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Compounds on a Crawler

Now that the brain cell is spinnin' a bit faster, I do remember that I had welded in a port for an external wastegate on the ATS exhaust manifold or made an adapter to bolt onto the flange that would exhaust into the downpipe between the turbos when it hit a certain PSI.
 
I will add this and that is if I had put a 4bt in my current build and I wanted to, but couldn't find one that fit my price budget I would've twin turbo'd it, so I like that you are looking into doing it.
 
'84 Bronco II said:
That is correct. No idea on the internal waste gate porting. It might help, but I doubt you will achieve enough additional flow to make it worth while.

Take a look at the ATS compound setups for the 6BT, they are set up with external wastegates like I am talking about.
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I'm planning on a gauge to monitor drive pressure (exhaust manifold pressure) so I'll be able to see if drive pressure spikes. Can make an educated decision based on that data when the time comes.

With the manifold chop I have a convenient place to add a waste gate that would point right at the hot pipe, so if I need to add one it wouldn't be too hard.
 
csutton7 said:
GLTHFJ60 - Sorry no on the pics that I can recall and now you are challenging my brain cell to remember what I did!! Originally I hung it off the small turbo, but I used a schedule 40 4" weld elbow and thick flanges for the hot pipe between the turbos. I will say that this wasn't much fun trying to connect them together by yourself, but I did it. Then I think I built a mount that either came off the ATS exhaust manifold or off the side of the engine somehow, but for the life of me I can't envision what I did or if it was what I was going to do on the last set that I never completed. I'll keep shakin' the noggin' to see if the brain cell rattles something loose.
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My plan is to hang the primary off of the block with bracketry. Going with a relatively thin wall hot pipe that I'm currently thinking I'll have coated (maybe high temp powder coat?) , then wrapped.

They say that the 24v manifolds like to crack, so I don't want to try to hang both off of the manifold.
 
Run longer exhaust manifold studs and then you could use those for brackets as well. I agree, I would not weld anything to the manifold itself.
 
Wuz-A-zuk said:
Run longer exhaust manifold studs and then you could use those for brackets as well. I agree, I would not weld anything to the manifold itself.
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Oh that's a good idea. Better than using bolts too, less chance of breakage.
 
just curious: what boost/egt do you currently run? super 30 on my 3.9 does about 32psi while keeping temps under 1k.
 
slow600 said:
just curious: what boost/egt do you currently run? super 30 on my 3.9 does about 32psi while keeping temps under 1k.
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Highest of each I've seen is about 1500egt and 37psi. Don't normally push it that hard though. Stock injectors, timing advance spacer kit on the ve pump, Denny t stage 2 fuel pin, full power screw in about a half turn from runaway.
 
The idea I had for supporting the primary turbo is apparently a thing already (good) and is called a mid frame turbo support. Love it. I'll make my own, maybe on the mill. $180+ for a mount seems silly.

www.motionraceworks.com

Maven Products Billet Oil Drain MID FRAME Turbo Mount for Tubular Supp

Maven Products Billet Oil Drain MID FRAME Turbo Mount for Tubular Support 871 THE MAVEN PERFORMANCE BILLET STEEL TURBO MOUNT SUPPORTS THE TURBO FROM THE BEARING HOUSING AT THE DRAIN INTERFACE. THIS MOUNT WAS DESIGNED SPECIFICALLY FOR MID FRAME TURBOCHARGERS SUCH AS THE BORG WARNER S400 SERIES...
www.motionraceworks.com www.motionraceworks.com
 
Hot pipe tacked up. Positioning turned out fucking perfect.

Next up building the mid frame mount for the atmospheric turbo. That mount style should keep it solid in any OffRoad situation.

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:smokin::smokin:
 
I built a HX30W/HX35W setup for my 4BT, with 5x12 injectors, P3000 pump. Power is not really a problem, but the 3-4 gear jumps in the NV4500 can be annoying. Sometimes I wish that I had gone with a modern auto trans with many gears, but I really like the simplicity of my truck. I know my NV4500 may fail, but it's not going to leave me stranded.

I had total boost going into the wastegate of the HX30W and I had to keep my eye on the EGT gauge while accelerating on long uphills. One day I noticed much lower EGTs and I thought the gauge had failed. I opened the hood and saw that the hose to the wastegate had come off.

