Cost of turbocharging

[Fingers]

For a given system, yes, more pressure, more flow. But pressure is NOT what spins the turbine! Pressure comes from the restrictions along the way. This includes the turbine. Necessary, no. Inherent, yes, just like friction. Actually, that is what back pressure is an indication of.

 

[Killerbee]

out of curiosity, what are you using for an intake and compressor mouthpiece.

 

[WolfLMM]

For a given system, yes, more pressure, more flow. But pressure is NOT what spins the turbine! Pressure comes from the restrictions along the way. This includes the turbine. Necessary, no. Inherent, yes, just like friction. Actually, that is what back pressure is an indication of.

Indirectly, it takes pressure. You have to have pressure to have flow. Youre right flow does drive the turbine, but like I said it takes pressure to generate flow. Think about a Dam, the more feet of water sitting over the turbine the more pressure and flow you get across that turbine. So it is necessary. Your turbine scavanges heat also. FWIW we build gas turbines.

A Ceramic turbine would be yet another option. It can take more heat and will have a lower mass ie less inertia = faster spool up. Drawback: it can fail easier.

 

[Killerbee]

You have to have pressure to have flow.

you have to have flow to have pressure. It may be semantics, but it is an important distinction.

 

[Fingers]

My point, and I'll drop it from here, is that it is not necessary to keep ramping up pressures to get more out of a turbine. Especially in cases like the VVT where a significant amount of the restriction is not in the turbine. You should know this from the uprate craze in the power industry. They can't increase the pressure ratings of their vessels, but by flowing more at the same pressure, they are making significant increases in the amount or power they get out of their turbines. But that is another story for another thread.

Dam example is a little skew because it is water, but you can get just as much power out of 10' of head as 100'. The scale difference between the turbines though would be outrageous since you would have to flow ~10x more.

FWIW I work in the Nuclear Power industry. Not as good as a Holiday Inn, but what do I know.......

 

[WolfLMM]

No pressure No flow

 

[WolfLMM]

My point, and I'll drop it from here, is that it is not necessary to keep ramping up pressures to get more out of a turbine. Especially in cases like the VVT where a significant amount of the restriction is not in the turbine. You should know this from the uprate craze in the power industry. They can't increase the pressure ratings of their vessels, but by flowing more at the same pressure, they are making significant increases in the amount or power they get out of their turbines. But that is another story for another thread.

Dam example is a little skew because it is water, but you can get just as much power out of 10' of head as 100'. The scale difference between the turbines though would be outrageous since you would have to flow ~10x more.

FWIW I work in the Nuclear Power industry. Not as good as a Holiday Inn, but what do I know.......

I was not meaning to come off like a jackass nor was I jabbing you. I agree with you we cant just ramp pressure up wildly and expect good results.

Nuclear power is cool and the way of the future IMO. I dont remember which of the three reactors and Browns Ferry (near me) is about to come online, but it cant happen soon enough. Its ashame more of our power isnt nuclear. But designing the J2X nozzle for NASA isnt lame either...

 

[WolfLMM]

I would like to see what you have done with the vane "angle". You mentioned it in an earlier post. Pics would be cool. Were you able to tweak the factory pieces (i would suspect not) or have to start with blanks?

 

[WolfLMM]

Another thought: and this may have already been touched on and may not even be relevant to the thread. But, How much expansion do we get post combustion chamber pre turbine housing in a totally stock truck.

 

[Fingers]

IIRC Browns Ferry Unit 1 is real close. I read they were scheduled to be doing power testing earlier this year and I see that the NRC has blessed them for full operation. Here is the blessing. It is a recommisioned old plant. Major rehab. Major $$$

I'll try to get some side by side pics of the vanes. I had access to FlowWorks when I made the initial design, but have since lost it. The program is only as good as the analyst using it and I am not the greatest. Still, the graphics were telling.

Expansion is not one fixed number. Too many variables. Vane position, RPM and Fuel rate all factor in.

 

[duramaximizer]

Okay, It is dang near 3 am, and I turned on my computer for the 2nd time to make this post while I was washing my face getting around for bed..... Anyway.

IMO you guys are trying to prove importance of flow over pressure... the importance of the Father over the Son or the Holy Spirit.... Torque verse hp/movement one is impossible without the other. The coexhist. In other words which came first, the chicken or the egg? IMO who gives a shit we are just trying to get more chicken and eggs ..... your loosing site over the big picture. It's not about one having importance over the other......it's about how to get more chicken egg salad sandwiches.....FOCUS here people. FOCUS!

