Torqued

Picked up a large used Garrett VNT turbo. Apparently came off a 14 liter Detroit Diesel Series 60 EGR motor.

There is a Detroit Diesel tag on compressor backing plate with two numbers:

23531102
FKM44621

Tag also says: "Garrett GTA"

Compressor cover says: 0339-4 M24 A/R 0.69
Turbine housing says: A/R 1.72 M3 J282
Center Section says: M52

Anybody have access to a catalog that can shed some light on this turbo?

Popped the compressor cover and took some measurements. 14 blades, 7 tall, 7 short. Inducer looks to be about 70mm. Exducer around 102mm. Works out to about a 47 trim. Looks to be somewhere between a GT4294 (70.3/94) and a GT4202 (74/102). Not much play on the shafts side to side or end to end, but noticed some oil on the vanes and the backing plate. Seems like it is seeping from where the compressor wheel is recessed down into the backing plate. Looks like it seeped after it was removed since it is not flung out in a radial pattern, but maybe it was leaking and this is why it was pulled. Any thoughts? Is it possible it doesn't leak when the compressor housing is pressurized and the turbo is installed in the proper position (i.e. this happens during shipping but not when you actually use it)?


Anyone know if I can swap in different compressor wheels and covers? The backing plate seals to the compressor cover with a large o-ring and is roughly 21cm/210mm in diameter at the seal. I can't tell you the diameter of the shaft, the nut that holds on the compressor wheel looks to be 18mm but is a little sloppy. An 11/16" socket will almost fit, but some of the shoulders on the corners of the hexnut are a bit rounded so it won't quite slide on.

Disconnected the actuator for the vanes. The lever that is attached to and moves the vanes moves smoothly. Looking into the turbine inlet with a flashlight, I can see many of the vanes and they move fine from almost all the way closed to an "open" position. Was going to pop the turbine housing off to inspect the mechanism and measure the wheel. It is attached to the center section with 8, 12-point bolts. A 5/16" 12 point socket fits on them with a little slop but it feels like these are metric. I only have 6 point metric sockets, so rather that booger them up with the 5/16" socket (they are rusty) I held off. Any tips for removing these rusty bolts after I pick up a set of metric 12-point sockets?

Been researching this turbo a bit, haven't come up with much.

A guy over on LS1 Tech (bigturboz28) put one on a 402, rigged up a wastegate actuator to move the vanes, made 3 psi going up his driveway at 1600 rpm, 10 psi at 2400, and 15 psi at 3000.

http://www.ls1tech.com/forums/showthread.php?t=670015&highlight=vnt

At higher rpms, he could only get it to deliver around 13 psi. I'm not sure if he had the vanes working properly, or if the compressor was simply too small for the 402. He measured the compressor and said his had a 74mm inducer (mine is only 70mm) and a 102mm exducer. He moved on to twin T70s.

Looking at the Garrett Catalog (pp. 66-67)....

http://www.turbobygarrett.com/turbobygarrett/images/catalog/catalog_common/catalog.pdf

...his compressor wheel looks very similar to a GT4202, although the A/R on his compressor cover could be different. Garrett says this turbo is good for 500 to 1000 horsepower on motors 2.0 to 8.0 liters. The compressor map is on page 51. My thought is his compressor should have been able to deliver more than 13 psi on a 402, so the issue may have been the hotside. Either the vanes wide open may not be big enough, or he couldn't get the vanes adjusted right. The specs on the VNT hotside supposedly are as follows: It can have an A/R of as small as 0.42 in fast spool mode. Then it can open up to provide lower restriction with an A/R as large as 1.72. I think I have the same hotside as his, mine is stamped 1.72. While 1.72 sounds big, maybe the vanes, even when wide open, "clog it up" so it acts like a smaller A/R.

