Pulling a 6000 pound trailer what is the maximum rpm’s on my 4L 80 E in third gear would be suitable for this motor?

[1993 chevrolet 2500 four]

Pulling a 6000 pound trailer 1993 2500 extended cab with a 4L 80 E motor has 269,000 on the odometer what would be a safe high rpm for pulling hills with this motor seems to run out real well. I replaced water pump with a high output replaced with a Duramax fan aluminum radiator 4 inch exhaust can I use Amsoil 1540 change oil every 3000 miles. What would be the maximum rpm for pulling this load up a grade? I never run it much over 2200 the temperatures don’t get much above 170 but I did pull a small grade recently and the temperatures got to about 195 would it be safe to run this thing at 230pulling a grade? Thanks for any help!

 

[Stoney]

If your talking about 230 degrees. HELL NO. . Don't even think about it..your engine will be toast..210 your kinda ok...215 stop at a church and pray for her...220 she's in trouble get her pulled over I don't care where you are... Personaly, I've always been told when it gets way to hot, not to shut it off , just park it and let her idle till she cools off...if it usually runs at 170 or so the thermostat has probably been replaced with lower opening ones..they usually run closer to 190-195 iirc. Do you have dual thermostats or single?...can be converted to dual with a trip to the junk yard pretty cheap.... remember though, these are Chevys, the temp gauges are notoriously unreliable...better to get a external temp gauge... As for rpms. I'll let others give you more advice, they will definitely chime in ,in the morning... My truck usually runs around 2500rpms doing around 70 or so...but in 3rd, she goes up to 3k rpms.. not saying that is ideal or not, but the other guys will direct you on that.

 

[Will L.]

Welcome.
Be is right on the temperature of 200 ok, 210. not good, 220 stop and idle.
160 is the point of being warm. I prefer 180, but 170 is ok. You might get better mpg towards 190, but you make the call if it’s worth it. If you can run 170- I wouldn’t change a thing.

factory turbo is at peak torque at 2200 rpm and that is where the engine is starting to choke at from air flow issue of too small turbo.
3,000 rpm is ok but doesn’t promote longest life. I can’t remember where the governor is set for your db2. Depending how much longer your gonna tow that kinda weight- a bigger turbo can pay for itself. There is a guy on here who has a great towing turbo used that ya might consider. He did his truck (I think 93 also) in the magazine describing the issue. @WarWagon care to post the article for him? Did you sell off your ATT yet? There are plenty of new options out there also obviously.
As to real top rpm for the transmission, this same trans hits double what this engine can handle on its best day ever. Keep trans temps under 220 is optimum. Heat kills.

 

[JayTheCPA]

Welcome to TTS!

Stated weight is not much for the truck and maintaining temperatures should not pose a big challenge. Related, Stoney nailed the coolant temperature concerns and the need for an *external* gauge. Might consider installing a ECT sending unit in the head above the #8 (there is a plugged port at this location) and reading ECT from that location. If temperatures are hard to manage in this configuration (per an *aftermarket* ECT gauge), then it is likely the cooling stack needs more help.

The RPM question has a little more nuance than max. Too low hurts as well. Am presuming the focus here is climbing a grade with the load. Goal is to keep the water pump spinning fast enough so that enough coolant moves through the motor to effectively shed heat. Back to the low RPM comment, with the '99, I found that the OE programming allowed the RPM's to drop far too low to allow good coolant flow, so I manually kept them above 2,200 when pulling up a grade.

Running up a hill or steeper grade in Direct (aka 3'rd gear) is fine. Take it to redline if you want. The better question is whether the torque converter remains locked. When the TCC unlocks it will create more heat to shed. IIRC, it is possible to get a manual TCC lock for the '93. Granted, some will argue that letting the TCC unlock unleashes power, but I am seeing where this is only generating unnecessary heat when the vehicle is moving and the motor is above 2,000 RPMs.

While not part of the question, the comment on oil changes seems a bit frequent. Changing the oil every 3K miles is Ok, although I would consider getting inputs from oil analysis to see if that is too frequent.

 

[MrMarty51]

Welcome to thetruckstop.

 

[Stoney]

How rude of me..YES welcome to thetruckstop!! We're glad to have you.
@Will L. , This is a question about what you said...you said running at 170 degrees is ok, which like his truck that's about where mine runs with the newer thermostats.. question is didn't somebody say you have to get above 175-180 or something like that for something to lock up? I thought it was something to do with the tranny, but not sure. Please correct me if I'm wrong..

