the truth about 4.10 gears in our cars

[86GT351]

That’s why in my little coupe I have 2.95 first gear in my world class liberty pro-shifted T-5.

4.30 rear was recommended with 2.95 and 4.10 with 3.35. I had 3.73 and left them because the car ran so good.

And that is where I am at now. Went from a road race set up with 3:73 to a Drag set up with a taller tire. Probably going with 4:10 or even maybe 4:30. Have to shoot for the sky in pictures! LOL!

 

[whitmanink]

Same size as my tires. At 769 tire revs per mile, your engine will be turning at 3150rpm at 60mph in 4th gear and at 2145rpm in 5th.

Would lito need to readjust for my tire? I didn't think he did... Only the rear gear ratio number?

 

[86GT351]

Would lito need to readjust for my tire? I didn't think he did... Only the rear gear ratio number?

Yes, If he will. Many tuners don't deal with tire adjustments for some reason.

 

[whitmanink]

Yes, If he will. Many tuners don't deal with tire adjustments for some reason.

the speed lazer sign down my street was like 2mph off from what my car showed ,, so i think i wont even bother lito for that ,.

 

[Juice]

Would lito need to readjust for my tire? I didn't think he did... Only the rear gear ratio number?

Did Lito not unlock the tire size and gear adjustments? You should see a "tune options" screen on the X4 before flashing. You could reqest your tune revised from him. It would take about 30 seconds of his time to "tic the box" for tune options and email it.
If he left the tune to use the VID block for gears and tire size, than the above does not apply.

Ps. I just went to 3.31s. Started with 3.73, than 3.90, 3.55, 3.73 back in.

With the 31s, 1-4 is for 'racing', 5&6 are for cruising.
1900 rpms @70mph in 6th, and 1st is no longer useless. lol (magnum xl w/2.97 first) Top speed in 4th ~160 mph per gear calculator.

 

[Midlife Crises]

My 2010 GT came with 3.73s and a 3650. Seemed like a good combination with the stock tires around 27” Dia. Added cams and sometimes it would buck a little at parking lot speed but still manageable. After killing the 3650 I went to a magnum xl with 2.66 first and 4.30s in the rear. Brutal acceleration if it hooks up on 28” slicks and rolls through a parking lot without the slightest jerk but it’s topped out at 125 mph or so in 4th. Looking for a little more speed in 4th I have gone to 4.10s with the same 28” slick but I have not been to the track to see how will run. It does take a bit more care to get rolling from a stop than it did with the 4.30s.
You should have a list of parameters you can adjust in the “tune options” menu if you’re using an X4 Tuner. Gear, Tire size, Rev Limit, Idle rpm and more is in there.

 

[Autokyrios]

Ran 3.73's on a 28.5" tire (0.71 final drive) for years. My new axle has 4.10's in it because I wanted to give a taller gear a try.

 

[Pentalab]

I Have a 2010 GT auto, with M90 blower + LT's + 94 tune. I left the oem 3.31 rear gear alone. Reason is, my 2nd gear on the auto is 14% lower than 2nd gear in the manual 3650. My 3rd gear is 16.5% lower vs the 3rd gear in the manual 3650.

With the manual 3650 tranny, it would need a 3.73 rear gear to equal my 2nd gear.....and a 3.90 rear gear to equal my 3rd gear. Where I lose out is in 4th gear. 100 mph @ 4 krpm. 125 mph @ 5krpm. 150 mph @ 6 krpm.

 

[Dino Dino Bambino]

I Have a 2010 GT auto, with M90 blower + LT's + 94 tune. I left the oem 3.31 rear gear alone. Reason is, my 2nd gear on the auto is 14% lower than 2nd gear in the manual 3650. My 3rd gear is 16.5% lower vs the 3rd gear in the manual 3650.

With the manual 3650 tranny, it would need a 3.73 rear gear to equal my 2nd gear.....and a 3.90 rear gear to equal my 3rd gear. Where I lose out is in 4th gear. 100 mph @ 4 krpm. 125 mph @ 5krpm. 150 mph @ 6 krpm.

