a few turbo and exhaust questions

when I return state side from this deployment, I plan to buy a new to me CUCV truck. preferably with the 14 bolt rear end, dana 60 front end, 4.56 gears and locking rear, and TH400 (my research has shown me that this equipment is available as a package).

im new to this forum, but have been trolling them for a while now. im also not new to diesels or turbo set ups. but I have very little experience with these motors, and even less in the pick up configuration.

with that being said, I do know I want to turbo the truck. what are my options for off the shelf, if you will, exhaust manifolds? is there a tubular design out there? what about flow and heat retention properties?

same thing for turbo up pipe(s)?

as for the turbo its self, FWIU, the factory 6.5 turbo is a GM-4? is there a turbo map/compressor map available for this? is there a VGT/VNT option? is it worth it to just go for a HX35 straight from the start? has any one ever exhaust wrapped/heat wrapped the hot pipes before?, turbo blanket/thermal blanket? what were the results in terms of spool up before and after?

from what I have seen, it looks as though the turbo blows straight in to the intake manifold hat, any one tried to intercool their set up? what about trying to smooth out the bend in to/at the intake hat? any other ideas on ways to make the intake track less restrictive, thus lowering boost?

for the rest of the exhaust, is 3-4 inches just right, or to big? straight pipe is a must for a quick spool up and responsive turbo. but how loud is it?

is there a way to keep the IP and install a lift pump? also, is there a way, or has any one tried to rebuild the injectors in and of them self? what about modifying the injectors to flow more fuel? same with the injector nozzles?

I plan on installing ARP head studs at a minimum. I would also like to install a motor oil and trans cooler. any other "insurance" or "safety" supporting mods I should look in to?

this truck is going to be my daily driver, and get me to and from my fishing holes, camp sites, hunting locations, and blaze some trails with the wife. not looking for a race car, just a reliable, dependable, street truck with good fuel economy, and very capable off road.

thank you in advance for any input and advise. I look forward to hearing from you all.

• Do not post in all CAPS or in giant run-on sentences without punctuation. Do not post as if texting and do avoid the use of texting abbreviations. We are not the grammar police but we want everyone to easily read your post in at least 8th grade English. It is extra work to post proper sentences from a smartphone but the result will be greatly appreciated. Please do your best to use capitalization, proper spelling and punctuation. It makes it easier for everyone to read!

Nice wright up, I just got my turbo setup for my M1009 and am interrested in some of your qusetions I will be following.

doghead said:

• Do not post in all CAPS or in giant run-on sentences without punctuation. Do not post as if texting and do avoid the use of texting abbreviations. We are not the grammar police but we want everyone to easily read your post in at least 8th grade English. It is extra work to post proper sentences from a smartphone but the result will be greatly appreciated. Please do your best to use capitalization, proper spelling and punctuation. It makes it easier for everyone to read!

Click to expand...

Please ask me what abbreviations I need to explain or expand and I have no problem doing so.

FWIU; a common internet forum abbreviation meaning From What I Understand. Can also be used by replacing the U with a K for Know.

VGT; Variable Geometry Turbo. This describes a class of turbochargers where the total volume of the exhaust turbine can be altered to increase the turbo spool up time, decrease turbo lag, while proving the same maximum flow of a larger compressor wheel. There are 2 different ways manufacturers accomplish this. VVT; Variable Vain Turbo, meaning that there is a portion of the exhaust housing that moves to allow more exhaust gasses in to the housing. The second is:

VNT; Variable Nozzle Turbo. Nozzles with in the exhaust housing adjust to allow more, or less, exhaust gasses in to the exhaust housing.

ARP; American Racing Products

IP; Injection Pump

remote6 said:

Nice wright up, I just got my turbo setup for my M1009 and am interrested in some of your qusetions I will be following.

Click to expand...

Personally, I would always use header tape, also known as heat wrap, on all the hot parts; exhaust manifold and turbo up pipes. My reasoning is this will decrease spool up time. Turbochargers work based off of the first rule of Thermodynamics;
"energy can be neither created nor destroyed. Thus power generation processes and energy sources actually involve conversion of energy from one form to another."
So, the hot exhaust gasses want to expand due to the combustion process. The exhaust gasses cant do this with in the confines of the exhaust manifold or exhaust pipe. Once the gasses enter the exhaust housing of the turbocharger, the available room there allows for rapped expansion. The exhaust turbine blades convert this rapped expansion in to torque that spins the Inducer wheel. Knowing this, the more heat one and keep with in the gasses, the more rapped the expansion is going to be, and as a result; faster spool up times.

It should also be noted that after the turbo, in terms of exhaust, less restriction or back pressure will equal an even quicker spool up and less turbo lag.

TTT, Hoping for some sort of educated input please?

