The secret to good 60' times?

Classic Mopar Racing Forum

  1. M_Body_Coupe

    M_Body_Coupe Well-Known Member

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    Guys!

    My coupe is set-up to be a great street riding/handling ride. That means both front & rear sway bars, adjustable KONI shocks, 5 leaf spring packs, poly bushings, etc, etc.

    Having made some engine changes over the winter (CR bump to 10.5 from 9.7, final clean-up head porting, move back to Perfomer RPM intake from a single plane Holley Strip Dominator, etc) I had expected to beat my previous ET best of 13.13@102mph, instead, the best I could muster was 13.22@103...grrhh....

    I posted a pretty extensive thread on the Moparts Racing Forum here => Combo changed, but ET still the same? | Unlawfl's Race & Engine Tech | Moparts Forums , including a compilation of the day's racing events on this YouTube video =>

    I then remembered that our forum here has a specific racing section as well, thus my request for your feedback/suggestions.

    For those of you running your street cars at the drag strip, what setups are you using to get decent 60' times?

    Both my 2014 and 2016 season's show terrible runs:

    REACTION - 60 FT - 330 FT - 1/8 ET - 1/8 MPH - 1000 FT - 1/4 ET - 1/4 MPH - TIRE PSI - LAUNCH RPM - COMMENTS

    2014 Season runs (single plane Holley Strip Dominator intake with 9.6 CR)
    0.460 - 2.006 - 5.580 - 8.571 - 80.65 - 11.262 - 13.533 - 99.62 - 32 - 3000
    0.449 - 2.660 - 6.579 - 9.609 - 81.51 - 12.248 - 14.482 - 101.15 - 32 - 3000
    0.603 - 2.333 - 6.119 - 9.132 - 81.96 - 11.749 - 13.966 - 102.08 - 32 - 3000
    0.100 - 1.870 - 5.379 - 8.341 - 82.40 - 10.937 - 13.138 - 102.33 - 32 - 3000 - BEST TIME
    0.153 - 1.973 - 5.519 - 8.473 - 83.17 - 11.056 - 13.254 - 102.54 - 32 - 3000

    2016 Season runs (dual plane Performer RPM intake with 10.7 CR)
    0.120 - 2.180 - 5.779 - 8.759 - 82.57 - 11.357 - 13.568 - 101.68 - 25 - 3000
    0.520 - 2.356 - 6.386 - 9.450 - 80.89 - 12.081 - 14.314 - 100.99 - 25 - 3500
    0.041 - 2.098 - 5.624 - 8.561 - xx.xx - xx.xxx - 13.316 - 102.75 - 19 - 3500
    -0.126 - 2.034 - 5.515 - 8.440 - 83.76 - 11.006 - 13.188 - 102.98 - 19 - 3500 - RED LIGHTED
    0.189 - 2.069 - 5.559 - 8.484 - 83.94 - 11.043 - 13.218 - 103.27 - 19 - 4000 - BEST TIME

    It was recommended that I un-hook the sway bars, OK, doable, but really, not much else beyond this as I really consider the street manners to be a top priority.

    Thanks!
    -Dariusz
     
  2. 80mirada

    80mirada Well-Known Member

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    Your chassis setup is to stiff for drag racing. The great street/road manners are from controlling body movements and for drag racing you need more, to allow better weight transfer. Probably need to adjust your shocks to softer settings, disconnect the front sway bar (don't drive on the street with it unhooked) maybe even add some weight to the trunk
     
  3. BudW

    BudW Moderator Staff Member

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    Disconnecting the front sway bar (both ends) will help weight transfer at take offs.
    There is not much friction at the front sway bar frame bushings – but for drag racing, you need that weight transfer ASAP.

    Removing the sway bar (or both if one in rear) would be best for drag racing (weight loss) – but not good for anything else – including driving too/from the track.

    Moving the Battery to the trunk is also advisable.
     
  4. CM360

    CM360 Well-Known Member

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    Looking at the video...your car does not accelerate out of the hole so a better rear gear or better yet work with a trans shop and get a torque converter that is set up for your weight and rear gear. 2.74 first gear? Seems you shift to early also. You want to bring up as much rpm that the converter will handle at launch. Your front shocks are too stiff and you are not getting enough weight transfer. You are not getting any squat at launch. Not sure how much power you are making but your not making enough power in the lower rpm's. Try bumping up the timing.
     
