Compounds

[dixiepc]

Anybody ever tried compound turbos on a 6.5? Not setup to make high boost but to provide a much more useable rpm range. Maybe something like a HX30 secondary and a HX35/40 primary.

 

[FellowTraveler]

I suspect the 30 would not play nice on a 6.5 liter diesel, the stock IHI turbo is 9cm2 and that chokes the 6.5 so a 35 in 12cm2 would be better choice IMO to a 40 w/50 compressor not looking for high boost just volume...just a thought.

 

[dixiepc]

I've run all kinds of ideas through my head. I have no experience with compounds but it seems like with them sized right it would be very useful.

I run a H1C with a H1E compressor housing and wheel. Pretty much the same as a HX35/HX40 hybrid. It has allowed me to swap all kinds of exhaust housings on there to try out. I've ran a 21cm, a 18cm, a 14cm that are all gateless. Now I'm running a 12cm gated. The bigger ones were great for towing but were laggy and smokey. The 14cm was pretty good all around but I don't tow as much as I just daily drive. Now with the 12cm gated it's much more enjoyable to daily drive but I haven't had a chance to tow with it yet.

 

[FellowTraveler]

I've run all kinds of ideas through my head. I have no experience with compounds but it seems like with them sized right it would be very useful.

I run a H1C with a H1E compressor housing and wheel. Pretty much the same as a HX35/HX40 hybrid. It has allowed me to swap all kinds of exhaust housings on there to try out. I've ran a 21cm, a 18cm, a 14cm that are all gateless. Now I'm running a 12cm gated. The bigger ones were great for towing but were laggy and smokey. The 14cm was pretty good all around but I don't tow as much as I just daily drive. Now with the 12cm gated it's much more enjoyable to daily drive but I haven't had a chance to tow with it yet.

I ran the BIG HX40 18cm2 on a 6.5td w/max fuel and 4.10 gear-sets it started to light up a 1.2k . Compounds do the best all around.

 

[dixiepc]

Rode in the mountains today with the 12cm for the first time. I'm pretty sure I'm gonna like it. I'm hoping that this setup will work for my secondary. Now to figure out a primary that will give me more volume and not too much boost.

 

[Husker6.5]

Compound that into an ATT?

 

[dixiepc]

Good idea but I'll probably use something like a HX50 or HX55. Much more affordable.

 

[Will L.]

If ya have an old gmX, use it into the hx50?

 

[dixiepc]

I've got a pile of those. Probably wouldn't ever have faith in any GM-X though.

 

[dixiepc]

I've got an early style Banks turbo manifold and a civilian H1 passenger manifold for the driver's side. Gonna run a short crossover under the balancer. I'm hoping to be able to mount the primary close enough to the orginal position so I can use the exhaust without any modifications.

 

[Will L.]

I've got a pile of those. Probably wouldn't ever have faith in any GM-X though.

Idk, when the engine didn’t have a lot of blow-by smacking the impeller, they lasted a long time. Frequently saw them break 300,000 miles.

 

[dixiepc]

I'm sure you're right but there would always be that nagging thought in the back of my mind. I've had lots of good luck with Holsets, so I guess I'll stick with them until one of them changes my mind.

 

[FellowTraveler]

Idk, when the engine didn’t have a lot of blow-by smacking the impeller, they lasted a long time. Frequently saw them break 300,000 miles.

RACOR has solved the oil hitting the turbine with their CCV.

 

[FellowTraveler]

I've got an early style Banks turbo manifold and a civilian H1 passenger manifold for the driver's side. Gonna run a short crossover under the balancer. I'm hoping to be able to mount the primary close enough to the orginal position so I can use the exhaust without any modifications.

X-over is perhaps the most mis-understood of all pipes to BIG and you raise start of boost to a higher rpm.

 

[Will L.]

RACOR has solved the oil hitting the turbine with their CCV.

I agree. Raycor, Provent, even a diy but they often cost as much by time you figure it out to working the best.
I have a provent 200, but it is not a good unit for going under water like deep pond or small river, so I am thinking of selling it for a different unit.
Many think the oil hitting the turbo doesn’t affect it, another big misconception by the gm group just because ‘gm engineered it that way so it must be ok’. As if they didn’t pinch pennies everywhere else

It’s like, everything falls into one of 3 options in mechanical devices:
1. No effect- a theoretical possibility but then real world testing always shows this incorrect.
2. Positive effects like Increase in longevity, or power or mpg. Obviously no one in racing adds it to win... And long life semi trucks dont have it as an optional feature to pay more for oil misting into it.
3. Negative effects. We want as much air going through uninterrupted- but lets lose a little to oil instead. And blades spinning 10,000 rpm get smoother and sharper or collect micro weight in random spots and have a streak of oil randomly catching any dust particles that make it through to disturb air flow on blades.

Part of the ‘service’ offered at dealerships was to clean out all the oil and install a new cdr to help limit it. Hmm.
Crankcase pressure gets higher with more rpm. But cdr job is to limit the removal of the pressure at higher and highest rpm. We know from all classes of racing higher vacuum in crankcase is more power and more mpg. So why the cdr? Because you will suck the engine dry of oil in 5,000 miles of freeway driving without it, and even if people top off the oil, the turbos die sooner.
In the dealership when a turbo went out under warranty 2 things were checked to see if customer had to pay for it:
Oil changes done and cdr changes done on schedule. If either was missed - customer pays.

In compound turbos, it is still something I would install.

I was wondering about even more dramatic separation of turbos. Like a small 4 cylinder turbo. I remember one v10 where a guy did 2 small primary (one each bank) then they fed a single large secondary. I’ll try to find the pic.

