Gear vs Power

[Jam421]

I know this is a silly hypothetical question. It has to do with what gear actually does on the street...

Got a good set of Mickeys out back…….
Nice day on a ...say 20-30mph roll …would you rather have approx 650rwhp/650rwtq and 4.10 rear gears …OR.....
680rwhp/675rwtq and 3.73 rear gears .

I had both ...now the 373 set up with more power.....I've not yet launched the car but went to the 373's precisely for that purpose.
I've not yet even hit it in 2nd gear with the 373's....just drove home with them.
But ....I did hit it in 3rd from around 3500rpm. I guess it made sense as the 4.10's felt "quicker".
Then.....as she was winding out....nearing redline ....I'm watching the highway....and the 373's felt " faster !"
Can't wait for some nicer weather this weekend to try some nice hard shifts thru the gears.
->)

 

[A.M.R]

Why is the difference in torque so big?

Think I'd go 3.73 for street and 4.10 for strip. Although, I'm pretty sure, even with a set of MTs with that much hp is gonna spin the tires like crazy on the street

 

[09Troublemaker]

Honestly I'd prefer a 3:55 with the current trans gearing as I like running up top. I'm thinking about trying them but I'm only running 725/720 tq. I ran 73's on my 09 at 800 to the tire and could only really use 4th-5th on the street. 3rd would be swing or miss

Not much help.... l

 

[Jam421]

My apologies fellas...my numbers were not accurate
Thanks to AMR for noticing the discrepancies.
The car made 650/650 improved to 680/675 !

BIG DIFFERENCE !!

 

[09Troublemaker]

My apologies fellas...my numbers were not accurate
Thanks to AMR for noticing the discrepancies.
The car made 650/650 improved to 680/675 !

BIG DIFFERENCE !!

Who set the gears for you? Realspeed has done all my work

 

[99VERT]

I just installed a set of 3.55s today! It makes 1st gear take offs nicer and rowing through the gears a pleasure! I have had a boat load of mustangs and ran everything from 3.27 all the way to 4.30s for a street car. The 3.55s feel just about right for me and the 1550 cruising RPMS in 6th on the highway just below 80MPH. This car makes soooooo much torque I don't feel the need for a steeper gear. To each his own though! I know if I was to going to the track the 3.73s or 4.10s would the choice but cruising the streets in and out of Atlanta the 55s feel just right for me.

 

[93 347 Cobra]

I just installed a set of 3.55s today! It makes 1st gear take offs nicer and rowing through the gears a pleasure! I have had a boat load of mustangs and ran everything from 3.27 all the way to 4.30s for a street car. The 3.55s feel just about right for me and the 1550 cruising RPMS in 6th on the highway just below 80MPH. This car makes soooooo much torque I don't feel the need for a steeper gear. To each his own though! I know if I was to going to the track the 3.73s or 4.10s would the choice but cruising the streets in and out of Atlanta the 55s feel just right for me.

I was also considering 3.55s. I'll never do 200 in my car but part of the appeal is knowing it's 200mph capable. At 6250-redline the car will go about 203 in 5th with 3.31s. I think it drops to about 193 with 3.55s at 6250 and if over-rev could be sustained it could theoretically still hit 200 in 5th at about 6700 rpm (high likelihood of engine damage at those loads). 3.73s drop the top-end a little too much for my taste. I enjoy the occasional 3AM banzai run in Mexico and have had my stock car to over 180 so I do indeed occasionally use that much gear. Adding power will shave time off of those super high speed pulls and I think 3.55s would be the perfect compromise.

 

[Jam421]

Wow ! You guys really wind them out on the open road ! My '13 convertible can't ever make the mph a few of you are talking about and it would be quite a splash for law enforcement in my eastern Long Island NY area if it did ! Mine is the same color combo as " 99Vert's" minus the light bar which will be done in the spring. Nice car Bud !
I think I should be very happy with the 373's especially from a 25mph burst.

09Toublemaker....RealSpeed did all the work on my '09 as I lived just minutes from the shop for a while. Prior to that I owned 3 different Cobra replicas and Mustang Magic did all the work on those cars. On this set up MM installed the VMP Stage 4, 4.10 gears , AMR headers and now the 3.73's. They also tuned the car as the VMP set up was not making the advertised power.

I will be posting a set of stock JBA Hi-Flo Catted XPipes for sale at a "really" good price. They were on my car for about 1 month (250miles?) never even got dirty to the touch before I decided on headers

 

[99VERT]

I went out for a 50 Mile cruise through some Georgia back roads today and the 3.55s are perfect for my set up! Going to the North Georgia mountains tomorrow with a buddy and his 2010 Shelby for a 100+ mile romp through the twisty roads! Weather should be in the high50s to lows 60s so tires should be decent with a little warm up time!

