Rear End Gear Thread #8,075,614

[BlackenedSVT]

I just HAD to start up another rear end gear thread
I want to go with 3.73 or 4.10 for my 02 GT next summer (leaning towards 4.10s), and i just want to know at what MPH do you top out 4th gear in? With both 4.10s and 3.73s and also: when u top out 4th gear then, at what RPMs does shifting into 5th gear put you at?

Everyone always talks about the car pulls with 4.10s in 5th gear on the highway because it puts u in the power-band. Well i want to know at what RPM then does it put u at when u shift into 5th gear, assuming u top 4th gear out. With both 3.73 AND 4.10s. Thanks

 

[Tylerb59]

http://www.wcfords.com/stuff/calcs/EGTcalc/egtcalc.php

 

[raykrv6a]

http://tchracing.com/tech/gearcalc....m&givenval=65&givenvaltype=MPH&selectedgear=5

 

[ZaC851]

http://www.corral.net/tech/gearcalc.html

 

[BlackenedSVT]

Holy moly, thanks a lot guys

 

[Rocketman]

http://www.bullittarchive.com/Misc/Gears/

 

[BlackenedSVT]

Ok well i went to some of these sights and played with the numbers, to see what kind of top end i'd have with 3.73 and 4.10s. According to them (with 265/40/18 wheels) i'd be doing like 174mph in 5th gear at 5650 RPM, and 191mph in 5th gear at 5650RPM with 3.73 gears. This is of course a gross speed, and wind not included, nor aerodynamics. But i see that i'm sure its possible to still max out the car at 150mph with 4.10s. I've heard it can and heard it can't be done. But i guess it can.

At what RPM should u be shifting into 5th when racing on the highway? (Not that i condone racing on the highway ) I played with these numbers and just said 5500RPM, but just want some input. ALSO, at 5500RPM while shifting from 4th into 5th gear, both 3.73 and 4.10s put u at almost exactly 3,400 RPM in 5th. So i guess that would mean 3.73 would be the better gear to go with, since 4.10s don't seem to have too much of an advantage.

From my calculations, 3.73 had a 20mph great top end, and put u within 100RPM difference of the 4.10s. maybe i'll get 3.73s...

...Or maybe my calculations are off with wrong tiresizes? because I actually will be going with 265/35/18 up front and probably 275/40/18 in the rear...which might throw off these calculations...but for all intensive purposes for my calculations i assumed that all 4 tires were at 265/40/18

 

[Tylerb59]

Honestly I wouldn't really ever be worrying about your top end.

Anything less then 4.10s is a waste of money.

 

[BlackenedSVT]

I'm not too worried about top end, i've never even gone 150 with stock gears...i AM worried about at what RPMS gears will put me at, at certain speeds etc. Because i will be going with a FULL SLP exhaust set-up And don't want any 5 grand "cruise" sounding like "BWWWWHAAAAAA!!!!" while going 80 on the highway So...thats all. I'm not worried about top end, as long as the car goes at LEAST 120.

 

[Back2Mustangs]

...i've never even gone 150 with stock gears...

Rookie

 

[BlackenedSVT]

lol no no no, i've gone 140 just not 150 yet

 

[Green4.6GT]

............i belive he said... rookie lol

 

[BlackenedSVT]

Bump... re-read my post #7. Let me know what you think