1/4 mile time

[jaackal]

hey, my 88 5.0 LX with 2.73 gears is as fast as my buddies 01 GT we both ran about a 14.2, what do you think i will run with 3.73 gears or at least how much do you think it will take off the 1/4 mile time

 

[CManT1914]

Hey man, those are some nice times for you mods. What was your 60'? They say gears are good for up to half a second, but you could probably expect 3/10s or so out of them. Good choice with 3.73s, they are the best all around for the 5.0L, in most people's opinions.

 

[rsw007]

1/2 second if you dont spin to much with them

 

[willys1]

Again,with traction and good driving 4-6 tenths

 

[5spd GT]

hey, my 88 5.0 LX with 2.73 gears is as fast as my buddies 01 GT we both ran about a 14.2, what do you think i will run with 3.73 gears or at least how much do you think it will take off the 1/4 mile time

What do you mean ya'll ran "about" 14.2...

What did ya'll trap at? (the mph)...

 

[PNY PWR]

I ran 14.1 with stock motor and 3.73's on street tires. The gears should help you out a bit. Going back this weekend with the drag radials on.

 

[TrickStang37]

yeah what were the MPH's?? actually just post the whole time slip so we can evaluate it. As for gears, if you can get traction, they are definetely a great mod, but without good traction, they really arent that usefull in actually makin the car quicker.

 

[88stangnut]

I got a 88 lx with just about the same mods as u, Let me tell u I just swapped the 373 rear into my car like 2 weeks ago, its nutz. 273's are horrible gears for a almost stock car, what I was running into was my gears were soo tall the everytime I shifted at 6g's it would jump back into 3700 rpms range and loose all teh power I built up. Now with 373's the car goes from 6 to 4700 and omfg can I feel the power Im pushing to the ground.. Oh yea I ran a 13.8 in the 1/4 mile on a g-tech, not accutate but what the hell I should be around there somewere

 

[TrickStang37]

actually gears wont change your tranny gear ratios, so technically if you were going from 6000 rpm to 3700 rpm on shifts, then it'll still do that. The gears WILL give you more torque multiplication though, so being at 3700 rpm with 3.73's is alot more torque, compared to with 2.73's, about 35% more so it'll help push you through that rpm. Though when you think abot it, at 3700 the motor is closer to peak tq so it should in reality accelerate its quickest at that point.

 

[GRGT1994]

Actually, I believe gears will tighten the overalll ratios. Ya the tranny gear ratios remain the same, but you are multiplying em all through a new rear end ratio. So in the end, the final ratio of each gear is closer together.

Somebody check me on this one, but I'm almost positive that a gear swap will BOTH increase perceived torque, AND tighten ratios (dropping the RPM swing between gears).

 

[millhouse]

Actually, I believe gears will tighten the overalll ratios. Ya the tranny gear ratios remain the same, but you are multiplying em all through a new rear end ratio. So in the end, the final ratio of each gear is closer together.

Somebody check me on this one, but I'm almost positive that a gear swap will BOTH increase perceived torque, AND tighten ratios (dropping the RPM swing between gears).

You are correct. People who run 2.73's usually shift to early, and their rpms will drop way out of the the ideal powerband. Back when I had a o/r h-pipe I was running 13.9's-14.0's shifting near 6k rpms. When I switched to 3.73's, I was then able to shift down around 5200-5400 rpms (on the stock tach).

As to the original poster, with just gears I'd say you'd be good for .2 reduction in e.t. With some dr's I'd say you could knock another .2-.3 off of that.

 

[ninety15.0]

I have to agree with trickstang....changing the rear end gears shouldnt have any effect on the rpm drop between gears. When you change the rear end gears you are only changing the ratio between the # of driveshaft revolutions and tire revolutions. It has absolutely no effect on the tranny ratios. Therefore you wont see any difference in the rpm drop between gears....even tho it may feel like it. as for the time difference....i think i noticed about 4tenths...if u can keep the tires from spinning.

 

[millhouse]

I have to agree with trickstang....changing the rear end gears shouldnt have any effect on the rpm drop between gears. When you change the rear end gears you are only changing the ratio between the # of driveshaft revolutions and tire revolutions. It has absolutely no effect on the tranny ratios. Therefore you wont see any difference in the rpm drop between gears....even tho it may feel like it. as for the time difference....i think i noticed about 4tenths...if u can keep the tires from spinning.

Instead of trying to explain why (which I'm not quite sure if I'm capable at this time), go here ------>rpm calculator. Hit the calculate button with all data being already entered as is. Subtract the 1st gear and 2nd gear rpms and take note (2911 difference). Now input 3.73 gears and and hit calculate again. Again, subtract the 1st gear and 2nd gear rpms and take note of the the difference (3320). The 3.73 gears have a larger diference. That acutally goes against what I said before .

 

[TrickStang37]

you have to look at differentely. with 3.73's it drops from 6000 to 3600 from first to second. with 2.73's it does the same. with 3.73's @ 6000 rpm in first your at 37 mph and in second your at 3600. With the 2.73's @ 6000 your at 51 mph and in second your at 3600 rpm at the same speed. See?

 

[millhouse]

you have to look at differentely. with 3.73's it drops from 6000 to 3600 from first to second. with 2.73's it does the same. with 3.73's @ 6000 rpm in first your at 37 mph and in second your at 3600. With the 2.73's @ 6000 your at 51 mph and in second your at 3600 rpm at the same speed. See?

Touche Lol, it shows you how well after I think after working extra hours all week . Anyways, yeah...I forgot to figure in the constant variable, speed. As it goes up and down, so does the rpm drop.

 

[millhouse]

Oops, DP.