3.55 gears vs rpms

XBAJBUSX · 10-26-2004, 10:38 PM

i'm think about putting 3.55 gears in my mustang and i was woundering in 5 spd where are the rpms at 70 mph it will be helpfull and if anybody know with 3.73 please let me know .thank you

GhettoPop · 10-27-2004, 10:35 AM

well, first off i would say go w/ the 3.73's in the T5!!!!

as far as rpm's, 3.73 vs. stock 2.73 is basically like losing a gear. 5th will feel and have similiar rpm's to stock 4th, 4th will feel like 3rd, and so on. 1st gear is the most fun

HoodStrype · 10-27-2004, 10:50 AM

A lil over 3000 rpm at 70 mph if I remember back correctly... it's been a few years since I had a five speed with 3.55's... go ahead with the 3.73- not much difference

90GT398 · 10-27-2004, 11:00 AM

Drove cross country with 3.73 gears in 5th, with the cruise control set and never turned more than 2600-2700rpm at 75mph, and this is with tires that are too short 2255015, with a 60 series tire it would be around 2400-2600. I also got 24mpg too using the cruise control.

HoodStrype · 10-27-2004, 12:26 PM

Oh that reminds me... I also had a world class tranny in it... if that makes up the difference in any way on my reply... then again I'd listen to 90GT398 since he has them now.

Jeff Chambers · 10-27-2004, 05:12 PM

http://home.neo.rr.com/chambersracing/gear_select.htm

90GT398 · 10-27-2004, 05:50 PM

Excellent graph's Jeff.

crazypete · 10-28-2004, 06:37 PM

On that note here's the one I like to use:

http://www.4x4cyberstore.com/website/rpmchart.html

I am the most gas milage/rpm oriented mustang out there and I thought 3.73's were too little still. 4.10's if not 3.73's. I think you will be unfortunatley disappointed if you go to 3.55's. I got 25 mpg with 3.73's and nonstop 1 week long highway vacation touring.

The 2000 rpms with 2.73's is a different 2000 rpms with 3.73's because of engine load. The motor doesnt have to work as hard to turn the wheels over because of torque multiplication.

I get 18 mpg with an AOD and 4.56's now and a 3k stall. It wont make that much of a difference dude. I cruise at 3100 rpms in OD at 80 mph and I can keep it up for hours.

Good luck!

Ieatcamaros · 10-28-2004, 07:24 PM

You could use this sites analyzer too. It is set up for the t-5's gear ratios. Yeah, and I am with pete on this one. 3.73's would be the bare minimum gear. I have 4.10's and love it. Drive your car on the highway in 4th gear, that would simulate the 3.73-4.10 gear. There is just a little bit of difference between the two. If I had an AOD car, I would probably have the 4.56's as well.

grey88gt · 10-28-2004, 08:02 PM

Wow I to was thinking about the 3.55s to but after reading this thread I may try to find some 3.73s for my AOD.

10-26-2004, 10:38 PM	#1
XBAJBUSX Registered Member Join Date: Oct 2004 Location: NEW JERSEY Posts: 41	3.55 gears vs rpms i'm think about putting 3.55 gears in my mustang and i was woundering in 5 spd where are the rpms at 70 mph it will be helpfull and if anybody know with 3.73 please let me know .thank you

10-27-2004, 10:35 AM	#2
GhettoPop Gimme a Drink! Join Date: Dec 2002 Location: NYC Posts: 694	Re: 3.55 gears vs rpms well, first off i would say go w/ the 3.73's in the T5!!!! as far as rpm's, 3.73 vs. stock 2.73 is basically like losing a gear. 5th will feel and have similiar rpm's to stock 4th, 4th will feel like 3rd, and so on. 1st gear is the most fun __________________ 1990 GT,stock T-5,K&N w/o air silencer,March underdrives,FMS wires,timing@14*,PA Perf 130amp alt,Steeda Tri-Ax Shifter,Steeda adj quadrant/clutch cable/firewall adj,Centerforce II clutch,o/r x-pipe,Magnaflow SS catback,g-load brace, subframes,Bilstein struts/shocks,Autometer gauges, 136k and running strong!

10-27-2004, 10:50 AM	#3
HoodStrype Rearview Mirror Haze Join Date: May 1999 Location: Huntsville, Alabama...a.k.a. "HuntsVegas" Posts: 387	Re: 3.55 gears vs rpms A lil over 3000 rpm at 70 mph if I remember back correctly... it's been a few years since I had a five speed with 3.55's... go ahead with the 3.73- not much difference __________________ 93 lx Notch 01 GT ...the epitome of Murphy's Law

10-27-2004, 11:00 AM	#4
90GT398 Registered Member Join Date: Jun 2003 Location: USA Posts: 25	Re: 3.55 gears vs rpms Drove cross country with 3.73 gears in 5th, with the cruise control set and never turned more than 2600-2700rpm at 75mph, and this is with tires that are too short 2255015, with a 60 series tire it would be around 2400-2600. I also got 24mpg too using the cruise control.