 

[Matt in Houston]

I just swapped out my 3.73's after running them for a couple of months in my '13 w/ ~720 rwhp. I changed to a set of 4.10's and now I am in love. I drive my car on the street two or three times a week in nice weather only and it seems like a perfect match. Off boost acceleration is much improved and pulling away from a stop or incline is effortless. The 13/14's have a taller 1st and 2nd ratio, and they seem to pair well with this gear. I would recommend this setup if you are running a large drag radial (28.5") like the 20" 555R or NT05R, or something similar. Some BMR suspension goodies (LCA/UCA) in the rear will also help put the power down. It has been cooler here lately but when the temps are in the 70's+ I wasn't having any problems with grip running the 3.73's and this setup.

In the OP's example, if nothing else was changed except gearing then the motor is putting out the same amount of power. The number difference is fractional driveline losses from the gears and some calculation differences on the dyno. All things being equal, I believe the 4.10's should slightly pull the 3.73's up through 4th gear.

 

[Jam421]

We had way colder temps here in NY than you guys in Houston yesterday ...sunny but 50 degrees .
With the 373's 1st gear was a challenge even with the 305/35/20 MT's that are 28.9". What I figured given the extra tire height I'm closer to a 3.60 rear gear. Just for fun I dropped my psi to 24#'s and it hooked hard with TC ON at 3000rpm (30-35mph/651rwtq) . No way with TC OFF. Then I worked my way with TC OFF to 2500rpm 2nd gear roll (20mph/524rwtq). With TC OFF hitting it from the lower 2500 rpm the car was " all out"...gobbling up pavement + the motor sounded like a pure beast !!
My buddy ('13GT500 & a ZR1) took the car for a spin (no pun) but he was rippin them loose even at 2500rpm. He was trying to be cautious by quickly lowering his foot to the floor versus a quick stab which set the tires for me every time. He tried a bunch of 1-2 shifts at WOT but I think he was just purposefully enjoying smoking up my Mickey Thompsons . I was LMAO . Damn these cars make power !

Earlier yesterday with the 3.73's (MT's @24psi) I tried some really low 1st gear rolls and a few launches success here will require some better temps and for me to be a bit more in "learning mode"...practice, practice, practice ->) .
I think this 373 combo is where I will stay for now . Matt...I get what you're saying about " off boost acceleration" with the 4.10's . No doubt the 4.10's are way more fun with a spirited off light acceleration ...no lag...no bog....just GO !
I kind of miss how the 4.10's pulled like mad in 3rd/4th gears in all the lower/mid rpm bands on a highway. Wow........
But the 4.10's will stay in the trunk for now. Winter is upon us here . I will likely keep them for the track in spring.

Matt....Are you hooking on the street with 4.10's & ~720rwhp ?

 

[Matt in Houston]

Jam, sounds like you had a fun day! Yes the 3.73 gears are a great gear. I might have kept them in if mine weren't so loud on the highway.

Anyway with the 4.10's, I haven't had a good chance to run them too hard at lower MPH or from a dig, as it has been in the 50's and damp but its warming up now. Unfortunately the warmth came in with more rain so that's no good either. I did get some highway blasts in on a dry day and from a roll they pull like no tomorrow. I have no doubt once it warms up and dries out, my 555R and BMR rear end will be up to the task with a little driver mod.

 

[Jam421]

Yeah Matt...it was a really fun day and I learned a lot about how to avoid trouble with the new set up . The 4.10 gear highway blast are an experience I will NEVER forget. I'd love to hear how you make out putting that BMR rear set up to it's test from a stop on a warmer day !

 

[BlueAngel2014]

I went out for a 50 Mile cruise through some Georgia back roads today and the 3.55s are perfect for my set up! Going to the North Georgia mountains tomorrow with a buddy and his 2010 Shelby for a 100+ mile romp through the twisty roads! Weather should be in the high50s to lows 60s so tires should be decent with a little warm up time!

I envy you! You lucky devil. :beer: I was born and raised in those N. Georgia mountains! :rockon: Love those roads. I need to bring mine "home" and put it through those curves.

Next time you're up in that neck of the woods, try US highway 76 driving east from Hiawassee to Clayton to Westminister SC. There are some nice curves through that part and you've got a nice long straightaway right after the GA/SC line through Long Creek SC as you go east to Westminister, SC.

