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Old 04-24-2021, 08:03 PM   #1
Bus Nut
 
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Join Date: Aug 2019
Location: Auburn, WA
Posts: 653
Year: 2000
Coachwork: IC / Amtran
Chassis: 3000 / 33' Flat Nose
Engine: IC T444E / Allison MT643
Rated Cap: 72 Kids / 48 Adults
T444E Boost PSI and a few other numbers

I bought a BlueFire. My 230hp, 190k mile, 33' flatnose, MT43 4 speed with 4.10 (originally 5.11) rear end does 60mph at 2050rpm.

My tranny electric modulator has proven challenging, yet we've road tested it with a toggle switch hooked up and when activated it downshifts and really pumps up the rpms.

Instead of using an limiting switch at the accelerator pedal, I added a tee to the MAP sensor port and then added a 15psi (14-24 adjustable) pressure switch to trip the modulator.

Unfortunately, when I took the bus out to test this setup, my BlueFire tells me my Boost goes up to a maximum of 15psi when manually shifted into 3rd, climbing a steep grade at 55mph and 2400rpm pedal to the floor.

Around town on the flat, with standard accelerator use, it shifts at about 8-10psi.

My plan is to get a different pressure switch and set it somewhere around 8-10psi, unless I hear something on here that changes my mind.

With rain and 49 degrees, my other numbers were:
Coolant - 195-210
Oil Temp - Rose up to 205 (seems high to me....)
Oil Pressure - 35-50+ depending on engine load
EGT - Around 500 - 700 around town, didn't check it climbing the grade as I was watching the RPMs and Boost.

My oil temp is the only one I'm really concerned about.

Around town with gentle accelerator use it runs and shifts great. On the freeway flat it runs great. When we manually activate the modulator it all works great. So, I'm not super worried, just checking in to see what you all think.

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Old 04-24-2021, 08:09 PM   #2
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Join Date: May 2009
Location: Columbus Ohio
Posts: 14,933
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
15 PSI is close.. I think the book has maximum boost at 17 on that engine.. I run a different turbo and push close to 23 but your turbo is the smaller one so it spools quicker for the higher amount of lower RPM fiuel given to the engine.. you might be able to adjust the wastegate a bit to gain more boost but unless your EGTs are running up or you are adding fuel, added boost only increases your backpressure and is wasted..



oil temp 205 is normal for a used engine.. I see mine hit that regularly when im climbing hills foot to the floor
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Old 05-01-2021, 04:14 PM   #3
Bus Nut
 
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Join Date: Aug 2019
Location: Auburn, WA
Posts: 653
Year: 2000
Coachwork: IC / Amtran
Chassis: 3000 / 33' Flat Nose
Engine: IC T444E / Allison MT643
Rated Cap: 72 Kids / 48 Adults
Update & Solution: This is the thread I posted as to the solution to my tranny modulator problem. Hope this helps someone.

https://www.skoolie.net/forums/f33/s...tml#post436690
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Old 05-01-2021, 04:44 PM   #4
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Join Date: May 2009
Location: Columbus Ohio
Posts: 14,933
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
Quote:
Originally Posted by Simplicity View Post
Update & Solution: This is the thread I posted as to the solution to my tranny modulator problem. Hope this helps someone.

https://www.skoolie.net/forums/f33/s...tml#post436690



I plugged a tuner into my 444E, nailed pedal, everything flew off the dash and my boost PSI went up to near 29


I dont think it squealed the tires though
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Old 05-01-2021, 06:10 PM   #5
Bus Nut
 
Simplicity's Avatar
 
Join Date: Aug 2019
Location: Auburn, WA
Posts: 653
Year: 2000
Coachwork: IC / Amtran
Chassis: 3000 / 33' Flat Nose
Engine: IC T444E / Allison MT643
Rated Cap: 72 Kids / 48 Adults
Quote:
Originally Posted by cadillackid View Post
I plugged a tuner into my 444E, nailed pedal, everything flew off the dash and my boost PSI went up to near 29


I dont think it squealed the tires though
Wow! What tuner??
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