Compound boost.

[JDLAutoDesign]

Originally Posted by DustinS

Okay. So doing more research on this. Kind of making plans. I have a friend doing a twin turbo V6 swap in an S2000 with custom A/C lines. As long as I can talk him into doing the A/C hard line on my car. I think I can get a V-Mount to work.

Using a greddy kit Evasive did a V-Mount for their pikes peak car








Running SBD kit (effectively the same kit)



My Current Turbo kit^^

So plans are the cut the straight section out of the manifold, effectively dropping the turbo down quite a bit. Using a Tial V-Band Exhaust housing to make mounting a little easier (and what is not to love about a Tial Housing). Also mounting an external Wastegate. This should allow me more room to get the intercooler in place and air routed correctly/better. Only hurdle will be how tall the Cosworth kit sits.

Was already planning on building the engine over winter. Element Tuning Built w/ head package. So this could get interesting. If it doesn't work, sell the supercharger/turbo and mount a GTX3076 on the manifold and I have a sick V-Mount set-up with A/C.

Running a V-Mount should take care of Heat Exchanger/intercooler cooling issue. The Cosworth A2W intercoolers have been proven to be super effective, so intake temps shouldn't be an issue at that point. Now I need to find a place to tune the car, I have a feeling I will be spending 15hrs+ driving to a tuner...

I'll be finishing up my A/C V-mount setup soon. I'm using the Aeroquip Ac hose and fittings. Super clean and high quality. I did have to do some welding for the adapters but may have some billet ones machined soon. I should have it plumbed with A/C in a week or so.

[DustinS]

Originally Posted by JDLAutoDesign

I'll be finishing up my A/C V-mount setup soon. I'm using the Aeroquip Ac hose and fittings. Super clean and high quality. I did have to do some welding for the adapters but may have some billet ones machined soon. I should have it plumbed with A/C in a week or so.

I love the work you have done.

I was just wondering last night if there were AN fittings/lines I could use. So you answered that. Thank You.

Edit: Some info from Hellion about their compound kits

Q: Is the Supercharger a Restriction?
A: No, not at all. The supercharger is not a stagnant, solid piece that air has to travel around or through. Rather, the supercharger is simply doing what it does, and that's take air and essentially make it smaller. The supercharger will simply take the air that has been compressed by the turbochargers and further compress it as it travels into the engine. In fact, the turbochargers will basically help to improve the overall efficiency of the supercharger. Roots and screw-type superchargers experience a condition known as "back flow." Back flow refers to air that doesn't make it into the engine when it is compressed, and actually comes back up into the intake tract. This air is heated, and is the cause of the loud noise heard from positive displacement superchargers. When the turbos are added in conjunction with the supercharger, they help to keep the airflow directional, minimizing the amount and effect of the back flow. Also, it's important to remember that boost itself is actually a measure of restriction, so to speak. The number that we read as "boost" is positive manifold pressure, or the byproduct of the engine only being able to flow a certain amount of air through it at any given time. The air that is being forced into the engine will eventually overcome the amount of air that the engine can ingest during every revolution, and the resulting "back up" of air is positive manifold pressure, or boost. Therefore, by using the supercharger to create a higher level of pressure, it cannot be viewed as a restriction.

Q: How Come the Turbos Alone Will Make More Peak Power at the Same Boost Level Then?
A: As previously stated, the turbochargers are the more efficient power adder (supercharger vs. turbo). In the compound setups, the turbo boost level is limited because the air will be compressed again by the supercharger. Therefor, 20psi of compounded boost will only be about 8 psi from the turbos and 8-9 psi from the supercharger. This means that you will see peak power characteristics that reflect the amount of turbo boost present, with low-end power characteristics of a supercharger. The total boost number is somewhat irrelevant. If we use the turbos only to create 20psi, they are in a more efficient airflow range, but will lack the low-end power of the supercharger. Also, the turbo combinations with lack the mechanical losses, however minimal they may be, which will lead to slightly higher peak power numbers.

Q: What are the Real Benefits of the Compound Boost Setup?
A: The real world benefit of a compound boost setup is average power and driveability. With the compound setup, you can still have the instant boost and low-end grunt of a supercharger, but the addition of the turbochargers will allow for a much more efficient and powerful top-end. This is referred to as "power under the curve." The average amount of power that we are able to produce with the compound systems will provide better driveability while still producing hair-raising amounts of power. Here's a quick example of how to think about it:
Let's say that we have a car that makes 1,000 hp peak, but only makes 500 - 1,000 hp for around 3,000 rpm. Now, we have another car that makes 900 hp peak, but makes 500-900 hp for 5,000 rpm. If we use a linear progression of power to calculate the average power through 5,000 RPM, the second car in question would have an average power output of about 700 hp through 5,000 rpm, whereas the first car mentioned would only have an average output of about 550 - 600 hp through 5,000 rpm. Using this equation, the first car in question has a higher peak power output, however the second car will most likely out-accelerate it due to the fact that it makes more average power over the same RPM range.

edit: Good, rather extensive discussion of Compound Charging. They are looking for 1400hp though.

http://www.eng-tips.com/viewthread.cfm?qid=174690

[weederr33]

Man this is come good stuff. Now I really want to twin charge my car! Ugh hahaha

[CSG Mike]

After much discussion and some clarification (cuz you can never fully convey everything you're trying to over the internet), let's just say I want to see where this goes

A proof of concept should arise soon.

[Jaden]

Originally Posted by CSG Mike

After much discussion and some clarification (cuz you can never fully convey everything you're trying to over the internet), let's just say I want to see where this goes

A proof of concept should arise soon.

Definitely some good convo and good beer.


