low and is thought to cause the right side pulling.

    Mine sits a fraction low and I picked up a slight right side pull.

    I chose to put up with it as opposed to milling / weakening as it is the front edge. Back edge is also low, like yours, but its overall effect against speed / control? Not sure I'd notice or care vs risk of weakening by milling material off.

    Just my balance of risk view. I like to make things as effecient as possible, but sometimes the reward isn't worth the risk. I think you're here now with this.

  5. #5
    Ken62465's Avatar
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    I also have that slight right side pull at higher rpms.

  6. #6
    JT jpt7779's Avatar
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    Quote Originally Posted by Ken62465 View Post
    I also have that slight right side pull at higher rpms.
    Several of us with this grate also have the right pull, some don't.

    I have filed on mine extensively to get it flush front and back, filed on the wings and even have a hole drilled in the back to help alleviate tunnel pressure stuffing above 83+ mph. This grate is still the best for my 10 T-X overall. The next best is the Riva SS grate.

  7. #7
    Bob 1tommygunner1927's Avatar
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    My R&D grate is milled to 7.9 mm and has been good to just under 83 mph. If I had a do over when installing the pump shoe, I would've raise the shoe some and not mill the grate as much!

  8. #8
    Ken62465's Avatar
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    You lost me there how the shoes placement has a negative impact on the grate hanging down or not? The shoe sits above the rideplate so if your shoe is installed low and pushing down on the rideplate I'd think once the rideplate it torques to hull it would stress the shoe and buckle it. I'd also prefer the shoes placement based on a solid thru hull fitting alignment.

    Quote Originally Posted by 1tommygunner1927 View Post
    My R&D grate is milled to 7.9 mm and has been good to just under 83 mph. If I had a do over when installing the pump shoe, I would've raise the shoe some and not mill the grate as much!

  9. #9
    Moderator Snoman's Avatar
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    Quote Originally Posted by Ken62465 View Post
    . I'd also prefer the shoes placement based on a solid thru hull fitting alignment.
    +1...I would want my shoe as true as possible also and mill some off the grate as needed or neccessary to a point....IF you have to mill your grate aggressively then ther is something IMO that needs to be checked/corrected..Once you start playing with shoe angles then you have to play with engine angles for proper alignment and then pump/thrust cone angle to complimnet the shoe being off...Not to mention the angle of the intake grate also now as it will not be fluch with the pump shoe and could allow unwanted pressure between the shoe and grate creating possible stress/issues on the grate/shoe also...

  10. #10
    Bob 1tommygunner1927's Avatar
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    Yup, and then add in angling of the ride plate.......my head hurts now!




    Quote Originally Posted by Snoman View Post
    Quote Originally Posted by Ken62465 View Post
    . I'd also prefer the shoes placement based on a solid thru hull fitting alignment.
    +1...I would want my shoe as true as possible also and mill some off the grate as needed or neccessary to a point....IF you have to mill your grate aggressively then ther is something IMO that needs to be checked/corrected..Once you start playing with shoe angles then you have to play with engine angles for proper alignment and then pump/thrust cone angle to complimnet the shoe being off...Not to mention the angle of the intake grate also now as it will not be fluch with the pump shoe and could allow unwanted pressure between the shoe and grate creating possible stress/issues on the grate/shoe also...

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