random question about gears

04mustang232 · August 25th, 2009, 10:56 PM

Originally Posted by mooses

It's mainly because the 4r70w has a longer 1st gear than the t5. The auto needs the extra gearing to get out of the hole quicker. A 4r70w with 4.10s has a torque multiplication of 11.644, and a t5 with 3.73s has a multi of 12.4955. You can see that even with the 4.10s, the auto has less multiplication than the manual with 3.73 gearing.

Personally, I'd go with 4.10s on a manual because 1st gear isn't that bad: using VAP's rpm calculator and shifting at 5800, you're at 32.3 mph with 4.10s, and 35.5 mph with 3.73. It's not like you'll be shifting to 2nd as soon as you start moving.

32 mph seems high, very high, for a manual with 4:10s. If I hit 30mph in an auto in 1st id be somewhat suprised.

mooses · August 25th, 2009, 11:12 PM

Originally Posted by 04mustang232

32 mph seems high, very high, for a manual with 4:10s. If I hit 30mph in an auto in 1st id be somewhat suprised.

You have to realize that it's at 5800 rpms, but yeah that's where you'll be. Back when I had an auto+4.10s, mine just about hit 40 mph.

edit: just did the math to make sure I wasn't remembering incorrectly. I had my tuner shift at 6k, which is 39.2 mph.

BadBlackGT · August 25th, 2009, 11:16 PM

Originally Posted by mooses

You have to realize that it's at 5800 rpms, but yeah that's where you'll be. Back when I had an auto+4.10s, mine just about hit 40 mph.

edit: just did the math to make sure I wasn't remembering incorrectly. I had my tuner shift at 6k, which is 39.2 mph.

Really? My car has stock gears and mine is at like 40 at 4,000 rpms... i thought it'd be way worse than that. Sweet! I think im going with 4.10's after all.
<- has auto

mooses · August 25th, 2009, 11:36 PM

Originally Posted by BadBlackGT

Sorry for the thread steal, but 04mustang, how are those on the highway? i have an auto and really leaning towards 4.10's because i heard they arent as bad as most people make them seem... like maybe 300-500 more rpm's at 70 than stocker gears?

stock @ 70: 2093 rpms
4.10s @ 70: 2624 rpms

531 rpm difference

BadBlackGT · August 25th, 2009, 11:38 PM

Originally Posted by mooses

stock @ 70: 2093 rpms
4.10s @ 70: 2624 rpms

531 rpm difference

So... worth it? Haha, i'm really wanting them. What'd it do to the shifts and stuff? Does it feel different normal driving, just shifts at a lil slower speed that it used to? Could you even notice it under normal driving conditions?

mooses · August 25th, 2009, 11:50 PM

Originally Posted by BadBlackGT

So... worth it? Haha, i'm really wanting them. What'd it do to the shifts and stuff? Does it feel different normal driving, just shifts at a lil slower speed that it used to? Could you even notice it under normal driving conditions?

Correct. Under part throttle, your transmission is programmed to shift for optimal fuel economy(obviously not true if you've had the part throttle shift points changed in your tune). So when you're driving along, it'll shift where it normally does, but you'll be at a few mph slower. You'll be able to tell that it's revving up faster even under normal driving conditions. You will definitely feel it when you mash it from a dig.

BadBlackGT · August 25th, 2009, 11:52 PM

Originally Posted by mooses

Correct. Under part throttle, your transmission is programmed to shift for optimal fuel economy(obviously not true if you've had the part throttle shift points changed in your tune). So when you're driving along, it'll shift where it normally does, but you'll be at a few mph slower. You'll be able to tell that it's revving up faster even under normal driving conditions. You will definitely feel it when you mash it from a dig.

Alright, sweet. Thanks for the help!

fasterv6 · August 28th, 2009, 12:14 AM

so how many revs would the 3.73's put me at around 70mph?

mooses · August 28th, 2009, 12:37 AM

Originally Posted by fasterv6

so how many revs would the 3.73's put me at around 70mph?

3.73: ~2319rpm
4.10: ~2549rpm

20cooper08 · August 28th, 2009, 12:42 AM

who makes 3.73 gears for the 7.5 rear end and where can i find them?

BadBlackGT · August 28th, 2009, 05:43 PM

Originally Posted by 20cooper08

who makes 3.73 gears for the 7.5 rear end and where can i find them?

I heard go with Ford Racing cuz others whine after a while.

04mustang232 · August 28th, 2009, 09:42 PM

Originally Posted by BadBlackGT

I heard go with Ford Racing cuz others whine after a while.

gears whine because of shitty installation, I have motive and have yet to hear a whine, and they are said to be the worst brand.

August 28th, 2009, 12:14 AM	#28
fasterv6 Regular 2004 3.9L mustang v6 Join Date: Dec 2008 Location: houston Posts: 69 iTrader: 0 reviews	so how many revs would the 3.73's put me at around 70mph? __________________ "silly ricer, useless wings are for penguins" 2004 mustang 3.9L steeda short throw, h&r lowering springs, shorty antenna, tinted windows, smoked headlights/taillights, new shift knob, homemade grille delete GT4 replica rims next: 3.73s and LSD

Threads Similar to: random question about gears
Thread	Thread Starter	Forum	Replies	Last Post
random question	Triple A	The Clubhouse	3	February 3rd, 2009 05:03 PM
Random Question	Blondie99	The Clubhouse	78	December 3rd, 2008 09:28 PM
random question	Dennis	The Clubhouse	22	January 3rd, 2008 02:47 PM
random question....	Blk01ponyGT	Feedback Forum	5	September 12th, 2007 06:27 PM
Random question...	OhhShorty	99-04	19	August 15th, 2007 02:13 PM

August 28th, 2009, 12:42 AM	#30
20cooper08 Newbie 2000 V6 Mustang Join Date: Aug 2009 Location: Ft. Madison Iowa Posts: 19 iTrader: 0 reviews	who makes 3.73 gears for the 7.5 rear end and where can i find them?

Remove Advertisements Sponsored Links
Ford Mustang Forum Advertisement

All times are GMT -4. The time now is 08:39 PM.
Contact Us - Modded Mustangs : Ford Mustang Forums - Privacy Statement - Top
Modded Mustangs is ©2005-2008, All Rights Reserved, And is Not Affiliated with Ford Motor Company. Forum is powered by vBulletin ©2000 - 2012, Jelsoft Ent. Ltd. & SEO by vBSEO 3.3.2 ©2009, Crawlability, Inc.