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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: basil on March 23, 2008, 10:07:42 AM

Title: 8V92T Torque Curve?
Post by: basil on March 23, 2008, 10:07:42 AM
I am having an 8V92T non-DDEC rebuilt inframe in a 1990 Eagle.  I am having the shop dyno the finished engine in the bus so I have a torque curve on the rebuild.  Does anyone know where I might find a reference torque curve for this motor?
Title: Re: 8V92T Torque Curve?
Post by: makemineatwostroke on March 23, 2008, 10:50:18 AM
Basil,in section 14 of your DD engine manual it will give you standard rating of the 8v92 but the torque is going to depend on how the engine was built because you can build that engine anyway you like, the power range will be between 1300 to 1800 rpms for most engines here in the states 
Title: Re: 8V92T Torque Curve?
Post by: Timkar on March 23, 2008, 10:50:37 AM
Don't know if this will help or not but it is an old sales brochure...

http://www.powerlinecomponents.com/literature/detroit_diesel/brochures/8v92ta-tta_automotive.pdf
Title: Re: 8V92T Torque Curve?
Post by: basil on March 23, 2008, 12:51:06 PM
Thanks, that is incredibly helpful.  I did not realize it is supposed to stay so tight between 1100 and 1250 across the curve.

Any idea what I should expect the loss to be through the Allison 740 down to the drive wheels?
Title: Re: 8V92T Torque Curve?
Post by: TomC on March 23, 2008, 01:14:18 PM
That truck brochure is based on having 90 injectors.  Most bus engines had 85, 80 or even 75 injectors.  Check with your rebuilder what injectors you have for proper horsepower curve.  Good Luck, TomC
Title: Re: 8V92T Torque Curve?
Post by: basil on March 23, 2008, 04:26:30 PM
He did put 90's in it.  Suggested they would provide better performance given I will never drive it more than a couple hundred thousand miles at the very most.

Do you have a guess as to what percent I should expect to lose between the motor and the tires?
Title: Re: 8V92T Torque Curve?
Post by: NJT 5573 on March 23, 2008, 06:25:30 PM
Have your rebuilder run the engine number. You don't have enough transmission gears to be very concerned with  the torque curve, with a 740 its going to pull at a big rpm range and you can't do much about it. I think mui and no atec is very rare for that year bus. It must have been quite a project to change over, you are fortunate in my opinion.

Last trip south I had a bus with a stronger torque curve pass my wife at the bottom of the Grapevine. 2 miles farther up the pull he had it hot and coded out. He was in low power mode with the flashers on looking for a parking spot! I just had to grin. Power is great stuff, but you gotta know how to use it.
Title: Re: 8V92T Torque Curve?
Post by: TomC on March 23, 2008, 07:06:24 PM
90 injectors will work well for you-that's what I had in my first big truck.  I regularly drove it by up shifting at 1800 and down shifting at 1400 with great success and good fuel mileage.  I would suggest that when you pull a hill that you manually down shift as soon as you can to keep the revs up.  In hot weather, I pull hills in first at about 32 mph where my engine is revved up with the fan turning and water pump turning the fastest.  In hot weather, it will make for a little slower hill climb, but you'll keep that engine below the nasty 220 degree mark.  Good Luck, TomC
Title: Re: 8V92T Torque Curve?
Post by: makemineatwostroke on March 23, 2008, 07:26:46 PM
Basil, do you know what 90 injector you have the spray pattern is different on every one