EGTs are certainly lower, but I need to do some comparison runs and see how it does power-wise. I know I was being careful with the throttle because of EGTs. Now I can't get to 1200F unless I lug the engine under heavy throttle.
 
Mikel said:
I built a HX30W/HX35W setup for my 4BT, with 5x12 injectors, P3000 pump. Power is not really a problem, but the 3-4 gear jumps in the NV4500 can be annoying. Sometimes I wish that I had gone with a modern auto trans with many gears, but I really like the simplicity of my truck. I know my NV4500 may fail, but it's not going to leave me stranded.

I had total boost going into the wastegate of the HX30W and I had to keep my eye on the EGT gauge while accelerating on long uphills. One day I noticed much lower EGTs and I thought the gauge had failed. I opened the hood and saw that the hose to the wastegate had come off.

EGTs are certainly lower, but I need to do some comparison runs and see how it does power-wise. I know I was being careful with the throttle because of EGTs. Now I can't get to 1200F unless I lug the engine under heavy throttle.
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Interesting. You saw lower EGTs when you disabled your primary turbo's wastegate.

Do you have a drive pressure gauge? Would be interesting to see what pressure ratios you're seeing.

This truck has a NV4500. The 3-4 jump is definitely annoying, especially with 4th gear synchro completely gone, lol.
 
GLTHFJ60 said:
Interesting. You saw lower EGTs when you disabled your primary turbo's wastegate.

Do you have a drive pressure gauge? Would be interesting to see what pressure ratios you're seeing.

This truck has a NV4500. The 3-4 jump is definitely annoying, especially with 4th gear synchro completely gone, lol.
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With the HX35W wastegate connected, pressure from the HX35W was always 15PSI below total pressure. With the wastegate disconnected, the difference in pressure between the two does widen as total pressure increases.
 
i never once considered twins for mine until now.....thanks for that.
 
In my mind, supporting the secondary turbo adequately is the key to success for compounds in a crawler. Can't have the turbo flopping all over the place.

Saw on YouTube someone using mid frame turbo mount and that solved the problem. Some research revealed that Porsche and other OEMs use that style of mount.

Whipped up this mid frame mount block on the mill, then cut and bent up this bracket to connect the block to the engine block bolts. Came out tits.

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Welded up and ported 24v manifold with studs to the head:

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Finished up hot pipe:

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Start of the intermediate boost tube between the turbos. Clearly I need some more aluminum TIG practice.

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Stainless downpipe:

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Software engineer. I work on this truck evenings and weekends whenever I feel like it.
 
Still could use a better air cleaner solution for long-term use, but I had a real offroad test week before last at windrock. No issues at all. No leaks, cracked pipes, anything. The mid-frame mount for the low pressure turbo works mint. Feeding the turbos via a Y-fitting off the oiler cooler also works mint. Two turbo drains into one with my custom Y-fitting into the block drain also works mint.

Testing, and project, complete.

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Very nice! I don’t know much about compounds. I assume the one boost gauge is the first turbo (20) and the second is manifold pressure (45)? Is 45 the max? We’re you excellerating like hell with 45? If your just cruising at 60, what would the two readings be?

When your serious wheeling like that, is there much boost? I suppose when you goose the throttle, the boost is right now!
 
WaterH said:
Very nice! I don’t know much about compounds. I assume the one boost gauge is the first turbo (20) and the second is manifold pressure (45)? Is 45 the max? We’re you excellerating like hell with 45? If your just cruising at 60, what would the two readings be?

When your serious wheeling like that, is there much boost? I suppose when you goose the throttle, the boost is right now!
Click to expand...

Far right gauge is the low pressure turbo boost, where it enters the high pressure turbo, and yes the middle gauge is manifold pressure.

Don't see a whole lot of boost on the trail, and honestly don't look at those gauges when on the trail either. My passenger noted that I hit 7psi on the low pressure turbo once on a hill climb, but that's it. Boost does come up pretty quick, it's nice.

Max manifold pressure I've got so far is 47-48#. It pulls real good all the way up to redline (3800rpm). I've got some tuning left to do, I think these turbos should be able to hit 55# on this engine with this injection pump. Cruising is 800* EGT, less than 15# of boost total, but it jumps up almost instantly if I jab the throttle.
 
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What does the plate say? I take it, this is street driven?

Edit, you guys both posted before I did. I assume it says “No Boost”. Why? It always had some, didn’t it?

I think it should say “got boost”?
 
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