 

[Killerbee]

I keep getting logged off...anyone else?

 

[Killerbee]

central to the discussion...The compressor is what ultimately delivers the power.

The compressor is the meat and potatoes, not to derail any good discussion.

It is an anchor to the turbine, and can be made dramtically heavier, or lighter with changes in conditions or configuration. IMO there is 75 HP potential improvement across the shaft. That results in lower vane angle and turbine TIP also. and lower rpm also.

IMO, the heat generation of the compression is the place where biggest gains can be made. It is also the side of things that affect the most other systems...radiator function for example.

 

[Fingers]

That's a stretch. IMO At best, it is half the story. The compressor sets the shaft power requirement. It is up to the turbine to provide it.

Considering the work that has been done recently on VVT turbos, the bigger gains have been gotten via compressor wheel changes. However, the choke point on the turbine side has been the vanes from what I can tell. Working on that, but the progress is slow.

There is a set of the new design vanes going into a modded VVT about mid week. I am looking forward to the results.

 

[Killerbee]

I have shown it on several occasions. Removing the cold side "dead weight" permits the VGT to work much more efficiently, with lower PR: More MAF also.

It has also been proven by another gentleman who put it to the test on a real grade. His results are going to be in the next issue of MaxxTorque if interested. The results are non-trivial, and the math backs it up. ECT's were controllable with changes in the compression tract. EG, there is 4+psi lost before air even gets to the compressor, and while this is not the only deficiency, this alone is a big anchor to efficiency, even moreso at higher elevations where these shortcoming hurt the most. Do a PR calculation at 8000 ft, with 4 psi of CIP loss.

I don't see how the turbine can be the choke point when PR's over 6.0 are routinely in choke on the cold side. I do realize that everything can be improved, finding the significant areas is what I think is important. If 1.6 drive ratio represents an average LLY, I would stop looking at the hot side, but only because of WHAT I KNOW of the "cold" side (misnomer).

There is no question in my mind that the compressor section, and associated tract plumbing is the main hinge point that evolved to LLY heatup, there is no work limit, no boost cap. Hence no heat limit to the CAC. Getting OT.

I keep meaning to ask, what intake, and compressor mouthpiece are you running on your vehicle?

 

[WolfLMM]

I have shown it on several occasions. Removing the cold side "dead weight" permits the VGT to work much more efficiently, with lower PR: More MAF also.

It has also been proven by another gentleman who put it to the test on a real grade. His results are going to be in the next issue of MaxxTorque if interested. The results are non-trivial, and the math backs it up. ECT's were controllable with changes in the compression tract. EG, there is 4+psi lost before air even gets to the compressor, and while this is not the only deficiency, this alone is a big anchor to efficiency, even moreso at higher elevations where these shortcoming hurt the most. Do a PR calculation at 8000 ft, with 4 psi of CIP loss.

I don't see how the turbine can be the choke point when PR's over 6.0 are routinely in choke on the cold side. I do realize that everything can be improved, finding the significant areas is what I think is important. If 1.6 drive ratio represents an average LLY, I would stop looking at the hot side, but only because of WHAT I KNOW of the "cold" side (misnomer).

There is no question in my mind that the compressor section, and associated tract plumbing is the main hinge point that evolved to LLY heatup, there is no work limit, no boost cap. Hence no heat limit to the CAC. Getting OT.

I keep meaning to ask, what intake, and compressor mouthpiece are you running on your vehicle?

I changed my mouthpeice with my truck and noticed more boost. I had the stocker on my HTT and was only hitting 40 psi. I fab'd a piece from a stainless steel elbow 4 inch. Now boost will hit 43 psi on a 60 lb gauge. I have no temp readings, and only the single boost gauge.

 

[Killerbee]

assuming fixed limits on the vane angle tables, more boost would be the result, your observation, as long as your tune is commanding a higher setpoint than the stock plumbing can support. If instead you, say, commanded only 30 psi, then you would get 30 psi before/after but after would be denser, and cooler.

 

[dmaxtruck]

I changed my mouthpeice with my truck and noticed more boost. I had the stocker on my HTT and was only hitting 40 psi. I fab'd a piece from a stainless steel elbow 4 inch. Now boost will hit 43 psi on a 60 lb gauge. I have no temp readings, and only the single boost gauge.

:nopic:

 

[WolfLMM]

I have got alot of that lately.

 

[WolfLMM]

Pics of the vanes?