 

[ak diesel driver]

170* for TCC lock up

 

[Stoney]

Thanks AK, knew it was something like that. Just couldn't remember

 

[1993 chevrolet 2500 four]

If your talking about 230 degrees. HELL NO. . Don't even think about it..your engine will be toast..210 your kinda ok...215 stop at a church and pray for her...220 she's in trouble get her pulled over I don't care where you are... Personaly, I've always been told when it gets way to hot, not to shut it off , just park it and let her idle till she cools off...if it usually runs at 170 or so the thermostat has probably been replaced with lower opening ones..they usually run closer to 190-195 iirc. Do you have dual thermostats or single?...can be converted to dual with a trip to the junk yard pretty cheap.... remember though, these are Chevys, the temp gauges are notoriously unreliable...better to get a external temp gauge... As for rpms. I'll let others give you more advice, they will definitely chime in ,in the morning... My truck usually runs around 2500rpms doing around 70 or so...but in 3rd, she goes up to 3k rpms.. not saying that is ideal or not, but the other guys will direct you on that.

I have replaced the thermostat with a 180 I put the high output water pump 180 GPM I’ve also put a Duramax fan on it it’s got a newer aluminum radiator. I have also put a two row power fan on the transmission I put a fluid dampener on it and I’m running Amsoil 1540 synthetic

Pulling a 6000 pound trailer 1993 2500 extended cab with a 4L 80 E motor has 269,000 on the odometer what would be a safe high rpm for pulling hills with this motor seems to run out real well. I replaced water pump with a high output replaced with a Duramax fan aluminum radiator 4 inch exhaust can I use Amsoil 1540 change oil every 3000 miles. What would be the maximum rpm for pulling this load up a grade? I never run it much over 2200 the temperatures don’t get much above 170 but I did pull a small grade recently and the temperatures got to about 195 would it be safe to run this thing at 230pulling a grade? Thanks for any help!

thankyou! For all your advice, much appreciated

 

[1993 chevrolet 2500 four]

I have replaced the thermostat with a 180 I put the high output water pump 180 GPM I’ve also put a Duramax fan on it it’s got a newer aluminum radiator. I have also put a two row power fan on the transmission I put a fluid dampener on it and I’m running Amsoil 1540 synthetic

thankyou! For all your advice, much appreciated

Welcome to thetruckstop.

Mr. Marty thank you for all your assistance I truly appreciate it respectfully

 

[1993 chevrolet 2500 four]

Mr. Marty;
Thank you for your advice and your assistance I appreciate it very much respectfully harry

 

[WarWagon]

The auto trans wants to rev up. GM's engines for these years choked at higher RPM. The airflow abortion and awful small turbo... You are hitting a brick wall over 2200 RPM. Any throttle and the shift happy trans revs up the engine to nowhere. The thing that's hard to wrap one's head around is this IS a HIGH SPEED DIESEL. The HP doesn't back up the TQ at low RPM. It's night and day with a bigger turbo and the engine actually pulls HARD from 2000 RPM till past redline. (A Cummins diesel is different where you have more power at a lower RPM.)

After X time temp or whatever with foot on the floor wound up in 3rd gear the TCM will lock the converter back up to stop the heat rise. The TCC clutch is weak IMO and a better triple disc converter helps. You actually can slip the converter clutch at low lugging RPM vs. higher RPM. I attempted to lock mine at 35 MPH as GM doesn't lock till 45MPH.

You dealing with hills out east or grades out west?

What are you running for a fan clutch? The KD low temp unit?

The 6.5L Diesel Factory Equipped Asthma Attack

Online Diesel Community featuring news and articles on 6.2L, 6.5L and Duramax GM diesel engines, Ford Powerstroke, Chevy Cruise, lubrication and more.

www.maxxtorque.com

 

[1993 chevrolet 2500 four]

The auto trans wants to rev up. GM's engines for these years choked at higher RPM. The airflow abortion and awful small turbo... You are hitting a brick wall over 2200 RPM. Any throttle and the shift happy trans revs up the engine to nowhere. The thing that's hard to wrap one's head around is this IS a HIGH SPEED DIESEL. The HP doesn't back up the TQ at low RPM. It's night and day with a bigger turbo and the engine actually pulls HARD from 2000 RPM till past redline. (A Cummins diesel is different where you have more power at a lower RPM.)

After X time temp or whatever with foot on the floor wound up in 3rd gear the TCM will lock the converter back up to stop the heat rise. The TCC clutch is weak IMO and a better triple disc converter helps. You actually can slip the converter clutch at low lugging RPM vs. higher RPM. I attempted to lock mine at 35 MPH as GM doesn't lock till 45MPH.

You dealing with hills out east or grades out west?

What are you running for a fan clutch? The KD low temp unit?

The 6.5L Diesel Factory Equipped Asthma Attack

Online Diesel Community featuring news and articles on 6.2L, 6.5L and Duramax GM diesel engines, Ford Powerstroke, Chevy Cruise, lubrication and more.

www.maxxtorque.com

 

[1993 chevrolet 2500 four]

I’m not certain I bought the clutch and fan assembly as a unit the Duramax fan I will when I get back to town if it doesn’t implode look into changing the impeller on the turbo and look into a clutch assembly recommended by some of the other gentleman that have contacted me I appreciate your reply. I’m coming up out of Laughlin Nevada Highway 162 coming up out of Laughlin Nevada Highway to hwy 95 heading north to Las Vegas final destination Spokane Washington respectfully harry

 

[DieselAmateur]

Welcome!

