Turbocharging a HMMWV with BMI's kit

[patracy]

We've spun up a new forum here and I thought I'd start with a new project of mine. I'm turbocharging my HMMWV. My HMMWV started life as a M1038 2 man soft top. It has gone through a few changes. To a 4 man soft top. And lastly I've set it up as a slantback with a full turret. I've also added on a airlift rear bumper and rhino spare tire carrier. The truck only has a 6.2 diesel. So needless to say all the added weight certainly has slowed it down greatly.



So first I'd like to start with an unboxing of BMI's kit as well as some pictures of parts in the kit. I purchased the kit from them last week and it was here Monday. I stay pretty busy with work, so I'm trying to do this as time allows.

I will say that my initial impression of the kit is good. BMI's manifold is very nice. I rather appreciate the NPT tap for the EGT probe from them. Also they've also thought ahead and tapped the intake manifold hat for the boost gauge as well. They also included Mahle gaskets for the exhaust side of things and a SB air filter. Nice to see quality parts. BMI also has their own silicone boots instead of just some generic ones. And a nice oil supply and return line setup for the turbo. The custom airbox is made from aluminum that is tig welded. Overall I'm very pleased with the setup.



















I'll be posting up another video tomorrow of a baseline run of the HMMWV.

 

[nikojo]

Subscribed.

Question: Are there differences in the 6.2 and 6.5 engines that are NA compared to the turbos? In other words are the NA engines/cases the same as they are in the turbos or were the turbos beefed up or somehow different?

 

[BMI]

Subscribed.

Question: Are there differences in the 6.2 and 6.5 engines that are NA compared to the turbos? In other words are the NA engines/cases the same as they are in the turbos or were the turbos beefed up or somehow different?

On the HMMWV, the factory turbo engines use different block and head castings than the N/A trucks do. The turbo block/heads are not necessarily any stronger, just a different setup to accept the rear mounted turbo they used on the factory turbo applications. The intake manifold to head bolts are at a different angel (60° for the turbo engine vs 90° for the N/A's) and there are mounting bolt bosses and turbo oil pressure feed and drain galleys cast directly into the valley of the turbo block where the turbo actually mounts to. You can't just take the factory HMMWV turbo parts and put them onto the N/A engine, that will not work, hense the reason for a retrofit turbo kit such as this. Compression ratio, bore stroke and cam profile remained unchanged between the N/A and later turbo engines, making the N/A engines a perfect canitate to upgrade to turbo.

 

[nikojo]

Love it. I think I’m going to have to do this too!

what’s the issue of any with air conditioner? I’m planning on putting it in but not in yet. Anything to do ahead of time to avoid issues later?

 

[BMI]

Love it. I think I’m going to have to do this too!

what’s the issue of any with air conditioner? I’m planning on putting it in but not in yet. Anything to do ahead of time to avoid issues later?

The issue with the A/C is the location of the A/C compressor... it is often put in the area where the turbo needs to go. The A/C compressor can be relocated (up and inboard a couple inches) to allow space for the turbo by modifying the compressor brackets and (sometimes, depending on the specific kit) using a different (longer/shorter) belt to accommodate. It is not a big deal, but will require some fabricating of the brackets for mounting the compressor.

 

[patracy]

Another update, I had planned on videoing the entire install. But Murphy (murphy's law) is really kicking my tail with it. No fault at all of the BMI kit. Just my sour luck. The HMMWV hadn't been driven in about a year honestly. I took it out prior to all this to a friend's son's birthday. (A huge hit BTW) I remembered seeing a wet spot under it after getting back, but didn't think much about it. I figured it was a hose or something. Well, turns out, it was the water pump coming undone. The bearings were shot in it. I've got a new water pump ordered and it should be in tomorrow. I had planned on getting the turbo in today, but that simply isn't going to happen due to the water pump. It's much easier to do the water pump first, then finish up the turbo install. I have been working around all the points I can. Things were going well, until I got to the IP adjustment. Two of the three top cover bolts snapped off! So after a run to two towns over for some cap screws long enough, the pump adjustment is done. (I didn't even try to remove the broken bolts, I didn't want to put a torch on the IP and ruin it.) I just drilled and tapped the two holes and replace them with those screws I picked up.

