Does anybody have a intercooler on their 6.5, and if so have you noticed more turbo whine than before installing intercooler?

im starting an intercooler project. does anyone know the outer diameter of the intake casting/turbo outlet? any help is appreciated

The O.D. on the turbo is 2.5 inch, which makes custom projects pretty easy as this is the standard size for turbo applications on foriegn sport cars and there is a good amount of plumbing available. I have built a custom upper intake as a foundation for an intercooler setup.

I used 3" ID on the one I have made so far. 3" will fit right over the stock pieces (turbo outlet, intake snorkel).


Ruben,


I've noticed a direct relationship between the turbo whine and removal of factory restrictions. An intercooler is the ooposite of a restriction, it's an expansion chamber coupled with surface area for heat transfer. The turbo must compress a greater volume of air to make the same psi in the intake Plus, it's a longer intake now which means turbo lag. I can see how all this could be heard as whine.


I have plans for making a water to air intercooler for under $100 in parts. I want to show step by step on the build to help other people who might want ideas for their own.


There is something of a restriction built into the exhaust-side turbo housing that is sapposed to dampen the turbo whine (baffle). If you like turbo whine, as I do, remove it.Edited by: quantum mechanic

I do like the the turbo wishtle. Were is this restriction, and how do I remove it any help appreiated. Also thanks for the help on the boost control. Thanks Quantum Mechanic you have been a big help.http://www.dieselplace.com/forum/smileys/Big Smile.gif

I guess it's that probiscus that TD stuck a freeze plug in.


http://www.dieselplace.com/forum/uploads/2B1_turbo2.jpg


Plenty room for improvement.








Edited by: quantum mechanic

Yes on the IC install, turbo whine diminished from stock, disagree on turbo lag , or if it's there can't tell by seat of pants test, but I also have boost control maybe that's the difference. with round filter and air box top off you can hear turbo spool up thought about installing a microphone & speaker to hear it all the time, inside the cab.


http://myweb.cableone.net/tbogemirep/Edited by: Turbine Doc

Tim, I run with the cover off the air box as well. I use the large Wix air filter and the cover would not fit so off went the cover. It sounds nice like a big rig. It is also a consistant tenth of a second off the 1/4 mile time in a 95 degree humid night.

What I ought to do to turn some heads is get a recording of a 30,000 shp LM2500 from work at full tilt into a PA have people wondering if I have a jet engine under the hood.

Quantum Have you you removed this restriction? If so is it in the discharge portion? What am I looking for. I have rebuilt many holset turbos, and have not seen any type of noise muffler incorperated. I am a cummins tech, and have not had the oppertunity to tear into a 6.5 turbo.

Ruben,


Go to my IC install link above you can see where I removed the turbo muffler and plugged with a freeze plug, also another trick on the hose coming from the CDR to the turbo small flex line from "tuna can' in valve cover rtv the hose joint it can let dirt to the turbo/engine.


The CDR is required to maintain proper scavenging air thru the crankcase.

TD,


Can you give me the core size, horsepower and flow rate specs and the part number for your Spearco IC?

I'll have to get the tape measure out in the morning.

The turbine housing has no "baffle" to quieten whine. The exhaust system does the rest.


When the turbo sings, it's the hi-rpm intake and compression you're hearing.


The '96-up has a plastic resonator chamber, or "muffler", attached to the compressor intake inlet elbow for 'passenger considerations', as TurbineDoc states.


The '95 GM-5 turbo was modified for improved compressor and turbine efficiency - the exhaust elbow was radically different than the early '92 - '94 turbos, allowing more exhaust flow with less back-pressure.


The '97-up GM-8 had minor upgrade in the wastegate shaft bushing due to early failure in the GM-5's.


To hear them sing, open up the intake shrouding.


But, remember, the engine likes cool, dense air. Open up the air box, and the compressor pulls in engine bay temp air at 200 to 800 degrees.