Just my 2 cents, already been said but next best upgrade for you is a turbo. Don't waste time trying to change parts on the factory unit. I've never run an ATT but from personal experience have been quite happy with the towing turbo from @uniquediesel. Other folks have run Holset turbos with positive results. Also on the subject of air, upgrade the crossover pipe to the single wall 2.5" diameter. Factory crossover was smaller and could collapse in on itself from the inside with no way of noticing from the outside. And not sure what your air intake system is, but best is cold air intake form the hole in the fender. Sucking in hot underhood air through any filter is not in the best interests of your engine.

 

[Stoney]

@1993 chevrolet 2500 four . Are you a fellow hotshot driver? Or towing for yourself?.

 

[WarWagon]

You are in my backyard... Been there and delivered that.

Many turbo's out there now, but no, there is nothing that can be done to the exhaust side restriction on a GM turbo to help it. Well other than removing it for something else that's bigger. The exhaust side restriction is what is keeping the heat in via back pressure and the engine is breathing through a straw. A new compressor wheel may make some difference, but, better choices out there that can pay for themselves and solve the hot side bottleneck. You use a GMx turbo modified or otherwise when you have no other choice like a Hummer. I HATE the damn GMx as it cost me a small fortune in diesel fuel that came off my bottom line.

If you are towing a lot vs. a daily driver makes a difference on what turbo you should use. Towing 550 miles a day I didn't care much about getting out of the hole so I went with a big towing turbo that was one of two or three options available. I needed power on the long grades and esp. MPG. Even slow out of the hole picking up 10 MPH on the long grades made it faster at the end of the day. I solved the out of the hole problem with a high stall converter.

Maybe I should have answered your maximum rpm question like this. This is on a small 6.2 pump with No Smoke. It could have been quicker with a 6.5 pump.

 

[1993 chevrolet 2500 four]

Welcome!

Just my 2 cents, already been said but next best upgrade for you is a turbo. Don't waste time trying to change parts on the factory unit. I've never run an ATT but from personal experience have been quite happy with the towing turbo from @uniquediesel. Other folks have run Holset turbos with positive results. Also on the subject of air, upgrade the crossover pipe to the single wall 2.5" diameter. Factory crossover was smaller and could collapse in on itself from the inside with no way of noticing from the outside. And not sure what your air intake system is, but best is cold air intake form the hole in the fender. Sucking in hot underhood air through any filter is not in the best interests of your engine.

The airbox is the factory box that goes through the fender I believe the factory downpipe crossover is a 2 1/2 and when I got home I was going to upsize that two or three. Upgrade the turbo it’s run out real good so far the temperatures were always remained about 170 but I pulled her grade coming into Bullhead city NevadUpgrade the turbo it’s run out real good so far the temperatures were always remained about 170 but I pulled her grade coming into Bullhead city Arizona and I noticed the temperature rise to about 190 to 195 I have Highway 162 which is the highway back out from Laughlin Nevada to Las Vegas and my plans are I’m just gonna manually lock it out of overdrive and run the great at third gear to about 2200 RPM keep my eyes crossed. Say my prayers and hope for the best. Thank you for all your information I certainly appreciate that.
Respectfully
Harry

 

[1993 chevrolet 2500 four]

You are in my backyard... Been there and delivered that.

Many turbo's out there now, but no, there is nothing that can be done to the exhaust side restriction on a GM turbo to help it. Well other than removing it for something else that's bigger. The exhaust side restriction is what is keeping the heat in via back pressure and the engine is breathing through a straw. A new compressor wheel may make some difference, but, better choices out there that can pay for themselves and solve the hot side bottleneck. You use a GMx turbo modified or otherwise when you have no other choice like a Hummer. I HATE the damn GMx as it cost me a small fortune in diesel fuel that came off my bottom line.

If you are towing a lot vs. a daily driver makes a difference on what turbo you should use. Towing 550 miles a day I didn't care much about getting out of the hole so I went with a big towing turbo that was one of two or three options available. I needed power on the long grades and esp. MPG. Even slow out of the hole picking up 10 MPH on the long grades made it faster at the end of the day. I solved the out of the hole problem with a high stall converter.

Maybe I should have answered your maximum rpm question like this. This is on a small 6.2 pump with No Smoke. It could have been quicker with a 6.5 pump.

Thank you for all your information I truly appreciate it
Respectfully
Harry

 

[WarWagon]

2200 RPM is merely peak torque. Use all 4 gears. If you are at 2200RPM 62MPH and foot to the floor you should be ok. I found 3RD just slowed me down with a steady headwind and slight grade. I ran a little faster in 4th at times vs. higher RPM in 3rd. You will notice at around 60 MPH it won't downshift out of OD by throttle position easy. So when I forced it to 3rd it just slowed me down.