Smarty UDC Initial Impressions

AH64ID said:
Your turbo setup will run cool at about any timing value :)
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I have noticed that ;) when making timing adjustments.. I will have to lower the timing and RP quite a bit in order to make the temps go up, then I'm spooled to high..
 
rlawless said:
ALL OF THE ABOVE ^^

Just an FYI for Dangerous06, the UDC sample files are called sample files for a reason, they are real world proven tunes after 1000's of hours on a dyno..

The sample files are very close to what works on the majority of motors, you need to only modify them to work for your mods..

Start with a sample tune and make small adjustments in one area at a time..

There is no need to modify the duration cells below 3000 rpm..

Notice how every sample file mapping is almost exactly the same below 1800 rpm and 50% load?
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Randy - Have you looked at some of the TNT samples? What do you think about calling for 26,000 psi @ WOT? I'm a little gun shy about going over stock. I have been keeping mine no higher then 23,206. Thx
 
Quick question how does cold weather effect rail pressure? This morning it was in the low 30's so after about 45 min of driving I noticed at cruising my rail was at 10,000 psi when normally it would be in the 13,000 - 14,000 range. I also would be in the 25% load area not the 6%-8% load range @ 1800 rpm. My truck never cruises in this range unless going down hill and that was not the case.. Just curious if this is normal to have rail drop in cold weather..
 
In the 06-09 trucks, there are several multiplier tables based on coolant, IAT and boost.

So I'd assume earlier trucks have similar tables, which would explain cold-weather rail being lower.
 
Is that where you suppose to drop the entire table by 3% or some value..
 
They do multiply the entire table but each area of temps dictates what factor.
 
It would be nice to see those adjustment tables in the professional version.
 
Are there any tools that can read and write these ecus and give us hex dumps?

And calculate checksums.
 
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Yeah my rail pressure is lower cruising and load values are off and it seems to want to be smokier with mod throttle input. I would assume that is due to the lower rail pressure. Idle rail pressure seems to be up when cold though.
 
cj42 said:
Randy - Have you looked at some of the TNT samples? What do you think about calling for 26,000 psi @ WOT? I'm a little gun shy about going over stock. I have been keeping mine no higher then 23,206. Thx
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No, I don't like the 26,000 psi, remember TNT was designed for racing and the equipment to go with the tune. If you have the equipment to support the tune go for it.
 
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cj42 said:
Quick question how does cold weather effect rail pressure? This morning it was in the low 30's so after about 45 min of driving I noticed at cruising my rail was at 10,000 psi when normally it would be in the 13,000 - 14,000 range. I also would be in the 25% load area not the 6%-8% load range @ 1800 rpm. My truck never cruises in this range unless going down hill and that was not the case.. Just curious if this is normal to have rail drop in cold weather..
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Are you talking about the 03 (maybe 04 as well) thing where under forty degrees the rail pressure is always lower? Few threads on this somewhere.

I always thought it would be neat to put a resistor or something similar to manipulate the temperature reading. A switch or potentiometer to raise or lower temp input. Colder than normal for hi idle option and higher than normal for cold weather driving.

Seems like a good idea.
 
2007 5.9 said:
In the 06-09 trucks, there are several multiplier tables based on coolant, IAT and boost.

So I'd assume earlier trucks have similar tables, which would explain cold-weather rail being lower.
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It only seems to be 2003's and 2004 305hp trucks that have the low rail issues for us up here.

I don't think my 04.5 does it.
 
My 05 doesn't vary pressure based on cold temp, but I will run much higher pressure at elevation with high IAT's. I haven't full pinned down the issue, but I know it's happened as low as 3500' with 130° IAT's, and at 8,000 feet it seems to take 75° IAT's.

Marco is working the issue.
 
Around 26K?

Email Brain at Smarty, and/or MADS and let them know. I know it's an issue, and so does Marco but he may not be sure how many people it effects.
 
High Rail Pressure

I had a few bouts of skyrocketing rail pressure as well driving around Divide and Victor Colorado (8000 - 9000 ft.). It shot up around 30,000 psi. at ridiculously low RPMs/load which is what your pressure blow off valve is for. I assumed it was a stuck bit or a latched relay/transistor, pulled over, cycled power (turned the truck off for about 5 seconds) and then powered back up and rail pressure was fine. I assumed then, that its a problem with my PPE gauges and the way they report the pressure because I'm hoping my valve wouldn't let that much pressure just happen. The truck's driving behavior didn't change at all. I wouldn't have even noticed if I don't scan my gauges every 10 seconds or so.
 
AH64ID, I have a question. I looked through the thread and couldn't find any reference to this so correct me if I am wrong. The 50/50 split (or 51/49) is allowing for the ignition delay of the fuel to pass. The ideal situation is for the diesel to begin combustion at or just barely past TDC because combustion before is just slowing the rise of the piston and slowing the crank. Do you have any figures for the ignition delay in the 5.9 Cummins at operating temperature? I know ballpark is probably the best we can ask for but even that is fine. Marco quotes 500µs in the UDC literature as an example but I expect that to be more of a round number to make practice calculation easy. I thought getting my feet wet in UDC would be enough but I'm waist deep and still chasing this thing. I assume you were a helo guy in 4th ID out of Killeen? I'm at Fort Carson, where 4th ID moved to and originally from Austin. I can't say how much we all appreciate the work you're putting in on UDC.
 
I haven't been able to find anything, but it varies based on IAT, rpm, fuel injected, pilot timing and qty, etc.

There will be probably be some ignition BTDC, the goal is to create peak pressure around 12-15° ATDC. Without cylinder pressure gauges we cannot be sure, the 50:50 max without dyno tuning is a number I have found in researching custom tuning while UDC was in Beta (think other brand...). The other issue is that if you have a 3,000us pulse at 3,000 rpms if you don't start early most the fuel is going to chase the piston down the power stroke, not increasing power only heat...
 
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