whats a good rear pinion gear ratio for a 03 mustang GT? - TriStateTuners.com :: Home of Tristate Auto Enthusiast

afarrell39116 · 04-08-2012, 02:17 PM

I have been debating this for a while and thought i would try to reach out to others for more opinions. Im wanting to try to find that perfect rear wheel gear ratio. Yes i know different ratios are ment for certain purposes as to what you want to be doing. I want to get a good start off in 1st gear and be up at a decent speed before getting into 2nd...was thinking around 20-25mph. Ive considered going with 4:10's but still unsure. Any feedback would be greatly appreciated. Thanks!!

devildog214 · 04-08-2012, 05:06 PM

if its a 5sp 4.10s wouldnt be too bad, for a auto no more than 3.73

jpalamar · 04-08-2012, 05:57 PM

Depends on your mods and driving plans.

afarrell39116 · 04-08-2012, 07:01 PM

Yeah ive seen alot of vids and alot of them had their mods listed, with alot of 4:10.s listed for the rear. When i get going from a stop in 1st gear i dnt want to be at like 4k rpm's and.be doing 15 mph lol i just want to have a lil more get up and go. I wish i knew what was in it now, but idk.

afarrell39116 · 04-08-2012, 07:02 PM

And yes its a 5 speed lol

schaffer · 04-08-2012, 07:18 PM

You should be able to find out what's in the rear on the axle tag. My ranger has one on the axle,printed on it was 3.73.

afarrell39116 · 04-08-2012, 07:49 PM

This is true i didnt think of that lol but what if the owner before me has already changed them out? How can i tell what ratio the rear gears are?

OutToWinPAHC · 04-08-2012, 08:07 PM

Count the teeth on the input pinion and out put pinion then divide the output by the input example 12 and 47 would be 3.916

afarrell39116 · 04-08-2012, 09:17 PM

Oh ok yeah i thought it would have to do with counting the teeth...i just didnt know what the formula was. Thanks!

schaffer · 04-08-2012, 09:34 PM

I'd check the axle tag first,maybe contact the previous owner.

mayer5oh · 04-08-2012, 09:46 PM

Spin the wheel at the end around one exact rotation and count how many times the pinion turns around. That's a good way to figure out the gears in the car. As for a stock-ish 4.6 the 410s would be great. What are your present and future mods?

Dilley · 04-08-2012, 10:24 PM

If you plan on ever going forced induction don't do the 4.10s

dnasty2g · 04-08-2012, 11:09 PM

Quote:

Originally Posted by afarrell39116

Yeah ive seen alot of vids and alot of them had their mods listed, with alot of 4:10.s listed for the rear. When i get going from a stop in 1st gear i dnt want to be at like 4k rpm's and.be doing 15 mph lol i just want to have a lil more get up and go. I wish i knew what was in it now, but idk.

4.10s would be making first shorter then stock..

dugganzx3 · 04-08-2012, 11:55 PM

There's calculators out there to figure out what rpm/mph you'll be spinning in each gear with different ratios. I know my car with the 3.8L and the t-5 5 speed, will be around 2200-2400 rpm around 62 mph with 4:10's. Right now with 3:42's i can do 62 around 1950-2100 rpm. Our car's are apples and oranges, but you should be close to the same RPM's I'd imagine. So that means doing 75 mph for a long trip on the highway will be a nightmare, if you daily drive this car on the highway, you may want the 3:73's or even 3:90's.

afarrell39116 · 04-09-2012, 08:17 AM

well as of now im still planning and deciding future projects for the GT. Moneys tight and everyone i know understands that lol. Im hoping one day to get it supercharged but i know that wont be for a loooonnng time due to how expensive they are. Im planning soon though to get rid of the bassani exhaust system thats on it currently and putting on flowmasters, the bassani just isnt loud enough for me lol. And yes i believe we're around the same RPM ranges. This is my daily driver and it does see a little bit of highway time every day to work and back. I can cruise pretty steady at about 70 mph and be at or around 2500 i believe is what i seen last.