I used to drive that Clayton to Westminister trek for 3 years as I commuted to Clemson to go to grad school! It is a fun twisty trek. I could make the 45 mile drive from Clayton to Clemson in 50 minutes; my old Escort radar detector saved me many a time!

Mike

 

[biminiLX]

The 4.10 gear highway blast are an experience I will NEVER forget!

100% agree here!
4.10s are the best strip gear until you start making over 800rwhp.
I had 4.10s, then did a fully built rear with 3.73s for the expectation of over 800rwhp soon, but the 3.73s started whining and I lost performance at the strip, so I am going back to 4.10s---can't tell you how much I enjoy them.
Makes the car fast and responsive at all RPMs when off boost and gets this heavy car rolling without effort until the power/boost comes in.
Remember we have Ford GT cams and the '13-14 peaks at 66-6700rpm and pulls til 7000rpm.

For the guys mentioning 3.55s, I'm glad it works for your use of the car, but unless there is an issue to go into the rearend, I would say 3.31 to 3.55 is not worth the effort as 3.73s would be even better.

Great to have options 3.31-3.55-3.73-3.90-4.10!
-J

 

[biminiLX]

I just swapped out my 3.73's after running them for a couple of months in my '13 w/ ~720 rwhp. I changed to a set of 4.10's and now I am in love. I drive my car on the street two or three times a week in nice weather only and it seems like a perfect match. Off boost acceleration is much improved and pulling away from a stop or incline is effortless. The 13/14's have a taller 1st and 2nd ratio, and they seem to pair well with this gear. I would recommend this setup if you are running a large drag radial (28.5") like the 20" 555R or NT05R, or something similar. Some BMR suspension goodies (LCA/UCA) in the rear will also help put the power down. It has been cooler here lately but when the temps are in the 70's+ I wasn't having any problems with grip running the 3.73's and this setup.

In the OP's example, if nothing else was changed except gearing then the motor is putting out the same amount of power. The number difference is fractional driveline losses from the gears and some calculation differences on the dyno. All things being equal, I believe the 4.10's should slightly pull the 3.73's up through 4th gear.

Welcome Matt, good site for tech and more members/experiences here.
Glad you understand the old drag race saying......................"don't fear the gear"
-J
:beer:

 

[Matt in Houston]

Welcome Matt, good site for tech and more members/experiences here.
Glad you understand the old drag race saying......................"don't fear the gear"
-J
:beer:

Thanks brother! It was because of your posts that I decided to try the 4.10's...Thanks for all of the helpful threads and feedback, otherwise I might never have thought to give it a shot.

Was that you posting in the last "gear thread" discussion inside the 13/14 owners group on Facebook? I saw someone posting about running an 11.02 with the 4.10's and DR's, no bolt ons.

 

[Jam421]

I know this is a silly hypothetical question. It has to do with what gear actually does on the street...
->)

For you guys with big power and 4.10's how about on the street ? With the 4.10's (650rw) I felt the need to pedal the car then shift immediately to 2nd. That was in summer temps. Of course there's no real consistency but the goal was to keep it straight & safe.
My buddy has an awesome '07 (654rw/633tq) which he can stick hard from 10-15mph in 1st every time.
With the '13 and another 60ftlbs any stab of my throttle in that range and it's goodbye Mickeys .
Pedaling out the 3.73's it's moving off like all get go... with way more straight away stability but I'd love to drop the pedal instead!
At the track I wasn't anticipating a problem hooking either gear.

So....4.10 guys .....you're sitting at a stop.....it's a warm sunny day....the urge rises......any good launch-1-2 shift street experiences ?

 

[biminiLX]

Thanks brother! It was because of your posts that I decided to try the 4.10's...Thanks for all of the helpful threads and feedback, otherwise I might never have thought to give it a shot.

Was that you posting in the last "gear thread" discussion inside the 13/14 owners group on Facebook? I saw someone posting about running an 11.02 with the 4.10's and DR's, no bolt ons.

No, I don't do Facebook but a few friends of mine may have.
I went [email protected] on 20" Alcoas with nothing other than 315 NT05Rs, 4.10s, safe mail order Lund 93 street tune.
Nothing else touched.
-J

 

[biminiLX]

So....4.10 guys .....you're sitting at a stop.....it's a warm sunny day....the urge rises......any good launch-1-2 shift street experiences ?

Yeah, learn to pedal and short-shift, never power-shift 1-2.
Guys with big power know 1st is your track launch/getting moving gear, SECOND is your acceleration gear.
I usually keep all the nannies on during street cruises, but I like to roll/feather it in first, shift early like 6 and then do a quick shift and progressively lay power in during second.
My car hooks really well with the NT05Rs with a 2nd gear roll.
-J