8.3 Cummins fuel plate for more power

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8.3 Cummins fuel plate for more power

May 31, 2021, 10:36:38 am

Anyone moved the stock fuel plate on the Bosch pump all the way forward to add more fuel with results? I know a pyrometer is needed as well. Injector changes? Turn the pump up with timing? Looking for about 50 more HP for the mountain passes without hurting the engine. When pulling my cargo trailer (5000lbs) it could use a boost. Besides that situation, love the 8.3.
Happy Memorial Day and thankyou to all the families who sacrificed a loved one

Re: 8.3 Cummins fuel plate for more power

Reply #1 – May 31, 2021, 10:59:03 am

In the early 70's it was common for us to take a smaller engine and turn on it for more power.. Putting a "turned up" engine in mountain elevations with thin air and expecting to be able to stay on the throttle enough to benefit from the added power is very risky.. We ended up buying bigger engines after the damage was done. My opinion is learn to live with what you have or buy bigger and operate within specifications.

Re: 8.3 Cummins fuel plate for more power

Reply #2 – May 31, 2021, 11:07:04 am

With our 350 and the Banks Stinger this is what we like when climbing mnts etc. I was pulling a Dodge Durango that was also close to 5k and we still had lots of power but did gave to watch the Pyro when climbing. They do not make them any more for this engine. It definitely is a plus having it
Johnh

Re: 8.3 Cummins fuel plate for more power

Reply #3 – May 31, 2021, 11:35:27 am

If there was a reasonably priced, reliable, safe way to increase the power of the Cummins C8.3 every motorhome owner with that engine would be waiting in line to buy it. I don't know why Banks dropped out of that market but they probably had a good reason. EPA regulations? I will be happy to stand by and watch as you experiment on your engine. Please keep us advised of your mods and publish the results. Good luck!

Re: 8.3 Cummins fuel plate for more power

Reply #4 – May 31, 2021, 11:52:02 am

Quote from: dans96u295ft – May 31, 2021, 10:36:38 am

I know a pyrometer is needed as well.

TST Power Kit Cummins 8.3 6CTA

Re: 8.3 Cummins fuel plate for more power

Reply #5 – May 31, 2021, 12:12:22 pm

EPA does not like "rolling coal" and for a good reason. We did turn up he pumps when we put turbos on the 300Ds but not to a point where they made any smoke. With a mechanical 4 cycle, you would need to have a pyrometer with a adjustable warning light. High altitude with high temperatures can make for high EGTs. Sea level EGTs are going to be less, perhaps, much less. And just because the road sign says 8,000 feet, in hot weather, the density altitude can be much higher with accompanying even lower efficiency of the radiator, fan, intercooler, etc. The mechanical injection pump keeps putting out the fuel but with fewer O2 molecules in a given space, the temperature goes up.

Damage from high EGTs is cumulative and may not seen for thousands of miles. Any failure of an internal engine component is going to cost $30K unless you can do the repair yourself.

Later electronic 8.3 engines fitted to the newer motorhomes may produce 380 hp but the computer with all it's sensors more closely monitor the internal temperatures and make a failure less likely plus the motorhome manufacturers work closely with the engine makers to keep all temps within specs.

Make sure the air cleaner is not restricting the intake as that can cause higher EGTs. Plus, make sure the intercooler is bug and dirt free. Higher RPMs by downshifting on grades also lowers EGTs.

Pierce

Re: 8.3 Cummins fuel plate for more power

Reply #6 – May 31, 2021, 03:15:44 pm

Get an EGT gauge to know where the limit is. I'd suggest going to an aftermarket plate instead of just moving the stock one. Look up Dynomite Diesel Performance out of Idaho. Not sure if they still sell the plates or not, but I'd think they do.

Aneroid setting will control the responsiveness vs. smoke, so no need to "roll coal." The 8.3 likely has a Holset HX-40, which is a good turbo to about 38psi or so.

Re: 8.3 Cummins fuel plate for more power

Reply #7 – May 31, 2021, 09:03:43 pm

Mechanical injection pumps used to have a user setting for altitude but the later pumps either have a Booster Aneroid or a Altitude Compensator. In an older coach, these should be checked for proper operation. If you are blowing black smoke up at altitude, it's not working correctly. EGTs will also be high.

Banks partial quote:
So the big question is, what constitutes excessive EGT? If everything is working properly, 1250º to 1300º F. is a safe turbine inlet temperature, even for sustained running, mile after mile. Above 1300º F. things can start to get edgy. Remember, excessive EGT damage is cumulative. Over 1400º F., you're usually gambling against a stacked deck and it's only a matter of time until you lose. The higher the EGT, the shorter that time will be. Note: post turbo probe will indicate 200-300 degrees less.

Pierce

Re: 8.3 Cummins fuel plate for more power

Reply #8 – May 31, 2021, 09:54:31 pm

Been my speriance from driving hot rodded 12-71Ts and 855" NTC Cummins back in the 70s, if your not real careful you'll need to get your wallet out much sooner than later. I've killed a few.

