Turbo problems?

Topic: Turbo problems? (Read 1681 times) previous topic - next topic

Re: Turbo problems?

Reply #25 – August 07, 2014, 05:58:35 pm

Dave I knew there was someone out there that could answer that I tried to get a hold of Clifford but I;m sure he's out working on something lol

Re: Turbo problems?

Reply #26 – August 07, 2014, 07:50:37 pm

I have a VMS II and I typically see a maximum of 21 psi during high rpms, full load - usually just before shifting. I don't know if this is the pressure before or after the blower. (i.e. turbo only or turbo+blower). I also have a very small exhaust manifold crack I need to get after soon. I have only had the VMS for about 18 months so I don't know what's normal long term.

My engine is 300 hp. Is it fair to assume a 350 hp engine should generate higher boost?

Might be interesting to compare turbo part numbers. Mine is 23503262 (s/n TF222)
There is also the configuration sticker on the valve cover (photo attached). It shows "1092" for the Turbo.
I also attached photos of the other stickers. Shows some interesting info.

@Pierce: Thanks for the offer - I hope I never need it!

Re: Turbo problems?

Reply #27 – August 07, 2014, 08:27:45 pm

Andy,

A waste gate dumps any excess pressure overboard or to make less noise, back into the exhaust system downstream, in other words, the excess is wasted hence the word "wastegate." Turbos with wastegates get boost at lower engine RPM but would produce more pressure than the engine was designed for so the wastegate keeps the boost pressure constant once the design pressure has been reached by dumping the excess. It also reduces turbo lag. Did your 8V-92 have a turbo?

Our blower bypass just routes the pressure around the blower lobes and back into the plenum chamber where the aftercooler is. The gain for our engines should be about 25HP.

Dave, we don't have to worry about changing injectors or changing the timing for more horsepower as a change in the DDEC II ECM firmware just keeps the injectors open longer for more fuel and will change the fuel and timing as the RPM, boost pressure, temperature, and altitude dictate. Don't know the setup on the 500-535 HP ladder trucks and boats as far as injectors go. The 500 HP 6V-92TA ladder truck engine on the YouTube dyno only had a single turbo. The DDEC is the big reason our engines don't smoke with a clogged air cleaner. The boost sensor sends the pressure to the ECU and it just keeps the fuel turned down. Smart! That's why electronic diesels get better fuel mileage, smoke less and are easier to hotrod (if you have the right engine serial number or go to a marine Detroit shop). A lot of boats use two turbos as the turbine/compressor wheel mass is less so they spool up faster, get more HP sooner and get the boat up on a plane faster.

Keeping the same turbo body but changing the turbine and compressor wheels can easily change the amount of boost pressure it puts out.

My 300SD has a wastegate that keeps the boost from exceeding about 15 psi. I plugged the line to the wastegate so it never opens. Running great at well over 400,000 original hard miles so must not have hurt it. My turbo kits were non-wastegate and only gave about 7 psi as the engines didn't have the HD parts the factory turbo engines have. (oil squirters, hollow dome pistons, different valves, different connecting rods, etc.)

Now for a short story. I was on the way home from Minneapolis St. Paul in a partially wrecked Ford PU with a mechanical turbo engine (for my SOB). I came across a Dodge PU fueling just past Salt Lake City. He had a long goose neck aluminum trailer behind and on the freeway on ramp, he left me like I was tied to a tree. Lots of black smoke. I still can't believe how fast it was. Several hours later as I was pulling into Winnemucca, NV, he was stopped on the freeway with his hood up looking at the engine. Guess you can give a diesel too much fuel and boost.

Pierce

Re: Turbo problems?

Reply #28 – August 07, 2014, 08:41:01 pm

Quote from: JohnFitz – August 07, 2014, 07:50:37 pm

My engine is 300 hp. Is it fair to assume a 350 hp engine should generate higher boost?
Might be interesting to compare turbo part numbers. Mine is 23503262 (s/n TF222)
There is also the configuration sticker on the valve cover (photo attached). It shows "1092" for the Turbo.