Another guy over on the Corvette Forum (BaldTurboFreak) shared some info on these turbos and said the compressor is made from billet titanium for high pressure ratios. The compressor may be a different design, so even if the inducer and exducer are the same dimensions as the GT4202 in the catalog, it may flow differently due to a different shape and a different cover. My compressor looks like aluminum to me.

http://forums.corvetteforum.com/showthread.php?t=1413757

I would really like to play around with the VNT aspect of this turbo which seems to be functioning just fine. To control the vanes, i picked up a remanned Detroit Diesel VPOD (variable pressure output device) that is used to supply various air pressures to the VNT actuator. You send the VPOD a PWM signal from a microcontroller to control the pressure output. The pressure works against a spring in the actuator and as it moves in and out, it moves a lever that controls the position of the vanes. I've got a Basic Stamp microcontroller that can send the PWM signal to the VPOD. I'm trying to tap into my ECM to get things like RPM, TPS, MAP, etc to feed into the Basic Stamp real time. The turbo has a built in tach sensor in the center section. If I can get these inputs into the microcontroller, I should be able write a program to control the turbo electronically via the VPOD the same way Detroit Diesel does.

I would be happy to find out I could throw different compressor wheels and covers on this turbo to dial in the cold side for an HT-502 I am planning to use it with. As it sits now, this turbo is probably more suited to a 350, or lower rpms and lower levels of boost on the 502. I'm running an EBL with a 2-bar map sensor with tables up to 200 kPa. I'm only looking for 15 psi max and not planning to take the motor over 5500 rpm. I would be happy for now if I could get the results bigturboz28 got. The problems I see are that my motor is 100 cubic inches larger than his and my compressor inducer is 4mm smaller. If his problem was the hotside simply was not big enough, it will only be worse for me. One guy in his thread mentioned removing some of the vanes to open it up. Sounded easy to do, I don't believe he tried it. If his problem was that he could not get the vanes adjusted right, I may be able to solve this problem by approaching it with a microcontroller, VPOD, and the factory actuator.

Seems like an interesting project, at least to me. Anyone know anything about this turbo? Where can I get seals? Can a bigger compressor be swapped in?

Torqued

Here are some pics of this turbo. The green wire leads to the shaft speed sensor.

Middle pic is the money shot. You can look up the turbine inlet and see the vanes. They are in the "full-open" position.

The last pic shows the VPOD and the microcontroller.

project89

iTrader: (1)

junckcltr on this board will prolly be able to fill u in on that turbo.

but im curious as to if u swap on a new coldside if u would sell the cold side off that turbo

Torqued

I would probably hang on to the coldside if I swapped it out. I've got a pile of small block parts begging to be put to use. It's hard to predict how things might evolve down the road. The current coldside might be ideal for a forged 355 in the 5-700hp range.

Torqued

Compressor appears to be from billet, not cast. Look at the tooling marks. Aluminum or titanium? How can I tell?

Torqued

Can't find a map for this compressor wheel. Trying to get an idea looking at maps of other GT compressors.


Turbo.....IND... EXD TRIM ..HP
Mine...... 70 ....102 ..47 ...?
GT4294.. 70.3 ...94 ..56 ...500-850
GT4202.. 74.7 .102 ..53 ...500-1000

Mine has an inducer the size of the 4294 but an exducer the size of the 4202.

This is why my trim [(INDxIND/EXDxEXD) x 100] is the smallest of the 3 at 47. Smaller trim flows less air. So definitely less than the 4202, but more or less than the 4294? Maps below.

Torqued

Anyone?

project89

iTrader: (1)

based on ur measurements those compressor wheel spects exactl;y match a masterpower gt42/gt45,

my quess is that is a gt42 series turbo off a small/mid side desil

Torqued

Actually, they come from 14 liter Detroit Diesel Series 60 EGR motors. I've seen them.

What I'm wondering is what size gas engine would this be well suited for and can I swap in larger compressor wheels and covers to use with the VNT turbine.

Found this on TiAL Sport.com:

GT4508: direct bolt on upgrade for GT4202
When 1,000HP Isn't Enough.

Already have a 4202R and want more power? What's that you say? A GT45 compressor housing will not fit? Here is your answer. We take a GT4508 and machine a GT42 Compressor housing to accept the GT45 compressor wheel, it looks great too!


http://www.tialsport.com/NewHotness.html

Followed up on this lead. Basically they are swapping a full GT4508 with a smaller cover in place of the GT4202. Their offering is not a compressor upgrade for the GT42.

project89

iTrader: (1)

the turbo shoudl be good for 900-950 witht he cold side it has.

u need to find out what size ar the housing is with the vgt closed and open, can u mechanically actute the vgt or does it have to be elec?

