Builds Moonshine - A Build Thread (7 Viewers)

[GLTHFJ60]

Other notes from the test drive. Oil pressure is good, so it doesn't look like I'll have to add the larger oil pump, so that's good. I do have an oil leak, which I thought was the low pressure return, but in looking back at the pics, it seems I just need to tighten up some of my AN fittings, so that's good. The Y-Block oil feed setup appears to be working well.

 

[boots4]

Excellent, you've got the right attitude and I know you will definitely get this dialed in. All those other gauges are neat but I'd like to see you start with at least the big turbo boost line reference, the intake manifold reference (you already have this), and a pyro (you already got this too). With big turbo and intake manifold references you can run the formula's to see how they are sharing the load. The other readings will also help in tuning and probably get you there quicker than just these three but with these three you can get started and see how adjustments will impact your numbers. Baseline now so you can always see the difference from what you started with.

For me it's not necessarily about having both turbos share the load evenly, it's about the most power at a reasonable EGT with minimum smoke to attempt to keep some longevity. The numbers guy could read the turbo maps for each turbo used and see what pressure ratio is the best for each turbo and make that a goal if wanted.

Other thoughts, things to try: pull the air filter off during a test run to see if you get any more boost. This will suggest if it's restricting or not. Part of your retune will be working with the star wheel, the boost reference going to the AFC housing is tricky now as this spring was never intended for the boost we are after so it ends up adding fuel quickly which can make it a bit smokey down low until the turbos spool, there is a balance you will find that works best for your set up. I've played with different kinds of springs and different spots for boost reference too.

I believe there is a ton of potential with your set up, you will find the settings that wake it up. I'm excited to follow your journey.

Formulas:

PR = (PSIg + At pressure)/At pressure
PR = pressure ratio, PSIg = gauge boost pressure reading, At pressure = atmospheric pressure (this changes depending upon your elevation, I'm only a couple hundred feet in elevation so the standard 14.7 works for me).

 

[GLTHFJ60]

I like that idea. I'll pick up another boost gauge to start. @Zjohnsonua has a bug in my ear about making an arduino sensor kit with logging, so that would be fun to do.

I've been going through your thread again when you were going through the initial twins tuning. You did a great job documenting everything.

Also, air filter, dang, I should have thought of that. That's an easy test too.

 

[GLTHFJ60]

Well it's definitely not the air filter. Same boost.

Made this guy and searching for a leak.

 

[Zjohnsonua]

The enginerd in me wants you to build this critter:

Then we get answers...

Start watching for oil in your pipework as you change things. If you see it, where it is and how much is present hints at system behaviors.

 

[GLTHFJ60]

The enginerd in me wants you to build this critter:

View attachment 2939579

Then we get answers...

Start watching for oil in your pipework as you change things. If you see it, where it is and how much is present hints at system behaviors.

Believe me, I want that too, but I'm trying to slow the bleeding at this point, lol

 

[GLTHFJ60]

Made a plug for the cold side of the intercooler and did some testing. Found some leaks and fixed them:

But there's a big leak coming out the back of the compressor housing of the hx30. There's no o-ring in there from the factory, so I gotta figure out how to get one in there.

These guys don't think there's supposed to be an o-ring in there, but there has to be a way.

hx30 compressor housing question - https://www.4btswaps.com/threads/hx30-compressor-housing-question.107111/

Once I get that figured out, then I'll go on a driving test again.

Edit: found this, should work, will be here wednesday:

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[GLTHFJ60]

Secondary boost gauge installed.

 

[GLTHFJ60]

Oh yeah. Did a hot retorque of the head and reset the valves after it cooled. Not sure what I was smoking before, but the valves were all over the damn place. Some tight enough I question if they were closing, others 50% over spec loose.

They're correct now. Looking forward to getting the o-ring in the primary turbo and taking her for another spin.

 

[cruisedeisel]

Holly f-balls you have spent alot of time on this rig. I have been looking at om606 for a lighter than cummins high producing power diesel engine. 4bt is a sick engine. That top turbo intake def looks restrictive.

 

[GLTHFJ60]

Holly f-balls you have spent alot of time on this rig. I have been looking at om606 for a lighter than cummins high producing power diesel engine. 4bt is a sick engine. That top turbo intake def looks restrictive.

@MrK was going to pull his 4bt to put a OM606 or something in his truck. They're getting more popular.

The intake is def a bit restrictive, but it's the best I could do. Unless I make my alternator bluetooth, that's the best it's gonna get.

 

[GLTHFJ60]

Installed the o-ring on the high pressure turbo. It makes the snap ring not seat fully, but it's seated enough.

Have more data now, but overall boost hasn't changed. Here's a screenshot, far right boost gauge is the atmospheric turbo boost, center boost gauge is manifold pressure.

I'll do another boost leak test another day. She definitely has more power than with a single turbo, but I haven't achieved that bragging right boost number yet

 

[boots4]

Ok, so that means:

PR = (PSIg + At pressure)/At pressure

Big: PR = (17 + 14.7)/14.7 = 2.16

Total: PR = (26 + 14.7)/14.7 = 2.77, then 2.77/2.16 = 1.28 (to get small PR), and (1.28*14.7) - 14.7 = 4.1psi

So this shows that your big turbo is making 17psi and your little turbo is making 4psi. That compresses to 26 total psi.

My thoughts:

I'd say that the small turbo is not doing enough work and by getting it to work more the boost should go up and your EGTs should come down. Where is your small turbo's wastegate reference signal coming from? If it's being fed from total boost it's probably opening up the wastegate too fast. Reduce/restrict that signal and tighten up the preload on the small turbo's wastegate.