Re: 8.3 Cummins fuel plate for more power

Reply #9 – June 01, 2021, 08:04:51 am

This is a timely subject! I ordered a TST kit a few months ago. I likewise had tried researching and only found one series of posts on a Monaco forum of a member who added the TST kit. He added the 150 hp kit and have been running it for 40k miles with no problems.

I called and talked to TST and really seemed quite confident that the 8.3L would be ok just need to have the gauges. I have all my gauges purchased, just trying to get the time to install it. I bought the 150 hp kit. TST really pushed this kit since it was the most noticeable power increase and according to them safe to run.

I also fully understand everyone's point to leave enough alone. I have been down this road a few times. I have owned the 8.3L in the past and always left it alone. Some reason..... this time I have this crazy idea to take this light 36ft GV and make it a little rocket. There is truly danger if not watched carefully. I would just like to see how it performs and watch to see what numbers the EGT gets to. I hate to be the test bed, even worse hate to have problems. I think I'm more concerned about the Allison, even though TST said it would be fine to.

I don't know why TST would sell something that would not be unsafe... right. Lol . Maybe almost seems to good to be true. The kit is cheap for the results you are supposed to achieve. The gauges cost me more. Just doesn't seem that TST is trying make a fortune on this kit.

I'm sure many will want to hear the results, as I get this accomplished I will post my findings.

Re: 8.3 Cummins fuel plate for more power

Reply #10 – June 01, 2021, 09:28:27 am

John, there isn't much in the kit so $199 is fair. I hope you do it soon and report back. As soon as I find a qualified mechanic, I will have the same kit installed. I have one in my 5.9 Cummins pickup (1997) 12 valve and have never had problems other than the NV4500 tranny being the weak point. 3rd tranny in 110,000 miles but that's not because of the fuel plate. My issue is a confident mechanic on an older, mechanical engine!

Re: 8.3 Cummins fuel plate for more power

Reply #11 – June 01, 2021, 09:29:40 am

As horsepower increases reliability and longevity decrease,no getting around it,your right,TST is not going to say it's unsafe.
PS,why all the tranny trouble,may need to try Amsoil synthetic.

Re: 8.3 Cummins fuel plate for more power

Reply #12 – June 01, 2021, 10:02:04 am

Those 8.3's make a lot more hp in marine trim... I suspect the street rating is a combination of emissions and cooling system limitations, although an 8.3 foretravel has the same radiator as a M11 so youre probably fine on cooling as well.

I suspect you could easily get 50-100 more hp without rolling coal or harming the engine. I wouldnt hesitate to do so if I had the 8.3. I roadtripped with a 8.3 U270 and he would always lose steam going up hills where my larger cat would keep pulling. It was pretty amazing, we could maintain the same speed for 100 miles until we got to a relatively large hill/mountain and my u300 would just pull away as he slowed

Re: 8.3 Cummins fuel plate for more power

Reply #13 – June 01, 2021, 10:34:40 am

In marine use, our engines will produce a lot more power. But there is unlimited cooling and the prop is sized for best performance while keeping all temps/readings within specifications. A high HP marine version in an RV could generate a large amount of heat and high EGTs in a very short time pulling grades, especially at lower RPMs.

Our 350 hp Detroit 6V-92TA is typically 535 hp in marine use with 620 hp seen in some boats. The down side is that at 535 hp, the TBO is about 2200 hours. At 620 hp, some do fail before normal TBO. Increasing horsepower will shorten the TBO along with the B10, B50 life.

TBO: Time Between Overhauls

B10, B50 engine life:

B10 Engine Life
The expected engine life, measured in miles of operation, before 10 percent of all engines in operation will require major repair(s), overhaul, or replacement.
Example: The 7.3L Power Stroke has a B10 life of 200,000 miles. Therefore, 10 percent of all engines in operation can be expected to require an overhaul at/near 200,000 miles.

B50 Engine Life
The expected engine life, measured in miles of operation, before 50 percent of all engines in operation will require major repair(s), overhaul, or replacement.
Example: The 5.9L Cummins has a B50 life of 350,000 miles. Therefore, half of the engines in operation can be expected to require an overhaul at/near 350,000 miles.

Pierce

Re: 8.3 Cummins fuel plate for more power

Reply #14 – June 01, 2021, 03:38:37 pm

Quote from: John hobbs – June 01, 2021, 08:04:51 am

I'm sure many will want to hear the results, as I get this accomplished I will post my findings.

Best of luck John. Installing a cam plate isn't a big deal as long as it's not a bear to get to the top of the fuel pump. In a former life, I worked for a company that built cam plates, injectors, etc, and made BIG HP with the little 5.9l Cummins in the pickups. My daily driver was over 500hp/1100ft-lbs since I bought it at 39k. Had 190k on it when I sold it and still ran great. The 8.3 is a good engine as well and will take to upgrades well. Here was our page about the motorhome 8.3 upgrades back in the day on archive.org: web.archive.org/web/20060512141257fw_/http://www.dieseldynamics.com/mhkits.htm

50hp/100ft-lbs from the cam plate. The higher level upgrades included modified fuel injectors.

