I'm going to do some runs with the scanner on to see what IAT's I'm making at 10, 12, 15, 18, 20 psi sustained before I get an IC. This is to settle some old questions about exacty what IATis seen at each psi and set a benchmark to compare my post IC IAT's to.

You still running the GM-4 turbo? Edited by: Bumpin' Yota

I'd be interested in your results.


How are you gonna do the testing? Loaded?

If you are hitting 20lbs, they will be sky high. I never did a full throttle run for that long when checking mine but maybe I will to compare. Maybe do a full throttle run for 1 mile to see what happens and we can compare.

I don't think you'll get close to 1 mile with boost pressures in the 15-20psi range.


ECM is gonna cut fuel in a big hurry w/o IC.


I'd be surprised if you get 500 ft.

I was able to do a full 0-60 at 20 psi without ses light. This is a GM-4 turbo and I'll sustain boost levels for at least 1min.

This is my results


Ambient air temp. 57*F


fuel temp at start 85*F


DEStime 8.8 measured 8.8


manifold IAT 70.1*F rising


fuel 1/2 tank


uphill, unloaded 9,500 lbs dry weight.


6 psi sustained for 30 sec temp rose quickly from 89.9*F to 140*F within 20 sec.


in between runs I slowed down at the bottom of the next hill and noted the IAT 91.8*F


8 psi sustained for 30 sec. IAT temp peaked at 155*F in 10 sec


105.8*F cool down


10 psi = 185*F peak in 15 sec


108.5*F


12 psi = 195*F peak in 6 sec.


108.8*F cool down


15 psi = 200*F instant and 235*F peak in 8 sec.


108*F cool down


18 psi = 260*F peak in 8 sec.


I was only able to achive 20 psi after getting the pyro up over 650*F


20 psi = 285* F peak in 10 sec. I couldn't get the IAT over 285* even after 30 sec 20 psi getting up to 80+ MPH (in a 60)


These numbers are very relative to ambient temps and I would expect much higher temps on warmer days and pulling heavier loads.

holy crap, much higher than I was expecting, very insightful QM!

You should have also watched the fuel rate. I bet it started dropping when the temps got close to 220.

It would be intresting to see what the numbers are on a hotter day. I've always wondered if they move up 1° to 1°F ratio with rise in ambient heat. Like at 60° Ambient your IAT would be 155° would be at 80°F ambient would be 175° IAT?

those GM junkers quit moving air in a hurry, past 12 pounds it's an expensive hair dryer and pecker measuring contest. If you do the density ratio calculations from your 12 and 18 pound boost settings...........you'll see that volume of air moved went down, I'd bet a large amount of money on that.





I'm too lazy to do the math on sundayEdited by: grape

Nice work QM.


I didn't think you would get too far.


It will help you appreciate IC/WMI that much more.

I only want to know 1 thing at this point, what did you do to get 20 PSI?

I did look at timing during one 18 psi run where I was WOT but didn't get to 20 psi. timing act/des was very matched and ran 11 up to 16-17-18 only for a split second before shifting to the next gear then back to 11 and slowly back to say 16, shift then back to 11 and in OD at WOT it never went passed 12.6*


CR,


I lost my vacuum from the pump so I added this:


http://www.dieselplace.com/forum/uploads/quantummechanic/2004-11-14_145347_spring.jpg


I found it on my scrap pile on an old lawnmower. It's just hooked between the WG actuator bracket and the bolt I welded to the wg-arm about yeah far off the bracket so I had to streatch the return spring with locking needlenose to put it on. If I deciede to put on a new vac pump I could just take the spring off to return it to normal function. I have a wild noise above 16 psi that could only be the wg flapper bypassing as a machinegun stacatto.Edited by: quantum mechanic

I have a wild noise above 16 psi that could only be the wg flapper bypassing as a machinegun stacatto.





Thats the inlet wheel surging.........it'll will explode shortly there after if you do that much. What happens is they cavitate much like a prop for a boat.....yet with destructive forces randomly put upon and taken off the inlet wheel blades. I'd put you a screen inline between the turbo and the intake elbow if you're gonna do that much morehttp://www.dieselplace.com/forum/smileys/smiley4.gif

Ah, i see now. Mine makes a similiar noise when i crank the pot past about 2/3 and i lose all boost, i can't get boost back until i crank it down. Only test it for a couple seconds.

Actually it does have a cavatation sound to it.


