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  1. #1
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    Default 8.8 relocation drilling hole for lower control arms

    I'm in the process of putting an 8.8" in my 85 GT. I've read some information in the Mustang Performance Handbook 2 about drilling new mounting holes in the lower brackets for the lower control arms to help the anti-squat. Since I'm in the position to do this, was thinking about doing this. I've got the maximum motorsports lower control arms on order. Any pros or cons to doing this modification? Its shown on page 69. Thanks!

  2. #2
    Moderator wraithracing's Avatar
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    Default

    I am not much of a drag racer, so I may be incorrect since I didn't read much of the section in the Mathis Handbook related to drag racing, but I thought you had to cut the stock control arm mount and weld a section of metal in between the two sections. Again I might be wrong.

    Personally the MM lower control arms are much better than anything that was readily available back when Mathis was testing and writing his book. There is some good stuff in there and I too have both of his books, but today there are so many suspension parts and pieces available, that much of what the book recommends is in some ways "old tech" or may not as effective or needed today.

    I would try the new control arms out and see what you think before making any major modifications. If I am wrong about the welding in of extra metal, then sure why not drill a second set of holes if you think it will improve your performance. Good Luck!
    ​Trey

    "I Don't build it hoping for your approval! I built it because it meets mine!"

    "I've spent most of my money on Mustangs, racing, and women... the rest I just wasted."

    Mustangs Past: Too many to remember!
    Current Mustangs:
    1969 Mach 1
    1979 Pace Car now 5.0/5 speed
    1982 GT Ongoing RestoModification
    1984 SVO Awaiting Restoration
    1986 GT Wrecked by PO, but still want to save!

    Current Capris:
    1981 Capri Roller
    1981 Capri Black Magic Roller Basket Case
    1982 Capri RS 5.0/4spd T-top Full Restoration Underway
    1984 Capri RS T-top Roller
    1983-84 Gloy Racing Trans Am/IMSA Body Parts

  3. #3

    Default

    The most used approach to adding anti squat today is to mostly address it with the upper arms.

    The very basic drag racing set-up is to make the lower arm level, or as level as you can get it, then work on the angle of the upper arms by 1) relocated uppers like those sold by Baseline Suspension or Team Z, 2) moving the front pickup point of the uppers down either by brackets or old school drilling a new hole 1" lower, 3) Jegs and others sell some brackets that move the housing end of the uppers, up ...

    There are some weld on / bolt on instant center brackets out there for the lower rear end housing, but I always view the as a way to get the lower level.

    By changing angles on the lower you can indeed affect instant center and anti squat, but it's always been an issue for me. Much easier for me to manage with the lower arm level (by ride height) and work with the top arms. I actually have shorter than desired springs and have a series of 1/4" spacers I put under the springs to make the arm level, and get a ride height that works.

    This is 120% AS - https://i1192.photobucket.com/albums...psxiez9xwy.jpg

    This is more neutral at 100% AS - https://i1192.photobucket.com/albums...psuwlm1zlw.jpg

    This is more dramatic at 130%+ AS (and a short instant center) https://i1192.photobucket.com/albums...psrinqsbbw.jpg

    Food for thought
    Bob Myers

    84 Capri RS Turbo - Only a 4 banger - 1/8th 6.48 at 104.74 MPH, 1/4 10.20 at 133.95 MPH

  4. #4

    Default

    Always love to see Four Eyed foxes hangin those hoops coming out of the hole. You can tell how well the setup works looking at how far the nose is up and what the 60’ times are.

    the pictures shared looked cool for sure!


    If the car is functioning as more than a straight line performance / drag car another point of discussion is torque arm based upper setups. The further forward they go the more they tend to help with weight transfer. The other advantage is greatly reduced brake dive.

    There are aftermarket weld in torque boxes available that let you pick lower control arm attachment points too.

    Easy to get things with pinion angle complicated pretty quickly.


    For me, I plan to see how my 85 build does with MM lowers and uppers and go from there.

  5. #5
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    Default

    This is just a weekend cruiser, but obviously I'm trying to make it more fun. As cool as pulling the front tires looks, it's not in the cards for mine. Mainly stock, but converting to duals and a 3.55 gear. I was reading the book, trying to get some more ideas and saw this as a relatively easy modification. He does want the factory holes welded back up, otherwise I'd leave the originals there just in case. I guess for now, I'll leave it alone and see how it does this summer. It's always good to bounce these ideas off the guys that have done more to these than I have. Thanks!

  6. #6

    Default

    I have that book too, and what I took away from it - as far as filling the holes - was making sneaky changes that were nearly undetectable, yet effective.

    This mostly applied to racing in a class that strictly followed using OEM suspension. Moving and filling holes was a way around that requirement.


    That was my intrepretation anyways. I have been wrong before. Good luck with that '85 neighbor!

  7. #7
    FEP Member
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    Default

    The idea of lowering the hole in the lower arm bracket is to give you a better angle of the lower arm to get it more in line with the center of gravity or the center of the car. This does two things. It gets rid of nose dive when you brake and it does the opposite when accelerating off the line hard. It will lift the car by it's center point and not cause the nose to wheel stand. All of that wheel stand takes away from the forward movement of the car off the line and slows down the cars reaction of going forward. Increase in 60 foot times is the result. Think South Side Lift bars.

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