3.90 Gears
Multi-Tasking Moderator!
Joined: Nov 2006
Posts: 15,618
From: Detroit Rock City!
RE: 3.90 Gears
So if I have 20's with 30 series tires on the rear and if I upgrade from the 3:55's to the 4:10's I shouldn't have a problem with driveability and gas consumption? I mean the car is used for show and is driven to the shows (up to 2 hrs away) will that affect cruising at 80 MPH or will the consumpion to reduced to a minimum as the rear tire is I think 27.5 inches (not sure)? Any advice would help -thanks J
ORIGINAL: wmtheflash
I've read and heard from others that you should always go up at least two "steps" when doing a gear change. Otherwise, it isn't really worth it. Has anyone else heard that?
Going from 3.55 to 3.73 is only going to increase your RPM by...let's see...4.8%, right? I can't see that doing much. If the performance benefit is so small, then perhaps you're better off just getting better gas mileage?
Now, if you started at 3.31's and went to 3.73's, that would certainly make some sense to me.
ORIGINAL: StowesStang
No, no, no! lol What my husband is telling me, is specifically for me! lol He has installed many 4.10s in mustangs,different year models,but for my stang he is saying NO! lol Basically, he does not see a need for me to have a set that low, based on how I drive itand the main use of my ride. Just wanted to set the record straight on that one! lol
ORIGINAL: mustangman02232
well just goes to show you that even if you work for ford, you still dont know everything
4.10s are fine for autos, they have the shorter .75 5th gear, the t3650s have a .62 5th gear, 4.30s are fine, and yes, for a DD, both will stick you about 3k rpms while driving, however, you must remember, that these are not back in the 70s with the old pushorod OHC V8s, these are SOHC 3Vs that make power north of 4500 rpms, so, you need shorter gears in order for the motor to rev up quicker and take advantage of that power, why ford ever stuck 3.31s in the rear i will never know but i think that there CAFE should be high enough they can sacrifice 2 mpg to put a set of 4.10/4.30s in the rear.
ORIGINAL: StowesStang
Well, just spoke to the old man and he said, "for you, NO!" So it looks like Im back to 3.73s. He told me that I drive my car too much to install those gears. He said its too low of a gear ratio for my "daily driver". He said 3.73 is the lowest he wants to go on my ride. So bottom line, I got shot down!!!! [&:]
Well, just spoke to the old man and he said, "for you, NO!" So it looks like Im back to 3.73s. He told me that I drive my car too much to install those gears. He said its too low of a gear ratio for my "daily driver". He said 3.73 is the lowest he wants to go on my ride. So bottom line, I got shot down!!!! [&:]
4.10s are fine for autos, they have the shorter .75 5th gear, the t3650s have a .62 5th gear, 4.30s are fine, and yes, for a DD, both will stick you about 3k rpms while driving, however, you must remember, that these are not back in the 70s with the old pushorod OHC V8s, these are SOHC 3Vs that make power north of 4500 rpms, so, you need shorter gears in order for the motor to rev up quicker and take advantage of that power, why ford ever stuck 3.31s in the rear i will never know but i think that there CAFE should be high enough they can sacrifice 2 mpg to put a set of 4.10/4.30s in the rear.
Going from 3.55 to 3.73 is only going to increase your RPM by...let's see...4.8%, right? I can't see that doing much. If the performance benefit is so small, then perhaps you're better off just getting better gas mileage?
Now, if you started at 3.31's and went to 3.73's, that would certainly make some sense to me.
4th Gear Member
Joined: Aug 2006
Posts: 1,516
From: NYC
RE: 3.90 Gears
I think 3.90s sound like the way to go for the auto. If Motive makes FRPP gears as well (as stated above Philip Clemmons)then I can't see any fault in going that route. I'm very interested in this now [&o]. This forum = me having no money and not moving out of my house because of mods.[sm=boosign.gif]
4th Gear Member
Joined: Nov 2006
Posts: 1,308
From: Now in Sunny SOCAL
RE: 3.90 Gears
Hey Bluestar. You might be interested to know that Richmond is the OEM manufacturer for Fordfor the rear ends that we enjoy so much in our Stangs! So whether you realize it or not if you got stock gears they are Richmond's. So are your axles, your housing ETC. ETC.
4th Gear Member
Joined: Aug 2004
Posts: 1,615
From: Texas
RE: 3.90 Gears
ORIGINAL: wmtheflash
I've read and heard from others that you should always go up at least two "steps" when doing a gear change. Otherwise, it isn't really worth it. Has anyone else heard that?
Going from 3.55 to 3.73 is only going to increase your RPM by...let's see...4.8%, right? I can't see that doing much. If the performance benefit is so small, then perhaps you're better off just getting better gas mileage?
