The Official Vortec 454 Info thread

[ralmo94]

Thanks. It’s a bone stock ’96 with 4.10 gearing and a 4L80e. I tow my 5500 - 6000 lb camping trailer with it in 3rd gear, on the advice of the transmission guy that recently rebuilt it.

I’m resisting the urge to mod the engine, though. The plan is to keep it stock.

Towing in OD won't hurt the 4l80. It's made for it. It even has a lower OD ratio than the 60e. What is hard on them is slow shifts in second gear for creature comfort, and pulling a long grade with torque converter unlocked, both can be solved with programming.

What size tires you run?

Mine did just fine cruising over 70 in od with the 265 tires grossing around 17k with 3.73 gears.
Unless you have huge tires, or constantly pull grades, I can't imagine you NEED to stay in 3rd.

 

[ralmo94]

Here is a compare of 265/75-16 4.10s vs 225/75-16 4.10s

 

[ralmo94]

Here is 4.10 vs 5.13 on 265/75-16

 

[ralmo94]

4.10 vs 4.56
265/75-16

 

[South VA]

Towing in OD won't hurt the 4l80. It's made for it. It even has a lower OD ratio than the 60e. What is hard on them is slow shifts in second gear for creature comfort, and pulling a long grade with torque converter unlocked, both can be solved with programming.

What size tires you run?

Mine did just fine cruising over 70 in od with the 265 tires grossing around 17k with 3.73 gears.
Unless you have huge tires, or constantly pull grades, I can't imagine you NEED to stay in 3rd.

Thanks. I’m running the stock size: 245/75 16.

I didn’t know that the 4L80 has a lower OD ratio. I suppose it makes sense, though.

The transmission guy didn’t say I couldn’t tow in OD, just that the transmission would last longer towing in 3rd. He said that towing in 3rd is his standard advice for older vehicles that don’t have a “tow” setting.

Next camping season we’ll be going to the mountains in VA and NC, so there will be some steep grades. Out here in the Piedmont and Coastal Plain, the terrain is a bit more rolling than strictly flat.

Also, I hardly ever tow any faster than 65 MPH. So a sustained 3000 RPM is ok for this engine?

 

[ralmo94]

3k is fine as long as you have good oil. Lots of opinions on that, but I had a GM calibration engineer tell me that the best thing to run in these is 10w30, and that aligns with what my own research is. That's what I personally run, and I don't change my oil on intervals, I check my oil Everytime I get gas, and when it starts getting dirty I plan an oil change.

so there will be some steep grades.

Advice I have for that is if you are on the stock tune, be careful about sustained 2nd gear pull with the tc unlocked. Heats atf up. I don't remember for sure, but I think if you pull the shifter to 2nd it should lock the Tc?

I have 2 shift schedules in mine. And both keep it locked in second over like 2300 or so rpm if I remember correctly.

I have a toggle switch hooked to ground out the cruise control pin at the PCM so I can use cruise shift as another shift schedule. 0411 swap would give actual tow haul mode that changes line pressure and shift pressures.

Just be mindful that heat kills ATF. Keep it cool or keep it fresh.

 

[ralmo94]

Here is 4.10 245/75-16 vs
3.73 225/75-16
Looks like you are still a little lower than me about 4 or 5 mph at cruising rpm.

I couldn't imagine towing in 3rd unless I couldn't maintain speed in 4th.

You might get better mpg in 4th.

 

[South VA]

Here is 4.10 245/75-16 vs
3.73 225/75-16
Looks like you are still a little lower than me about 4 or 5 mph at cruising rpm.

I couldn't imagine towing in 3rd unless I couldn't maintain speed in 4th.

You might get better mpg in 4th.

Pretty sure I’d get better gas mileage in OD. My last tank while towing in 3rd was 7.6 MPG.

When he rebuilt the trans, he upgraded (at my request) the torque converter to a billet TC, which supposedly handles heat better than the stock version.

I’d certainly prefer to tow in OD. I’m just not sure what to do, given seemingly conflicting advice.

Anyway, I didn’t mean to get @BNielsen ’s thread off track. I was mainly curious about the 454’s most efficient rpm range.
Thanks!

 

[ralmo94]

I guess kinda back on track, lol, mine seems to do best between 2200-2400

 

[South VA]

I guess kinda back on track, lol, mine seems to do best between 2200-2400

Thanks!