Boost vs Drive. Does this look right?

4x4dually

4x4dually

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II PS62/65/14.

One of my data logged WOT run looks like this. If drive pressure is 50+psi, shouldn't I be seeing more than 32 psi of boost?

Educate me. Started in 2nd gear. I don't know why the drive pressure drooped in 6th. But, regardless, does this look normal? I forget what my AR is.

DataLogWOT178-208Cam.png
 
Set to start opening at 40psi. This only happens when the amibient air is cold. Once outside air gets to around 70F or higher and IAT air get above 100F or so, it will quit.
 
Looks like hx35 boost vs drive numbers. First graph is wot right?



Cold weather timing affecting it maybe?
 
jmd025 said:
Looks like hx35 boost vs drive numbers. First graph is wot right?



Cold weather timing affecting it maybe?
Click to expand...

It better not freakin' be HX35 numbers. LOL

Yes, first graph is WOT. I've heard about folks putting a potentiometer on the AIT sensor and maybe that will fool the ECM into adjusting timing. Seems a little....well...southern Eng to me, but maybe I'll have to try it.

I'd rather not bandaid it and find the actual reason and fix it correctly...but hell, after three winters of this crap, I'll try it if I have to.

You'd think Edge could read the AIT and adjust to correct this....but I've called them several times and "I have a turbo issue" or some crap. I'm pretty certain there are 100 trucks on the road doing this same thing.
 
Ok, so maybe I'm seeing the light.

Cold air = more dense.

Drive pressure is so much higher than boost, the cam duration won't let that boost go through the motor fast enough, that the turbo flutters which is basically a very slight "bark". Hmmmm. Savvy?
 
I was saying only 32 psi with 50 drive is similar to what a hx 35 does.
 
4x4dually said:
Ok, so maybe I'm seeing the light.

Cold air = more dense.

Drive pressure is so much higher than boost, the cam duration won't let that boost go through the motor fast enough, that the turbo flutters which is basically a very slight "bark". Hmmmm. Savvy?
Click to expand...

That could be part of it...or you have a tiny turbine wheel...or both.
 
4x4dually said:
Ok, so maybe I'm seeing the light.

Cold air = more dense.

Drive pressure is so much higher than boost, the cam duration won't let that boost go through the motor fast enough, that the turbo flutters which is basically a very slight "bark". Hmmmm. Savvy?
Click to expand...

I think it's timing related thru the edge box. I was one of those people that used the resistor on the IAT sensor wiring, flip a switch to fool the truck into thinking it was warmer out and pull some timing out.
 
Looks fairly normal for a smaller turbo. EGT's look really good. I just don't really understand the flutter up top, anyone else?
 
jmd025 said:
I was saying only 32 psi with 50 drive is similar to what a hx 35 does.
Click to expand...

I'm an idiot. I didn't see my own typo. Notice on the first chart, max is 43psi, not 32. Don't know why I typed that.

JAWilson said:
Looks fairly normal for a smaller turbo. EGT's look really good. I just don't really understand the flutter up top, anyone else?
Click to expand...

EGT's are great. Even better with this 178-208 cam. Spool is excelent now. I was hoping the cam would cure this. No dice.

I think I'll back the wastegate up a tad and see if it does it with lower drive pressure and see what that does to my max boost.
 
morkable said:
Jory,, define cold temp... 50, or 20... or...
Click to expand...

AIT is normally around 30F higher than ambient, outside air. That being said, the flutter clears up completely once ambient is 70F or above. At this point, AIT reads 100F. If I stop for a light and the engine heat soakes the intake and gets AIT up to 110 or so, it will not flutter until I take off and the AIT gets pulled back down by new, cold air.
 
GOT-Torque said:
I was one of those people that used the resistor on the IAT sensor wiring, flip a switch to fool the truck into thinking it was warmer out and pull some timing out.
Click to expand...

Did this completly work? What were the resistances you had to add?
 
maybe you need to get a bigger turbine wheel to drive the charger harder, and get closer to 1:1
 
WUnderwood said:
maybe you need to get a bigger turbine wheel to drive the charger harder, and get closer to 1:1
Click to expand...

Always wanted to find someone that would swap me a SPS 62/71/14 for a week or two and try it out.... but I can't justify buying one and putting it on to find out it don't work.
 
4x4dually said:
Always wanted to find someone that would swap me a SPS 62/71/14 for a week or two and try it out.... but I can't justify buying one and putting it on to find out it don't work.
Click to expand...

Make a trip or two to the Omaha area....you wouldn't be the first I let borrow a turbo.
 
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