Now, if you started at 3.31's and went to 3.73's, that would certainly make some sense to me.
ORIGINAL: StowesStang
No, no, no! lol What my husband is telling me, is specifically for me! lol He has installed many 4.10s in mustangs,different year models,but for my stang he is saying NO! lol Basically, he does not see a need for me to have a set that low, based on how I drive itand the main use of my ride. Just wanted to set the record straight on that one! lol
ORIGINAL: mustangman02232
well just goes to show you that even if you work for ford, you still dont know everything
4.10s are fine for autos, they have the shorter .75 5th gear, the t3650s have a .62 5th gear, 4.30s are fine, and yes, for a DD, both will stick you about 3k rpms while driving, however, you must remember, that these are not back in the 70s with the old pushorod OHC V8s, these are SOHC 3Vs that make power north of 4500 rpms, so, you need shorter gears in order for the motor to rev up quicker and take advantage of that power, why ford ever stuck 3.31s in the rear i will never know but i think that there CAFE should be high enough they can sacrifice 2 mpg to put a set of 4.10/4.30s in the rear.
ORIGINAL: StowesStang
Well, just spoke to the old man and he said, "for you, NO!" So it looks like Im back to 3.73s. He told me that I drive my car too much to install those gears. He said its too low of a gear ratio for my "daily driver". He said 3.73 is the lowest he wants to go on my ride. So bottom line, I got shot down!!!! [&:]
Well, just spoke to the old man and he said, "for you, NO!" So it looks like Im back to 3.73s. He told me that I drive my car too much to install those gears. He said its too low of a gear ratio for my "daily driver". He said 3.73 is the lowest he wants to go on my ride. So bottom line, I got shot down!!!! [&:]
4.10s are fine for autos, they have the shorter .75 5th gear, the t3650s have a .62 5th gear, 4.30s are fine, and yes, for a DD, both will stick you about 3k rpms while driving, however, you must remember, that these are not back in the 70s with the old pushorod OHC V8s, these are SOHC 3Vs that make power north of 4500 rpms, so, you need shorter gears in order for the motor to rev up quicker and take advantage of that power, why ford ever stuck 3.31s in the rear i will never know but i think that there CAFE should be high enough they can sacrifice 2 mpg to put a set of 4.10/4.30s in the rear.
Going from 3.55 to 3.73 is only going to increase your RPM by...let's see...4.8%, right? I can't see that doing much. If the performance benefit is so small, then perhaps you're better off just getting better gas mileage?
Now, if you started at 3.31's and went to 3.73's, that would certainly make some sense to me.
]
1st Gear Member
Joined: Sep 2006
Posts: 147
From: New York
RE: 3.90 Gears
I decided on the 3:90gears because I enjoy long state to state driving, I still haven't installed because everyoneI spoke to says it
will whine. WhichI know its B.S. ,soImtrying find someone in New York Citywho can tackle the job without the B.S.
[IMG]local://upfiles/48703/07E7E985789E4762AB84579585051BBA.jpg[/IMG]
will whine. WhichI know its B.S. ,soImtrying find someone in New York Citywho can tackle the job without the B.S.
[IMG]local://upfiles/48703/07E7E985789E4762AB84579585051BBA.jpg[/IMG]
4th Gear Member
Joined: Aug 2006
Posts: 1,516
From: NYC
RE: 3.90 Gears
Are you close to Long Island? There's a really good shop there that GUARANTEES no whine. I will be going there after my suspension & brake stuff are done (which they are installing as well).
ORIGINAL: fredlo69
I decided on the 3:90gears because I enjoy long state to state driving, I still haven't installed because everyoneI spoke to says it
will whine. WhichI know its B.S. ,soImtrying find someone in New York Citywho can tackle the job without the B.S.
[IMG]local://upfiles/48703/07E7E985789E4762AB84579585051BBA.jpg[/IMG]
I decided on the 3:90gears because I enjoy long state to state driving, I still haven't installed because everyoneI spoke to says it
will whine. WhichI know its B.S. ,soImtrying find someone in New York Citywho can tackle the job without the B.S.
[IMG]local://upfiles/48703/07E7E985789E4762AB84579585051BBA.jpg[/IMG]
5th Gear Member
Joined: Feb 2007
Posts: 2,997
From:
RE: 3.90 Gears
Fred I live in Brooklyn also, I've had two gear changes done 4.10's and 3.73's no problems whatsoever. Installs were completed in just under two hours. PM me and I'll fill you in . Re: Richmond being the OEM of our rear ends, maybe that's why some guys are having noisy rear end problems.