As was mentioned previously, the EGT gauge is the key. Install and see how hot the EGT gets now, with the pyro probe in the exhaust manifold before the turbo. Clearly that max EGT is safe. We found 1250*F continuous was the limit, but transients could be quite a bit hotter for quick bursts like getting up to speed on an on-ramp, etc. If yours will only get to 1100 now, you've got some room for more power/fuel (heat). Turning the boost up will also help EGT's. Likely the TST kit will come with a "boost elbow" which will bleed some boost off going to the wastegate actuator, to increase boost and help those EGT's.

Re: 8.3 Cummins fuel plate for more power

Reply #15 – June 01, 2021, 08:11:54 pm

Yep if your going to add fuel, you'll need air to burn it. Getting rid of the trash can muffler may help as well.

Re: 8.3 Cummins fuel plate for more power

Reply #16 – June 02, 2021, 08:35:40 am

Might be a good idea to, when boosting hp on a 20+ year old engine, to keep in mind when comparing it to a dodge pickup bump that in order to be a legitimate comparison the pickup needs to be 20 years old and attached to a 20K lb trailer, full time.

Probably be a good idea to stack the deck a bit by going through the cooling system, including pressure test of CAC, ,add boost gauge, inspect and clean radiator etc. Gotta say, thoughthat another 50 hp or so would be very welcome, and wish you success.

Re: 8.3 Cummins fuel plate for more power

Reply #17 – June 02, 2021, 10:24:47 am

Yes, my Pickup is a 1997 and I actually did pull 16000 to 18000 on a regular basis. Egr's never went higher than 1150. Good point however

Re: 8.3 Cummins fuel plate for more power

Reply #18 – June 02, 2021, 10:40:37 am

Quote from: dans96u295ft – June 02, 2021, 10:24:47 am

Yes, my Pickup is a 1997 and I actually did pull 16000 to 18000 on a regular basis. Egr's never went higher than 1150. Good point however

But where was your probe located, exhaust manifold or at the turbo discharge side? 1150 degrees plus 200° is 1350° and plus 300° is 1450° .

So many people are afraid the probe will melt and destroy the turbo if the probe is installed in the exhaust manifold. It won't.

Pierce

Re: 8.3 Cummins fuel plate for more power

Reply #19 – June 02, 2021, 11:53:33 am

Quote from: Pierce & Gaylie Stewart – June 02, 2021, 10:40:37 am

So many people are afraid the probe will melt and destroy the turbo if the probe is installed in the exhaust manifold. It won't.
Pierce

The probe should be mounted in the exhaust manifold, before the turbo, for "performance" measurement applications. I can't see how someone could think that a type-k thermocouple, which has a range of measurement up to 2500*F, would melt before the pistons.

Re: 8.3 Cummins fuel plate for more power

Reply #20 – June 02, 2021, 12:02:36 pm

Quote from: WS6_Keith – June 02, 2021, 11:53:33 am

The probe should be mounted in the exhaust manifold, before the turbo, for "performance" measurement applications. I can't see how someone could think that a type-k thermocouple, which has a range of measurement up to 2500*F, would melt before the pistons.

Old wives' tales die hard.

P

Re: 8.3 Cummins fuel plate for more power

Reply #21 – June 02, 2021, 12:24:12 pm

More likely is damage caused by poor procedure drilling the hole for the thermocouple (metal shavings falling into the exhaust pipe and being ingested by the turbo).

Re: 8.3 Cummins fuel plate for more power

Reply #22 – June 02, 2021, 10:54:52 pm

Talked to TST the maker of the fuel plates today. He told me to get a pyrometer installed first and see where the stock egt's are then decide on a fuel plate rating. You can mount your probe in the exhaust elbow to avoid filings in the turbo but add 250 degrees to the reading. SO. That's what I will do!

Re: 8.3 Cummins fuel plate for more power

Reply #23 – June 03, 2021, 08:53:28 am

I'm having trouble seeing much danger for turbo damage from a few specks of iron shavings.. Exit for them is through the hot section of turbo and expect they would be ejected into exhaust a few milliseconds after engine is cranked.

Between running vacuum while drilling, and a small fishing magnet, non issue.

Re: 8.3 Cummins fuel plate for more power

Reply #24 – June 03, 2021, 10:28:38 am

Chuck is right. Put some grease on the drill bit and go slow, and do the same for the tap. If you really want to make sure it's clean, hit the hole with a shop vac when you are done.

Pre-turbo vs post-turbo EGT can vary dramatically. When we used to test this, we could see from nothing (at low boost/drive pressures) to as much as 400*F temp differences. This is why my EGT thermocouple is in the exhaust manifold...where the quick transient heat measurement will be...between the engine and the cork (turbo). The higher the drive to boost pressure ratio, the larger the difference in EGT measurements generally. For performance applications, make SURE to install it pre-turbo.

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