 

[The Phoenician]

I think i remember having to close both waste gates for me to feel any kind of real boost.

 

[Zjohnsonua]

EGTs look good. Healthy compounds shouldn't break over that much.

Fuel pressure is close, but a little low. You want surplus flow.

Those are straight psig readings. The turbs are just summing pressures, as pumps in series. 17 and 4 isn't 26...where's the delta?

Looks like you just need more fuel, man. Can't spin turbines without heat and blowdown pressure.

 

[GLTHFJ60]

Ok, so that means:

PR = (PSIg + At pressure)/At pressure

Big: PR = (17 + 14.7)/14.7 = 2.16

Total: PR = (26 + 14.7)/14.7 = 2.77, then 2.77/2.16 = 1.28 (to get small PR), and (1.28*14.7) - 14.7 = 4.1psi

So this shows that your big turbo is making 17psi and your little turbo is making 4psi. That compresses to 26 total psi.

My thoughts:

I'd say that the small turbo is not doing enough work and by getting it to work more the boost should go up and your EGTs should come down. Where is your small turbo's wastegate reference signal coming from? If it's being fed from total boost it's probably opening up the wastegate too fast. Reduce/restrict that signal and tighten up the preload on the small turbo's wastegate.

I think i remember having to close both waste gates for me to feel any kind of real boost.

OK! Starting to make some sense of the equations now.

Small turbo boost reference is on the compressor outlet elbow with a boost fooler spring thing. I'll adjust it in a good amount, which will delay the high pressure wastegate, and have another test drive.

EGTs look good. Healthy compounds shouldn't break over that much.

Fuel pressure is close, but a little low. You want surplus flow.

Those are straight psig readings. The turbs are just summing pressures, as pumps in series. 17 and 4 isn't 26...where's the delta?

Looks like you just need more fuel, man. Can't spin turbines without heat and blowdown pressure.

Fairly certain the pressures aren't just summed up between the two turbos. They're not operating independently, the high pressure turbo compounds the boost it receives from the atmospheric turbo.

Turbo Tech: Compound Turbo Systems

Compound turbo systems use different size turbos and operate in series where the first turbo feeds the second turbo boosted air and the effect is compounded

www.garrettmotion.com

 

[boots4]

Your fuel pressure is plenty for a VE injection pump. Any more and you start running the risk of pushing fuel out of the front seal on the injection pump and into the crankcase oil so I wouldn't go after more fuel pressure. I am getting 60+psi (compound boost) on 7-8 psi of fuel pressure and it doesn't drop on throttle hits. I've run 12-15 psi fuel pressure before and it didn't change anything, just added risk on that front seal. After a couple of these tuning experiments you can look into bigger injectors but adding fuel to a 1200F EGT without fiddling with the turbo settings will only make it hotter. Tuning isn't free (fuel and time spent) but it's cheaper than dropping in a set of bigger injectors at this point and then having to chase higher EGTs. Since you seem to be topping out at 26 psi total and the formula's have shown your small turbo isn't doing much there is work there that can be done first.

Weren't you getting more psi on just your single?

 

[GLTHFJ60]

Yeah, I was able to max out at about 37psi with the single, boost fooler about closed. I intentionally opened the fooler up when I put this system together, but it seems I opened it too much.

Fuel pressure has been at 15psi for years, so I'm not inclined to mess with it, but I hear you.

As far as adding injectors, they'd drive the turbos harder, making more boost (in theory) which would keep egts in check.

Like i said before though, not inclined to throw money (injectors) at it just yet. I've always wanted to see how much power I could get out of the stock injectors, so I'd like to dyno this system on those injectors before changing them out.

 

[A10Driver]

Yeah, I was able to max out at about 37psi with the single, boost fooler about closed. I intentionally opened the fooler up when I put this system together, but it seems I opened it too much.

Fuel pressure has been at 15psi for years, so I'm not inclined to mess with it, but I hear you.

As far as adding injectors, they'd drive the turbos harder, making more boost (in theory) which would keep egts in check.

Like i said before though, not inclined to throw money (injectors) at it just yet. I've always wanted to see how much power I could get out of the stock injectors, so I'd like to dyno this system on those injectors before changing them out.

I agree with boots, wake the small turbo up with wastegate adjustment first after checking for leaks and I think u will be surprised

 

[boots4]

37psi on a single on your system would suggest to me that you've got fueling now (plus the egt reading seen on your gauge) to be able to spin this compound set beyond the 26 you are currently getting. With some turbo setting adjustments you'll be able to harness more of your current exhaust energy and convert it into boost (and hopefully more power ). I would expect your EGTs to come down some with more boost on your current fueling but the small turbine housing on your big turbo has me curious on how that will react. It should spool faster but restrict more. Hopefully the wastegate on it is enough added exhaust flow. I suspect you'll run the small turbo's wastegate tight and the big turbo's wastegate a little looser.

I'm glad you opened up your boost fooler at the beginning and now we have a baseline of what that current setting will achieve. It was safer. Better to have low boost at the beginning than runaway boost and pop your new head gasket. Also glad you did another round of retorquing the head.

The challenge with running your small turbo wastegate signal off of compounded boost is that this signal will easily override your spring tension in both the fooler and the wastegate (something I've learned with our set ups). But, it's wise to keep it as is at this point since you already have a fooler there and to see what the potential is. It may be just right with a little fiddling.