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wanting to make a drag car, need help.

Discussion in 'The Hokey Ass Message Board' started by SixFour, Jul 26, 2009.

  1. SixFour
    Joined: Jun 3, 2009
    Posts: 146

    SixFour
    Member
    from So cal

    i decided to re-do my coupe and make a new frame and decided i wanna build more of a drag car, but i am still unsure on some things that will help it in hooking up with a fourlink, suspension. my car will be pretty short, much like Littlemans' Deaths Door Step. i see some drag cars with their motors angled pretty far back, what does that do?

    trying to learn as much as i can about this stuff so i can do it right.

    thanks!
     
  2. Nothing. In fact, if you look at pro door slammers the engine is usually pointed down toward the front about 3 degrees. Engine height and distance front to back is important. The angle at which it sits in the car will affect how you need to set your pinion angle and how much pinion angle change your car can stand under load before your U-joints fail.
     
  3. squirrel
    Joined: Sep 23, 2004
    Posts: 45,227

    squirrel
    Member

    Do you want it to look like an old drag car, or work like a (modern) drag car?
     
  4. By "angled pretty far back," I presumed you meant the angle at which the engine and tranny sit in the car. If you meant how far back in the chassis the engine sits relative to the the front axle centerline... roughly farther back promotes better weight transfer.
     
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  5. gypsy
    Joined: Apr 23, 2006
    Posts: 295

    gypsy
    Member
    from florida

    Find a copy of Dave Morgan's Doorslammer Chassis Book, it will explain everything you need to know relative to setting up your chassis.
     
  6. SixFour
    Joined: Jun 3, 2009
    Posts: 146

    SixFour
    Member
    from So cal

    im shooting towards sort of the same look as Deaths Doorstep, im running a 429 with a c6.
    the driveshaft is only about 15 inches long, it may even be a little shorter if i decide to set the motor back a little more

    my buddy has a copy of that doorslammers book in his shop ill take a look at it.
     
  7. pastlane
    Joined: Oct 4, 2007
    Posts: 1,064

    pastlane
    Member

    Does this book cover A arm setup as well? I've done several o/t strut front ends but never welded up an A arm front suspension.



     
  8. SixFour
    Joined: Jun 3, 2009
    Posts: 146

    SixFour
    Member
    from So cal

  9. Glen
    Joined: Mar 21, 2001
    Posts: 1,789

    Glen
    Member

    I am really happy with my sedan but it took some time to get it right. Once I got the instant center setup and invested in a set of double adjustable shocks I was able to control the launch. The shocks were one of the best investments I made.


    Take a look at Chris Alston's website he has some tech pages there that will give you some ideas too.
     
  10. rc.grimes
    Joined: Aug 14, 2007
    Posts: 698

    rc.grimes
    Member
    from Edmond, OK

    Shocks and weight distribution/transfer will make or break(sometimes literally) how the car launches. Putting a ton of work into a tire fryer is no fun.
     
  11. Hey sixfour,keep this thread going! It will help me out alot with my 27 t coupe aswell. Im running a 390 and building an old style drag coupe with it.
     
  12. jokerjason
    Joined: Oct 18, 2006
    Posts: 356

    jokerjason
    Member

    Hey man, to save alot of headaches at the track, make sure to go over the NHRA rule book to make sure you have no hassles. Too bad the rules had to change so much too make it hard on a guy that just wants to haul ass an have some fun!!! JOKER JASON.
     
  13. SixFour
    Joined: Jun 3, 2009
    Posts: 146

    SixFour
    Member
    from So cal

    hey 56 ford, you got any pictures of your ride?
     
  14. SixFour
    Joined: Jun 3, 2009
    Posts: 146

    SixFour
    Member
    from So cal

    ive been looking that over, gonna take some work to meet up with all their standards, but oh well, im gonna be haulin' ass, so better be safe than sorry haha
     
  15. Hey sixfour, I only have pics of bits and peices right now> The car isnt even a roller yet. Im still trying to get my fairlane running and out of the garage then all hell will break loose. So i will have to build it nhra approvd to run anywhere?
     
  16. brandon
    Joined: Jul 19, 2002
    Posts: 6,324

    brandon
    Member

    this will be probably the biggest thing on a ride like this.....especially when trying to make it actually work and not put it on the back bumper area:D

    do a search , as there are other post on this subject ....
     