HickRocket1258 · 04-09-2012, 10:00 AM

If it won't be for a long time just do 4.10s. You'll run out of 1st gear in no time but who cares. Make sure you don't just change the ring and pinion out, but also get the bearing rebuild kit. 3.73s will be going in my auto once my Vortech is tuned.

jpalamar · 04-09-2012, 10:13 AM

Quote:

Originally Posted by afarrell39116

well as of now im still planning and deciding future projects for the GT. Moneys tight and everyone i know understands that lol. Im hoping one day to get it supercharged but i know that wont be for a loooonnng time due to how expensive they are. Im planning soon though to get rid of the bassani exhaust system thats on it currently and putting on flowmasters, the bassani just isnt loud enough for me lol. And yes i believe we're around the same RPM ranges. This is my daily driver and it does see a little bit of highway time every day to work and back. I can cruise pretty steady at about 70 mph and be at or around 2500 i believe is what i seen last.

Bassani > Flowmaster.

You want louder get long tubes.

HickRocket1258 · 04-09-2012, 10:22 AM

I was planning on doing a lot with my 2002. Wanted to keep it N/A, but realized, I want to have some fun. Superchargers you can find cheaper used and that's the route I went.

I have SLP Loudmouth II and love it. Good for cruising and has some rumble, and then when you get on it, it's loud.

afarrell39116 · 04-09-2012, 10:22 AM

Well actually i stand corrected lol it has a bassani x pipe with earlier style magnaflow mufflers. So id like to run flowmasters from the x back and yes im considering long tubes...just dont know which to go for

bmatyeah · 04-09-2012, 10:24 AM

For gears I would stay away from 4.10 if you drive at 65+ and drive a lot. It will put you higher up in the rpms, not horrible but who wants to put more money in the gas tank? For a dd, I would put in 3.73 or possibly 3.90.

Get long tubes, if you want a louder exhaust the bassani is better quality then the flowmasters.

SLP long tubes sound awesome. Remember you get what you pay for with headers.

04-08-2012, 02:17 PM	#1
afarrell39116 Tri-State Aficionado Join Date: May 2011 Location: New Holland, Pa Member #20738 My Ride: 2003 Mustang GT iTrader: (0)	whats a good rear pinion gear ratio for a 03 mustang GT? I have been debating this for a while and thought i would try to reach out to others for more opinions. Im wanting to try to find that perfect rear wheel gear ratio. Yes i know different ratios are ment for certain purposes as to what you want to be doing. I want to get a good start off in 1st gear and be up at a decent speed before getting into 2nd...was thinking around 20-25mph. Ive considered going with 4:10's but still unsure. Any feedback would be greatly appreciated. Thanks!!

04-08-2012, 11:55 PM	#14
dugganzx3 Tri-State Addict Join Date: Oct 2010 Location: Scranton PA Member #17852 My Ride: has leather and T-tops. iTrader: (0)	There's calculators out there to figure out what rpm/mph you'll be spinning in each gear with different ratios. I know my car with the 3.8L and the t-5 5 speed, will be around 2200-2400 rpm around 62 mph with 4:10's. Right now with 3:42's i can do 62 around 1950-2100 rpm. Our car's are apples and oranges, but you should be close to the same RPM's I'd imagine. So that means doing 75 mph for a long trip on the highway will be a nightmare, if you daily drive this car on the highway, you may want the 3:73's or even 3:90's. __________________ Daily-1996 Chevy Camaro RS y87 (3800 sII v6, t-5, bolt-ons, tune) Project-1980 Chevy Camaro Base (305 v8, th350)

04-09-2012, 10:00 AM	#16
HickRocket1258 Tri-State Post Whore Join Date: May 2005 Location: West Chester, PA Member #415 iTrader: (0)	If it won't be for a long time just do 4.10s. You'll run out of 1st gear in no time but who cares. Make sure you don't just change the ring and pinion out, but also get the bearing rebuild kit. 3.73s will be going in my auto once my Vortech is tuned. __________________ -Rob Just a mustang that's lowered.....that's about it. Work harder....Millions on welfare depend on you!

04-09-2012, 10:22 AM	#18
HickRocket1258 Tri-State Post Whore Join Date: May 2005 Location: West Chester, PA Member #415 iTrader: (0)	I was planning on doing a lot with my 2002. Wanted to keep it N/A, but realized, I want to have some fun. Superchargers you can find cheaper used and that's the route I went. I have SLP Loudmouth II and love it. Good for cruising and has some rumble, and then when you get on it, it's loud. __________________ -Rob Just a mustang that's lowered.....that's about it. Work harder....Millions on welfare depend on you!

