ETH Governed at what RPM's? (Had a little race today)

[Shelby Griggs]

Got in a race with a sooper duty today. I was first in line at a left turn signal. Light turns green. I guess I was too slow for the PSD behind me. This is in town in a 35 zone, and he decides to pass on the right. That pushed my buttons the wrong way. I nailed it, and started rowing through the gears. Too much traffic, so no one really won, but we were side by side up to about 50 MPH when I nailed the brakes. OK, now the question. I assume the Cummins is governed at some RPM. Let me put it this way, this was definitely the most R's this Cummins has ever seen. I looked at the tach once, to see it in the 3000+ range, but I was mostly watching traffic and shifting when it sounded like it had had enough! All you racers out there, can you hurt the Cummins racing like this, as long as it is under load? Don't know what came over me, I usually drive moderate, some would say slow. I guess it was just the thought of this guy passing me on the right. Only got 3000 miles on it, if that influences the wisdom of red line shifts!!

Shelby

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2001. 5 2500 QC LB 4WD, ETH, DEE, 3. 54 gears, Laramie SLT, Camper Special, Trailer Tow, Travel Convenience Group, Power Driver Seat, Alarm System, Remote Keyless Entry, Fog Lamps, Cab Clearance Lamps, HD Transfer Case, Bright White with a Gray Interior. Built 09-15-00, took delivery on 10-06-00, 1749 miles as of 11-25-00. Custom aluminum work body / flat bed. Coming soon: E-Brake and gauges.

 

[HVAC]

You better throw a set of injectors in that engine if your going to toy with those "Landshark PSD's"! #ad


My truck will go to 3500 rpm's @ 120 mph. At that point the fueling is shut off.

Regarding rpm's, we shift at 2800 at the strip. You will see defueling over 2700 and the torque peaks before you hit 2000.

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Nowel/Performance Diesel

 

[Shelby Griggs]

Nowell,

Being new to the upper side of the tach, I wasn't sure if I could overrev the ETH or not. Sounds like not, as it will defuel before that happens.

Probably leave the thing stock, at least for awhile. Not really into racing, this just happened, because I did not like the attitude of the PSD driver, at least I thought I would make him work to pass me. It is funny, since I added the flatbed, I get a lot of people automatically thinking they are going to be stuck behind some big lumbering truck.

I had visions of the engine grenading as I hammered it into uncharted territory.

Shelby

 

[Old Account - 243]

Nowell-

TXRam let me try out his EZEdge for a week so we piggybacked with my PE. As you know, the stock clutch won't hold the combination reliably even when the PE is on Level 1 at lower rpm's.

I went out of town for a day and on the way back, a Z71 extended cab 4x4 wanted to play. I had left the PE on Level 3 for exactly this reason #ad
It was about 11:00pm and the freeway was wide open as far as I could see (no cars). He goosed it while going about 70mph so I rolled on the throttle and flat blew his doors off to a tad over 120mph @ 3600rpm. He caught back up and gave me a thumbs up... I really don't think he expected me to walk away like that.

I like the PE for the low end power; however, the top end is where the fun is. I wish I had the money for a clutch to hold the full power of the two boxes.

243


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99 QC 2500 ST 4X4 SB 24V/5speed 3. 54/LSD Driftwood/Agate
Walker 21468, VDO, Bridgestone 285/75/16 MT's, RS9000's, Hella 500's

-- email address removed --

 

[Jeff Clark]

Shelby, you shouldn't have problems at redline. You will run into problems at the 4000 rpm range which won't happen unless you downshift. The governer doesn't work backwards, at least not on my 98. The highest rpm I've seen is 4100. Pretty close to piston-valve contact.

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98. 5 3500 QC 4x4, Driftwood/Mist Grey, 5 spd, 3. 54, 19. 5 Alcoa's, Ranchhand bumpers, DeeZee toolbox, "Scotty Air", TST PowerMax2, VA, 275's, Autometer Gauges, Centerforce clutch, Upgraded fuel lines (JRE and Aeroquip), MagHytec Diff Cover, PacBrake, Cowl Induction Hood

 

[cjackg]

sounds like a case of "Road Rage"

Maybe a 12 Ga Shot Gun is the answer!

 

[jmeehan]

I was in a similer situation last month with my ETH (with only 2200 miles on it). A gasser Dodge pulled up along side me at a light and revved his engine, so I figured he wanted to play. I wanted to see how things went so I nailed it and shifted when it sounded like it needed it. I never heard those sounds out of my engine before or sense, it worried me a little. Anyway when I looked at the dash I was doing 40 in a 25 and had gotten my doors blown off. The gasser had a chipped 360 with duel exhaust. I think I could have caught him if it weren't for the speed limit.