The 800deg comes from exhaust gas temperature, just inside the exhaust manifolds and turbine housing. Cast-iron mass retains and radiates heat. Heat rises.


Science 101http://www.dieselplace.com/forum/smileys/Wink.gif Edited by: gmctd

JD I put the lid back on in the summer ya I know it's 200+ under there but will sacrifice some performance for sound, cowl hood is on wish list to drop under hood temps.

Wasn't pointin' any fingers, my friend - just detailing the facts (as I know 'em)http://www.dieselplace.com/forum/smileys/Cool.gif

Yeah ritehttp://www.dieselplace.com/forum/smileys/Embarrased.gif


Those that haven't figgered it out JD & I banter lots, good guy to have your back & to keep you in perspective & sounding board for your goals.


I went to the turbonetics/spearco site http://www.turboneticsinc.com/air.html


Based on measurments I took when I installed the thing see my site located in above thread 25" x 4.5" x 7" closest core I see at their site is pn 2-175 rated for 615 Hp & 920 cfm, I don't think I'm encroaching on flow restriction problem with the IC which is why I worked so hard to fit the bigger IC in a 1/2 T truck.

gmctd, my 93 has the GM-4 turbo. Which of the GM lineup will bolt on without issues? As you stated, the other turbos are significantly more efficient? I'm running a boost controller and like the adjustability, but the turbo has about 180,000 miles on it and wouldnt like it to blow on me at 18lbs boost!

This is a GM 3&4 turbo from my '93.


http://www.dieselplace.com/forum/uploads/4A8_turbo3.jpg


To the left is the rotating assembly, wastegate/exhaust turbine housing middle and the transition for the downpipe right. The rotating assembly wears its' bearings out occasionaly, but if you catch it in time, you can replace them for about $75. Let it eat the shaft and it's $250.


http://www.dieselplace.com/forum/uploads/B97_turbo4.jpg


I can see where I need to grind these edges down to a smother transition.

Has anyone tried to powerflow (ExtrudeHone) the exhaust turbine housing in an attempt to increase flow? Would this be similar to clipping the turbine wheels? In other words, gaining flow in the upper range while sacrificing response down low?

I did my air cover removal test at New England Dragway on a hot and muggy night. It was worth a tenth of a second. I made bunch of runs back to back cover, no cover ,cover and then no cover and it worked everytime.


The cover site in the garage now as it sounds nice. I think underhood temps are only a concern if sitting in traffic, once moving the flow of air will drop the temp.


Tim, I have my ECM from Heath installed and ready to try. I did a quick road test to see if any codes poped up and all is good, except for the theft loc on the radio. Can't remember the code. I will make some comparision runs this weekend to see if it offers any noticable increase in performance.

Actually, QM, that area of the 'snail' is unimportant - it's just dimensional spacing.


The area just back of there (in the picture) is the nozzle area, where exhaust gas is directed into the turbine blades. If the nozzle directs flow into the outer diameter, the turbine spins slower. Directed into the inner diameter, the wheel spins faster. This is represented by A/R, the ratio of nozzle area center to turbine wheel radius, is cast into the housing, and is changeable only by replacing housing or wheel, or both.


Notice those units have the wastegate in the turbine housing (snail). Now check the exhaust elbow - see how the lower wall sharply curves back on itself, making for a bottleneck?


Pull the heat shield cover on your dad's '96 truck - you'll notice the wastegate is in the exhaust elbow, allowing for a shorter turbine housing, and a longer smoothly curved elbow, conducive to exhaust flow. Efficiency.


Turbine wheel and compressor wheel are identical across the series, and center section, exhaust elbow, and compressor housing are identical GM-5 and -8, but for the wg shaft length and bushing.


Compressor housing shape was re-designed in the -5, to more efficiently convert velocity to pressure, and the inlet area was re-designed from stepped to tapered reduction to prevent intake turbulence.


