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Rear Gears
#1
How much of an RPM drop will I see going from a 3.90 to a 3.55 rear gear? I figure around 200 in 5th gear.
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#2
ring-pinion has a nice calculator for rpm/speed/gear.
For RPM, you need to put in your tire diameter, speed and what the tranny and rear gear ratios are.

1971 Mach1
351C-4v
C6 is history-->>now TKO-500
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#3
Somehow I thought there might be a tad more math involved.

[Image: 2rr7aiv.png]

Just cruising along minding our own business when BAM!!! The LAWS show up.
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#4
What is your engine speed at 70 MPH? My 2.75 gear is about 17-1800 @ 70 with a 27" tall tire.

Jeff T.

Low buck, touring style, '73 Convertible "rolling restoration", 351c, 2v heads with a shave and a haircut, Performer intake, Holley 650(ish), roller rockers, screw in studs, guideplates, stainless valves, Duraspark / Motorsports MSD, T-5 conversion. 1-1/8" front, 3/4" rear swaybars KYB shocks and some home brewed subframe connectors. Future plans; JGC steering box, Cobra brakes and... paint, interior, etc.

When I die I want to die like grandpa, peacefully in my sleep... not screaming, like his passenger.

[Image: 1_12_09_14_10_15_11.png]
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#5
droptop73;101762 Wrote:What is your engine speed at 70 MPH? My 2.75 gear is about 17-1800 @ 70 with a 27" tall tire.
Let him do the math Jeff!Tongue It'll keep him sharp in the noodle.

[Image: 2rr7aiv.png]

Just cruising along minding our own business when BAM!!! The LAWS show up.
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#6
Roy, Go here. You need to know the tire diameter.http://www.wallaceracing.com/calc-rpm.php
Give a man a fish .............
Chuck
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#7
Yeah I already have the answer just wanted to see where this wentBig Grin
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#8
Roy, Thanks for continuing to be the master of entertainment, no one better. Chuck
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#9
c9zx;101775 Wrote:Roy, Thanks for continuing to be the master of entertainment, no one better. Chuck

Not the response I expected Chuck. I'm thinking of changing the gear set in the toploader. Help me out here! Tongue

[Image: 2rr7aiv.png]

Just cruising along minding our own business when BAM!!! The LAWS show up.
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#10
Tnfastbk;101774 Wrote:Yeah I already have the answer just wanted to see where this wentBig Grin
LOL...keep em on their toes
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