Torqued

A/R on the turbine: 0.42 to 1.72 Not sure what size turbine wheel I have, the exducer is right around 75mm, inducer diameter: unknown.

The vanes are actuated pneumatically. I'm planning to use a DD vpod to control the air pressure electronically.


From first post:

The specs on the VNT hotside supposedly are as follows: It can have an A/R of as small as 0.42 in fast spool mode. Then it can open up to provide lower restriction with an A/R as large as 1.72.

To control the vanes, i picked up a remanned Detroit Diesel VPOD (variable pressure output device) that is used to supply various air pressures to the VNT actuator. You send the VPOD a PWM signal from a microcontroller to control the pressure output. The pressure works against a spring in the actuator and as it moves in and out, it moves a lever that controls the position of the vanes. I've got a Basic Stamp microcontroller that can send the PWM signal to the VPOD. I'm trying to tap into my ECM to get things like RPM, TPS, MAP, etc to feed into the Basic Stamp real time. The turbo has a built in tach sensor in the center section. If I can get these inputs into the microcontroller, I should be able write a program to control the turbo electronically via the VPOD the same way Detroit Diesel does.

junkcltr

iTrader: (1)

Basically, a GT42 cold side. Check out Dave at Majestic at theturboforums and give him a call. Ask what he thinks about the boreless compressor wheel (no exposed threads and nut). They have been known to break the shaft easier.
You have plenty of compressor there for a 402. I think the other guy could only get 13PSI because of WG control. Good luck getting the air setup to work. Are you going to try it using that basic stamp? You may want to look at the Atmel AVR series. I prefer them over the PIC stuff. You can use the C language instead of Bill Gates error prone BASIC language (which makes slow and cumbersome assembly instructions).

Torqued

Thanks for the info and advice. I hear you on the Basic Stamp, I've got it, and it's so simple to program, I figure I'll give it a whirl. If I were better at C programming, I'ld probably go the route you suggest.

The guy over on LS1 Tech was running the 402, I've got an HT-502. If it could get me up to 650-700hp on 15psi or less I'ld be fine with that.

I was originally putting together a RamJet 383 for it, had the RamJet up and running with an EBL on a tired L05 short block to get some tuning experience and spun a rod bearing. Was getting close to pulling the trigger on the 383 forged rotating assembly, then this 502 with 2500 miles pops up for less than the parts for the 383. 4-bolt mains, forged crank, rods, and pistons, 8.75CR, suitable for boost. The deal was just too good to pass up, I went big block.

The coldside seems up to 650-700, not sure if the hotside would choke the 502. Not planning to spin it more that 5500. The exducer on the turbine is 75mm, not sure about the inducer, haven't cracked it open. This plus an A/R of as much a 1.72. What do you think?

junkcltr

iTrader: (1)

You may have already posted this......but what size is the exhaust wheel. I will run some calcs tomorrow to get a rough idea what it flows with that 1.72 A/R housing.

That should spool fast depending on the vane control setup. First guess is that the exhaust wheel is big enough to not choke it.

Torqued

Well, that's the question. I haven't cracked open the turbine to put a caliper on the major diameter. Takes a 12 point metric socket I don't have...yet. I don't want to strip the bolt head with something that is "close". They're a bit rusty, so I want to be careful. The minor diameter of the turbine wheel is right around 75mm. Does that put you in the ballpark?

snowman383

that is off of a freightliner..i drove trucks for 13 yrs..that is about a 25# boost you have..they have a problem with the seal leaking thats why there is oil in it..they would supply boost to my truck up to 2200 rpm..so on a car that would be close to redline.. or around 5500 rpm..call a frightliner dealership and they will tell you what ytou have for sure though

Torqued

Garrett services these as a unit so parts are hard to find, but Dave at Majestic says he's been able to use parts from other turbos to get these up and running again. I've seen these in Volvo trucks as well, probably any brand they put a DD Series 60 EGR motor.

