Wastegate size??

[Diesel Freak]

Hey Jim, what is gonna happen when in three more years you will be saluting my sorry butt?



Salute you and say here is the Navy now... ... ... it's changing fast!



Jim

Well, if things go as planned, I will be in Charleston SC for four years after I graduate, then it is off to grad school!!! Oo.

 

[Fishin Guide]

nah, I will just have my Ohio Intelligence contacts get it for me!!!



If his turbo is really that good, then what is the issue in posting the info to back it up?



Or is it just hype?



Ah I got it... . the Ohio Hilljacks are using too much of their crop "between" the corn rows!! Dont ya hate it when the local Po Po digs it all up!!!

Now that's just plain funny! :-laf



Dave

 

[Bpostel]

So how do you expect your Ohio buds to get any info? Any info they get will just be speculation anyway. Not all J. R. s H4's have the same wheels in them. Why don't you call Scheids, EEP or Haisleys and see if they will give out there information, I bet they'll tell you to get lost. I think all that heat from the engineroom that you was talking about has effected your brain :-laf

 

[Diesel Freak]

yep, brain is a little fried these days. Thank goodness I only have two more math classes to take.



Speculation, well since this thread took a turn from discussing wastgates, that is all it is... on both sides of the discussion. And BTW, the back channels are more fun than direct call-ups.



Bottom line is that I do not believe you, and with air in the neighborhood of 900F comming out of the seccondary, Density Ratio is in the toilet!!!. I am willing to change my mind if documentation is presented to prove me wrong.



Billet Ti wheels are cool, but all they allow you to do is turn the wheel faster (faster=more heat) since it can handle the stresses better than Aluminum. Efficiency will still drop off to less than 65% on a wheel that can flow over 150 LBM/min shoot, even a 200 LBM/min wheel will run over 500F when pushed to a PR of 5:1 and higher regardless of the material used in the wheel. The only benefit is that the wheel can handle the heat... and at 5:1 and < 65% things are friggin HOT!!!!! There is no way around it!!!!



Sorry dude, but you are wrong.

 

[Bpostel]

Say whatever you want. You don't have a clue!

 

[Diesel Freak]

prove it!!!

 

[Devan Manis]

Not trying to be a smart ***** but one way you can prove it (this is mostly for my own understanding, and why not hijack this thread and learn something from it?) but DF or anyone can you explain exactly how to read a these maps? Such as what it means in between the surge line and in the fat part of the maps? How and what does this tell you about a compressor or turbo? Then how does this help you make your decision on what size turbo's you would need?

 

[Fishin Guide]

prove it!!!

I think you may be asking too much.



Dave

 

[Diesel Freak]

BManis here ya go!!



Basicly, the area left of the surge line is no mans land where crazy flow irregularities and the infamous turbo bark run rampant. The area to the right of the right most efficiency line is the choke line. If you are operating here the turbo is too small.



All the garbage in between is where you should operate a turbo.



The 'x' axis is air flow



The 'y' axis is pressure ratio in atmospheres. One atmosphere is 14. 7 psi absolute. What you read on your boost gauge is in gauge pressure.



Pabsolute = Pgauge + 14. 7



The numbers in thousands is turbo RPM.



The percentages are the turbo compression efficiencies at those specified flow rates and pressures.



When computing tempratures and pressures, you MUST be in an absolute scale. I use the Rankine scale for temperatures (Kelvin can also be used) Using Farrenheit or Celcius will give you incorrect results.



To get the nitty gritty of the compressor, you need a few things. First the correct part number and the Compressor map for that part (however you can fudge a bit here to get close if you know the basic compressor trim and flow rate. Also, there are limits to single stage compression efficiency.



Compressor trim is a ratio of area between the inducer and exducer. The inducer is what you see when you look at a turbo-compressor. It is the small diameter. The exducer is what you do not see... . the part that is inside the housing. This is the large diameter. The turbine trim is the exact opposite.



Here are the basic equations to get you close to the actual post compression and post intercooled temperatures.



P1 = turbo inlet pressure

P2 = turbo outlet pressure

T1 = turbo inlet temperature

T2 = turbo outlet temp from basic adiabatic compression

T3 = turbo outlet temp from compressor ineficiency

CE = Compressor efficiency

IE = Intercooler efficiency

Tin = T3

Tout= aftercooled air temp

Tamb = T1 = the air that the turbo is sucking in



T2 = T1 x (P2/P1)^(0. 286)



T3 = T1 + (T2-T1)/CE



Tout = Tin - IE x (Tin-Tamb)





I hope I answered more questions that I may have just caused.

 

[Bpostel]

DF & Fishin Guide, since you still don't believe, get up to northern Ohio (Bowling Green). Mike has invited you up to take a ride in his truck to prove you wrong. This will be the best way to keep you guys from :{ If you can't get up there then I don't know what to tell ya. Or you may not want to go up there because your afraid that you would be proved wrong.