Remove the inlet elbow on the '96 for a comparo to the '94 - smooth, right? Efficiency.


dslhead, the GM-8 fits all the earlier trucks, with some modification to the wastegate controller.


EFI trucks, just re-route the vacuum line.


Mechanical trucks will require adaptation of the spring-cannister mounting bracket(s)


BUT (and, notice - that's a mighty big but!) the GM-X series are designed for an engine of 250 ~ 300 cu in range. This was to allow for quick spool-up at low rpm, where exhaust energy is low, but where trucks need power to move loads.


It works as designed, but as rpms and power output increase, so also does exhaust volume, velocity and heat, increase - exhaust energy - and the small turbine becomes a bottleneck due to rising Exhaust Back Pressure.


The GM-8 has maximum efficiency at 12 psi Boost. Above ~12psi, EBP in the turbine rises much more rapidly than does Boost, and at 15psi and up, the engine will produce less and less power.


At 20psi Boost from GM-8 with wastegate modification , EBP can approach 60psi, and the vehicle will not accelerate at full throttle demand, oem chip, EGT rising quickly.


Add more fuel, and Exhaust Gas Temperature skyrockets, as does Engine Coolant and Intake air temps.


So, the GM-8 is the more efficient design, because the GM-2~4 was an inefficient design, but has limited hi performance capability with the 6.5L 397 cu in engine.


Joey D - You are correct - underhood temps drop when the vehicle is moving. Imagine how performance would have improved by simply routing the closed airbox inlet to the front of the truck, taking advantage of the pressure-front available there to 'ram' cooler air into the compressor inlet, instead of 'drawing' radiator-heated air into the intake.


Ever stick your hand out the window, palm forward, at traffic speeds? That's a general idea of the pressure available up front.


And it's ambiently cool, not having passed thru the 200deg radiator.


I believe your experiment proves the airbox may be restrictive, not that the engine runs better on warm air.


For real improvement, add charge-air cooling , via heat-exchanger or water-mist, to get the compressed air temps down to ambient. It works.


SuperT - honing and turbine wheel trimming are available, but, from what I have read, as-tested results have not been favorable - general consensus is, not worth it. I have not tried it, having a working knowledge of this turbo and preferring other solutions, including a larger turbine application.








<edited><editID>gm

I have the water injection kit and it is set to come on around 10.5 lbs of boost. I have not tested it yet but the truck would not hold over 10lbs due to stock programming. I have Heath's new ECM in just have not driven it much to test it out. I plan on doing a full test this weekend with the water to see what it does.


I agree the filter assembly and duct work is limiting air flow thus the extra power when the cover is off. I do have the issue of the large Wix filter not fitting in the box so the cover stays off. I am going to move the battery to the wheel well and make a air box for the spot behing the headlight from sheetmetal with a hose coming from the front. If only I had more time....

thanks GMCTD, nice writeup. Sounds like a new turbo non GM-X should be in my future. "Sweet spot" now is certainly 1900- 2400 RPM, anything over that just lots of black smoke and high EGT.


The only two non GM-X options that I know of are JK (mid sized?) and Penninsular's mid size and large size. ANy other options you are aware of?

Joey D - You are correct - underhood temps drop when the vehicle is moving. Imagine how performance would have improved by simply routing the closed airbox inlet to the front of the truck, taking advantage of the pressure front available there to 'ram' cooler air into the compressor inlet, instead of 'drawing' radiator-heated air into the intake.


Ever stick your hand out the window, palm forward, at traffic speeds? That's a general idea of the pressure available up front.


And it's ambiently cool, not having passed thru the 200deg radiator.


I believe your experiment proves the airbox may be restrictive, not that the engine runs better on warm air.





gmcdt,


You may recall we were involved in quite a long thread on this issue back when the snow was still flying.


Just for fun, I thought I would run some air box temperature tests today using a remote temp sensor in the air box. The display unit/receiver was located in the cab. I was running on the interstate at sustained speeds of 65 mph; no trailer, no load.