junkcltr

iTrader: (1)

I would not take it apart. You said the exhuast minor diameter (exducer) is around 75mm. If you look at the GT42xx frame you will see it has a 82mm major (inducer) and 84 trim. This comes out to a 75-76mm minor diameter {sqrt(84/100)}*82mm = 75.x mm.
So you have a GT42 unit for the most part with a 94 to 02 ish comp. wheel. Looking at the turbine maps, a 1.44 A/R will flow about 45 lb/min. That is plenty for your 502ci. Since yours is a 1.72 A/R then you will not choke assuming you get the WG control right. The 402ci guy only got 13 PSI probably because he was opening up the vanes too much at the top end.

The cold side is small for your 502ci if you wanted to make max. HP in the 1000+ BHP range, but you don't want max HP out from the engine/turbo setup. I haven't run the number but I am guessing that at 10-15 PSI you will be at around the 60% efficiency line and making 650 - 750 BHP (flywheel HP). I will run some actual numbers later when I have more time.

Dave is a smart guy with lots of experience and great customer and sales service. Glad you called him.

Projects like these are a lot of fun. I hope to someday get a VGT/VNT for one of my vehicles. I have been eyeballing the Holset line because of the straight electronic control. The air setup is a little more than I want to deal with. I do have a GT1549 VNT (vacuum actuator controlled) waiting to go on a bike, but that project is far in the future.

Torqued

Thanks for all the information junkcltr, much appreciated!

You're two steps ahead of me . I was looking at the GT42 info in the Garrett catalog yesterday and saw the 84 trim and the wheel size. I went to get my calculator with the square root function to see if it had a 75mm exducer and the batteries were dead. I went to fire up excell, then got side tracked. Even if I got the answer, I don't know enough about turbines to make an educated guess using it with a 502. It's good to hear you believe it is big enough. Thanks a bunch.

I suspected the compressor is a bit small to feed a 502. Maybe clamp down the vanes and spin it a little faster, not sure this would work. If I could get good low end and 650 to 700 on the top end, I think I would be happy.

That being said, I was looking to see if there were ways to upgrade the compressor. I mentioned it to Dave in my message, he didn't respond to this question. BTW, Dave is no longer with Majestic. He's got a new website:

http://www.turbodaves.com

I'm guessing it might be possible to upgrade to the GT4202 compressor since mine is also a 102mm wheel and this would bump my 70mm inducer up to 74mm (if my shaft would work with this wheel). I would have to get my compressor cover machined or maybe a GT4202 cover slides right on. I assume everything would need to be rebalanced.

When I saw that TiAL ad, I thought I might be able to get an 80/108 compressor to work, but I found out they are really just packaging a complete GT4508 with a smaller compressor cover to fit in the space that a GT4202 would.

So I'm still exploring compressor options. If the current compressor really won't work with a 502 and there aren't other options, I'll save this turbo for a 355/383 project down the road.

Another question is: Can the VNT mechanism stand up to the heat of a gas engine. Jay K. Miller mentioned the heat problem with these turbos in his new book, pp. 16-17.

http://www.amazon.com/Turbo-Real-Wor...6272264&sr=1-2

Even though this turbo would be mounted under hood, I was thinking of running long tube headers partially to cut down on the fabrication, partially to help bleed heat. Then run some tubing down the vehicle a ways, then bring them back to the engine bay to reduce heat on the VNT. Lots of extra piping, but I don't think spooling would be a problem. Just tighten the vanes a bit if need be. I don't know if this would do the trick.

I've been told that the turbine wheel is Inconel 718 which is only reliable up to about 1600F and the VNT mechanism is temperature limited to about 1300-1350F. Maybe mount an EGT probe just before the turbine to keep an eye on it.

That would be really helpful. Thanks again.

junkcltr

iTrader: (1)

This may be of interest to you:
http://www.gnttype.org/techarea/turbo/turbocalcs.xls

At 12 PSI aftercooled and 5000 RPM you should be around 700BHP and 65% efficiency of that turbo. The interesting part is the 700 ft/lbs of torque at 2600 RPM and 12 PSI of boost if you can get that VNT closed down.