Anyhow, I did manage to get a baseline run done of the HMMWV. So we can all confirm what we all know. A stock 6.2 HMMWV is sloooooow....

 

[patracy]

Today's hurdle.

Sent from my SM-G965U using Tapatalk

 

[SandBar]

When I looked into adding a turbo to my 6.2 years ago the consensus was that more than a couple psi and the motor would not take it, and the gains would be marginal. Looking at the companies website they make some impressive power claims , without head studs or other block upgrades. Has it been found that those power levels are safe long term for these engines with egt monitoring?

 

[patracy]

I've had my CUCV turbocharged for probably 10 years now. I've even towed way more than I should. (26K gross at least) I've never had a problem. The BMI kit comes with boost and EGT gauges as well. If you keep it under 10 psi you'll never have an issue. The power gains have been very noticeable in the CUCV at least.

Matter of fact, I've noticed it on my NHC-250 that I turboed, VW 1.6 that I added a turbo to, as well as another 6.2 I had years ago I added a turbo to. NA diesels all gain a noticeable amount of power from a turbo. The key is not overfueling or allowing too much boost. Now, I can't say I'm out there racking up thousands of miles on them. But I can honestly say I'm not always "nice" to them be it peddle or weight.

 

[BMI]

Before GM developed the factory turbo setup for the Chevy / GMC pickup trucks (in 1992) Gale Banks Engineering developed a kit (similar to ours in function, but not fit) that became a dealer installed option on new 6.2 diesel trucks. That kit also used about 9-10 PSI of boost and a similar adjustment to the injection pump, with no internal engine modifications to the factory-issued 6.2. GM worked with Gale Banks and their dealer network to develop that kit so the trucks that received the dealer installed turbo kits would retain their factory GM backed warranty. While the old Banks kit will not physically fit the HMMWV's due to differences in engine compartment layout, the effect on the engine was very similar to the Commander 6200 / 6500 turbo kits now available for the HMMWV and will offer engine longevity caomarable to an unmodified engine, but greater efficency and power output.

 

[gringeltaube]

........the effect on the engine was very similar to the Commander 6200 / 6500 turbo kits ......

Curious to know: how does your 6500 turbo compare to the stock GM-4 turbo that comes on the civilian 6.5L engines? And do both share the same 3.38" x 1.75" mounting bolt pattern?

 

[BMI]

Yessir, The turbo used in the kit/s is based upon a modified GM3 turbo and uses the same standard "T-3" (officially 86mm x 45mm) mounting flange configuration as the GM2, 3, 4 , 5 & 8 turbo/s.

 

[SandBar]

Before GM developed the factory turbo setup for the Chevy / GMC pickup trucks (in 1992) Gale Banks Engineering developed a kit (similar to ours in function, but not fit) that became a dealer installed option on new 6.2 diesel trucks. That kit also used about 9-10 PSI of boost and a similar adjustment to the injection pump, with no internal engine modifications to the factory-issued 6.2. GM worked with Gale Banks and their dealer network to develop that kit so the trucks that received the dealer installed turbo kits would retain their factory GM backed warranty. While the old Banks kit will not physically fit the HMMWV's due to differences in engine compartment layout, the effect on the engine was very similar to the Commander 6200 / 6500 turbo kits now available for the HMMWV and will offer engine longevity caomarable to an unmodified engine, but greater efficency and power output.

This is great information, as many people have told me the 6.2 will not tolerate even moderate boost levels. Thank you.

 

[patracy]

So life in general has been kicking my tail lately and I haven't been able to devote time to this like I wanted to. This weekend I know I have to work Saturday too. But I'm going to work as I can in the evenings on it. I managed to get a few things buttoned up while I'm waiting on some parts. I've wired up the gauges and installed them under the gauge cluster. Kinda "hidden" but still easy to read. I've got the intake charge air manifold installed too. The water pump is installed as well as all new gates belts. I'm probably going to replace the hoses too, but not until I've flushed the entire system. The water pump was a pain in the butt to be honest. I'm glad I held off on the turbo install while I worked on that as it'd have truthfully made things harder. A few other things were done like the oil supply and drain lines/adapters installed.