At 83* ambient air temp., thermo sensor in the airbox, air box top off - 114* reading on the display unit in the cab.


With the air box top re-installed, temperature reading decreased to 103*. The thermo sensor was located in the same position for both tests; snuggly fit between the round K&amp;N filter and the inside wall of the air box base.


With the truck at rest and engine idling, temperature readings for both tests started to climb rapidly towards the 150* mark. My "equipment" wasn't designed for temperatures greater than 155* so I ran like a jackalope to retrieve the thermo sensor so as not to ruin it. Otherwise I would be facing the wrath of the little lady who keeps this nifty little gizzmo in the trailer.


What did my exercise prove? Well, I'm extremely surprised that the temperature delta wasn't greater than 11*, which might suggest that the air flow path design leaves a bit to be desired. In my '98, the mouth of the snorkel is directly behind the headlight assembly. This can't be good.


On the other hand, I'm achieving full boost. Does that suggest the engine is getting all the air it requires and therefore the air delivery system is adequate?


How's this for an analogy. I run 1 mile with a 75# pack on my back in 7 minutes. Allow time for my body to recover. Then I run the same mile with a 40# pack on my back in the same 7 minutes. During which run did I burn more calories?


That's about as scientific as I can get. But I think it's enough to tell me that my truck needs more air.

Spin you ought to check out the heat at post shutdown following hard drive heat soak my -40 to 125 indoor/outdoor house thermometer went out of range in about 15 min,


Sears sells for about $25 a thermocouple module to convert your DVM to a digital thermometer -40 to 500F,


I havent run any under hood temp tests in a while, I bought it to see how hot the Factory PMD location was 180 at cruise convinced me to remote mount mine, not such a big problem with fuel and drive air flow but idling in traffic temps rose to 200+ pretty quickly.

Joey,


My Heath reflash came in last nite just test drove it with factory boost control, finally this truck does what it's supposed to do. Acceleration about the same as with the many previous mods plus GM Hd L65 PCM, but it keeps accelerating, boost does not clip back, gear change is positive you can actually seat of pant feel the gear change under power at each gear, boost stays up with gear changes, doesn't clip and build back up.


My little test track area was busy today maybe if weather holds I'll be able to get to run it for some scanner snapshots tomorrow. One thing about this program boost and acceleration are linear to APP, more throttle more boost, more acceleration, more speed, also more top end I was at 100+ mph before I ran out of road max used to be 98mph.


Bill says try it with TM set for max of about 14-15 psi, got to reinstall it, I don't recommend this to anyone reading this without gauges or cooling (WMI or IC) EGT is also linear to other increases.


If this works like I suspect it will, there will be another surplus JK boost control on ebay, it works well, but I'm not sure I'll need it with this reflash.


Edited by: Turbine Doc

The turn down that bolts up to this is a severe bottleneck and I can see how you could improve the &gt;5 turbo with an improved outlet piece. I realize that I may be sacrificing low end torque for potential gains, but any measurable flow improvement should be felt in the 2200 rpm+ range where highway hauling happens.





http://www.dieselplace.com/forum/uploads/6F4_turbo11.jpg


http://www.dieselplace.com/forum/uploads/F1B_turbo12.jpg


The bushing on the waste gate is gone and it's possible for the waste gate to not fully close. I am going to modify it with a ball peen hammer to seat.


http://www.dieselplace.com/forum/uploads/567_turbo13.JPG


I'm sure a $2500 ball bearing trubo is the lick, but doing the grind only cost my time and I get to test it out and deciede if I want to do it two more times.


Edited by: quantum mechanic

dslhead - Banks sells the Mitsubishi MHI TE06H with their Ford 6.9\7.3 kits - may be next size up from GM-X by IHI, but I don't know that for sure. Requires comparing compressor wheel and housing, turbine wheel and housing, and wastegate diameter.