  17. Glen
    Joined: Mar 21, 2001
    Posts: 1,789

    Glen
    Member

    Be careful with that weight setback....My car weighs 1200 on the front tires and 1300 on the rear tires and I really dont have any setback.
     
  18. SixFour
    Joined: Jun 3, 2009
    Posts: 146

    SixFour
    Member
    from So cal

    ya the 429 is a heavy motor, its moved back halfway in my cowl, might move it back a little more. i need to figure out if i wanna cut the cowl so i can work on the motor easy
     
  19. Larry T
    Joined: Nov 24, 2004
    Posts: 7,679

    Larry T
    Member

    You do need enough weight on the front end to keep the front wheels down when you launch it.
    Larry T
     
  20. Yeah i agree, dont move the motor too far back or you will be counting stars
     
  21. SixFour
    Joined: Jun 3, 2009
    Posts: 146

    SixFour
    Member
    from So cal

    the front should still weigh a little more than the back so it should keep the fronts planted on the ground.

    with a triangulated 4link, how much longer can the lower arms be than the uppers, and what difference does it make if the uppers are shorter
     
  22. Hey sixfour, sorry if i seem to be bugging you but could you post more pics of your frame and front suspension?
     
  23. SixFour
    Joined: Jun 3, 2009
    Posts: 146

    SixFour
    Member
    from So cal

    ya sure, i will PM you some tomorrow. I'm on my lady's computer none of my pictures are saved on it. its going to be redone though
     
  24. brandon
    Joined: Jul 19, 2002
    Posts: 6,324

    brandon
    Member

    the pinion will have more movement , or is this wrongful thinking...?:rolleyes::D was going to go with a true 4 link setup in my deal i'm working on now....if i can package it well enough , as to not see any of the suspension from the sides
     
  25. Alright, thanks alot!
     
  26. Mat Thrasher
    Joined: Nov 5, 2007
    Posts: 1,106

    Mat Thrasher
    Member

    I'm going to suscribe to this thread. I'm building a 34 PU that will see some strip time and I'm curious to see what everybody else is doing.

    I would'nt think you're going to need much set back into the firewall. I would think where the motor sits in relationship to the front axle centerline it's techincally all ready set back. Comparing a hot rod to a full bodied car. That's just my theory someone tell me if I'm wrong.

    When I set up the chassis for my truck I tried to use proven technology. For the rear suspension I'm running a competion engineering 4 link. I also have a chassis builder building my cage for me and I picked his brain a lot when it came to motor placement and driveline angles. What he told me was the driveshaft angle off of the back of the tranny should be 0 and 3 negative at the pinion. I took it as it didnt matter what angle the motor and tranny are at as long the driveline angles stayed the same.

    Also I think the crazy set backs a high motor placements from the sixties had to do with inferior tires. I'm guessing extreme weight transfer was the idea and is not needed with good tires and would be counter productive.

    Here's a shot of my chassis so far to show you what I did. I am by no way a chassis builder.

    [​IMG]
    Mat
     
    Last edited: Jul 27, 2009
  27. SixFour
    Joined: Jun 3, 2009
    Posts: 146

    SixFour
    Member
    from So cal

    that frame looks like it will be way strong enough blown34 coupe, and the car in your avatar looks wicked!
     
  28. SixFour
    Joined: Jun 3, 2009
    Posts: 146

    SixFour
    Member
    from So cal

    i cant decide on whether i wanna run Hursts 10'' slicks or Radirs'. which kind are better, i know Radirs are a lot more expensive, but that duznt always mean their better
     
  29. Mat Thrasher
    Joined: Nov 5, 2007
    Posts: 1,106

    Mat Thrasher
    Member


    I would say niether if you want to hook up. If you want the look either one will work. It's been hashed out here many times before do a search for both. I'm going to run my radir's on the street and running modern wrinkle walls for the track. Thanks for the compliments.
    Mat
     
  30. temper_mental
    Joined: Oct 22, 2006
    Posts: 2,718

    temper_mental
    Member
    from Texas

    This may have been covered. The more you can bring the motor back behind the front axle you will help bring the weight to the rear of the car. My coupe is right at 50 50 I am running a BBC 871 . This will really help get the weight off the nose.
     

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