Mine goes to just under 20 psi just as it shifts. No cracks in the manifold. Will check my turbo part number and let you know if different. Expect the ECU is controlling the amount of fuel so less horsepower but turbo is the same. That's why a Detroit dealer can plug in the ECU and with a firmware change, get an instant 350 HP on your engine. When I turn on my Pro-Link 9000, it reads the DDEC type, RH or LH rotation and the horsepower (350 HP). 350 HP is the maximum EPA limit for that engine in a vehicle other than a fire truck so a dealer can't go any higher unless they have the serial number from a fire truck engine.

I like your valve covers. Mine don't have the raised letters. Bummer for the evening!

Pierce

Re: Turbo problems?

Reply #29 – August 07, 2014, 09:42:13 pm

Wow you guys know your stuff, Thanks for all the info going to take me awhile to digest it all.

Re: Turbo problems?

Reply #30 – August 07, 2014, 10:16:20 pm

Quote from: Pierce & Gaylie Stewart – August 07, 2014, 08:41:01 pm

I like your valve covers. Mine don't have the raised letters. Bummer for the evening!

Pierce

Don't feel too bad, I'd rather have the extra 50 hp!

Re: Turbo problems?

Reply #31 – August 08, 2014, 11:58:08 am

Quote from: JohnFitz – August 07, 2014, 07:50:37 pm

I have a VMS II and I typically see a maximum of 21 psi during high rpms, full load - usually just before shifting. I don't know if this is the pressure before or after the blower. (i.e. turbo only or turbo+blower). I also have a very small exhaust manifold crack I need to get after soon. I have only had the VMS for about 18 months so I don't know what's normal long term.

My engine is 300 hp. Is it fair to assume a 350 hp engine should generate higher boost?

Might be interesting to compare turbo part numbers. Mine is 23503262 (s/n TF222)
There is also the configuration sticker on the valve cover (photo attached). It shows "1092" for the Turbo.
I also attached photos of the other stickers. Shows some interesting info.

@Pierce: Thanks for the offer - I hope I never need it!

Your trans was the power limitation. Trans is nominally rated at 780 pound feet. Original 89 300's were rated at 277 and 840 torque.

Customers buddies were on them saying they had 300hp.

At the unihome seminar on oct 87 I met the Detroit and Allison rep and I mentioned this issue.

So we agreed to rerate the engine to 300/820. Allison guy liked it as it put less strain on his trans.

You may be able to change yours back to the 89 specs. In a side by side race the 89 was noticeably faster.

The two reps just told Foretravel the change was required.

Sorry marketing the product was the key. Lost a lot sales because of the 277 hp rating. Buddies razzed the owners.

Re: Turbo problems?

Reply #32 – August 10, 2014, 01:03:51 am

John,

Thanks for the PDFs. I will print them out and add them to my manuals. How do you manage to keep your engine so clean? My engine could use a good cleaning! I think mine was a result due to the disintegration of the insulation under the bed. I removed most of it today as it was falling off in big pieces and probably not very effective. Don't want that stuff touching a red hot turbo. Pierce's pics showed what could happen as it easily burns!

I found an excellent troubleshooting checklist for DD6v92 turbos from Diesel Pro Power. It's a quick reference for some situations and can help you in determining the health of your engine by looking at the exhaust. It's in pdf format and is a one page printout. I printed one and added it as the first page to the DDEC II troubleshooting manual that Pierce sent to me on a CD.

http://www.dieselpro.com/FreeResourcesPDF/Dieselpro_DD_6v92_turbo.pdf

Jerry

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Re: Turbo problems?

Reply #25 – August 07, 2014, 05:58:35 pm

Re: Turbo problems?

Reply #26 – August 07, 2014, 07:50:37 pm

Re: Turbo problems?

Reply #27 – August 07, 2014, 08:27:45 pm

Re: Turbo problems?

Reply #28 – August 07, 2014, 08:41:01 pm

Re: Turbo problems?

Reply #29 – August 07, 2014, 09:42:13 pm

Re: Turbo problems?

Reply #30 – August 07, 2014, 10:16:20 pm

Re: Turbo problems?

Reply #31 – August 08, 2014, 11:58:08 am

Re: Turbo problems?

Reply #32 – August 10, 2014, 01:03:51 am

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