I would run that stock comp. wheel. If you try to close down the vanes to spin it faster, you risk over-speeding it and you are also making more hot air than HP. You should be fine with that comp. wheel and your HP goals. If you plan on spinning that engine higher than 5000 RPM (wanting more HP) then I would go with a bigger wheel.

If you wanted to spin to 6000 RPM and keep the 700 BHP then you would reduce the intercooled boost to 8-9 PSI, but this cause the efficiency to go to around 55% which is more hot air. So you would have to increase the boost to make up a little HP. Overall, I think you would be better at 12 PSI and 5000 RPM limit than 9 PSI and 6000 RPM limit.

Try out that calculator for different RPMs and boost levels. Put in a realistic engine VE. That is, one for an engine with accessories, not the typical 85% VE most people use.

EDIT: on a 383ci at 5000 RPM, that turbo would make around 700BHP at 20 PSI if you could cool the air enough. In this case I would rev it higher and reduce the boost. I would rev the 383ci to 6500 RPM and run 16 PSI for the 700 BHP using that turbo.

Torqued

Good stuff.

Reading through that spreadsheet reminded me of something important I've left out. I'm at 6600ft. Sea level is 14.7psi, I get only 11.53psi (map reads 80 kPa max). This would push my pressure ratios up to get the required pounds of air to produce the power goals.

I'm not averse to running higher levels of boost since the first 3 psi are just to get me back to sea level. Likewise, my fuel and spark tables go up to 200 kPa and since I'm starting at 80kPa, I've got 18 psi of boost left in my tables. Might be a weird way of looking at it, but it is the truth.

I'll try to reproduce what you've done using the spreadsheet and then adjust for elevation, but based on where you put me on the map, would this put me in better or worse efficiency islands?

By the way, which compressor map are you using as a proxy for my compressor? GT4294 (70/94) or GT4202(74/102)...mine is 70/102?

Torqued

With respect to accurate VE estimates. I was reading a turbo tech book, and was building a spreadsheet to work through the math and try to figure this out. Laptop harddrive crashed and I didn't have a backup... I'm not sure I was doing everything right, but I was learning alot.

Anyway, I had got to the point where I was estimating VE based on the torque curve. Don't remember exactly how I was doing it, I'll have to go back and re-research it, but here is what the torque curve looks like. Funny, I've seen this same engine rated at 340hp and 370hp by GM, this is the 340hp curve.

700 ft-lbs at 2600 rpm at 12 psi doesn't sound like a stretch. The write up says the torque peak is 512 at 2800, naturally aspirated.

http://www.gmperformanceparts.com/En...0534&engCat=bb

junkcltr

iTrader: (1)

Yes, air is less dense so you need more boost compared to sea level

If you are using an GM ECM is will do a BARO calc at startup and during driving to correct the internal VE tables to your elevation. So, You get the full range of the tables. That is using $8D and $58 code. I don't know what the aftermarket guys do.

Pressure ratio and lb/min flow increase. You are still riding pretty much the same efficiency curve.

I was biasing more towards the GT4294.

junkcltr

iTrader: (1)

That is the fun part of turbo stuff. There is lots to learn.....especially once you start playing with the ECM/computer side of things.

After looking at the curve and literature it dawned on me that my calc was wrong. I forgot to put in the correct VE for 2800 RPM. I was using a 5000 RPM VE. With that info it is more like 750-800 ft/lbs at 12 PSIg and 2800 RPM at your altitude (3 PSI or 6 inHG loss from sea level) using 94% VE.

Torqued

Running Rbob's EBL Flash with the port mod. I don't think it rescales automatically since I see the cursor dancing around the cells, but they never go above 80kPa and there are columns with values above 80kPa that I never reach.