I have 6.5's in civy trucks and have started/run them with only a few feet of exhaust pipe. Not very loud at all in my opinion. This was done while changing out the exhaust system and just in my yard. I do plan on having a straight pipe on one I put into a Jeep Cherokee.

My trucks came with a lift pumps.

There are marine injectors (not Marine) available that flow a little more. S and S Diesel Supply specializes in these engines and has parts like the injectors. sixfiveturbodiesel.com is a forum just on the 6.5/6.2.

The easiest and least expensive way to turbo the 6.2 in the CUCV is to get the Intake Manifold, Exhaust manifold, Turbo, cross over pipe, and down pipe off of a 6.5 GM Turbo Motor. This is all factory items and will be a basic bolt on plug and play system. Do a search on here as there have been many write ups about turboing the motor including what injectors to use and how to tune the pump up to make the system work. GM made several styles of turbos for the 6.5. Get he one from a Pick up and not a Van or HMMWV. Also the trubos go from GM-4 through GM-8.

Or you can spend a lot of money on the Banks Turbo System, though it is my understanding that new systems for the 6.2 are few and far between. So again you are looking at finding a used system, but they are more expensive than a take off from a junk yard.

Safety mods would be to install a new Harmonic Balancer and a Stud Girdle. Just do a web search for stud girdle. For heat I'm thinking about using a product on the intake and exhaust cross over pipe and down pipe called Jet-Hot. http://www.jet-hot.com/ From everything I've read the coating is very strong and helps reduce heat buildup in the pipes. I haven't tried it yet and I'm a long way from having it done in my project, but am giving it serous thought.

Thank you for your service!

Wrap is great for 321 SS or thicker wall 304, crappy China 304 or thin wall the added retention will crack the manifold/DP and usually at the weld (ask me how I know). I have done bare metal, ceramic coated, and wrap. I like the newer lava wrap stuff because it doesn’t make you itch for days and no need to soak it before wrapping. Coating seems to wear/burn off after a while (especially if you wrap over it). Adding wrap and a blanket I think I dropped 200rpm on a 23psi tune, but on an E85 car, so apples to orangutans maybe.

An HX35 would be a good turbo but a 9cm Hy35W would be my first choice. Have not seen a map for an old GM turbo but have never looked, Im sure there out there or at least max lb/min. What is the turbine A/R or CM^2, what is the comp inducer/exducer size? They (GM) had pretty moderate goals so I wouldnt expect much from the old OEM stuff. If your not after much go with the bolt on 6.5T stuff, it has proven to be cheap, easy, and economical.

I understand the 6.5T manifold that will make the GM turbo work as a bolt on leaves very little room so if doing a Holset, BW, ect, plan on some welding/fab work. At that point I would just retain the NA manifold and build a crossover. You could make a HE351CW or the Ford Garret (VGT) work but see previous note about welding/fab work. Also get ready for some heavy lifting as these are monsters in terms of weight and footprint. I have one on the shelf but the form factor has led me to more conventional stuff. It would obviously have to be mechanically controlled with a WG or similar pressure differential device and actuating arm. If they are available get MLS gaskets. Cometic and Felpro make good ones.

You can rebuild these poppet style injector nozzles but they are dumb and just act as a relief valve for what the IP is sending. 6.5 Injectors may have larger tip orifices’ but the same or very close to the same opening pressure so that may work (check the -34 for opening psi spec). Modifying the injector nozzle for higher opening pressure is not a good idea because they are tuned to work within the pressure range of the IP and I believe this will throw off timing. There is a ST for checking injector timing but Im not sure you would have enough degrees of adjustment if you went too far with adjusting the nozzle opening pressure. I would stick with nozzle orifice. A 6.5 IP works just fine on a 6.2 with either 6.2 or 6.5 injectors. I have done all combinations of these parts in the field and never had an issue but never got a chance to dyno and check results. Better idea is to simply turn-up the pump (increase roller to roller) via the cam ring access port on the side of the pump. 1/8-1/4 turn works.

You dont see intercoolers because these motors will only tolerate such low boost that it falls into the category of diminishing returns (cooling not worth the pressure loss With a narrow efficiency range and low boost). An electric lift pump or higher flowing pump is not at all necessary unless yours is already tired. The internal transfer pump on the IP is what is doing the real work to get fuel past the delivery valve and into the rotor at which point the plungers and cam ring are making true line pressure.

DP size bigger than 3" your throwing your money away. 4" costs allot more than 3" and at the power level you are capable of achieving with this motor you will never max out the 3". 2.75 is what I would do and I would run a high flow muffler (pick one). The old OE GM turbines I have seen have such small volute area that I wouldnt at all be worried about a single 2.75 with high flow muffler hurting spool.

