355 rear end gears - Ford Mustang Forum
 
LinkBack Thread Tools
post #1 of 5 (permalink) Old 11-14-2016 Thread Starter
Apprentice
 
MarkMartinez's Avatar
 
Joined: Mar 2016
Location: Fontana
Posts: 153
 
Question 355 rear end gears

Anyone here have the 355 rear end with the automatic transmission? If so, can you tell me what rpm your at when traveling 75mph on the freeway, 6th gear?




2011 GT/ California Special, Silver, Auto, 3:15's, Airaid race CAI, Hypertech tune, Roush axlebacks and lowering springs, Boss 302 splitter, SR front and rear swaybars, 19x9.5 SVE gloss black Drift wheels,BMR lower control arms, Brembo big brakes up front,Stainless steel brake lines, JMS Pedalmax.
MarkMartinez is offline  
Sponsored Links
Advertisement
 
post #2 of 5 (permalink) Old 11-15-2016
GT Member
 
pmr2000's Avatar
 
Joined: Nov 2007
Location: RTP area
Posts: 1,420
 
Good question there are calculators out there, I would estimate about 10% more rpm's than the 3.15's.


Now: 2016 Mustang GT Fastback-Magnetic Metallic, Ford Racing Touring axle-backs, Ford Racing front strut and k-brace, K&N CAI, sound tube delete, 1975 Corvette Coupe-L48, 4-speed

Past Lives: 2001 Corvette Z51 Coupe, 2012 Mustang Grabber Blue Coupe, 2008 Mustang Torch Red Vert, 1988 Mazda RX-7 Vert, 1985 Nissan 300ZX, 1979 Mazda RX-7, 1971 Datsun 240Z, 1972 Fiat 124 Vert, 1971 Chevelle, 1970 Challenger
pmr2000 is offline  
post #3 of 5 (permalink) Old 11-15-2016 Thread Starter
Apprentice
 
MarkMartinez's Avatar
 
Joined: Mar 2016
Location: Fontana
Posts: 153
 
Quote:
Originally Posted by pmr2000 View Post
Good question there are calculators out there, I would estimate about 10% more rpm's than the 3.15's.
My engine spins 2000rpm at 75mph in 6th gear (auto trans). If my rpm would only increase by 200-300 rpm that would be perfect for my use.



2011 GT/ California Special, Silver, Auto, 3:15's, Airaid race CAI, Hypertech tune, Roush axlebacks and lowering springs, Boss 302 splitter, SR front and rear swaybars, 19x9.5 SVE gloss black Drift wheels,BMR lower control arms, Brembo big brakes up front,Stainless steel brake lines, JMS Pedalmax.
MarkMartinez is offline  
 
post #4 of 5 (permalink) Old 01-02-2017
PONY Member
V6 Member
5.0L Member
S197 Member
 
6Bolt's Avatar
 
Joined: Jan 2013
Location: Georgetown
Posts: 354
 
Garage
RPM can be calculated at any speed given the tire diameter, axle ratio, and transmission gear ratio.
You say yours runs right at 2000 RPM at 75 MPH with the 3.15 axle ratio and the 6L80 automatics 0.69 6th gear ratio so your tire diameter must be 27.38 for that to be true.
Using those values and only changing the axle ratio to 3.55 results in 2254 RPM at 75 MPH.
Math, it figures...

Oxford White 2015 Premium GT with 50-Year Pkg | 3.55 Gears | Roush CAI (105mm Velocity tube) | Stainless Works Headers (Jet-Hot ceramic coated), high flow cats, H-Pipe CatBack full 3" with 4" tips| BAMA V2 93 Octane Tune | Baer EradiSpeed-Plus 2-Piece Rotors | JLT 3.0 Oil Separators | FRPP M-20201-M STB | Silver PP Wheels 19x9, 19x9.5 | NITTO G2 255-40-19, 275-40-19 Tires | J&M Jacking Rails & Subframe Alignment Kit | Steeda Subframe Connectors & Bushing Supports | BMR Front Subframe Brace | Cervinis 1232 Functional Ram Air hood | Ford Performance door sills | White Madness Garage Chrome Shifter | Diode Dynamics interior LED conversion stage 1 & XP80 reverse light | 3M Dark Ceramic Tint (25% sides/20% rear) | Lloyds "50 Years" floor and trunk mats...

Performance White 2012 Premium Pony Package | Torsen T2R 4:1 TBR | FRPP 3.73 Gears | GT500 Differential Cover | DSS 3.8" Carbon Fiber DS | Airaid CAI | BAMA 93R tune | Baer DecelaRotors (drilled/slotted) | BMR Adjustable Panhard & Brace | JLT Oil Separator | Boss 302 STB | Nexen N3000 255-45-ZR18Y tires | PP Engine Cover | 25% Tint

All cars should be rated for Smiles Per Gallon!
6Bolt is offline  
post #5 of 5 (permalink) Old 01-02-2017
Rookie
 
Lastshot's Avatar
 
Joined: Dec 2016
Posts: 16
 
I have the 3.55 in a standard. it runs about the same RPMs as previously posted on the automatic, just slightly above 2000 rpm at 75. Just a note to say, I really like the 3.55 gear ratio.
Lastshot is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Mustang Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a VALID email address for yourself, otherwise you will not receive the necessary confirmation email needed to confirm, validate and activate your new AFM member account.

Failure to provide a VALID email address, will result in the cancellation of your new AFM member account registration.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome
 


Search Engine Friendly URLs by vBSEO 3.6.1