Yeah, the problem after you've added a blower on a 3V automatic is that you soon realise the five gear ratios of the 5R55S aren't enough (you really need six).

5R55S: 1st 3.22 2nd 2.29 3rd 1.55 4th 1.00 5th 0.71

Top speeds in each gear (6500rpm redline, 3.31 axle gears, and factory option 770 revs/mile 255/45R18 tires):

1st 48 2nd 67 3rd 99 4th 153 5th 180+

6R80: 1st 4.17 2nd 2.34 3rd 1.52 4th 1.14 5th 0.87 6th 0.69

1st 37 2nd 65 3rd 101 4th 134 5th 176 6th 180+

By comparison the 6R80 has significantly shorter 4th, & 5th gears that are more performance orientated. The only downside is that 1st gear is very short for a car with over 450 crank HP even with 3.31 axle gears, and would require exceptionally good traction to prevent the rear tires from vaporizing into a cloud of smoke.

 

[Miker]

I can't imagine turning 2100 at 60MPH. I think I'm turning 2000rpm at 70 with 355s. But the acceleration would be great!

 

[lwarrior1016]

I can't imagine turning 2100 at 60MPH. I think I'm turning 2000rpm at 70 with 355s. But the acceleration would be great!

Why are you scared of the rpm? It’s really no issue.

 

[MrBhp]

Would lito need to readjust for my tire? I didn't think he did... Only the rear gear ratio number?

Manuel has stated often that he does not lock anything on your tuner. It's yours. The tune and the tuner is yours, you paid for it.

 

[Miker]

Why are you scared of the rpm? It’s really no issue.

Not afraid of the RPM I am usually traveling at 75 to 80 on CA freeways. If 60 was as fast as I drove 2100 would be fine.

 

[lwarrior1016]

Not afraid of the RPM I am usually traveling at 75 to 80 on CA freeways. If 60 was as fast as I drove 2100 would be fine.

Put it at 80 and let it sing at 3k rpm. These engines love rpm and will live there for a very very long time.

 

[Miker]

I always check my MPG at fill ups with a calculator. I usually get around 15 MPG in town and If I am station to station on a freeway run I get about 23 MPG running 75 to 80. I usually shift at points that keep the rpms at around 1800 to 2000. I always wondered if I would get better MPG if I ran the motor in a higher RPM range? Seems like the more cycles the engine turns the more gas it needs but is the motor more efficient in a higher rpm range?

 

[MrBhp]

Before the mods my car would get 26 highway at 70 mph. 25 mpg at 60. I seldom check anymore. Bigger injectors, bigger turbo, 4.10 gears has dropped it considerably in the city, and maybe 5-6 on the highway.

 

[Juice]

I always check my MPG at fill ups with a calculator. I usually get around 15 MPG in town and If I am station to station on a freeway run I get about 23 MPG running 75 to 80. I usually shift at points that keep the rpms at around 1800 to 2000. I always wondered if I would get better MPG if I ran the motor in a higher RPM range? Seems like the more cycles the engine turns the more gas it needs but is the motor more efficient in a higher rpm range?

Its possible but....
I run Torque, and I have Maf & instant MPG guages setup. At times, a lower gear is using less air and shows better instant mpg. But the difference is not a great amount. So, just dont lug it.

 

[Autokyrios]

Da phuk is MPG?

Stop talking such blasphemy, heretic!

 

[07 Boss]

Last time I checked my mileage it was 11.6 mpg. I got depressed and never checked it again.

 

[Dino Dino Bambino]

Da phuk is MPG?

Stop talking such blasphemy, heretic!

if only all of us could get cheap gas.
I'm lucky to be paying only $5.90 for a gallon of E10 95 RON gas in Cyprus whereas our German friends pay something like $7.50.
That's why @GriffX and I have been trying to squeeze every mpg we can out of our cars (somewhat successfully) with aero drag reduction and other efficiency mods.