Mike's a good guy and he may have talked me into going to the track even...


Thanks for the beer and the conversation.


Jaden

[EAGLE5]

Drivability is great, but it all depends on your goals. A single twin-scroll turbo essentially makes twin-charging obsolete. A pair of variable-vane, twin-scroll turbos can give massive power at essentially all RPMs. All this mucking with twin-charging is masturbation.

In the real world, a single small twin-scroll, a la the GTI, is perfect. Low rpm power up to a reasonable redline.

On the track, you need enough RPM range to stay in the big power. More power beneath that range makes the car easier to drive, and that can win races, but a truly talented drive doesn't need that, and automated clutches make shifting so easy, power under the curve becomes less important. Or am I wrong?

[JustAnEngineer]

Originally Posted by jsimon7777

twin-charging is masturbation.

Pretty much, yeah.

And I say this as a person that thinks twincharging sounds badass albeit incredibly complex, hot and expensive.

[CSG Mike]

Originally Posted by jsimon7777

Drivability is great, but it all depends on your goals. A single twin-scroll turbo essentially makes twin-charging obsolete. A pair of variable-vane, twin-scroll turbos can give massive power at essentially all RPMs. All this mucking with twin-charging is masturbation.

In the real world, a single small twin-scroll, a la the GTI, is perfect. Low rpm power up to a reasonable redline.

On the track, you need enough RPM range to stay in the big power. More power beneath that range makes the car easier to drive, and that can win races, but a truly talented drive doesn't need that, and automated clutches make shifting so easy, power under the curve becomes less important. Or am I wrong?

Those two turbos cost more than what your car's current market value... no joke.

[EAGLE5]

Originally Posted by CSG Mike

Those two turbos cost more than what your car's current market value... no joke.

Porsche has had VNT turbos for years. They seem to run <$5k each, at least for the older ones, the BV50. Are you thinking of a different turbo?

No matter what, tuning would be difficult. Just getting the right tube lengths and diameters and bends would be awful. Then you'll need to program it, and I don't think EcuTek is going to cut it. Not like EcuTek is going to be great on a twincharged engine either.

The smart money is on buying a used 997 turbo, or better yet, a used P85D w/ludicrous, or a P90D w/ludicrous. That does 5-60 in 3.0, faster than a 911 Turbo S, Z06, and anything else I know of.

The new P100D looks delicious. The 5-60 on those cars must just be crazy. <3.0, if the P90D Ludicrous is already at 3.0 flat. I could have a lot of fun with that power without ever breaking 90.

[DustinS]

Originally Posted by jsimon7777

Not like EcuTek is going to be great on a twincharged engine either.

I don't think Ecutek will have any issue tuning for a twin charged set-up. There aren't any super complicated things it has to deal with.

Edit: Torque Curve of a Twin Charge Evo T04Z leading to a Eaton 1320



Edit: Something that was brought up. Would/could the internal A/W intercoolers become a restriction? @Matt@Cosworth Any info on the limits of the Cosworth Intercoolers?

[Jaden]

Originally Posted by DustinS

I don't think Ecutek will have any issue tuning for a twin charged set-up. There aren't any super complicated things it has to deal with.

Edit: Torque Curve of a Twin Charge Evo T04Z leading to a Eaton 1320



Edit: Something that was brought up. Would/could the internal A/W intercoolers become a restriction? @Matt@Cosworth Any info on the limits of the Cosworth Intercoolers?

That's the main reason I was concerned with running the edelbrock as a secondary.

Jaden

[EAGLE5]

Originally Posted by DustinS

I don't think Ecutek will have any issue tuning for a twin charged set-up. There aren't any super complicated things it has to deal with.

Edit: Torque Curve of a Twin Charge Evo T04Z leading to a Eaton 1320



Edit: Something that was brought up. Would/could the internal A/W intercoolers become a restriction? @Matt@Cosworth Any info on the limits of the Cosworth Intercoolers?

Wouldn't a builder want a lot of data than EcuTek can gather?

[DustinS]

Originally Posted by jsimon7777

Wouldn't a builder want a lot of data than EcuTek can gather?

More data would be nice, but I don't think necessary to have for tuning. I would only dyno tune a twin charge set-up as it is unknown territory on the FA20 at this point. So those extra parameters may be able to be displayed/logged extra.

The only extra data that would be nice to log is manifold exhaust back pressure, pressure/temperature after turbo, Temperature out of first intercooler (going into throttle body), and possibly temperature/pressure after supercharger before A/W Intercooler. Mostly for data really.

Final Tempurature and Pressure after A/W Intercooler(after supercharger) will be logged by MAP sensor and is the important factors for tuning. Final pressure is also where you want to grab boost source for Wastegate.

I could totally be wrong, but that is how I understand it.

[Jaden]

Originally Posted by DustinS

More data would be nice, but I don't think necessary to have for tuning. I would only dyno tune a twin charge set-up as it is unknown territory on the FA20 at this point. So those extra parameters may be able to be displayed/logged extra.

The only extra data that would be nice to log is manifold exhaust back pressure, pressure/temperature after turbo, Temperature out of first intercooler (going into throttle body), and possibly temperature/pressure after supercharger before A/W Intercooler. Mostly for data really.

Final Tempurature and Pressure after A/W Intercooler(after supercharger) will be logged by MAP sensor and is the important factors for tuning. Final pressure is also where you want to grab boost source for Wastegate.

I could totally be wrong, but that is how I understand it.

Yeah you would base wastegate control on MAP so long as one of the charge units is a known factor, i.e. a S/C.

When running a turbo into a smaller turbo, you have to know individual after turbo pressure and have great control over each wastegate at all times AND know and control both wastegates from MAP.

Jaden