I broke a blade previously Tihs spring and it was instant screaming from the out of balance inlet wheel gouging the inlet housing. I put on the spare.Edited by: quantum mechanic

I don't think mine cavatates, boost just goes away with pot cranked, PCM must not like what it see's.


I will be taking a week off of work here in a couple of days. Hopefully i can get some hi-pops up here somewhere, get a new PCM and have the timing done, get the pyro probe in place and i should be ready to rock & roll again. If time permits i may get a 6" lift also.


Then i can get started on some IC ideas and re-fabricating my intake. I hardly tow and with the pyro hooked up i should be ok for awhile.

The compressor wheel does not cavitate as Exhaust Pressure blows the wastegate open, relieves, wg pops shut, building pressure again blows the wg open, and so forth.


The noise is nothing more than wastegate chatter at the spring pressure vs Exhaust Pressure point.


Tie wastegate arm down - immobilize it - with a large chunk of bailing wire, or a hose clamp, or whatever.


You'll have no more noise - but watch EGT rocket as Exhaust BACK Pressure chokes exhaust flow out of the cylinders and thru the turbine housing.


I've run sustained 20psi on vacuum, with no cavitation, with GM-8 on OEM FACTORY chip, 63mm3 fuel rate, 8.5deg\-1.5deg TDC Offset.


All boils down to engine SWEPT volume at Xrpm - nothing you can do to get more swept volume outta this thing, without increasing BORE or\and STROKE or\and RPM.


Swept volume is gonna be ~450cfm at 3500rpm - period.


Written in stone tablets, down from the mountain many, many years ago.


300hp at 8psi? Outta 450cfm @ 3500rpm?


Don't make me laughhttp://www.dieselplace.com/forum/smileys/hihi.gifhttp://www.dieselplace.com/forum/smileys/hihi.gifhttp://www.dieselplace.com/forum/smileys/hihi.gifhttp://www.dieselplace.com/forum/smileys/hihi.gif


Difference in POWER capability is 1cfm at 20psi contains same oxygen content as 20cfm at 1psi.


Long as compressor flow rate exceeds engine flow rate - no cavitation.


There are some exceptions to this, but not here.


When compressor flow rate exceeds engine flow rate, it stacks up as pressure in the intake tract.


EXHAUST BACK PRESSURE is the GM-X series Achilles heel.


Don' believe it?


Hook up a 0-60psi gage pre-turbine - compare Boost to EBP.


And EGT.


With wastegate tied shut.


Wanna prove some MORE datum I've been posting since I first logged in here, QM?


Do a search on my posts, folks - it's all there, scientifically proven\proveable\repeatable, all promptly ignored for snake oil.


Till now......


And I am not referring to the Optic Sensor 'bump' - that is one of the FEW things I've seen on here that is workable.


If your engine ain't ragged out.......


So - come on, folks - bring on yer tar and feathers!


I got Science on my side............http://www.dieselplace.com/forum/smileys/smiley2.gif


Edited by: gmctd

Holy cow, forget the line in the sand, you just build a wall instead.


Glad were on the same side....we are on the same side right? ;)

Sure -


Still need to convince you to get an engine oil analysis just BEFORE your next oil change, post it here for comparison to TurbineDoc's, tho........

Hey now, let's play fair here. I'm no mod, but come on now. I'm not lookin for flames my way either here, but I have a great deal of respect for tried and true, and new investigation too. Let's just make sure that speculation is disspelled and true science is revealed here. There is a lot of things left to be desired in these engines here. Sometimes it looks like the engineers kinda went, that's close enough, and forget the rest. Bravo for those who'd like to make the difference for the rest of us, yet at the same time regarding the experience of those too.


QM fine job on the numbers, and GMCTD fine job on the experience end.

Oh, one last thing, I don't have the rock solid math on this one, but GMCTD, help me out if I missed something here. 1# @ 20cfm doesn't add up to 20# at 1 cfm. I think all figures are to be figured up in absolute measurement(psia), as opposed to gauge (psig). I think that the only measurement that holds true for being a reciprical would be 1 cfm at atomspheric would be equal to 1/2 cfm at 14.7 psig boost (1 bar) which would be double the air/oxygen as compared to at atomspheric pressure. Know what I mean? Did I get it right?

Post was not intended to knock QM's testing - I've not run across anyone in years so willing to get down and experiment for cause and effect.


QM 's figures are good, duplicating my early testing even as to method - very cool day here in Texas allows some simulation of charge-air cooling..


Gotta be quick, tho, as IAT rises quickly.