 

[Fishin Guide]

DF & Fishin Guide, since you still don't believe, get up to northern Ohio (Bowling Green). Mike has invited you up to take a ride in his truck to prove you wrong. This will be the best way to keep you guys from :{ If you can't get up there then I don't know what to tell ya. Or you may not want to go up there because your afraid that you would be proved wrong.

I appreciate the offer! But I for one am NOT going to drive to Ohio to prove my own thoughts correct, that's just plain silly!



BTW, I have been proven wrong enough times in my own state to avoid the need to travel! :-laf



Besides, the fish are biting. And they are huge! See, we get these 200lb salmon here. What? You don't believe it? Well, they were released by some of the finest fishery managers in the world! And when you compound that with our weather, it's just a fact.



Now I can't explain why that would be, but if you ask the Hatchery directors, I am sure they will be happy to tell you it DOES work, but they won't be any help with technical information.



If you don't believe me, come on out to Washington. You have an open invitation! I would hate to prove yet another non believer wrong! BTW, I catch these monsters all the time, but something about these fish makes them impossible to photograph, disect, or otherwise document in any way.



Must just be another black art!



Have a great day! :-laf



Dave

 

[Diesel Freak]

I don't care who you are, That's funny!!!

 

[Diesel Freak]

I backed up every single aspect of my opinion in the post I made for BManis. There is enough info allow anyone to calculate the temperature at the discharge of ANY turbo.



Please explain what aspect of that post is crying?

 

[Diesel Freak]

BManis, to get density ratio (the condition of the air at the discharge of the turbo or after intercooling referenced to ambient) you need the following equation.



T1/T3 x P2/P1



T3 can be substituted with Tout to find aftercooled density.



Manifold pressure is slightly less than P2, but usually no more than 4 to 6 psi on a 500 HP truck with the stock intercooler.



Also, I normally use an intercooler efficiency of 74%. On a dyno, CAC efficiency is crap, but on the highway it is quite good.



Now that you have density ratio, you can calculate the air demand of the engine.



(0. 1038 x RPM x VE x DR) / 14. 5 = Mass flow rate in LBM/Min for a 359 cubic inch displacement engine.



Now you have enough info to size a turbo for a Cummins B series engine. VE is always less than 1. 00 when used in the above equation. I use 0. 92 for a stock ISB head and cam.

 

[Bpostel]

DF&FG, you guys come up with some fancy numbers. We know what works and thats all that matters. While were out making serious HP, you two are still working on some math calculation to try and figure out how to make HP. I'm tired of :-{} with you two. You 2 are intitled to your own opinion, if you could see it you would definitely believe it.

 

[Fishin Guide]

DF&FG, you guys come up with some fancy numbers. We know what works and thats all that matters. While were out making serious HP, you two are still working on some math calculation to try and figure out how to make HP. I'm tired of :-{} with you two. You 2 are intitled to your own opinion, if you could see it you would definitely believe it.

While I fully appreciate the need to defend a position, I also concede that I don't know everything. Or, even most things. I learn more and more every day.



BTW, the fancy numbers aren't mine, but I do know how to use them.



Have a great day!



Dave

 

[Diesel Freak]

Fancy numbers? Nope, just verifiable thermodynamic principles.



I am not arguing anything. I am simply stating a fact, and backing it up. This is just a discussion to educate the masses, nothing personal on my end.



I can not help it if you can not back up your end of the discussion or if you do not understand how to use some very basic concepts like the Combined Gas law, Adiabatic Compression, and absolute temp/pressure scales.



With all due respect, you should have learned these in High School Physics and Chemistry. I have presented nothing new or earth shattering here.



I guess the typical Washington State Redneck has a slightly higher IQ than the typical Ohio Hilljack. (my appologies to the Moderators I just could not help it)

 

[Devan Manis]

just a quick thought Bpostel, *IF* you can do these calculations *AND* they are correct then you save your self some serious money and still make the big horsepower. (simple laws of phisics) Im not gonna take sides here because i don't know enough to make an informed desicion, but so far Diesel Freak's "fancy numbers and equations" are making some sense to me.



Diesel Freak, thanks for replying to my questions... remember that report you did for some college class about compounding turbo's and posted on the tdr for the members to read? I still have and read that from time to time. I may have some questions later once i really read and try out some of those equations but so far so good thanks alot.

 

[Devan Manis]

With all due respect, you should have learned these in High School Physics and Chemistry.

Hey im still in high school! I haven't even learned these yet but the year just began and you can bet that im in physics.

 

[SRadke]

Quick question here...

The low pressure charger (HT4C) is making 60psi of boost. I don't think there out of there map. I think it's hard for people to believe we can drive these big turbo's that hard, thats the advantage of the big external wastegate.

Is this 60 psi actually measured in the cold pipe (maybe not so cold lol) or are you just assuming it's there because the wastegate is set at 20 and you've got 80 psi total?



-Scott