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'01. 5 2500 4X4 QC LB ETH/DEE SLT 3. 54, Patriot Blue

 

[sport bike]

Worried about break in. My truck was on the dyno with it,s first fueling box at 900mi. When i drove 18wheelers you broke them in by hooking up to a trailer,letting the clutch out and nailing the petal to the floor.


HVAC is right,shift it at 2750 or so. Lets you use more of that cummins torque.

 

[Vaughn MacKenzie]

I have seen a video taken of Pier's instrument panel during one of his burnout sessions. He was cranking his 12-valve at 3900-4200 RPM for seconds on end. I've heard Dave Mithell runs his to 6000rpm, but I don't know if that is true or not--that is insane RPM for a long-stroke heavy rod & piston diesel.

Vaughn

 

[sport bike]

Thats because there 12v,ers. The 24v trucks are limited to 2750 by the ecm. There is no way around that with out reprograming the ecm.

 

[Shelby Griggs]

Sport,

I respectfully will disagree. During my little incident, I saw my tach at around 3000 RPM. I don't have a service manual, but I am quite sure the 24V will exceed 2750 RPM before being governed. It may have already started de-fueling, but it will rev higher.

Shelby

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2001. 5 2500 QC LB 4WD, ETH, DEE, 3. 54 gears, Laramie SLT, Camper Special, Trailer Tow, Travel Convenience Group, Power Driver Seat, Alarm System, Remote Keyless Entry, Fog Lamps, Cab Clearance Lamps, HD Transfer Case, Bright White with a Gray Interior. Built 09-15-00, took delivery on 10-06-00, 1749 miles as of 11-25-00. Custom aluminum work body / flat bed. Coming soon: E-Brake and gauges.

 

[Piers]

4000 rpm is insane??? My friends always told me I was crazy, #ad
didn't realise I had gone insane though #ad

 

[sport bike]

Take your truck and dyno it. Peak hp will be at 2750. After that the ecm slowly starts to defuel the truck. You will see it on the dyno sheet. At 3000 the defueling is much greater. After 3200 it all over. A total waste of time because you not making any hp.


Piers,

The 24v don,t have to turn at those kind of rpm to make good hp.

 

[Joseph Donnelly]

Piers and I have our 12 valve Rams governed to 4000 rpm. Since the tach quits there, the engine must not be revving any faster, right #ad


4000 is not insane, just earnest. It is only 2000 injection pump rpm, and we know 2000 rpm is safe. #ad

 

[tmacc]

Shelby, I have to agree with you. When I was checking the rpm drop between shifts on my auto trans I kept waiting for the shift to 4th when I noticed, OOPS, I had the OD off. The tach definitely went over 3000 rpm. It sure seemed like it was pulling pretty hard up the that point. Still, It's not something I want to repeat anytime soon. It was kind of noisey.

 

[Archive]

I run my lil ol ETC up to 3000rpm all the time, its fun and loud. Lets just say I like to take off fast #ad
People next to me get kinda scared sometimes tho... ... . Peak HP is 2700rpm. I have no worries about running the rpms up, that is what the engine is designed to handle.

 

[jkern]

the best way to tell what rpm that your truck is governed at is to check it. the book for the '99 ISB says 3400rpm, limited by the ECM. i checked mine by finding an empty flat parking lot(must be flat or slightly uphill so the weight of the truck doesn't overspeed the engine) putting it in 1st or 2nd gear and flatten the smoke pedal. the tach will climb to 3400rpm and thats all. you will also notice that the engine will sound different when running up against the govener, and when on the road, it doesn't feel like it has a lot of power above 3000rpm, because of the ECM defueling the engine to save the drivetrain from damge.

it should also be noted that a long stroke engine such as most production diesel engines were not designed for high rpm speed, but rather low rpm torque and power

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Jeremy Kern
1999 2500HD 4x4 QC,SB, ISB, 5spd, 3. 54LSD, 33x12. 50 cooper STT's Denver off-road bumper with Ramsey RE12000, PIAA series 520, Rancho RS9000's, heavy ft. springs, and a bunch of other little things!

 

[sport bike]

Usually the biggest problem with high rpm on a long stroke motor is high piston speed. That usually causes excessive piston skirt and cyl wall wear. The other problem is if you don,t liten the rotating assembly it,s hard on the rod bearings. Some motors have a problem with blowing head gaskets caused by excessive piston speed. The cyl sleeve actually starts to move up and down with the piston.

 

[Big-D]

Shelby... how many cones did you lose off the back end?

 

[Shelby Griggs]

Originally posted by Big-D:
Shelby... how many cones did you lose off the back end?

LOL, none, they have a padlock holding them down.

Shelby