It's kinda like eating a tomato soup sandwich - ya gotta lift and eat fast, lest the sandwich fall thru the crust.


IAT base-temp figure of ~105deg is induced heat from engine and coolant-fan blast.


If you could weigh 1cuft of atmosphere at 20psi, and 20cuft of air at 1psi, the result would be identical.


The statement was pointed towards swept volume - displacement - in relation to flow rate.


A 7000rpm 400cuin engine will move similar mass of air at only 8psi Boost as 3500rpm-limited 400cuin engine at 16psi Boost.


And power is all about flowed air mass in lbs and fuel rates.Edited by: gmctd

I think I follow your thinkin' pattern, but my numbers aren't quite lining up as they should.


1 cubic ft of air = .075 lbs by weight at atomspheric pressure 14.7 psia. at what's denoted in my book as "normal temp" whatever that means. [which proably' don't apply to the diesel world at the moment]


1 cubic ft of air at 29.4 psia (14.7psig of boost pressure) would then be equal to .15 lbs by weight of air.


1 cubic ft of air at 34.7 psia (20 psig of boost pressure) would then be equal to .177 lbs of air by weight.


PSI pressure measurement doesn't equate to actual weight of air, if that is what measurement you are after. Now throw in heat, and the whole equation goes out the window.


Source: Modern Refrigeration & Air Conditioning C1992. Page 1006 Table 30-3

I might have the opportunity to run a spearco and then a cummins IC from a '94 or newer and do these numbers again. Then we will have a good comparrison between no IC, a small IC and a larger one on the same truck. Edited by: quantum mechanic

Alas - my math unskills have been exposed.


On a scale of 1 - 10, I have attained life-long ranking at square root of minus one......


The 20:1 statement is erroneous in content and scope, according to AGA-3,-7,-8, and API 2565 tables.


Point of fact is: uncorrected density of 1cuft air at 15psi is 4.5kg\m3 - 20cuft would be 88.8kg\m3


1cuft is 4.5kg\m3 at 15psi - 45psi (x3) would yeild 12.5kg\m3, uncorrected.


Gas measurement (air is a gas) world wide is corrected to 14.7psia and 60degF (metric-ized where applicable) to provide some equitable disposition.


However, volume content is essentially directly proportional to pressure increase - double the pressure per unit volume, double the oxygen content per unit volume.


I yield to the gentleman from the North, and you may withdraw your possibly premature kudos......... Edited by: gmctd

gmctd,


My next oil change?


I would think this first one would look terrible how 'bout the next one.

Now, if you want some intresting numbers to chew on. . . take a look at this link:


http://www.heatcraft.com/pdfs/HighSeaLevel.PDF


This is a psycrometric chart, with every stinkin' number you never wanted.http://www.dieselplace.com/forum/smileys/smiley1.gif Take a look at the blue lines that go in a diagonal fashion from the top left to the bottom right. These numbers are the amount of volume it takes for one 1 pound (weight) of air to fill at sea level atomspheric pressure. The intresting thing is, as you look at the chart, you can start to see what happens with adding humidity. This is what really kills the WMI end of things. The more humidity, the less volume for the oxygen.


At 108°F at 10%RH your volume of air is about maybe 14.4 ft3/lb of air.


Now at 108°F at 100%RH your volume of air maybe around 15.5 ft3/lb of air. That's an 8% difference in volume. That isn't oxygen either. WMI does make a difference in sensible heat, but it does add volume, not oxygen.


Just thought this would be some intresting bathroom literature for anyone intrested.


Hey, just thought of something here. Do intercoolers have a water drain? Usually with a traditional air compressor systems you have condensate to deal with, do IC's have the same problem, or not?

Me thinks he's refering to the checking of the silicates in the oil of TDG's dual breather setup.

yeah i think a lot of people would like to those results.


www.blackstone-labs.com (http://www.blackstone-labs.com)


free test kit and 20 bucks for the analysis

Holy cow, forget the line in the sand, you just build a wall instead.


Glad were on the same side....we are on the same side right? ;)





I wouldn't bet on it. http://www.dieselplace.com/forum/smileys/smiley18.gif

So tell me, as one of the mathematically disinclined...for a given set of variables, what happens to the volume of air by adding, say 32 oz. of water per minute to the air column? It doesn't make sense that you would achieve 100% RH because at that saturation level you would be extinguishing the flame, no?

The Scare Crow singing ............whiling way the hours conversing with the Flowers.........


Is this something I really need to know to put my foot on the Go pedal?