Good tests, spindrift - please tender my thanks to she, who must be obeyed, for kind permission to use the instrumentation. http://www.dieselplace.com/forum/smileys/Wink.gif


Um...you did get permission, right? spindrift?


I would expect those temps to be correct, for 65mph freeway cruising. Large volume of air moving thru the engine bay at hiway speeds.


The difference being the insulation afforded by the plastic air box - it blocks underhood heat, allowing cooler air flow from the front.


You can see how the temps climb when stopped, and slow-moving is only somewhat cooler.


In that previous communication, my intent was that the inlet be plumbed directly to an opening in the front bulkhead, which would then be pressurized by any forward vehicle movement.


If the turbo can make full boost, the air intake system poses little\no problem for normal driving conditions.


At only 405cfm at 3500rpm at Baro, Boost intake to 1/2 atmosphere, 7psi, and flow increases to about 600cfm at 3500rpm.


2200rpm at 65mph is not a lot of air flow, compared to the volume of air the vehicle is moving thru at that speed.


Figure the frontal area in square feet, say 36, move the vehicle forward 1 foot for 36 cubic feet displaced, times 5,280 feet\minute at 60mph would give that volume. Give or take.


I'm a zero at math, and probably overlooking something there, but it is considerably more than the 6.5L can flow during that same minute.


When applied volume is greater than required volume, it stacks up as pressure at the intake. 'Ram-air' - natural Boost.


Now, I don't suppose 'she, who must...etc', would happen to have a pitot tube with digital readout in her repertoire (trailer), by any chance?


I've intended to measure that pressure-front at various speeds, but have not, yet.

This from the Banks web site on why backpressure is bad see full text here: http://www.bankspower.com/Tech_SecrettoMakingPower.cfm


More importantly, if the exhaust backpressure rises higher than the induction pressure generated by the compressor, some exhaust gases will remain in the cylinder after the exhaust stroke to dilute and reduce the incoming air/fuel charge, and in worst-case scenarios, exhaust gases will actually flow backward into the induction system during the “overlap” period inherent in most camshaft designs where both the intake and exhaust valves are open simultaneously (see Fig.6). In this last case, such backflow is very detrimental since it raises the temperature of the incoming air/fuel charge and promotes damaging detonation.
Edited by: Turbine Doc

GMCTD,


Thanks for the info on the ExtrudeHone process. Powerflowing the turbine housing always struck me as a great way to remove some of the backpressure in the system, but as you pointed out, the cost of the procedure may not justify the gains.


Also, here is a link that I posted in another thread on modifying an airbox for maximum flow. Even though the test box in the article is for a 4 banger, the information could be applied to almost any turbo application. http://www.autospeed.com/cms/article.html?&amp;A=0629

QM, the wastegate 'flapper' is attached to the arm such that it has free movement. Make sure it is not stuck - it should rotate and 'wiggle'.


Here is some info on cleaning, may be of interest to you.


Drain opener is sulfuric acid - can be used to clean paint, oil and grease and such from parts. Rinse with clear water, dip in water\baking soda solution (1/2 box to 5gal water), rinse again.


Bowl cleaner is hydrochloric acid - can be used to de-rust parts after above steps. Rinse with clear water, dip into water\baking soda solution, rinse again.


Immerse in (choose one) varsol\petroleum naphtha\paint thinner, blow dry to prevent immediate re-oxidation.


Sulphuric acid burns skin immediately.


Hydrochloric acid is more subtle, but still burns.


DO NOT MIX, thinking to save steps.


Keep running water handy for immediate flush - splash water\baking soda on affected area(s).


Wear safety goggles and rubber dishwashing gloves.


Auto Zone carries water-rinseable automotive cleaner in white can. Cleans most-excellently when rinsed with hot water, as from the bottom spigot on the water heater in house\garage.


Added benefit - when the water dries, there is no residue - the part is paintable, if required.

