Boost increase on ISC-350 by adjusting wastegate

[imnprsd]

randomledder: You are looking at a ceramic compressor wheel that was the last Cummins shipped in their 2003-ISC-350 engines. And it's not uncommon for pits like this to occur.

Cummins, Colburg Oregon told me I needed a new turbo in 2015 at 72,000 miles. I said no to the $4,500 price tag, because my engine tested very well when they did a "back pressure test" and because I was getting 24PSI of boost.

Now I have 104,500 miles and my engine is running very strong (before and after I added the Ag-Diesel Performance Module) and it only burns ~1 quart (and I don't mean 1-gallon) of engine oil every 4,000 miles (and this includes climbing grades).

My only complaint is that I don't get more than 26PSI of boost at sea level and I think it's because my compressor wheel is a different type of compressor wheel than what everyone has -- who is getting 30+PSI of boost. IF ANY ONE HAS A PICTURE OF THEIR COMPRESSOR WHEEL TO SHARE THAT WOULD BE MUCH APPRECIATED!

[nehog]

Originally Posted by imnprsd

... IF ANY ONE HAS A PICTURE OF THEIR COMPRESSOR WHEEL TO SHARE THAT WOULD BE MUCH APPRECIATED!

I may still have my old compressor wheel, and will check and take a picture. Feel free to remind me if I forget. (Old CRS problem! )

[randomledder]

My apologies. I have never seen a ceramic compressor wheel in a holset turbo. I’m not sure why the ceramic flaking off would be acceptable when it is 100 X more abrasive than any aluminum from a comparable aluminum compressor wheel.

[Boe]

So I returned from my trip. The most boost I achieved was 32 psi with the boost fooler. I confirmed that with 2 separate gauges reading the same thing. What was more impressive was the Snow Performance Water/Meth injection system I installed Was able to keep EGT below 1250 at all times including large climbs all while outside temp above 105-112. I was able to maintain speed in the 60 going up these grades which I was never able to do even with my Banks System. I was quite impressed. Before I added this system I did install a FASS pump on my RV. I installed the FASS system on my RoadMaster chassis right next to the fuel tank. Now my system runs 4 fuel filters The 2 that come with the FASS system and the 2 on my coach. I did change up the filtering media as to not restrict flow. I also just put in a small delay in FASS pump coming on using a relay delay. But I can confirm no need to. And no need to turn off your factory lift pump. If factory pump working fine I say leave alone. The combining of pumps DOES NOT increase pressure you will only get 18-21 psi. If anything the FASS pump gets the lift pump priming done sooner My coach did fire up very quickly. I will get some pics and post. Very happy with system and over all performance

[oldeguy]

great conversation on adding HP to the ISC Cummins. Thank you Vanwill and IMNPSD and others...lots of good info. Now, I want to mod my 8.3 350HP. My plan is to #1. put on the Aero turbine muffler and install a after turbo EGT sensor (don't got the gonads to drill the manifold). #2 FASS lift pump...If I don't mess this up...#3 do the AG Diesel fooler...still need to investigate that more. That is the plan...comments weclome

[Mlfiedler]

I’m way behind most folks here. Bought the EGT, a fuel pump upgrade, and a “boost fooler”, in anticipation of the Ag-Diesel kit. Intent was to add them in that order.

OK, now I’m feeling a little queazy about this process. Putting iron filings and chips into the turbo certainly seems like a very bad thing.

All the discussion of coating the drill bit and tap with heavy grease sounded pretty straight forward. I even have a small hose setup for use with the shop vac, which I imagined could help assure any stray chips were recovered.

Then I looked at my turbo, and realized the position it is installed in, pretty well assures drill-chips that enter the manifold WILL fall straight down into the turbo. After thinking about it a while, I thought, easy-peashooter, remove the bolts between the turbo and manifold, slip out the gasket, insert a sheet of paper or thin plastic to block the entrance to the turbo!

Only after soaking those “bolts” with penetrating oil, did it finally register, Cummins illustrates those as double ended studs, not headed bolts!

So, it appears there’s nothing to gain undoing those nuts. (Unless a slip-in sheet slides down between the studs?). Am I likely to get enough “slack” to do that?

Or am I over worrying about this? Is the exhaust manifold on my engine pretty standard? Has everyone who added an EGT sensor — without removing the turbo completely — felt the question of debris entering the turbo was manageable?

Is removing the first section of exhaust piping, and trying to vacuum out the turbo through the axial opening worth the effort?

[nehog]

Originally Posted by Mlfiedler

I...
OK, now I’m feeling a little queazy about this process. Putting iron filings and chips into the turbo certainly seems like a very bad thing.

That's understandable. I've done these in the past, and my suggestion is to carefully drill until you are very close to breaking through. Remove the drill and flush the hold and surrounding area with solvent (brake cleaner) and clean the drill bit too. Regrease the drill bit, and carefully drill, frequently removing the bit and clean/regrease it. Slow and easy, clean it frequently. Once done, take a cotton swab with the end coated with grease and stick it into the hole (don't drop it in!) and try to swab out the manifold.

You can install an EGT after the turbo, with the realization it will read lower due to heat loss in the turbo. If you compensate for that loss, that is fine.

IIRC the Cummins engines have a boss on the exhaust manifold for a EGT sensor.

[Boe]

If your worried about drilling don’t. Drill almost thru go slowly and it won’t make small chips. Stop before you go thru. Not sure your situation and access but start your motor and finish drilling slowly. Turn off motor and let cool and now tap hole same way. Still coat tap with grease. It will go easy and assure no chips go into motor Hope you have room. Mine is easy to access from bedroom cover. Basically starting motor will force everything back out the hole as your doing it. Hope this helps

[Smitty77]

A second on Boe's comment about starting the engine, just before you do the final penetration into the manifold.

And of course, would be be ideal to do an EGT drill of a manifold, while it is 'on the bench'. Say when having to replace the exhaust manifold from being warped or cracked. (Not uncommon, in a ISC or ISL!).

Best.
Smitty

[Mlfiedler]

Too late smart . . . Had Freightliner replace a cracked manifold about 2,500 miles back!

[Boe]

Yes. Start motor before you drill thru. The exhaust pressure will blow any chips back out. If you go slow it should peal metal. So I would use new bit to punch thru. Motor should only be running for few seconds to get done. And do the same when you tap hole.

[Colin Jarvis]

OK, I installed the adjustable elbow and set it fully in. Only got 5 psi boost

Adjusted it fully out and got 5 psi boost. Remove boost tube at actuator and

got 5 psi boost. The vehicle was stationary and I increased RPM up to 2000

Am I doing something wrong or bad elbow or ???

Do I adjust set screw in or out for increased boost?

Any advice would be welcomed

One good thing, I got to re-glue the hatch insulation!!

Colin

[TR4]

Originally Posted by Colin Jarvis

OK, I installed the adjustable elbow and set it fully in. Only got 5 psi boost

Adjusted it fully out and got 5 psi boost. Remove boost tube at actuator and

got 5 psi boost. The vehicle was stationary and I increased RPM up to 2000

Am I doing something wrong or bad elbow or ???

Do I adjust set screw in or out for increased boost?

Any advice would be welcomed

One good thing, I got to re-glue the hatch insulation!!


Colin

You’re not going to see maximum boost when stationary, you have to check it under full load.

Bill

[Colin Jarvis]

Thanks Bill

I thought about that, but this old guy's brain didn't register it properly


Anyone out there know about adjusting the set screw?

Colin