4:56 Gears

[gtpowered4.6l]

Right now I have a solid axle swap in my 99 Cobra. I have 4:10 gears. My car runs 12.6's-.7's@110. Would I benefit going to 4:56 gears at the track? I just dont feel that the 4:10's are enough for my car. I do daily drive my car but rarely am on the highway unless I am on my way to the track. If I do the gears the Chris@Excessive will be doing them

 

[Almo]

Get a good tire under it and it would help. Otherwise, I recall you saying something about worn out DRs and those will not cover it for steeper gears.

 

[01SVTSnake]

Almo hit the nail on the head pretty much. Good tires and launch will only help. Also what RPM are you running through the trap in 4th gear. You also want to make sure you dont run out of gear and have to to 5th

 

[VirtualSVT]

When are you hitting 4th?

 

[qwikhuh]

4:56 gears are the absolute best strip/street gear for the 96-01 Cobras. As long as you have enough traction to be able to take advantage of them they are absolutely the way to go.

 

[gtpowered4.6l]

Get a good tire under it and it would help. Otherwise, I recall you saying something about worn out DRs and those will not cover it for steeper gears.

yeah my dr's are on there last leg. They are Nittos but on my last run I cut a 1.68 short time with them launching at like 4500. They still have a little life since nittos hook better when worn. I am going to be going with some ET streets when I get new ones.

 

[gtpowered4.6l]

When are you hitting 4th?

I think I am trapping in 4th gear around 5800. I will have to pay more attention next time. What should I be trapping under in order to switch gears. meaning if I am trapping 6200 with 410's should I switch?

 

[8URZ-28]

Try some 430's

 

[2bscrewed]

I think I am trapping in 4th gear around 5800. I will have to pay more attention next time. What should I be trapping under in order to switch gears. meaning if I am trapping 6200 with 410's should I switch?

If you are trapping around 110, then 4.56's would be perfect on a 26" tire. Here is an easy RPM/MPH calculator.

http://www.wallaceracing.com/gear-speed.php

Engine Speed (RPM) Speed (MPH)
8000 RPM 135.70 MPH
7500 RPM 127.22 MPH
7000 RPM 118.74 MPH
6500 RPM 110.26 MPH
6000 RPM 101.78 MPH
5500 RPM 93.29 MPH
5000 RPM 84.81 MPH
4500 RPM 76.33 MPH
4000 RPM 67.85 MPH
3500 RPM 59.37 MPH
3000 RPM 50.89 MPH
2500 RPM 42.41 MPH
2000 RPM 33.93 MPH
1500 RPM 25.44 MPH
1000 RPM 16.96 MPH

 

[wheelhopper]

MM&FF did a project car a while back called " Red Hot chilli Pepper", I think. Anyway, they tried different gears in a naturally aspirated Cobra and liked the 4.30s the best. Not a Ford racing part though, which means you may get some gear whine.