Thanks, SuperT, and to all who post links - I am an internet illiterate, finding it most difficult to 'surf' and find information.


I would urge anyone with further interest to visit the Banks website for their 'Banks Talks Tech' series. TurbineDoc lists one such excerpt, above.


I learned via the school of hard knocks during 57 years of infatuation with the infernal combustion engine (my dad 'initiated' me at 6yrs), doing it myself, and reading everything I could get my hands on.


Banks has it all indexed there, for your perusal. There is some Banks product association, but the specific info is universal.


With the internet, anyone can become very knowledgeable in a very short time. Experience is the vehicle. If you enjoy working on the vehicle you drive, experience awaits you.http://www.dieselplace.com/forum/smileys/Cool.gif

For benefit for JD &amp; others new to the internet; copy &amp; paste into a post is pretty easy unless it's protected &amp; incapable of being copy &amp; pasted, with left mouse drag across text or url address you want to copy it will highlight, after highlight then with right mouse button click copy, it will go into the clipboard, then go to where you want to insert it and then click paste, it will insert to your message.


Might take a couple of times until you get hang of it, now there might ber several ways to do this as well I've just exposed the limit of what I know but this way works for me.

SuperTuscan,


I have found AutoSpeed to be an excellent source of information as well. Note the reference to "Intercooling" at the bottom of the page for your link.


AutoSpeed also has an excellent series of articles about WMI for those of you contributing to this thread, who also have exhibited an interest in alternate forms of charge-air cooling.


gmctd,


Of course I got her permission. I may be in my 40's, but I haven't completely lost my mind. In fact, she came along for the ride. To her credit, she knows I can't do more than one thing at the same time. She was a little concerned about me trying to keep my eyes on the road and watching the temperature gauge at the same time.

Good deal, spindrift. I'm still collecting data, and it would go much quicker with two pairs of eyes and hands. Difficult to write at 65mph.


Now - about that pitot tube?http://www.dieselplace.com/forum/smileys/Wink.gif

before I reassembled the turbo, I gave the turndown all I could with the grinder.


http://www.dieselplace.com/forum/uploads/35A_turbo15.jpg





http://www.dieselplace.com/forum/uploads/C83_turbo14.jpg


One last look because I misalinged the rotating assembly to the oil return line. I also managed to shear off one out of three of the remaining bolts taking it back out. The flap was only part of the problem, the shaft the wastegate is on has enough play in it to become askew when pulled closed. I find this turbo set-up to be a tedious knuckle buster and I would redesign the system as much for ease of disassembly as performance. I only drove it five miles due to the leak, but it seemed to get to the 2000+ RPM range quicker. I need a little more time behind the wheel to say for sure.Edited by: quantum mechanic

You guys with intercoolers ,what do your EGTs drop with your ITC. I have not noticed much drop. Edited by: Ruben

Ruben,


where is your probe pre or post turbo, mine is post I run about 800 hard acceleration or heavy towing

If you can drop 100deg on the intake, you'll usually get 100deg drop EGT.


You'll notice more effect under load - hi boost required, more heat generated by compression, hi IAT.

i forgot who it was but someone said they had a intercooler ran trought their a/c system. I would like to know more info about it and if you have any pics of it. It sounds like a good idea and would be very cool as long as it didn't hurt your a/c to bad. That and someone else was talking of making a water/air intercooler out of a heater core by encasing it but not sure how to figure out how much it woulf flow and if it would be enough to suffice the truck.

I put a second evaporative core piggybacked after the stock one and before the compressor. The coolant (r134a) is cold as it leaves the first core and is about to be compressed, so your doing the system a favor by warming it. The a/c blows cold inside the cab and all the water you condensate from your intake is now part of the combustion cycle in a liquid form.


http://www.dieselplace.com/forum/uploads/CCB_acintercooler.jpg


The water to air could be put together for less than $100 if you weld.