CUCV comes with an oil cooler (the lines will be leaking when you buy it). With the modest increase in power I would invest in a temp gauge before adding a cooler. Better still run good oil and a good filter (after you fix the leaks it will come with). Over cooling oil is just as bad as cooking it. A trans cooler is a good idea for the long haul but not required for adding a turbo.

Thank you so much for this good quality read! I have been doing my research as well. The turbo I have selected to use is a GM-8 for the N/A to turbo conversion. Also plan to go with a HMMWV intake manifold. I think with some port matching, removing some material internally, and smoothing it would have a decent increase in flow. Also, from what I have researched, this is a single plane intake manifold that has some extra clearance under it. In compliment to these modifications, the SS Diesel marine Injector Kit is in order. While I'm there, the Kennedy diesel high capacity water pump kit is good insurance. Speaking of coolant, is there a way to build or install a coolant filter? To finish up the turbo conversion, a DSG main stud girdle with ARP head studs are in order. To fix the leaking oil cooler lines, a DSG oil cooler and line kit will be installed. What is the thought and opinion on the Kennedy Diesel gear drive timing set? If its a good idea, I'll also install this as well at the time of the turbo conversion. Currently I'm looking and researching what are my options for stock or aftermarket exhaust manifold and how they flow. I can make a set custom, but I don't want to take the time to do so for what is stage 1 for the vehicle, and for daily driver duties. The cross over pipe or up pipes as some guys have called them; I can also fabricate if need be. Personally, I would like to see what is out there in terms of Remove and Replace parts for upgrading. If there is much of a demand for things such as this, I'll see what I can do to help others out.

When you wrapped your hot pipes, were there any bellows at all in the exhaust system? If not, I suspect that is the cause of your issues. The bellows allow for expansion of the pipes due to heat, and now increased heat retention. This is the reason I have a feeling that I'm going to end up building my own system; nothing I have seen out there has these at all.

Speaking of heat, would any one have what kind of flow data and exhaust temperatures through the heads? This data could really help me in building a quality, efficient exhaust manifold and back exhaust system.


Kennedy Diesel sells a lift pump that is advertised as "the same one we use on the Duramax." I'm interested in this, but now I wonder if its worth the money. I wonder because of the internal transfer pump. Before the turbo conversion I plan to replace all filters and fluids, along with rebuild or get a new IP, but I cant understand how sending pressurized fuel from the tank to the transfer pump would have no effect on power or how the motor runs. Your basically sharing the work load between the 2 pumps. Also with an inline filter pre-lift pump, the fuel will be clean, with a decreased chance of cavitation. Please elaborate on this?

When it comes to VGT set ups, is there a way to get a vacuum source for a vacuum operated turbo? I have a twin VGT set up rolling around my head! Twin VNT17/22s in conjunction with an intercooler. They can be held back to 10-11 PSI of boost, but the CFM they will flow combined should allow for much more power to be created.

How much power are you looking to make? What you are describing sounds like a max effort build, but then your going to keep the boost low (counter intuitive). I have a feeling that this motor is going to be very disappointing for you. I think you would be much farther ahead swapping a D-max or Cummins. For the money it sounds like your ready to throw down I think it would be wise to consider any of the many better power plant options. Slow down and consider your end game, the parts are not going anywhere, but when that deployment money is gone, its not coming back.

Not hardly a max effort build at all. Power wise, if I could get 400-450 LB-FT to the ground, I would be ecstatic. Boost is nothing more than a measure of restriction. In every build I have done, I try to have an attention to detail in terms of efficiency, reliability, and safety. The raw materials, tools and equipment I have complete access to. What I will end up buying is as follows; header tape/wrap, complete turbo set up from a donor 6.5T vehicle, possibly the HMMWV intake manifold, head studs and random nuts and bolts along the way. Hardly a super expensive build. The only reason I mentioned the TT-VNT system is because I can get those turbos for a case of beer; literally. The are not new turbos, and have 100,000 or more miles on them, but have been inspected and are in proper working order. I have an extensive, max effort D-max truck build I'm in the middle of right now, and will pick back up when I return. No need for another of ether; Duramax or a max effort build. Besides, these motors are not, and never will be, power houses. My end state goals are to have a reliable and fuel efficient truck (hoping for 15 MPG city, 20 or more MPG highway) that is moderately capable in off road conditions.


The hard parts I mentioned earlier I did not intend to buy. If that is how I came across, I'm sorry for the confusion and will do my best to more clearly communicate my intentions and thoughts in the future. I was merely asking what the consensus was on these parts or similar ones. I asked about the lift pump because the information you gave me goes against what I have learned over the years. Mind you in the diesel world, my hands on experience comes from VW TDI builds of various degrees, and D-max builds also of various degrees. This would actually be the first time I have done any extensive wrenching on an IDI motor.

edit: this is not my first or my second deployment.