I'm going to change the kit setup a little bit when it comes to the exhaust. I want to route the exhaust downpipe differently. I'm going to make a custom downpipe and snake it along the manifold and drop it back down inside the framerail. There's two tabs I cut down on the hmmwv tub for clearance. Nothing that will cause any structural weakness. It looks like I can pass the 3" pipe with room to spare. I will however be wrapping the exhaust to keep the heat down.

 

[TLambert]

Just ordered the kit today! Looking forward to the upgrade.

 

[TLambert]

So life in general has been kicking my tail lately and I haven't been able to devote time to this like I wanted to. This weekend I know I have to work Saturday too. But I'm going to work as I can in the evenings on it. I managed to get a few things buttoned up while I'm waiting on some parts. I've wired up the gauges and installed them under the gauge cluster. Kinda "hidden" but still easy to read. I've got the intake charge air manifold installed too. The water pump is installed as well as all new gates belts. I'm probably going to replace the hoses too, but not until I've flushed the entire system. The water pump was a pain in the butt to be honest. I'm glad I held off on the turbo install while I worked on that as it'd have truthfully made things harder. A few other things were done like the oil supply and drain lines/adapters installed.

I'm going to change the kit setup a little bit when it comes to the exhaust. I want to route the exhaust downpipe differently. I'm going to make a custom downpipe and snake it along the manifold and drop it back down inside the framerail. There's two tabs I cut down on the hmmwv tub for clearance. Nothing that will cause any structural weakness. It looks like I can pass the 3" pipe with room to spare. I will however be wrapping the exhaust to keep the heat down.

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looking forward to seeing how the re-route works out to keep inside frame rails

 

[nikojo]

looking forward to seeing how the re-route works out to keep inside frame rails

What Is advantage to keeping in frame rails?

 

[BMI]

Inside the frame rails could potentially improve ground clearance by a couple inches on the exhaust downpipe

 

[patracy]

Sorry for the delay folks, but progress is happening. I've had some shipping mishaps with parts for the exhaust. But I'm happy to say it was started up this afternoon and I was able to see a pound or two of boost by power braking it.

I managed to make the 3" downpipe fit along side the engine. It had to be split into two parts though to install. The fitment is tight to say the least. The 3" v band flange had to be milled down on two sides just to get it through! I wrapped the around the tub and transmission in header wrap. The downpipe follows along side the manifold, then 45's into the v band flange. From there it dips down over the frame rail and then follows under the transmission out to the exhaust. I can see why this wouldn't be sold as a kit, as I've got several hours in these two pipes and I bet it'd be impossible to cover every install. Also note, the fuel lines and transmission cooler lines were relocated. (Transmission cooler hose isn't cheap BTW)





Now for another oddball thing from my truck. My truck didn't have the snorkel setup. I had just removed part of the intake and used a silicone elbow to plumb the snorkel into the stock airbox. The BMI setup just gets mounted to the factory firewall. Unfortunately that won't work for my setup. But I fixed it with my 3D printer. Just a simple flange I made up to sandwich between the firewall and airbox with a shoulder to connect the elbow I used.










Now for another issue that popped up from the exhaust mod. The coolant tank "drain line". It would have routed behind the turbo, but the downpipe being back there now prevented that. I needed to 90* it out from the tank, but the stock hose/extension wouldn't work without putting a knik in it. I picked up this hose from the parts store and simply cut it down to fit. Worked great. (BTW, it's a 1" hose, so it's kinda hard to find something like this)


I've got to finish the air lines, splash guard, airbox, and button up all the other little lose ends. Hopefully if time/weather allows I'll be test driving it soon!

 

[patracy]

Here's a thread about the adapter I designed.

HMMWV intake adapter for BMI commander turbo system for a snorkle

A little background can be read/seen here: https://www.steelsoldiers.com/threads/turbocharging-a-hmmwv-with-bmis-kit.201878/post-2354178 This is a very simple file I created to make a flange to sandwich between the BMI air box and allows you to plumb up a silicon elbow to connect to a snorkel.

www.steelsoldiers.com

If someone doesn't have the means to print this, I can make one for you.