  5. M_Body_Coupe

    M_Body_Coupe Well-Known Member

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    Alright, so please explain what makes you conclude this. How can you tell that the car is not accelerating out of the hole? Disregard the last part of that video (Dave's Run), my friend ran this and he was seriously slow, like a full 2 sec slower then my best ET. My gear today is 3.91 SG, I am looking for a 4.10 setup to try.
    I tried different staging/launch RPMs, from 3k to 4K, each time, given the feedback so far, I must have had tire spin given the terrible 60' times. Regaridng the shift point, boy, that's already at 6300-6500 RPM, I would not be comfortable going much higher given the street miles I am still hoping to get out of this motor...LOL.
    I agree, the chassis goal was to make it as stiff as possible, really meant for good street manners. Power wise, I think I have the parts in the motor to do 400hp at the crank, but the ET does not suggest I am getting that. Timing is already at 36 full mech advance. Given that my static CR is 10.5:1 I really didn't want to push this any harder.
     
  6. jasperjacko

    jasperjacko Well-Known Member

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    Your difference in 60' is the diff in your et. I think your et vs mph is on par. Slight wind and humidity/temp differences can make quite a difference in et. I would actually try lowering your shift point by 2-300 rpm. You may also need to roll into the throttle and not mash it at launch. What tires and psi?
     
  7. jasperjacko

    jasperjacko Well-Known Member

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    I see you cut the heads .030, did you also cut the intake to compensate for the heads being closer. did you you check valve lash too?
     
  8. jasperjacko

    jasperjacko Well-Known Member

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    My car has a mild 360, stock j head, 9:1 comp., 484 cam, performer intake, tq carb, 1.625 dougs headers w/ single 3" exhaust, 904 manual, 2500 stall, 3.55, 255/60/15 coopers, Stock replacement springs, original shocks, front n rear sway bars. Best et 1.89 13.65 99.5 this was on a cool fall night. I foot brake to 1500-1800 and roll on the throttle. Tires and suspension won't allow full throttle launch.
     
  9. jasperjacko

    jasperjacko Well-Known Member

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    I run about 11.8-12.2 afr at wot. Still a work in progress.
     
  10. jasperjacko

    jasperjacko Well-Known Member

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    Very cool car by the way. I'm sure you will get it dialed in and it will be a beast. I wonder if a 3-3500 convertor would fit the combo better?
     
  11. jasperjacko

    jasperjacko Well-Known Member

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    I think 2-3 tenths in the 60' will give 4-5 in the 1/4
     
  12. CM360

    CM360 Well-Known Member

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    Front end sway bar reduces front end lift. Without go weight transfer, whatever you throw and it won't make and difference. Can't get it to hook then everything else is just top speed. Pump up your front tires to 40 psi once you get to the track. Get under the car and crank the torsion bars 2-3 turns. Put 100lbs of ballast in the trunk. Then try to launch the car around 2500 rpms. This should get it started. These mods can be changed before you leave the track. It might be a little lite on the top end. After you get the car to hook, then get a converter. Don't waste your time and $ on a out of the box converter. Call ATI, Continental or Dynamic and have a converter built for your combo. You'll be surprised what the car will then do. NO WEIGHT TRANSFER=NO TRACTION>
     
  13. BudW

    BudW Moderator Staff Member

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    Well worded.
     
  14. MoparKidD-4

    MoparKidD-4 Well-Known Member

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    From watching the video, it looks and sounds like the engine falls flat for a second when you first launch, the engine then picks up and overpowers the tires for a decent distance. I'd look at tuning the carb first and foremost for a crisp clean launch off the line. Then try cranking up the torsion bars to raise the front end a tad, and like others said the shocks seem very stiff I don't see ANY body rise in the back or front at launch. If you can take more air out of the rear tires I'd do that too.
     
  15. Oldiron440

    Oldiron440 Well-Known Member

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    Do you still have the iso mounts on the rear spring's? I don't see much it any rear end lift , you need to turn the axial rotation into body lift for the most traction.