Into the @m*m^2

[kozakvod]

(05-06-2020 )snailexpress Wrote:  

(05-06-2020 )kozakvod Wrote:  

(05-06-2020 )schISM Wrote:  

(05-05-2020 )kozakvod Wrote:  The hottest exhaust manifold temp I saw during the entire trip about 600 deg. Most of the time it would hang out at around 425 deg.

The turbo needs a little tweaking, it’s running too cold. Depending on where your pyro temp probe is your gonna make your best mpg’s at around 575 to 625 degrees post turbo probe in pipe less than 15 psi boost and the 1450 to 1600 rpm range. Get it dialed in and you’ll probably be in the 6’s pretty easily.

I mounted on the outside of the exhaust manifold just as Rawze showed in his video.

Make sure probe very tip, where is sensing junction, is in contact with manifold.

I added, at your suggestion, that second clamp up closer to the end of the probe.

[Rawze]

(05-06-2020 )kozakvod Wrote:  I added, at your suggestion, that second clamp up closer to the end of the probe.

What others are saying have to do with actual exhaust temps, not heat soak. There is a difference there between the 2.

With the probe on the outside, your measuring heat soak, not manifold temps. I (and many others) prefer monitoring heat soak instead of EGT's for watching overall turbo temps and for fuel mileage savings. Longevity of the turbo and fuel savings has the most impact with regards to monitoring exhaust temps once the engine is performing up to spec.

I have not seen any issues with what you describe so far outside of the boost needing to be lowered a bit when you get a chance, so I would not worry too much about it.

[kozakvod]

Load 2 - Part 2

In continuation of my OP. I just took my second load to Colorado after engine "adjustment."

(See attached Image for the numbers)

This was the exact same route, time of day, etc. The only thing I did differently was the gear I used. After reading several posts from Rawze on RPM's and at his advisement I brought it down a gear to 12th to get my RPM's up and in doing so my MPG came up with it, even in spite of being 4k pounds heavier. Coolant temps stayed the same. Exh Mani Heat Soak temps varied very little from the first load.

No doubt a higher gear ratio would serve me better, a 3.55 perhaps. And why so many car haulers are spec'd to 3.36 I don't know other than most of them run 70 mph +, I don't. I am a 60 - 64 mph guy. The 3.36 requires me to run 70 mph minimum to get my RPM's above 1500.

[Rawze]

(05-09-2020 )kozakvod Wrote:  Load 2 - Part 2

In continuation of my OP. I just took my second load to Colorado after engine "adjustment."

(See attached Image for the numbers)

This was the exact same route, time of day, etc. The only thing I did differently was the gear I used. After reading several posts from Rawze on RPM's and at his advisement I brought it down a gear to 12th to get my RPM's up and in doing so my MPG came up with it, even in spite of being 4k pounds heavier. Coolant temps stayed the same. Exh Mani Heat Soak temps varied very little from the first load.

No doubt a higher gear ratio would serve me better, a 3.55 perhaps. And why so many car haulers are spec'd to 3.36 I don't know other than most of them run 70 mph +, I don't. I am a 60 - 64 mph guy. The 3.36 requires me to run 70 mph minimum to get my RPM's above 1500.

thats pretty decent for a full-on car hauler. keep working at it and you'll likely see 6's before too long. whole truck and engine will thank you with less down time too.

[Lonestar10]

you also get more efficient dropping gears as you get closer to a 1:1 ratio with engine rpm transmission RPM and drive line RPM. hence why most of these companies are using direct drive 10 speeds their just using the wrong rear gears for the speeds their running but everything is spinning the same RPM in top gear.

[amermextrucker]

I completely get what you guys where talking about regarding 3.36 gears ratio with a 10 spd. I usually run in 9th gear at 1700 rpm 60 mph. At 1500 rpm in 10th im like at 73 mph. which is too fast IMHO . I know Rawze has said he runs at 1800 rpm for periods of time , can I do that in 9th gear? hopefully get closer to 65 mph. Hope this aint a dumb question guys. Im still trying to get used to this ISX all the while being gentle with it. Thx.

[amermextrucker]

(05-09-2020 )kozakvod Wrote:  Load 2 - Part 2

In continuation of my OP. I just took my second load to Colorado after engine "adjustment."

(See attached Image for the numbers)

This was the exact same route, time of day, etc. The only thing I did differently was the gear I used. After reading several posts from Rawze on RPM's and at his advisement I brought it down a gear to 12th to get my RPM's up and in doing so my MPG came up with it, even in spite of being 4k pounds heavier. Coolant temps stayed the same. Exh Mani Heat Soak temps varied very little from the first load.

No doubt a higher gear ratio would serve me better, a 3.55 perhaps. And why so many car haulers are spec'd to 3.36 I don't know other than most of them run 70 mph +, I don't. I am a 60 - 64 mph guy. The 3.36 requires me to run 70 mph minimum to get my RPM's above 1500.

Those Cassens car haulers in the red day cabs are ALWAYS flying! crazy.

[Chamberpains]

When your doing ANY kind of up hill pull or fighting wind, you can drop it in whatever gear that keeps your RPM's up in the 1800+ range all day long. You just want to upshift when your not pulling. Flat ground and down hill and such.

You find your foot pushing on the accelerator, then back down the in the gears it goes and RPM's up. And repeat about a 1000 times a day.

This is how you pull freight with out working the hell out of the engine. Its minimal stress and heat the engine is exposed to in order to complete the task. The fuel mileage and savings is in getting good at doing this over and over again.

[JimT]

Follow your boost and pyro gauges and pick your gears accordingly. keep the boost as low as possible. If you can roll down the road in top gear with 5-10psi of boost and rpms down around 1500 then go for it! If you need more psi then drop down a gear and try again. Even pulling most grades can be done with less then 20psi boost, the trade off is speed. Basically try to use the highest gear that allows you to use the least boost pressure. You'll find you get the best overall fuel mileage along with the least stress on the engine. If you can be flexible with your speed then you can find the best rpm/psi for the conditions. If you have to maintain a certain minimum or average speed then you'll be limited in what you can do.

Took me a while, but I recently got down to using 5-10psi of boost, max. Only occasionally up to 20psi for a steep grade. With the gearing in my tractor it keeps me around 58-62mph, sometimes down around 45mph, but the results for fuel usage have been great. I started simply by trying to keep the boost under 20psi, which was difficult at first. Then I worked my way lower and lower over time.

I pull flatbed with a mid-roof tractor so wind plays a big factor in my fuel mileage too. It actually has a bigger impact than gross weight, for me. When the wind is howling through my doors I can see up to a full mpg loss along with higher boost pressures for the same workload.

I actually had a scare recently because of my newer habits. I started climbing some minor hills that I pass regularly and my speed dropped fast, multiple down shifts, could barely make it up the hills (local roads, not highway) at 20mph. I started freaking out, thinking something was wrong with the engine or maybe the turbo stopped working... The turbo... Then I looked at my boost gauge and realised why I didn't have any power... I was subconsciously limiting my boost to 5-10psi like I would do on the highway... Needless to say, once I pushed down on the pedal a little more I made it up the hills no problem. I had gotten so accustomed to barely pushing on the pedal that I didn't even realise what I was doing.

It's gotten to the point that I rarely hear the turbo spooling up anymore. Every once in a while I actually have to purposefully push down on the accelerator to make sure the turbo is still working and can actually produce boost pressure above 22psi. It's really weird.