Rev-limiter saved me on recent tow - when does it kick in exactly?

DaveS · 09-13-2005, 02:59 PM

Last Thursday, I towed 550 miles home from Lake Powell, Utah to San Diego, CA. This is the 6th time I've done this tow, all in 110 degree heat, with no problems at all - my oil, water, and tranny temp guages have never moved while lugging the 8,400 lb boat.

Climbing the steepest grade along the route (southbound I-15 just south of Primm, NV) I was watching the heavy traffic instead of the tach and was doing about 60 in 2nd gear, when the rev limiter kicked in and nearly gave me a heart attack. It felt like the engine just totally died. The RPM dropped to about 4000, then power was restored. Not a fun experience, but totally my fault.

Does anyone know at what RPM the limiter will kick in and how it works?

nthomp16 · 09-13-2005, 03:07 PM

I don't have an answer to your question, but I just wanted to say that is one beautiful boat!

DaveS · 09-13-2005, 03:21 PM

Thanks! I'll take you out for a ride if you pay for gas. It holds 120 gallons at $3.93 at the marina I visited. I can use a whole tank in just 1 day if we are skiing and tubing a lot.

**HudsonValleyTitan** · 09-13-2005, 05:03 PM

Quote:

Originally Posted by DaveS

Last Thursday, I towed 550 miles home from Lake Powell, Utah to San Diego, CA. This is the 6th time I've done this tow, all in 110 degree heat, with no problems at all - my oil, water, and tranny temp guages have never moved while lugging the 8,400 lb boat.

Climbing the steepest grade along the route (southbound I-15 just south of Primm, NV) I was watching the heavy traffic instead of the tach and was doing about 60 in 2nd gear, when the rev limiter kicked in and nearly gave me a heart attack. It felt like the engine just totally died. The RPM dropped to about 4000, then power was restored. Not a fun experience, but totally my fault.

Does anyone know at what RPM the limiter will kick in and how it works?

The rev limiter kicks in just a few hundred RPM below redline on our trucks. Next time, leave the shifter in 4th/or with TOW MODE on. It sounds to me like you had it in another, lower gear and were shifting yourself, otherwise it should have upshifted way before the rev limiter kicked in.

DaveS · 09-13-2005, 07:39 PM

I did have it in Tow Mode, but was shifting myself to hold it in 2nd for an especially long, steep grade. Totally my fault for not watching the tach while keeping the revs so high. I was finding that on this grade, even in Tow Mode, it would kick down to third too soon for me, and I'd loose speed that I'd never be able to get back.

Thanks!

**HudsonValleyTitan** · 09-13-2005, 08:48 PM

Quote:

Originally Posted by DaveS

I did have it in Tow Mode, but was shifting myself to hold it in 2nd for an especially long, steep grade. Totally my fault for not watching the tach while keeping the revs so high. I was finding that on this grade, even in Tow Mode, it would kick down to third too soon for me, and I'd loose speed that I'd never be able to get back.

Thanks!

Oh you'll get it back alright! Let the auto tranny do its' thing. It works. You may not get it up to 60 MPH, but it'll get you up to proper speed for the climb. Don't expect to ba able to do 75 MPH climbing a really long, steep uphill. If you had it in 4th and left it there, I bet it would have gone up that hill at the same speed you did while self shifting. If must have been doing ok because you hit the rev limiter.

PrerunnerGreg · 09-14-2005, 08:38 AM

THere's no way a titan would even pull that grade in 4th with that boat. may be thrid for most of the grade then into second towards the top. But its pretty cool that you could rev it that high, for that long, and still have no problems.

mopar · 09-15-2005, 09:03 PM

Quote:

Originally Posted by PrerunnerGreg

THere's no way a titan would even pull that grade in 4th with that boat. may be thrid for most of the grade then into second towards the top. But its pretty cool that you could rev it that high, for that long, and still have no problems.

When the titan is in 4th it just elimninates the overdrive(doesn't just stay in 4th gear) and shifts through the gears as normal but never going into OD. Tow mode adjust the shiftpoints for towing a load.

Austin · 09-16-2005, 12:15 AM

Quote:

Originally Posted by DaveS

Does anyone know at what RPM the limiter will kick in and how it works?

The rev limiter cuts fuel to each cylinder - just as if you took your foot off the throttle.

Don't worry about hitting the rev limiter. It's there to prevent engine damage.

**HudsonValleyTitan** · 09-16-2005, 02:15 PM

Quote:

Originally Posted by PrerunnerGreg

THere's no way a titan would even pull that grade in 4th with that boat. may be thrid for most of the grade then into second towards the top. But its pretty cool that you could rev it that high, for that long, and still have no problems.

It'll pull it just fine but you're right......it'll shift between 2nd and 4th accordingly and it'll never hit the rev limiter.

SoulFish · 09-16-2005, 02:55 PM

2nd or 3rd maybe.... I tow a 6,500lb boat You definatly feel it on the grades!

aztitan4x4 · 09-16-2005, 07:47 PM

My toyhauler is about 9k loaded and on the steep grades in AZ I also have to hold in 2nd gear or I will lose momentum that I couldn't get back once it shifts to 3rd. I've also found that manually shifting it from a stop to cruising speed seems work better than letting it shift on it's own.

RockyMtnTitan · 09-17-2005, 12:08 AM

Quote:

Originally Posted by Austin

The rev limiter cuts fuel to each cylinder - just as if you took your foot off the throttle.

Don't worry about hitting the rev limiter. It's there to prevent engine damage.

Exactly! You guys ever been to the track when the little ricer compacts are in the burnout pits? All you hear is spit/sputter from the rev limiter constantly cutting fuel.

I've hit my rev limit a couple times while doing WOT filter/intake tests....I'm glad it's there. Now when I get a set of performance cams someday....then the rev limiter may be a problem.