3.73s and 4.11s

['02~'vert~GT]

What kind of gains can I expect to make on the 1/4 from putting in 3.73s or 4.11s?

 

[Bone Racing]

4.11...chevy?

 

['02~'vert~GT]

4.11...chevy?

Sorry, 4.10s

 

[GinoGT]

I don't know about the exact gains, but you'll never forgive yourself for taking 3.73's over 4.10's.

 

[03trubluGT]

I don't know about the exact gains, but you'll never forgive yourself for taking 3.73's over 4.10's.

Depends on if he is staying N/A.

Most power adders reccommend that you stick with 3.73s or lower, from what I've read.

Matt

 

[Dark Knight GT]

It depends on a lot of things. If he's driving an auto, then he wants no less than 4.10's. You can also run 4.10 gears with boost, many do it. Although it is easier with 3.73's.

If he's staying n/a, I say go with 4.10s, no less. Im planning on going 4.30's in my auto. Ide go with 4.56's but hey, I run a 26in tire and I drive my car everyday. Got to keep the interstate rpms down at least somewhat lol.

Conduct a search on here for both 3.73s and 4.10's. Read others results and judge for yourself.

 

[03trubluGT]

It depends on a lot of things. If he's driving an auto, then he wants no less than 4.10's. You can also run 4.10 gears with boost, many do it. Although it is easier with 3.73's.

If he's staying n/a, I say go with 4.10s, no less. Im planning on going 4.30's in my auto. Ide go with 4.56's but hey, I run a 26in tire and I drive my car everyday. Got to keep the interstate rpms down at least somewhat lol.

Conduct a search on here for both 3.73s and 4.10's. Read others results and judge for yourself.

I have seriously thought about 4.10s, but I drive 46 miles round trip to work everyday since I moved (down from 110 miles).....

I still think I'll do 3.73s though.. I really need to drive a car with both and make a decision so I can get it done.

Matt

 

[Dark Knight GT]

I have seriously thought about 4.10s, but I drive 46 miles round trip to work everyday since I moved (down from 110 miles).....

I still think I'll do 3.73s though.. I really need to drive a car with both and make a decision so I can get it done.

Matt

Mustang92(Bill Putnam) drives his Mustang 70miles every day doing a round trip back and forth to work. He has 4.30 gears and his Mustang still averages above 20mpg on the open highway. He also has over 100k miles on his car.

I think if youre staying n/a, youre better of with 4.10's. If youre getting a power adder, then you may want to stay with 3.73s.

 

[GinoGT]

Don't fear the gear!

From all of us with 4.10's........please, just trust us on this one.

 

[trinity_gt]

I took the opportunity to do some calculations in Excel to give some real numbers. These are based on a P245/45ZR17 tire with 809 revs/mile and the TR-3650 gear ratios of 1:1 (4th) and 0.67:1 (5th). YMMV.

4th gear engine RPM (3.27/3.73/4.10) @ MPH
50 - 2204/2514/2764
60 - 2645/3017/3317
70 - 3086/3520/3869
80 - 3527/4023/4422
90 - 3968/4526/4975
100 - 4409/5029/5528
110 - 4849/5532/6080*
120 - 5290/6035*/6634*

5th gear engine RPM (3.27/3.73/4.10) @ MPH
50 - 1477/1684/1851
60 - 1772/2021/2222
70 - 2067/2358/2592
80 - 2363/2695/2963
90 - 2658/3032/3333
100 - 2954/3369/3703
110 - 3249/3706/4074
120 - 3544/4043/4444

* - at or past redline

5th gear theoretical redline limited top speed is right around 160MPH with 4.10s. With 3.27s, its out of the ballpark at just over 200MPH and for 3.73s, it's about 178.

If you cruise typically in 5th gear at 70MPH, with 3.27s your turning right around 2000RPM. With 4.10s, you'd be around 2600. To see how comfortable you are with the engine at that speed, shift to 4th and slow to 60MPH and get a sense for engine noise, urgency and all that.

Only you can decide if the 4.10s are too much for you based on this stuff. Certainly, the car can take it...

What will you gain in terms of 1/4 mile performance? Likely not much; you're not putting any more power to the ground and what you're gaining in torque at wheels you're losing in MPH at a given engine RPM. I think the gears would help get you out of the hole, especially if you've got traction, with less chance of bogging, which can help the ET. But I wouldn't expect miracles.

Also, correct me if I'm wrong 4.10 guys, but with 3.27s, you can run the traps at about 100MPH in 3rd gear with the engine just below redline (around 5780) but with 4.10s (and 3.73s), you need that extra shift into 4th (otherwise the 3rd gear RPM at 100MPH, typical trap speed for a well driven, otherwise stock GT is a rod-busting, PCM-angering 7240 for 4.10s and 6600for 3.73s...) That extra shift can cost time...