How you do placement of them under the hood has my interest peaked. Move batteries underneath and relocating fenderwell items to open up? On of the cool things about the square bodies- room for extras.

 

[ak diesel driver]

I think you need to reexamine how the CDR works Will. It's wide open until high boost and then starts to close. So the crankcase is being exposed to maximum available vacuum until the boost comes up, which is also when the vacuum gets higher. So IMO the CDRs job is simply to keep oil in the crankcase during high vacuum situations.

 

[ak diesel driver]

Unless you are running 10 pounds of boost going down the freeway the CDR doesn't adjust or limit vacuum

 

[dixiepc]

I ran a CDR for a long time and finally decided to try just a road draft. Been running that for about a year and a half and I'm not experiencing any of the negative affects that people talk about.

 

[FellowTraveler]

I agree. Raycor, Provent, even a diy but they often cost as much by time you figure it out to working the best.
I have a provent 200, but it is not a good unit for going under water like deep pond or small river, so I am thinking of selling it for a different unit.
Many think the oil hitting the turbo doesn’t affect it, another big misconception by the gm group just because ‘gm engineered it that way so it must be ok’. As if they didn’t pinch pennies everywhere else

It’s like, everything falls into one of 3 options in mechanical devices:
1. No effect- a theoretical possibility but then real world testing always shows this incorrect.
2. Positive effects like Increase in longevity, or power or mpg. Obviously no one in racing adds it to win... And long life semi trucks dont have it as an optional feature to pay more for oil misting into it.
3. Negative effects. We want as much air going through uninterrupted- but lets lose a little to oil instead. And blades spinning 10,000 rpm get smoother and sharper or collect micro weight in random spots and have a streak of oil randomly catching any dust particles that make it through to disturb air flow on blades.

Part of the ‘service’ offered at dealerships was to clean out all the oil and install a new cdr to help limit it. Hmm.
Crankcase pressure gets higher with more rpm. But cdr job is to limit the removal of the pressure at higher and highest rpm. We know from all classes of racing higher vacuum in crankcase is more power and more mpg. So why the cdr? Because you will suck the engine dry of oil in 5,000 miles of freeway driving without it, and even if people top off the oil, the turbos die sooner.
In the dealership when a turbo went out under warranty 2 things were checked to see if customer had to pay for it:
Oil changes done and cdr changes done on schedule. If either was missed - customer pays.

In compound turbos, it is still something I would install.

I was wondering about even more dramatic separation of turbos. Like a small 4 cylinder turbo. I remember one v10 where a guy did 2 small primary (one each bank) then they fed a single large secondary. I’ll try to find the pic.

How you do placement of them under the hood has my interest peaked. Move batteries underneath and relocating fenderwell items to open up? On of the cool things about the square bodies- room for extras.

RACOR CCV 4500 does the trick even plumbed into the compressor inlet piping but some rely on a catch can.
Tech experts in Sweden long ago, discovered that compounding turbocharging would do everything except adding piss into the mix for clean emissions...the piss part reminds me when interstate coaches used to incinerate the human waste piss and all through their exhaust systems.

 

[Will L.]

I think you need to reexamine how the CDR works Will. It's wide open until high boost and then starts to close. So the crankcase is being exposed to maximum available vacuum until the boost comes up, which is also when the vacuum gets higher. So IMO the CDRs job is simply to keep oil in the crankcase during high vacuum situations.

No, I get it. I dealt with vacuum system on dry sump and wet sump engines. Both race and equipment.

The higher the rpm, the more oil particles in the crankcase. The higher the compressive blow by, the more crank case pressure. Added together is worst case scenario.

Why / when does it restrict. Higher volume of air moving through the airhorn sucks in the crankcase air. It isn’t just turbo boost. All the n/a pickups and hummers see the same if not more oil in the intake than turbo. the airflowing creates the Venturi sucking in the air and the pressure in the crank case is still high- thats why the cdr was made on the n/a 6.2 &6.5 before turbos were ever added.

the added turbo simply creates more crankcase pressure because it induces more blow by even with brand new rings. Thats why they are different part numbers. The turbo ones regulate sooner than the non turbo ones because of this.

This is a dyno provable issue, we did it at work. I can tell you directly on a new engine bypassing the cdr is worth 3-4 ponies at 3500 rpm and same tains torque around 2300 rpm iirc. all stock engine. And it isn’t the “free fuel” of the oil burning because all clean intake manifold shows it. I can’t promise exact power gain and rpm, but I remember it was a tiny improvement on both ends. Rate of acceleration was also a tiny improvement but so little it was timer shown, not noticeable.

Something you could do to see it isn’t boost causing it warm up engine first then shut off- put a white t shirt over the hose opening and connect hose to trap a layer of the shirt. Block wastegate for no boost and start truck and immediately hold it at 3,000 rpm for a bit. Shut it down and inspect the oil on the shirt material. Do the same test low rpm. Do it with and without the cdr. Then again with the turbo and trap the gate to build 7 lbs. you’ll see it plain- higher rpm creates more oil to become drawn through than low rpm regardless of boost. Again, adding more boost (or more volume and lower boost pressure from bigger turbine) willhave more blowby and ramp up more oil loss.

the cdr works by volume of air drawn through it. When X amount occurs it closes more. Take an old one and adapt shop air compressor hose to it, then use a leaf blower. The volume of air going through the cdr creates pressure differential to close it.

I think we both agree it is wide open at idle and closes upper end- but I think you are saying it is boost related- incorrect. If boost then it would tap a hose from turbo output to control and there never would have been one on n/a engine.