10-27-2004, 12:26 PM	#5
HoodStrype Rearview Mirror Haze Join Date: May 1999 Location: Huntsville, Alabama...a.k.a. "HuntsVegas" Posts: 387	Re: 3.55 gears vs rpms Oh that reminds me... I also had a world class tranny in it... if that makes up the difference in any way on my reply... then again I'd listen to 90GT398 since he has them now. __________________ 93 lx Notch 01 GT ...the epitome of Murphy's Law

10-27-2004, 05:12 PM	#6
Jeff Chambers Moderator Join Date: Aug 2000 Location: Milan, OH Posts: 2,699	Re: 3.55 gears vs rpms http://home.neo.rr.com/chambersracing/gear_select.htm __________________ Jeff Chambers 1990 Mustang GT 10.032 Seconds / 137.5 MPH 14-time Street Warrior World Record Setter CRT Performance 2001 Tropic Green Mustang GT - 12.181 / 113.2 MPH 2002 Ford F-250 Crew Cab 7.3l Power Stroke - 17.41@77.2 "There's nothing boring about a small block automatic shifting gears at 9400 rpm!"

10-27-2004, 05:50 PM	#7
90GT398 Registered Member Join Date: Jun 2003 Location: USA Posts: 25	Re: 3.55 gears vs rpms Excellent graph's Jeff.

10-28-2004, 06:37 PM	#8
crazypete Registered Member Join Date: Sep 2002 Location: Boston Posts: 592	Re: 3.55 gears vs rpms On that note here's the one I like to use: http://www.4x4cyberstore.com/website/rpmchart.html I am the most gas milage/rpm oriented mustang out there and I thought 3.73's were too little still. 4.10's if not 3.73's. I think you will be unfortunatley disappointed if you go to 3.55's. I got 25 mpg with 3.73's and nonstop 1 week long highway vacation touring. The 2000 rpms with 2.73's is a different 2000 rpms with 3.73's because of engine load. The motor doesnt have to work as hard to turn the wheels over because of torque multiplication. I get 18 mpg with an AOD and 4.56's now and a 3k stall. It wont make that much of a difference dude. I cruise at 3100 rpms in OD at 80 mph and I can keep it up for hours. Good luck! __________________ 91 GT Carb conversion, holley 600 double pumper, edelbrock performer intake, FMS "C" drop springs, march 1000 underdrive pullies, crane 1.7 roller rockers, GT-40P headers, bassani x pipe, american thunder catback, FMS 4.56's, msd aL6, trunkmount battery, A/C eliminator kit, 3000 stall tci streetfighter, AOD with transgo kit, A+ servo, 300M hardened lockup shaft, kevlar bands and 28,000 gvw trans cooler, 3 core radiator, 300 lbs stripped with a full interior

10-28-2004, 07:24 PM	#9
Ieatcamaros Domestic Rice really sucks! Join Date: Apr 2002 Location: KY Posts: 973	Re: 3.55 gears vs rpms You could use this sites analyzer too. It is set up for the t-5's gear ratios. Yeah, and I am with pete on this one. 3.73's would be the bare minimum gear. I have 4.10's and love it. Drive your car on the highway in 4th gear, that would simulate the 3.73-4.10 gear. There is just a little bit of difference between the two. If I had an AOD car, I would probably have the 4.56's as well. __________________ The sig says it all.

10-28-2004, 08:02 PM	#10
grey88gt Registered Member Join Date: Feb 2004 Location: Skiatook, Oklahoma Posts: 193	Re: 3.55 gears vs rpms Wow I to was thinking about the 3.55s to but after reading this thread I may try to find some 3.73s for my AOD.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
3.55 gears	gtjeremy	Modular Madness	5	07-28-2004 12:32 AM
ce in 3.55 and 3.73 gears?	1jimmy__d	Windsor Power	6	03-24-2003 12:27 PM
3.55 gears.	66StangGuy	Classic Mustangs	6	08-12-2002 02:40 PM
3.55 gears and affects on high end accleration?	Sonics2042	Windsor Power	20	12-27-2001 04:27 PM
Hard To Install 3.55 Gears???	BowTie Eater 5 Liter	Windsor Power	5	05-01-2001 04:59 PM