4.10 Cruising rpm

SN90FiveOh · Mar 5, 2015

Ok just wanted to know what peoples numbers were at 60 mph, 70mph and 80mph.
I had 3.73s in my 98 v6 auto and it screamed 3k rpm at 80 mph which seemed really high.I think that tranny was going out so anyone with 4.10s let me know what your numbers are like. Auto, Stick, 5spd,6spd. Whatever.

McCloud · Mar 5, 2015

When I had 4.10s in my car, with my 4R70W and 315/35/17s in the back I was running approximately ~28-2900 rpm at 70 mph. At 80 mph I think I was ~31-3200 rpm.

SN90FiveOh · Mar 5, 2015

McCloud said:
When I had 4.10s in my car, with my 4R70W and 315/35/17s in the back I was running approximately ~28-2900 rpm at 70 mph. At 80 mph I think I was ~31-3200 rpm.

Have you ever driven far like that? Ever had problems riding at high rpms?

the5.ohh · Mar 5, 2015

I had 4.10s awhile ago, 5 speed 95 GT. At 50mph in 4th I was way past 3k. I couldn't imagine 60+ When it was auto with 4.10s it was around 2600ish. 5 speed at 60+ would be almost 3k plus easily. Way too high imo

lutter94 · Mar 5, 2015

These numbers aren't making any sense throwing them into an excel spreadsheet with all the ratios and such. I've entered my numbers into online calculators and they are matching up, idk.....

3.73 Gears in a 1998 4R70W @ 80 MPH (assuming 245/45-R17 tires, stock tire height) = 2734 RPM in 4th

4.10 Gears in a 4R70W @ 70 MPH (315/35-R17 Tires, same tire height as 245/45-R17) = 2630 RPM in 4th

4.10 Gears in a 4R70W @ 80 MPH (315/35-R17 Tires, same tire height as 245/45-R17) = 3005 RPM in 4th

4.10 Gears in a 95 T5 @ 50 MPH (same tire height as above) = 2683 RPM in 4th (1825 RPM in 5th)

4.10 Gears in a 95 T5 @ 60 MPH (same tire height as above) = 2189 RPM in 5th

SN90FiveOh · Mar 5, 2015

Cool. I like that whole layout. I think I'll be alright with 4.10s and I'm going to do a 5 speed swap later mainly for the extra gear on the highway and because this auto sucks.

lutter94 · Mar 5, 2015

The specs I found, 94/95 4th Gear is 0.667 ratio. The 94/95/Fox T5 has a 5th Gear ratio of 0.68. About 2% higher, so your RPM's will increase that percentage. However, if you got a T5 with the 0.63 5th gear, your RPM's would drop 5.5%.

4.10 Gears - AODE - 245/45-R17 @ 60 MPH = 2148 RPM
4.10 Gears - T5 - 245/45-R17 @ 60 MPH = 2189 RPM

4.10 Gears - AODE - 245/45-R17 @ 70 MPH = 2506 RPM
4.10 Gears - T5 - 245/45-R17 @ 70 MPH = 2554 RPM

4.10 Gears - AODE - 245/45-R17 @ 80 MPH = 2864 RPM
4.10 Gears - T5 - 245/45-R17 @ 80 MPH = 2919 RPM

lwarrior1016 · Mar 5, 2015

Which t5 has the higher overdrive ratio?

Ferocious · Mar 5, 2015

I run about 2600-2700 at around 70mph with my T45 and 4.10s. Most of the time I'm on the freeway i'm doing more like 60 and it juts a bit over 2500K.

McCloud · Mar 5, 2015

SN90FiveOh said:
Have you ever driven far like that? Ever had problems riding at high rpms?

In 2013 I drove 5.5 hrs to Mustang Week and back, doing 80+mph with a/c on the entire way, and I still got 20-21 mpg.

lutter94 · Mar 5, 2015

lwarrior1016 said:
Which t5 has the higher overdrive ratio?

The T5Z that Ford Racing sells has 0.63, Ford put 0.68 in the foxes and 94/95 GT/Cobra. There might have been 0.63 in some other fox trannies, but I don't think they have the same power limits.

Keep in mind the T5Z has the fox length input shaft. You'd have to swap to the longer input shaft to use a 94/95 bellhousing.

kb1982 · Mar 5, 2015

Tremec 3550 close ratio with .82 5th gear, 4.10 and 275/50 R15 MT ET Street Radials. These are the numbers from wallace racing which is pretty accurate.

Engine Speed (RPM)	MPH 4.10 Gear	MPH Gear	MPH Gear
8000 RPM	179.81 MPH	MPH	MPH
7500 RPM	168.57 MPH	MPH	MPH
7000 RPM	157.33 MPH	MPH	MPH
6500 RPM	146.10 MPH	MPH	MPH
6000 RPM	134.86 MPH	MPH	MPH
5500 RPM	123.62 MPH	MPH	MPH
5000 RPM	112.38 MPH	MPH	MPH
4500 RPM	101.14 MPH	MPH	MPH
4000 RPM	89.90 MPH	MPH	MPH
3500 RPM	78.67 MPH	MPH	MPH
3000 RPM	67.43 MPH	MPH	MPH
2500 RPM	56.19 MPH	MPH	MPH
2000 RPM	44.95 MPH	MPH	MPH
1500 RPM	33.71 MPH	MPH	MPH
1000 RPM	22.48 MPH	MPH	MPH

SN90FiveOh · Mar 6, 2015

What year cars did the t5z come in?

lutter94 · Mar 6, 2015

They didn't. It's Ford Racing aftermarket.

http://www.americanmuscle.com/frpp-t5-super-heavy-duty.html

lutter94 · Mar 6, 2015

kb1982 said:
Tremec 3550 close ratio with .82 5th gear, 4.10 and 275/50 R15 MT ET Street Radials. These are the numbers from wallace racing which is pretty accurate.

Where did you find this? I was on their site, seemed a little dated, but a few simple calculators were matching mine. My numbers aren't matching yours, not saying they're wrong, just want to fix mine if I have a mistake somewhere......

kb1982 · Mar 6, 2015

lutter94 said:
Where did you find this? I was on their site, seemed a little dated, but a few simple calculators were matching mine. My numbers aren't matching yours, not saying they're wrong, just want to fix mine if I have a mistake somewhere......

Did you use the .82 ratio for the transmission. This isnt with the T5, but for a close ratio Tremec 3550 TKO 500/600. The same trans without close ratio has a .68 5th, with the exception of the 600, which is .64. Here is the websit for the calculator. They have another one, but it assumes a 1 to 1 trans ratio that most 3 speed autos are. http://www.wallaceracing.com/gear-speed.php

lutter94 · Mar 6, 2015

What are you using for tire height, I have 25.826"? Still not getting to match your 179.81 mph. I'm guessing we're not jiving there, since .82 and 4.1 are pretty fail safe...lol.

talltim · Apr 24, 2015

I wish I had 4.10s! My mustang was for track only for a few years so I ran 4.30s. The recession happened and now Im trying to use it as a DD; considering 3.73s.