What will RPMs be with 373 gears in auto

MrPerfect2

5 Year Member

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Oct 4, 2019

#1

• Oct 4, 2019

• #1

I have 327 gears in - rpm 1850 @ 65mph - any idea on rpm with 373 or 410s

 

FastDriver

I was uncomfortably high & wearing a helmet

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#2

• Oct 4, 2019

• #2

I'm not an auto guy. Does the converter slip or lock up? If it slips, how much?

 

Rdub6

So while I wait to figure out my rear end issues

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#3

• Oct 4, 2019

• #3

Gear Ratio Calculator

Gear Ratio Calculator

www.tremec.com

 

FastDriver

I was uncomfortably high & wearing a helmet

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#4

• Oct 4, 2019

• #4

Rdub6 said:

Gear Ratio Calculator

Gear Ratio Calculator

www.tremec.com

Click to expand...

I notice that calculator does not allow for converter slip. So, basically, he could use that and then multiply by (1- slip%) to get the speed.

 

MrPerfect2

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Oct 5, 2019

#5

• Oct 5, 2019

• #5

Is tremec only for sticks not auto

 

96pushrod

I think they're a little easier to get off

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#6

• Oct 5, 2019

• #6

MrPerfect2 said:

Is tremec only for sticks not auto

Click to expand...

Really it’ll be close enough.

 

pats91

15 Year Member

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Oct 5, 2019

#7

• Oct 5, 2019

• #7

Try this one:

Simple RPM Calculator | RANDYS Worldwide

To find your vehicle’s RPM enter your Ring and Pinion Gear Ratio, Tire Height and Speed and press "Solve".

www.randysworldwide.com

 

FastDriver

I was uncomfortably high & wearing a helmet

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#8

• Oct 6, 2019

• #8

MrPerfect2 said:

I have 327 gears in - rpm 1850 @ 65mph - any idea on rpm with 373 or 410s

Click to expand...

So, let's just make this easy, though my engineering/physics mind would prefer all the data:
373/327 * 1850 = 2110 RPM
410/327 * 1850 = 2319 RPM.

The answers should be as accurate as your RPM estimate is.

 

J

junkyardwarrior

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Oct 7, 2019

#9

• Oct 7, 2019

• #9

What auto are you talking about? AOD? C4? Powerglide? C6? 4R70W? AODE? A904? AXOD????

 

Real time recon

Mustang Master

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#10

• Oct 7, 2019

• #10

Don't know about Auto trans. But I'm pushing 1,500 RPMs... at 50 MPH... in 5th gear. with 373 posi

 

MrPerfect2

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#11

• Oct 7, 2019

• #11

Its a 91 AOD

 

FastDriver

I was uncomfortably high & wearing a helmet

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#12

• Oct 7, 2019

• #12

Real time recon said:

Don't know about Auto trans. But I'm pushing 1,500 RPMs... at 50 MPH... in 5th gear. with 373 posi

Click to expand...

Enlightening! Well, the 3.73s with my viper-spec trans have me at 975 rpm at 42 mph.

 

pats91

15 Year Member

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Oct 7, 2019

#13

• Oct 7, 2019

• #13

~2000 rpm at an indicated 65 (My speedo is fairly accurate, checked with GPS)
1991 LX 3.73's, AOD w/lockup converter, 245/45/17 tires (25.70" theoretical diameter)
OD ratio in an AOD is 0.67/1.

 

Noobz347

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#14

• Oct 7, 2019

• #14

I went the other way. I added torque and horse power instead of a reduction gear.

 

Reactions: General karthief

MrPerfect2

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Oct 7, 2019

#15

• Oct 7, 2019

• #15

Got to check my tire height - 30 years ( maybe the gears have been changed )

 

MrPerfect2

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Oct 30, 2019

#16

• Oct 30, 2019

• #16

I have 225/60/16 on stock pony rims - when tire change is needed , if I drop down in height a bit to a 55 or 50 it should give more off line torque ? It will harden the ride a bit with less air though and may look too short on tires - maybe a half inch drop in height would be nice compromise before I do gears ( 373 sound reasonable for daily driver with highway option )

 

a91what

SendMeUrDataLog

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#17

• Oct 30, 2019

• #17

I would not put smaller tires on the car, gears are much cheaper than tires are.

 

Rdub6

So while I wait to figure out my rear end issues

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Oct 30, 2019

#18

• Oct 30, 2019

• #18

It will have an effect on gear ratio and make it higher (number). Whether it will effect it enough to notice, I doubt it. It will, however make your speedometer off enough where you’ll probably notice that!

 

CarMichael Angelo

my rearend will smell so minty fresh,

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#19

• Oct 30, 2019

• #19

MrPerfect2 said:

I have 225/60/16 on stock pony rims - when tire change is needed , if I drop down in height a bit to a 55 or 50 it should give more off line torque ? It will harden the ride a bit with less air though and may look too short on tires - maybe a half inch drop in height would be nice compromise before I do gears ( 373 sound reasonable for daily driver with highway option )

Click to expand...

The tires, and or the rear end ratio do not affect the rwtq in any way.
The engine will make the same rwtq number with a 2.73 or a 3.73 rear gear set regardless.

 

MrPerfect2

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Oct 30, 2019

#20

• Oct 30, 2019

• #20

Yes I realize the actual torque produced won’t change - I am talking the feel of torque