Now I'm wondering if my "skip" while towing up the Cascades late October was actually the Powermax turbo. Will be watching this one.

 

Why not give Matt a call and ask him about this problem and options.

Sean

 

I've gotta get the clutch figured out first,,, then I'm gettin some shocks,,,, lol. Really tho,,,, then the pmax is up. I don't want to make calls until I can order it. I will be revisiting this mid January at the latest.

 

Here's a video of the popping

 

Mine did that sort of thing. But, when it did it, I was on the shoulder real quick. All I did was look things over, wiggled some wires and it never did it again.

Had the TT hooked on, going over Santiam Pass. Starting from the valley side of the mountain, so low elevation starting point, to a high of 4600'.

It was almost like a '94 E150 I had. (gasser) Going up to higher elevations, it would chug or skip, like it was adjusting the fuel/air mixture. After a few seconds, it would clear up and run well.

My 6.0 that trip, never did it again. On the return trip, my starting elevation to get up over Santiam Pass. was much higher, so the elevation change was less drastic.

I have since, gotten a SCT with Matt's SRL and 8000# tow tune and Unlimited tow. But, I wont get a chance towing until spring.

Thanks Anthony for the video.

 

From a turbine mechanic point of vies it sounds like a compressor stall.
What is the boos looking like when it's doing that?
The way it is handled in a turbine is by bleeding some of the pressure off the
the compressor. I replayed it and that is what I hear. The problem is how to
deal with it. Does that turbo have VGT ? If it does can you watch the
reading? Also the compressor absolute pressure. The odd thing is a single
stage compressor should not stall. A bit of back pressure may help hold
the speed of the exhaust down. It's too bad that there is no way to see the speed
od the turbo.

I will do some head scratching and let you know what I find.
Hope your Christmas went well.

Sean
NOTE :

I found this and it supports some of what I was saying
http://www.thedieselstop.com/forums/...e-stall-86156/

 

Thx guys,,, I'm normally running 20-25 lbs boost when it does it. If I stay n the throttle, I can see the popping n the boost gauge,,,, it drops with the popping. What sux is,,, it never did it with the stock turbo. Yes Sean, it is a vgt turbo.

 

I would bet it's a tuning issue. I've heard of several people that have corrected some weird Powermax issues with a custom tune. I've heard a lot of good things about Gearhead tuning. I wish I knew you were in the market. I just sold my SCT two days ago for $200. I know most of the Edge tuning issues were related to the Auto tranny. I don't know a whole lot about em. One thing I do know is that you have logged a lot of miles with one onboard. There is a lot of difference between the air density at elevation I would guess it's a fueling issue in relation to tuning.

 

Anthony,
I have a feeling that a properly written tune should
solve the problem. The VGT part of the program needs
a new power curve so it's not going into compressor stall.
For the ones that don't know what I mean by stall. It's not
the compressor stoping but the are not lowing along the
surface of the compressor blade (air foil) and becoming
turbulent and then the air flow stops and you get a POP sound.
You should hear that on a big jet engine.

Sean

 

Database Error keeps showing up and I get a
double post because of it.

Sean

 

Ok, I've gotta revisit this issue. I talked to Matt at gear head, n he said that the best he can do is "try". I'm on the fence about that.

The issue, wasn't an issue until the day I installed the pm. And the engine is just a big air pump. So what are your thoughts about, either stalling the flow by reinstalling either the cat n muffler(really doubt that's gonna happen), possibly limiting the outflow. Or do I go for opening the whole system up even more. 4" dp with full exhaust, do they make ported ex manifolds for us, high flow elbow, maybe a ported intake manifold???

I'm not sold on the sct,, obviously since I'm considering spending much more on hard parts than the sct would cost.

Or, do I just ditch the pm n get a stock turbo n be done? I was happy with the truck with the stock, but the whistle is a conversation starter,,, people are always asking me wtf did I do to get it to sound like that (no muffler, cat, with the pm sounds awesome). But the popping should overrule the "being cool" aspect.

I want to keep the pm, not lose mileage from a power tune, n not pop in elevation. Cake n eat it too huh. Lol

I would gladly pay for the sct, but if it fixes the issue n it "rolls coal" or uses much more fuel,,, that would be wasted $$$ in my book. I've burnt enough fuel through this truck to buy a freakin house. Estimated about $155k. So $500 here, or $1000 there, don't bother me at all. But I try n research all aspects before I actually pull out my wallet. Doesn't always work out tho. Lol

 

As a turbo engineer, I concur with Yahiko's initial assessment that it is likely compressor stall - probably on the exhaust side of the turbo. What is your EBP sensor reading? Since the Powermax's have variable nozzles, I would suspect that it's trying to vary the nozzles at a curve point where the EBP is too great or too little to support the new geometry.

Try a different tune, I would start with one closer to stock initially.

 

Anthony,
Want to swap?
It will be about 45 more days till the Dr says I can do more things.
But I think I can.

Sean

 

Anthony, Mine did the same while towing last summer. Doesn't do it while unloaded. I haven't been able to tow with the tunes and Powermax yet, but I do know the tuning changed the way it reacts now. The low end lag is gone with both the 8000# tow and SRL.

I am looking forward to this summer and trying the unlimited tow tune with it.

I'm enjoying the Powermax more and more each day.

And, I'm getting MPG with the 8000# tow tune than I did with the SRL. These tunes are for non-studded. And, Matt says they are written with the Pmax in mind.

 

I think I ruled out a swap. I am planning on buying another stock one n keeping the pmax. U busy on Sunday??