WOW.....http://www.dieselplace.com/forum/smileys/smiley5.gif

Is this something I really need to know to put my foot on the Go pedal?


Absolutely not. However, knkreb appears to be using part of his argument to suggest that WMI is some kind of voo doo science. I have always assumed that the amount of oxygen in the cylinder displaced by water vapor in a WMI system isn't enough to adversely impact engine performance. Given my results, I'm very comfortable continuing to assume.

It doesn't matter whose side your on we're all pretty much in the same boat.


I've heard you can't run a diesel too lean, that is, you can increase the o2 content and it will run better, but what could O2 be increased to? I know you can achive this with no2 but why not o2? what would 5 psi of o2 look like once it's mixed with intake air at a pressure controlled 12 psi?

Sorry, WMI is legit, sorry to make you think otherwise. It does work, I was just illustrating the changes in the dynamics of the air and how it affects things. Sorry WMI guys, my appoligies extended.


You can burn at 100% RH, it's when you start to get to 101%+ you start havin' some troubleshttp://www.dieselplace.com/forum/smileys/smiley2.gif.

O2 mixed with any kind of oil burns at a level you cannot control - doesn't matter if it's inside the cylinder, or in the intake, or on the intake, or the block, or firewall, or fenders, or your clothes, or you..........


Paint also burns like magnesium when exposed to pure O2.


As does vinyl wiring, engine, and body parts.


And clothing.


O2 must never be used around oil or oily conditions - period.


Don't even think about it, QM............


Proper procedure to increase oxygen content is compressed air - Boost - via super- or turbo-charging.

Awsume post folks. http://www.dieselplace.com/forum/smileys/smiley32.gif


Being an Engineer and married to a Scientist generates "yield".... Is E=mc2 REALLY true????? Scientists generate fact and working relationships. Engineers start with this knowledge and apply it.


Guess what, we all learn, as I did from this post.


Excellent exchange of information!!! Makes me think.......

There is some stuff out there on using propane to give you more getty up. You've just read all I know about that. May be a slightly better alternative than flirtin with O2? or not. who knows.


Someone who reads this post, please note that I do not endorse you goin' out an upendin' your BBQue tank and let it fly into the air filter of your truck to see what it would do. I here by advise you to put down your tools and keyboard and slowly back away so no one gets hurt.http://www.dieselplace.com/forum/smileys/smiley36.gif

Knkreb,


One of the member's here was sharing some number's he made on a dyno. It was something like 275 hp w/o and 305 with propane, Tq 485-495 in an 18:1 intercooled 6.5L with the heath chip.

coming from the boost side of things (non-scientific non-engineering!), no question the GM-XX turbos are brutal at high boost. With my penninsular turbo, the more you hammer it the more it goes: I max at 20lbs boost, but going from 15 to 20 generates more smoke AND more power. I've killed my bottom end a bit but the top end way more than makes up for it. Having said that it is a "lazy" turbo- it spools up a bit slow, so it generates smoke on the way to building the boost. I'm sure there is a better turbo than the Penninsular one, but time/money do not currently allow for more experimenting! I would think a bigger one WITH a wastegate (the penninsular is non-waste gated) would be the ticket. Kind of like the 3 little bears: I started with the too small, I have the too big, I want the just right!

You could try grape's solution - check the external dump valve on his setup......


I've had something else in mind for a long while, but I keep watching for a wastegated upgrade - possibly the Mitsu TE06H, but I need one up close and personal to compare.

I think a dump valve for me would make the problem worse- Im spooling too slow, I need every bit of boost I can get and then some.

TD IIRC has a ceramic x-over and heat taped it 2 or 3 times plus used some heat resistant kind of paint on his, told me his spools up real quick!http://www.dieselplace.com/forum/smileys/hihi.gif

Yah, I need to try the heat tape, I have the ceramic pipe from Kennedy. Every bit helps I guess.

get me the numbers off of the exhaust housing you have.......I'll fix your slow boost problem


the numbers I'm looking for should be cast into the housing somewhere near the inlet. And does the downpipe have 6 bolts attatching it to the exhaust housing?

oh yeah, you guys were trying to figure cfm and pounds of air earlier. Not sure exactly what you're looking for but the conversion is &nbs p; .069 CFM = 1 pound per minute of air


300 hp diesel = 300/8 = 37.5 pounds per minute of air


37.5/.069 = 543.47 CFM that's outlet flow without taking into account density ratio formulas........yet again...I'm too lazy for that right now.

thanks grape, I'll check and get the casting # and # bolts info to you.

