Is a turbo control table a possibility?

[Idaho CTD]

Because the wastegate on the turbo is electronically controlled it would be nice to have the tables to tune it, especially for mpg. They run way too much boost IMO for optimal mileage cruising down the highway. Tables like the Duramax VVT trucks have would be sweet so at a certain throttle position it dumps some boost.

[GMPX]

I'm not sure how smart (or how well) a wastegate can be used to do what you want Rob. I think what you would need to do is log the wastegate PID's on a stock truck and see what it does. Does it actually change any more than open or shut?

[Idaho CTD]

I'm not sure how smart (or how well) a wastegate can be used to do what you want Rob. I think what you would need to do is log the wastegate PID's on a stock truck and see what it does. Does it actually change any more than open or shut?

This is actually Nathan @ MPI. I haven't logged the wastegate to see what it is doing but I can. I didn't even see a wastegate PID or I probably would have. It may not change anymore than open or closed now that I think about it but I'll try to find out. If it's PWM controlled can a table be made to control it?

[DoghouseDiesel]

Nathan, you can control the wastegate, but not to the degree that you're wanting.

All you can do is limit boost. It's a little bit of trial and error, but on a stock turbo, about 70% duty cycle limits it to around 38 psi of total boost.

12762

[GMPX]

This is actually Nathan @ MPI.
Sorry Nathan, I am so used to seeing "IdahoRob" post on here, I didn't really give it a second thought who I was responding to.

[Idaho CTD]

If it reads in duty cycle, which I forgot it did, it might be PWM and a table could be made to control the boost at cruising speed. Dropping the boost down to 4-6psi instead of 10-12psi should help mileage. Plus you could also hold the gate closed a bit longer to aid in spool up and start to open it when the drive starts to climb. That would keep the egt's down towing.

[2006Cummins]

I was wondering about this a while back also. An aftermarket electronic boost controller is just a pwm/duty cycle controlled valve. We already have the valve and controller on the truck, why not be able to make full use of it? I would like to plumb the factory solenoid into my non-stock turbo and control boost more efficiently-similarly to what Nathan is describing.

Mike

[Idaho CTD]

It says the Boost pressure sensor voltage and the Boost pressure solenoid duty cycle pids are invalid. Will they still read? I don't have my truck here at work to test it.

[DoghouseDiesel]

Not while it's showing invalid they won't.

You may need to hook everything up to the truck and validate the PID's.

[Idaho CTD]

I did the latest update and updated the firmware and boot block but now it wont recognize the truck when it's plugged in. I get a error and no interface cable found. Any ideas?

[DODGE74]

Do you have the Scan Tool and Scan and Tune open at the same time?

If so, you can not have both of these tools open at the same time. It will give you the cable prompt. You must exit out of one or the other.

[Idaho CTD]

I didn't have them both open at the time.

[Idaho CTD]

It says the Boost pressure sensor voltage and the Boost pressure solenoid duty cycle pids are invalid. Will they still read? I don't have my truck here at work to test it.

I got it to read but in the new update the above 2 pids aren't there or not called the same thing. There is a wastegate duty cycle pid but it doesn't change as I have mine set a 75. I don't think changing it to 0 is going to get the info we need.

Can we do a duty cycle/rpm/throttle position graph if it isn't hard to make and see what we can get out of it? I can test it to see what happens. I have boost and drive pressure gauges in addition to a egt gauge. Right now my truck hits 40psi of boost and 60psi of drive.

[AH64ID]

The wastegate itself is not electronic, just the solenoid. The wastegate will open at about 22-24 psi with the solenoid full open, so at lower boost levels you couldn't regulate boost like you want to. You could go to a super soft wastegate, and then work from there but I am not sure if the WG PID is load/rpm/pressure specific or just pressure.

It would probably help mileage, I pickup up a little bit with my Garrett turbo and run about 1/2 the boost and 1/3 the drive while cruising. I was seeing 60 psi of drive at 33-35 psi of boost peak on the stock turbo.

[Idaho CTD]

I realize that and pressure is pressure so if it's open a little bit or a lot it doesn't matter. Now if it's controlled by PWM then it would work because it is "fluttering" (for lack of better terminology) the solenoid and the gate to get the right results.

[AH64ID]

It is PWM, but with a standard WG on it you could flutter 12 psi of air to it all day long and the WG won't crack. It's the same WG as the 03-04's without the command valve, and they have full pressure to them all the time.

[Idaho CTD]

I realize that as well but you can set it to open at a lower pressure and control when it opens. So you could set it light enough to open with full boost to the diaphram at 8-10psi and dump some boost cruising. Then towing you could set it up to not feed any air until it's over 20-25psi when the drive really starts climbing and only open it enough to keep drive in check. The lighter you set the diaphram the easier it is to control the top end boost because it has more room to travel before the spring in the diaphram is maxed.

[AH64ID]

Yeah, it would defiantly take a weaker diaphragm.. but the benefits would be good.