AJSpags

How much freeway driving do you do? I drive about 10 miles a day to work on the freeway and have thought about 4:10's but not sure if it's worth it.

moosestang

70mph is going to = about 2500 rpms in 5th. You won't have any problems at the track if you can shift fast enough. You should pick up a few tenths and gain a few mph. you'll be able to finish the 1/4 in 4th gear near redline, which is what you want.

bakerjd

My daily drive is 80% highway (80mile/roundtrip) and I have no problems/regrets with my 4.10s.

slickman

I think im going to go with the 4.10's. I found FRP for $135 shipped.

E_cox310

I totally agree with 07BLACK GT. Just had mine installed a couple days ago and I'm experiencing the same.

copestang

i have the 4:10 at the house, but getting ready to send them back to AM, for the 3:73 cause there been no consistent about people that are DD and drive alot of highway, even rpm and mpg is way different, i got the basic mods and cams and 95,000 mi, dont want pay twice to have gears put in

slickman

Well, your RPM should be about 2300 RPM at 65 MPH. That would vary depending on your tire size dia.. MPG will vary depending on your driving habits so, you need to take all this into account.

My only concern is, would going to 4.10's be to deep for first gear on the track. That's what I'm not sure of. Shifting.. I'm good at power shifting, going from 1st to 2nd for example you would think I had an auto.

Here's a RPM calculator I use. http://www.ringpinion.com/Calculators/Calc_RPM.aspx

slickman

I found this posted on allfordmustangs forum, it makes perfect sense to me.


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Everything you need to know about Gears!
Mods : Sticky this if you want....

Why am I writing this? I see alot of people asking about what gears they should get, and in others replies I constantly see false information being passed on. I know first hand what 4.30's feel like in a Modded 96 Cobra... 4.10's feel like in a Modded 2000 GT, and 3.73's feel like in a 95 GT.

First off... DONT FEAR THE GEAR

There are many misconceptions when it comes to choosing the right gears. Now you might be saying to yourself, 4.30s!? That's WAY too much. But in all reality, they work perfect. In a 1/4 mile race, you want to be crossing the finish line at your peak Horsepower RPM in 4th gear.

For our modular Cobra's (pre 2003), with that beloved 6800rpm redline, 4.30's puts you at that peak HP RPM when you cross the line in 4th.
For our modular GT's with a slightly less rpm range... 4.10's would suit best.

For those of you with the pushrod 5.0's, 3.73's work great, since you make all your power in the midrange, as opposed to us modular guys making our power up top. Although, I've heard several people say they should have gone 3.90's or even 4.10's as well.

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What does such a short gear ratio feel like?

It feels like the car lost 1000lbs. Yes, that's right. It just pulls like no other. You hardly have to push the pedal to get up to speed... and that's even keeping it under 3200 rpms. I had a Viper try to pass me in the passing lane the other day on my way out to my girlfriend's house in the country... I dropped her to 2nd at about 45.... let her rip... That Viper didn't get passed my door. Maybe he wasn't flooring it, but the look on his face sure told a tale.

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Ahhh, another concern that has probably crossed your mind is, but what about my gas mileage?!

I drive probably about 40% city 45% highway and 5% 'givin it some'

With my 3.27's, I would consistently get 19 miles per gallon.

I've gone through 2 tanks on my 4.30's now.... each with probably 35% city 50% highway 15% lettin her rip.... 22 and 23 miles per gallon.

Yes you heard me right.... my gas mileage IMPROVED.

And YES I am taking 5% off my mileage total, due to my speedometer being slightly off (even with the 23 tooth speedo gear)

As long as we modular guys keep the rpm's under 3250rpm's, where the intake runners switch over to the 'performance' square runners.... we are in 'economy' mode.

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Ricardo

4.10s on highway are no issue. My wife's G6 V6 turns more RPMs at speed than my GT. Most 4 cylinder cars are turning at much higher RPMs on the highway than your GT will with 4.10s.

1st gear works just fine and when racing or doing a burnout you'll simply start in second.

Also I get better gas mileage than with my 3.31s that came with the car because I shift ALOT less, get into the throttle less, and 5th gear is really all my car sees 90% of driving time since I can shift from 2nd to 5th and that's it.

Norm Peterson

Most of it I can buy into, having done a gear swap or two myself.

The line that doesn't belong is that "don't fear the gear" bit, which is little more than somebody else's emotions pretending to be tech.

Around town gas mileage can improve, as long as you use the deeper axle gears to allow earlier upshifts. On the highway gas mileage will also depend on your ECU enrichment strategy (does the higher rpm cost you more or less than any enrichment that might have been invoked in your specific highway driving?). My educated guess is "usually 4.10's will use a little more on the highway than numerically lower gears".

We really need a larger sample size that two tanks here. Partly for having a better overall average and partly to get the "tester" all the way back to his normal driving rather than have any conscious or subconscious effort to obtain better fuel mileage results be skewing the numbers. Don't think that wasn't happening.


Norm