4.56 vs 5.13s

-
racing340

racing340

Member
Joined
Apr 14, 2010
Messages
22
Reaction score
1
Location
Leicester NC
do you think it would be at least a tenth changing from 4.56 to 5.13s gears in 1/8 mile or more? Just curious if any one has used both?
 
Used 4.30, 4.56, and 5.13 no difference in ET. The 5.13 made the 60 ft erratic. I race 1/8 mile(Duster 340 7.5 ET 90 MPH 1.6 60ft) and I have seen numerous guys swap in deep gears thinking that they will shave off some time, never works.
 
What stall are you running. List out your combo more info helps on the responses.
 
I ran 5.38 and changed to 4.56 and no change in et but I run 1/4 mile more so that was the only reason for gear change.My 60fts are the same with both.1.336 to 1.344 with 40 passes.
 

Attachments

  • Jesse (2) (640x427).jpg
    122.4 KB · Views: 638
  • downsized_0707121753.jpg
    48.4 KB · Views: 675
No way of even guessing without knowing your complete drivetrain combination. Is it a stock 318, a built to the hilt 340, or a stroker of some sort? What works on one combination may not work on another.
 
hi, I ran 5.13 gears changed to 5.57 , dropped .3 tenths in 1/4 mile, gained one mph in speed. in 1/8 mile was bout 1 1/2 tenths. mph was faster also. gear ratio is leverage, I ran 29.5 tires with 5.13, 30" tire with 5.57 gears. like anything else need to tune it to get gains. if gear ratio wasn't important, then should run 3.91. leverage is basic physics, can move more and easier with longer lever. just food for thought. btw , 340 duster car
 
fishy68 said:
No way of even guessing without knowing your complete drivetrain combination. Is it a stock 318, a built to the hilt 340, or a stroker of some sort? What works on one combination may not work on another.
Click to expand...


340 9.5 to 1 motor 727 trans 3500 to 4000 stall verter ptc with 456s gears its and 1/8 mile car 29.5/9 mt slicks cam is 520 540 lift
 
The driving factor is where your rpms are at the traps. You want to keep the motor in the power range through top gear. Too much of a gear can take take that away
 
4.56 to 5.13, my opinion is virtually the same ratio. Your not making enough of a change to see a difference. Find a calculator online and figure out your finish line rpm...
 
I think a converter change would do what you're looking for. An 8" 4500-5000 stall unit would likely get you a tenth.
 
skrews said:
I think a converter change would do what you're looking for. An 8" 4500-5000 stall unit would likely get you a tenth.
Click to expand...

X2 Or more! Have pretty close combo, did a 3.91-4.88 gear swap didn't pick up enough to say so,
 
at one time i had a quick change rear end so i tried a 5.83 or 6.00 i cant remember exactly but it went through all three gear and ran 6.90 @110mph with a 340 and 32x14 tire
 
racing340 said:
29.5/9/15
Click to expand...

my opinion is that you do not have enough cam now to pull the 4.56 with that size slick. using a 5.13 will be worse as you are already buzzing through the torque range with the 4.56's. i feel like some of the other's stated that a 8" convertor will do the job. also a cam change to something in the .650"-.700" range will produce the torque numbers in the range that the gears will want would be worth while checking into.
 
racing340 said:
340 9.5 to 1 motor 727 trans 3500 to 4000 stall verter ptc with 456s gears its and 1/8 mile car 29.5/9 mt slicks cam is 520 540 lift
Click to expand...
I'm running 9:1 360 with 508 Mopar cam, same gears and slicks as you are. My Demon was using a 9.5" 3500 stall, switched to 8" 4600, car went 6 tenths and 5 MPH quicker in the 1/8. I race 1/4 mile tracks. Right now I go through the lights at 6200 at 114 MPH. Swap the converter, leave the gears alone.
 
ditto on the converter... Theres alot of time in getting a good converter. Get a good one around $1,000.

Theres also a couple tenths in an aluminum drum and needle bearings in your 727 and a couple more in an aluminum gutted 904.
 
You must log in or register to reply here.
-

Back
Top