Great product, makes a lot of the tuning super easy, but having said that, you still need to know what you're doing and I've got a lot to learn.

junkcltr

iTrader: (1)

I run a modified version of the $8D. In the $8D it does the baro calc internal so you would never see anything about it at the ALDL port. Knowing how RBob does things ECM wise I would not be surprised that he added that to his 747 ECM code that he is selling. I bet if you ask him it has the BARO correction in there so you get the full table use.
I have a 427 ECM in the works that is running off a 1 bar and 3 bar in the works right now. It is the updated version of the 747 ECM that can control the 4L60E or 4L80E.

Torqued

Trans control and boost? Impressive. The shift controllers I've seen are really pricey. I'ld love to be able to tune and run a trans with it. Do you have a thread going on this project?

junkcltr

iTrader: (1)

Nah, not impressive. I have the ECM installed along with the sensors and it is running the boost code I made for it. I still haven't installed the E-trans. It probably won't be in until summer. I need to finish mapping all of the $0D tables in the XDF file. After I got done the additional code for boost I have taken a break from it for a while.

No thread on it. It isn't a thirdgen. I usually only post that stuff when people are doing similar interesting things.........like you wanting to use the VNT with air actuated control. That is different in the same way I coded the $8D_AUJP 730 ECM for boost and now the $0D 427 ECM for boost.

Torqued

I've never been a big fan of automatic transmissions, but Fast355 posted the following picture in a thread and I've gotten more interested in them (especially with a turbo). Problem is finding a cost effective way of controlling an e-trans and boost. Sounds like you're beating down a path.

junkcltr

iTrader: (1)

I am too lazy to manually shift. It always messes up enjoying my coffee. Maybe driving truck all those years made me tired of it.
My original reason for wanting the E-Trans was so that I could bring it to the races and put a driver in that would normally not shift fast enough when the turbos spooled up. With the E-trans and 427 ECM I can have a switch on the dash to change shift points (the 427 ECM has a lot of usable inputs that GM wired but don't use in the code) and have them just mash the throttle. Flip the switch and have it set to 5000 RPM shifts. Although, I kind of see something like them not letting off and having the tires doing 130 MPH at the 60' mark.

Torqued

Performed a quick test of the VNT actuator to be sure it was working properly. The spring in the actuator causes the system to "fail safe" to the low restriction/low boost mode if you lose air pressure.

Hooked the actuator up to my air compressor and adjusted the regulator from 15psi to 75psi and watched the actuator move the vanes as the pressure changed. Works as it should.

Here's a quick vid cycling the vanes moving from full close to full open with the regulator set at 75psi. The leaking air sound is the temporary contraption I rigged up to get air into the actuator. I don't think it will take much volume to make this work.

Torqued

Figured out the VPOD. Hooked up 120 psi from my shop compressor to the inlet port of the VPOD and a 0-100 psi pressure gauge in the output port.

Wired up the VPOD to 12v and a PWM line to the Stamp. I played around with it quite a bit and tried a number of different things. I ended up getting the VPOD functioning really well. I can get it to output from 22 psi to 77 psi completely microprocessor controlled. It adjusts the output pressure fast, precisely, and constitently both up and down. Should work really well.

Trying to get the turbo speed sensor working as an input to the Stamp. If you overspeed the turbo, the compressor or turbine can grenade. I've read 100k is the redline for this model. Clamp the vanes down at the wrong time or hold them tight too long....bang! Getting the speed sensor working so turbo shaft speed can be monitored and used as an input for the vane control program seems worth the effort.

Not sure at what speed this sensor comes to life. Might have to rig up a temporary oiling system and jamb a leaf blower up the turbine inlet to get it to spin on the bench fast enough to get the sensor to come online. Restrict the compressor outlet a bit so it doesn't just freewheel. Not sure if I'll need to do this yet, still working through it and trying different things with the electronics.

Any ideas for a quick and dirty bench test oiling system? I've been contemplating spinning an old oil pump from a SBC I've got laying around with a drill motor. Not unlike when you prime a new engine before initial start up. Mount the pump in a reservoir, feed line, return, and maybe a gauge.

Being able to bench test the turbo while actuating the vanes might be useful to developing the software program in addition to testing the speed sensor.

kabir1405

Hi -I'm looking for a VPOD, new or reconditioned. Anyone know where I can buy one? thanks!