Ford's official answer to what gears you should put in your car

#21
willys1 said:
It is alot faster in the low rpm's then it is in the high rpm's!!
Click to expand...

That is way way way to general of a statement...give me some rpm specifics. I still say, even in general, you are wrong.

Where do you think (during a race or spirited driving) your rpms are at for 90-95% of the time (upper rpms)...once the car is launched (assuming you even race from stop) you are only below 3k for almost literally a second with a geared car...so where do you think the rest of the 11-14 seconds is spent? In the higher rpms where it makes more pulling power and the torque starts spinning itself to horsepower and they begin to overlap nicely to provide a flat torque pull. Look at dyno sheets.

How bout this...you race your 5.0L (identical to mine for example) from 1,000-3,000rpm where you shift it at...and I'll "race" mine from 3,000-6,000rpm and will see who gets to the end sooner and who out accelerates who to 60mph :p I'm hoping your just a big ball of confusion right now because what your saying or stating is simply not true... :bang: Talk about early shifting :rlaugh:
 

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#22
Wouldn't a higher (4.10) geared car naturally reach its top speed (or benchmark speed) faster than a lower (3.55/3.73) geared car anway? Identical cars and power bands aside, considering they are the same all the way around anyway.
 
#23
stang22 said:
Wouldn't a higher (4.10) geared car naturally reach its top speed (or benchmark speed) faster than a lower (3.55/3.73) geared car anway? Identical cars and power bands aside, considering they are the same all the way around anyway.
Click to expand...

Yeah I would say so...in general of course.
 
#25
willys - it's the 3.73's that'll get there quicker - assuming we're staying within the power band.

But it's pretty academic -- there's only about 5% difference in rpm between the gears. Any one of us would be hard pressed to tell the difference once they're in the car.
 
#28
Yup - WAY MORE variables on a 1/4 mile run than just the gear change. Temp, traction, driving, shifting, etc.

The only way for a direct comparo would be to run the same car, same (consistent) driver on the same night with the the different gears (some major wrenching in between rounds). If you did that and driving/launch were consistent, the 4.10's would have gotten you to the lights quicker.
 
#31
Michael Yount said:
Yup - WAY MORE variables on a 1/4 mile run than just the gear change. Temp, traction, driving, shifting, etc.

The only way for a direct comparo would be to run the same car, same (consistent) driver on the same night with the the different gears (some major wrenching in between rounds). If you did that and driving/launch were consistent, the 4.10's would have gotten you to the lights quicker.
Click to expand...

My first time out with 4.10's having switched from 3.73's I was slower too, even with all the math of 60 foot and d/a factored in, "I" was slower in the car.
Once I learned how the car wanted launched, and got the timing down on the quicker rev-ing new gear set the car started going quicker.
In the end, when the combo was utilized (driver education) the car was 18/100ths quicker, and 1.5mph faster... almost all of it having showed up by the 1/8th mile, but, it did still pull harder from 1/8th to 1/4 mark... not much, but still a bit more.

The FoMoCo suggested gear ratio's sound perfect for a spirited street car, but I'd agru for deeper cogs if 1/4 mile performance is your priority.
 
#32
Michael Yount said:
Yup - WAY MORE variables on a 1/4 mile run than just the gear change. Temp, traction, driving, shifting, etc.

The only way for a direct comparo would be to run the same car, same (consistent) driver on the same night with the the different gears (some major wrenching in between rounds). If you did that and driving/launch were consistent, the 4.10's would have gotten you to the lights quicker.
Click to expand...
I got the comparison before I learned how to launch.The best I could muster with my 373's was a 14.1(Were talking about a stock motor here)Then I put in 410's and used the same method to launch and my best I could get was a 14.3..THEN I saw the light and learned how to launch :banana: But since then Ive added a few mods,and my best to date is a 13.8...My 373's are going back in,but before that Im adding a set of Thumpers.I will go one night probably make 5-8 runs and will have a # to compare to when I put the 373's back in.
 
#33
Not sure about the car being faster with higher gears. Mine would pull up to 4500 rpms in 5th (once or twice with the 2.73's) which is where the car drops off HP for stock. Now that it has extra power over stock I haven't tried any higher speeds. I think what he was getting at was the torque down low on a stock 5.0 pulling harder to top end but I still would have to see it. With the lower gears you can stay in the throttle longer becasue you don't have to shift as much but if you have the traction gears make sense. Someday I may lose the 2.73's but my quest for 12's with 2.73's has me wondering, trying to use the low end power to pull the lower gear ratio on street tires. I just think after the H/C/I swap the low end power might fade to much to do so which would call for gears and better tires.
 
#34
being identical, there is a possibility that the car with 3.55 may never reach top speed as the transition from 4th to 5th may drop engine rpm's enough to allow torque production(or mulitplication in this case) to not be sufficient enough to allow the vehicle to overcome the airloads. i have learned alot lately on building a car for top end being that i am going to race silver state and have found that gearing based on your engines torque curve and frontal area is extremely critical. meaning your car may have enough hp to go 200, but could have the improper gear ratio and never top 150. just ask the jappers trying to do 200 in a 350z. they hit a whopping 162(in nelson voice) ha ha.
 
#35
5spd GT said:
...In the higher rpms where it makes more pulling power and the torque starts spinning itself to horsepower and they begin to overlap nicely to provide a flat torque pull. Look at dyno sheets....:rlaugh:
Click to expand...
5spd What the he** does this mean :shrug: ?(maybe just the way I'm reading it?)
Torque is the only component that can be measured in the equation. Horsepower is simply an formula that tells us how much work torque is doing. H.P.= RPM x Torque(lbs/ft) / 5252

In this case with both cars being equal, save diff gearing, with 25.6" tire hight(stock I believe), both engines are actually past the torque peak and are on the decline. The 3.55 geared engine is actually producing more torque. However once the torque is transfered into the transmission and onto the differential the 3.73 torque multiplication edges out the very slight engine torque advantage of the 3.55 engine. Therefore we all agree the 3.73 would win. :)
 
#36
CrazyCobra said:
5spd What the he** does this mean :shrug: ?(maybe just the way I'm reading it?)
Torque is the only component that can be measured in the equation. Horsepower is simply an formula that tells us how much work torque is doing. H.P.= RPM x Torque(lbs/ft) / 5252

In this case with both cars being equal, save diff gearing, with 25.6" tire hight(stock I believe), both engines are actually past the torque peak and are on the decline. The 3.55 geared engine is actually producing more torque. However once the torque is transfered into the transmission and onto the differential the 3.73 torque multiplication edges out the very slight engine torque advantage of the 3.55 engine. Therefore we are all in agreence the 3.73 would win. :)
Click to expand...
He's not talking from his head,he gets all his info from books and the internet.He probably copied it down wrong!! :rolleyes:
 
#37
CrazyCobra said:
5spd What the he** does this mean :shrug: ?(maybe just the way I'm reading it?)
Torque is the only component that can be measured in the equation. Horsepower is simply an formula that tells us how much work torque is doing. H.P.= RPM x Torque(lbs/ft) / 5252
Click to expand...

Just what I put...yeah I didn't explain it to well...lol.

willys1 - You have been :owned: so go off and get some higher gears so you can accelerate quicker :rlaugh:
 
#40
Why is there even a debate? 3.73's will be at an ever so slightly higher rpm at those speeds.... and even if they werent compared to the 3.55's it is still a steeper gear...like on a bicycle and u will have ever so slightly better acceleration at those speeds with the 3.73's.......I'M WITH MICHAEL AND 5SPD ON THIS ONE
 
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