3.90 Gears
05-17-2007, 02:47 PM
#11
4th Gear Member
Join Date: Aug 2004
Location: Texas
Posts: 1,615
RE: 3.90 Gears
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!!!! [&:]
05-17-2007, 04:01 PM
#12
5th Gear Member
Join Date: May 2006
Location: Florida
Posts: 3,881
RE: 3.90 Gears
One reason no one uses them is the people who have tried them complain that the Motives whine too much, and Motive seems to be the only company who makes them. Also, like 28hopup said, tire diameter has alot to do with it. It also has to do with your future plans for the car... N/A or FI. With FI, 3.90 is a tad too low... so almost everyone says 3.73 is perfect (if you like traction). Whereas for N/A you want 4.10s or 4.30s. So 3.90s are in a middle area that people arent interested.
05-17-2007, 04:17 PM
#13
4th Gear Member
Join Date: Aug 2004
Location: Texas
Posts: 1,615
RE: 3.90 Gears
ORIGINAL: bl1nkage
One reason no one uses them is the people who have tried them complain that the Motives whine too much, and Motive seems to be the only company who makes them. Also, like 28hopup said, tire diameter has alot to do with it. It also has to do with your future plans for the car... N/A or FI. With FI, 3.90 is a tad too low... so almost everyone says 3.73 is perfect (if you like traction). Whereas for N/A you want 4.10s or 4.30s. So 3.90s are in a middle area that people arent interested.
One reason no one uses them is the people who have tried them complain that the Motives whine too much, and Motive seems to be the only company who makes them. Also, like 28hopup said, tire diameter has alot to do with it. It also has to do with your future plans for the car... N/A or FI. With FI, 3.90 is a tad too low... so almost everyone says 3.73 is perfect (if you like traction). Whereas for N/A you want 4.10s or 4.30s. So 3.90s are in a middle area that people arent interested.
05-17-2007, 05:15 PM
#14
I ♥ Acer
Join Date: Aug 2006
Location:
Posts: 1,527
RE: 3.90 Gears
ORIGINAL: 28HopUp
Before deciding on rear-end gear ratio, you need to also consider how rear tire diameter will affect final gearing. Stock tires have a diameter of 27". If you go with a short diameter tire (most 275's are 25.7"), you will increase the numerical gear ratio. A taller tire (like my 28" DR's) will reduce the numerical gear ratio. Tire diameter is a critical factor to consider before deciding on a set of gears.
Before deciding on rear-end gear ratio, you need to also consider how rear tire diameter will affect final gearing. Stock tires have a diameter of 27". If you go with a short diameter tire (most 275's are 25.7"), you will increase the numerical gear ratio. A taller tire (like my 28" DR's) will reduce the numerical gear ratio. Tire diameter is a critical factor to consider before deciding on a set of gears.
05-17-2007, 09:13 PM
#16
3rd Gear Member
Join Date: Jun 2006
Location: Indiana
Posts: 619
RE: 3.90 Gears
Another point I've heard mentioned before is that most tuners like SCT don't have preset adjustments for the standard FRPP gear ratios, but nothinng for 3.90s.
I think the biggest reason is the fear of the whine from Motive gears. Although, I believe I read somewhere that Motive is now manufacturing all the gears for FRPP, so I don't know that there's really a difference anymore. Can anyone confirm that?
I think the biggest reason is the fear of the whine from Motive gears. Although, I believe I read somewhere that Motive is now manufacturing all the gears for FRPP, so I don't know that there's really a difference anymore. Can anyone confirm that?
05-18-2007, 03:52 AM
#17
5th Gear Member
Join Date: Feb 2007
Location:
Posts: 2,997
RE: 3.90 Gears
Two reasons I didn't get 3.90's, which by the way is my favorite choice of gears for a N/A Stang. One the SCT tuner dosen't have a setting for them, and two, the only one's offered are from Richmond and Motive, neither of which I'd want in my car. So my happy medium was 3.73 ........
05-18-2007, 11:32 AM
#19
1st Gear Member
Thread Starter
Join Date: Mar 2007
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Posts: 93
RE: 3.90 Gears
ORIGINAL: jaiasmit
Another point I've heard mentioned before is that most tuners like SCT don't have preset adjustments for the standard FRPP gear ratios, but nothinng for 3.90s.
I think the biggest reason is the fear of the whine from Motive gears. Although, I believe I read somewhere that Motive is now manufacturing all the gears for FRPP, so I don't know that there's really a difference anymore. Can anyone confirm that?
Another point I've heard mentioned before is that most tuners like SCT don't have preset adjustments for the standard FRPP gear ratios, but nothinng for 3.90s.
I think the biggest reason is the fear of the whine from Motive gears. Although, I believe I read somewhere that Motive is now manufacturing all the gears for FRPP, so I don't know that there's really a difference anymore. Can anyone confirm that?
05-18-2007, 12:01 PM
#20
RE: 3.90 Gears
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.