22.2cuft of air at 14.7\60deg weighs one pound


x 37.5lb\60sec = 832.5cuft\min @ 14.7\60deg


Fits well within ~900cfm of 400cuin @ 7000rpm

I love it when it everything get's reduce to an equation. The only thing better is a table of variables.


What about Tempature and density?


I know the drop in density is proportionate to the rise in Temp. and that a larger volume of air (higher psi) of uncondensed air doesn't mean an increase of O2.

That is true - only if higher pressure and volume is result of heat - higher temperature.


Increase volume by increasing pressure alone - charge-air cooling - results in increased density with increased oxygen content.


Which is why you will see a pressure drop across the charge-air coolerEdited by: gmctd

the formulas for this junk is on www.turbomustangs.com (http://www.turbomustangs.com) there are pressure drop formulas for intercoolers, along with density based on temp rise from ambient to pressurised air works in relation with the pressure ratio at which the temperature rise occurs. Then you can figure out that a GM turbo at 20 pounds is about 30 percent efficient. 30% of it's effert goes into moving air at that boost level, and the other 70% of the energy is used to heat that air.http://www.dieselplace.com/forum/smileys/smiley4.gif Edited by: quantum mechanic

What about that formula you posted earlier - I am dyslexic, but even at that, I still couldnt make heads or tails of that second line.


Mistake, or me?Edited by: gmctd

grape, the info I can see on the Penninsular turbo I have is: 4 bolts attaching it to the exhaust manifold, on the top of the intake side of the turbo is the code060W, bottom of the intake side code is 696488B. I have a 1 1/2" to 2" adapter hose from the turbo to the intake manifold as the turbo outlet is 1 1/2" and the intake manifold horn is 2"

Thanks for the link grape. If I had a 6.5L website, I would like it to be that thurough.


http://www.dieselplace.com/forum/uploads/quantummechanic/2004-11-17_115220_dodgeic.jpg


I could make it fit.

grape, the info I can see on the Penninsular turbo I have is: 4 bolts attaching it to the exhaust manifold, on the top of the intake side of the turbo is the code060W, bottom of the intake side code is 696488B. I have a 1 1/2" to 2" adapter hose from the turbo to the intake manifold as the turbo outlet is 1 1/2" and the intake manifold horn is 2"





Hmmm......not what i expected. Did your right side manifold need any modification to make the turbo fit? If not, it's probably a euro housing just like Banks uses......the question would be what is the A/R, which will be hard to read on the truck as it is cast into the housing itself somewhere. Does the downpipe come out of the turbo at 3" OD? I also thought the inlet for the 6.5 intake manifolds was 2.5" OD.Edited by: grape

That's the compressor housing info - what's needed is the numbers off the turbine housing, where the exhaust down-pipe is

GMCTD, you are correct, those were off compressor. Okey Dokey, back with the flashlight I go for more measurements/turbine casting #'s...


in the mean time grape, very minor mods were necessary to bolt it up to exhaust manifold.

that's what i figured, they used a standard T3 exhaust manifold inlet......the same tiny stuff used on 3 litre turbo'd gas engines. You'd know what I was talking about if it needed the mods i was talking about.......as in cutting the turbo mounting flange off of the manifold and welding a T4 framed inlet flange in place of it.

Grape


What turbo would that mod allow you to run?


just curious now that I have a cheap salvage to call.

any of the T4 framed aftermarket turbos. This would be an N,O,P, or Q trim exhaust wheel N trim = 2.071" exd/2.922 major, O trim = 2.296" exd/2.922" major. P trim is the most common and what I'm using 2.54"exd/2.922" major, or the Q trim which is the largest available wheel in the T4 family 2.693"exd/3.111" major. On the compressor side of that turbo you can run anything from a T04e (dinky-like the GM series) all the way to a T88. Below the T88 you have a T76 which just for refernce as to its flow and hp potential will flow 60 pounds per minute of air at 14 pounds of boost in the 75% efficiency range.............that's enough for 480 hp in diesel fuel figures at 14 pounds of boost.

Hmm.. Not gong to find one of those at the salvage. It was all garret turbos off PS and the dodge turbo too. I'll have to keep reading the mustangturbo page there was alot to digest there.

http://www.peninsulardiesel.com/compare.htm


picture of the turbo I have (I think...), at a minimum the turbo outlet pipe looks identical. Havent crawled around yet.

Just based on eyeball deminsions the exhaust housing looks huge......which would make it lazy as you describe.