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04-08-2012, 05:06 PM	#2
devildog214 Tri-State Aficionado Join Date: Dec 2009 Member #15356 My Ride: 1994 Pontiac Trans Am iTrader: (0)	if its a 5sp 4.10s wouldnt be too bad, for a auto no more than 3.73

04-08-2012, 05:57 PM	#3
jpalamar TST Ruined My Life! Join Date: May 2009 Location: Orefield, PA Member #13773 My Ride: '14 Mustang GT iTrader: (3)	Depends on your mods and driving plans.

04-08-2012, 07:01 PM	#4
afarrell39116 Tri-State Aficionado Join Date: May 2011 Location: New Holland, Pa Member #20738 My Ride: 2003 Mustang GT iTrader: (0)	Yeah ive seen alot of vids and alot of them had their mods listed, with alot of 4:10.s listed for the rear. When i get going from a stop in 1st gear i dnt want to be at like 4k rpm's and.be doing 15 mph lol i just want to have a lil more get up and go. I wish i knew what was in it now, but idk.

04-08-2012, 07:02 PM	#5
afarrell39116 Tri-State Aficionado Join Date: May 2011 Location: New Holland, Pa Member #20738 My Ride: 2003 Mustang GT iTrader: (0)	And yes its a 5 speed lol

04-08-2012, 07:18 PM	#6
schaffer Tri-State Addict Join Date: Apr 2010 Location: Central PA Member #16147 My Ride: 2015 Tacoma. iTrader: (0)	You should be able to find out what's in the rear on the axle tag. My ranger has one on the axle,printed on it was 3.73.

04-08-2012, 07:49 PM	#7
afarrell39116 Tri-State Aficionado Join Date: May 2011 Location: New Holland, Pa Member #20738 My Ride: 2003 Mustang GT iTrader: (0)	This is true i didnt think of that lol but what if the owner before me has already changed them out? How can i tell what ratio the rear gears are?

04-08-2012, 08:07 PM	#8
OutToWinPAHC Tri-State Post Whore Join Date: Jun 2007 Location: Tokelau Member #5081 My Ride: R33 GTS25T, RHD E46, Truck, part R32 GTR iTrader: (2)	Count the teeth on the input pinion and out put pinion then divide the output by the input example 12 and 47 would be 3.916

04-08-2012, 09:17 PM	#9
afarrell39116 Tri-State Aficionado Join Date: May 2011 Location: New Holland, Pa Member #20738 My Ride: 2003 Mustang GT iTrader: (0)	Oh ok yeah i thought it would have to do with counting the teeth...i just didnt know what the formula was. Thanks!

04-08-2012, 09:34 PM	#10
schaffer Tri-State Addict Join Date: Apr 2010 Location: Central PA Member #16147 My Ride: 2015 Tacoma. iTrader: (0)	I'd check the axle tag first,maybe contact the previous owner.

04-08-2012, 09:46 PM	#11
mayer5oh Tri-State Training Wheels Join Date: Jan 2010 Member #15503 My Ride: 92 Mustang "the street sleeper" iTrader: (0)	Spin the wheel at the end around one exact rotation and count how many times the pinion turns around. That's a good way to figure out the gears in the car. As for a stock-ish 4.6 the 410s would be great. What are your present and future mods?

04-09-2012, 08:17 AM	#15
afarrell39116 Tri-State Aficionado Join Date: May 2011 Location: New Holland, Pa Member #20738 My Ride: 2003 Mustang GT iTrader: (0)	well as of now im still planning and deciding future projects for the GT. Moneys tight and everyone i know understands that lol. Im hoping one day to get it supercharged but i know that wont be for a loooonnng time due to how expensive they are. Im planning soon though to get rid of the bassani exhaust system thats on it currently and putting on flowmasters, the bassani just isnt loud enough for me lol. And yes i believe we're around the same RPM ranges. This is my daily driver and it does see a little bit of highway time every day to work and back. I can cruise pretty steady at about 70 mph and be at or around 2500 i believe is what i seen last.

04-09-2012, 10:24 AM	#20
bmatyeah Tri-State Post Whore Join Date: Apr 2007 Location: West Chester PA Member #4478 My Ride: 1997 Ford Mustang iTrader: (2)	For gears I would stay away from 4.10 if you drive at 65+ and drive a lot. It will put you higher up in the rpms, not horrible but who wants to put more money in the gas tank? For a dd, I would put in 3.73 or possibly 3.90. Get long tubes, if you want a louder exhaust the bassani is better quality then the flowmasters. SLP long tubes sound awesome. Remember you get what you pay for with headers.