{Edited to add a 3.73 column...11/13/03}

 

[GinoGT]

Or you could have just gone here: http://www.wcfords.com/stuff/calcs/EGTcalc/egtcalc.php



Once I get some DR's I'll be heading out to the track to see what the Stang can do. I think tires, 4.10's, pulleys, and a T/A might even take .5 off with some practice.

And about the extra shift: yeah you do spend a little more time shifting, but the 3rd-4th shift is probably the easiest and fastest one there is.

 

[forpit2000gt]

with 4.10s you can trap at 101-102 in 4th. you will get to the end of the track before those with 3.27s. Trap speed is important but not everything. I have seen cars run 13.6 and only trap 96 with 3.73. Suspension and your 60 ft will increase your ET.

 

[trinity_gt]

Or you could have just gone here: http://www.wcfords.com/stuff/calcs/EGTcalc/egtcalc.php

Er...yeah. Well, my post still helps directly contrast the two...

And about the extra shift: yeah you do spend a little more time shifting, but the 3rd-4th shift is probably the easiest and fastest one there is.

This is true. But at about 80-some MPH, where 3rd is nearing redline and you've got to shift, you're travelling at 117 feet per second. Even if you could pull off a shift in a quarter of a second, you'd still travel two car lengths (about 30 feet) coasting - no power being put down. Is this countered by the additional acceleration offered in 4th? Hmmm...

The final drive ratio in 3rd with 3.27s is 4.28 (1.31 * 3.27) while a 4.10 gearset in 4th gives a final drive of 4.10 (1.00 * 4.10). The overall ratios are pretty close. Engine RPM in 3rd at 80MPH is about 4620 with 3.27s while in 4th at 80MPH with 4.10s the RPM is 4400. Since the overall ratios are quite close, and both gears find the engine at very close to the same point in the RPM band, I wouldn't expect to get much more (if any) acceleration in 4th with 4.10s than I would in 3rd with 3.27s. Basically, the charge to the traps at the instant of shifting of a 4.10 car with a 3.27 car in 3rd beside him would be a wash.

 

[speed545]

would 3.90 be a good compromise??

 

[jorge]

im leanin more and more towards 3.90 every day
u also have to look at ur exhaust ( well i do anyways) cuz some exhausts drone at 2000rpms, i hate drone. had it on my old stang, wouls always drive too fast to get rid of drone

 

[2002BLKGT]

4.10's all the way baby!

would 3.90 be a good compromise??

Damn, I've know for months I want the 4.10's, I just haven't had the cash. Hell, I'd go with 4.30's if my stang wasn't a daily driver. Being a first time home owner, spare cash is a term I haven't uttered in quite a while now.


Don't Fear the Gear!! Get the damn 4.10's dude!


Maybe the moderator should put a stick on a gear thread that leads to the 4,697,250 other threads covering the same topic? Just a thought.

 

[GinoGT]

Er...yeah. Well, my post still helps directly contrast the two...



This is true. But at about 80-some MPH, where 3rd is nearing redline and you've got to shift, you're travelling at 117 feet per second. Even if you could pull off a shift in a quarter of a second, you'd still travel two car lengths (about 30 feet) coasting - no power being put down. Is this countered by the additional acceleration offered in 4th? Hmmm...

The final drive ratio in 3rd with 3.27s is 4.28 (1.31 * 3.27) while a 4.10 gearset in 4th gives a final drive of 4.10 (1.00 * 4.10). The overall ratios are pretty close. Engine RPM in 3rd at 80MPH is about 4620 with 3.27s while in 4th at 80MPH with 4.10s the RPM is 4400. Since the overall ratios are quite close, and both gears find the engine at very close to the same point in the RPM band, I wouldn't expect to get much more (if any) acceleration in 4th with 4.10s than I would in 3rd with 3.27s. Basically, the charge to the traps at the instant of shifting of a 4.10 car with a 3.27 car in 3rd beside him would be a wash.

But I would think the extra time needed for the 3rd-4th shift doesn't mean anything, because with 4.10's second pulls almost as hard as 1st, and 1st with some sticky tires has got to be one crazy mother****er.

Getting a faster start gives better ET's.

 

[AJ99MustangGT]

i like 3.90 personally

 

[trinity_gt]

But I would think the extra time needed for the 3rd-4th shift doesn't mean anything, because with 4.10's second pulls almost as hard as 1st, and 1st with some sticky tires has got to be one crazy mother****er.

Getting a faster start gives better ET's.

Yep. However, you're not making any more power at the wheels. You may be pulling harder in each gear but each gear runs out of steam (speed) sooner too. In the long run, it's a wash. Making up for bogging out of the hole is, I think, where the key lies for improving 1/4-mile performance with gears.

 

[DeadLurker]

If you cruise typically in 5th gear at 70MPH, with 3.27s your turning right around 2000RPM

I think your off by 5mph. If were talking about the tranny in the 99-01(mid year) mustangs then yes that is correct 70mph, but with the 01.5-up models the t3650 is at 75mph at 2,000rpms.