Sävar Turbo Site

Is it possible to modify a HX40 twin scroll exhaust housing?.
What I mean by modify is to put a "flap" valve that guides all the exhaust gas into the scroll near the bearing house.
And hopefully get a wider powerband.

Something like this:
https://www.google.com/search?q=twin+sc ... PoqSITVzsM

Check DieselPumpUK, they preffer to use that type of valve onto diesel engines with bigger turbo.
They even have on their YT page a clip about the benefits according to them.

https://www.dieselpumpuk.com/shop/turbo ... tercooled/

I'm not sure if it's something like this that you're trying to do, this is external though.
They have some really great videos as well where they talk about their RX engine and the development.
https://shop.elmerracing.com/billet-mer ... in-wg.html

jag trodde jag uppfan detta tidigt 90tal vid skol bänken skissandes på helt andra grejor än skolan ville men som med allt här i värden så fans det ett patent från typ -40talet haha.

det har en plats speciellt på 5 cyl motorer och då man bak monterar turbos skulle jag säga!

mvh jens

psa skrev: ↑tis dec 28, 2021 9:26 pm I'm not sure if it's something like this that you're trying to do, this is external though.
They have some really great videos as well where they talk about their RX engine and the development.
https://shop.elmerracing.com/billet-mer ... in-wg.html

I have seen this spool valve, but I think the valve deflects the pulses too much, because the flow has to be directed at the valve.
And cyl 1-4 and 2-3 are not separated.

The turbine does not absorbe energy from the pulses that the valve deflects, and the pulses interfere with one another.
Therefore the turbine needs more "average" exhaust pressure to drive the compressor.
This is how I think about this valve.

But it's a clever idea

For example:
I'm thinking about an exhaust housing that guides exhaust from cyl 1-4 and 2-3 to one scroll to spool the turbo at 2500rpm. And when the turbo has reached 1 bar then it opens up both scrolls and guides exhaust from 1-4 to one scroll and 2-3 to the other scroll.
Then the wastegate opens at 2 bar from 4000rpm to 7500 as a true twin scroll.
However im not sure how the motor will respond to 1 bar at 2500-3000 if its possible to reach than pressure.
Will it be too much torque for stock pistons?
Will it knock because the piston is too long in top position?
Does the valve(flap) have to seal perfectly in both positions?
Will there be too much compressor surge at low rpm?

In that example im using b21 with:
kg004 cam, 531 head, 8.3/1 CR, super hx40 t3 60in/65out 16cm2, twin scroll manifold, cheap klracing intake, intercooler(550x300x115 3"pipe).

Hopefully water/meth will be installed next february

The reason I'm thinking about this, is that I want to try this on my drift volvo 244

All Ideas are greatly appreciated.

Jens Gustavsson skrev: ↑tis dec 28, 2021 11:04 pm jag trodde jag uppfan detta tidigt 90tal vid skol bänken skissandes på helt andra grejor än skolan ville men som med allt här i värden så fans det ett patent från typ -40talet haha.

det har en plats speciellt på 5 cyl motorer och då man bak monterar turbos skulle jag säga!

mvh jens

Jens are you talking about the Elmerracing spool valve?

Det finns flera olika typer av ventil lösningar men ja den typen. men som sagt på 4 och 6 cyl motorer förstör det nog ett bra grenrör mer än vad det ger skulle jag tro. 5 cylindriga och bilar med bak monterade turbosar så skulle det nog kunna fungera om man har en bra turbo för det och en bra ventil som inte stryper för mycket.

mvh jens

RX engines are restricted as well so they don't need boost control in the same way, they do need to make sure that the turbo doesn't over rev though.
It's also a matter of reliability in racing, using complexity at the right places, like 3D printing or machining the collector for perfect shape, that's expensive but they can avoid the internal valve.

Jens Gustavsson skrev: ↑ons dec 29, 2021 9:14 am Det finns flera olika typer av ventil lösningar men ja den typen. men som sagt på 4 och 6 cyl motorer förstör det nog ett bra grenrör mer än vad det ger skulle jag tro. 5 cylindriga och bilar med bak monterade turbosar så skulle det nog kunna fungera om man har en bra turbo för det och en bra ventil som inte stryper för mycket.

mvh jens

The valve I'm talking about would only work on 4 and 6 cyl engines. Very simple flap valve inside the exhaust housing, not the manifold.

Like this turbo; https://www.motorauthority.com/news/110 ... -of-turbos

psa skrev: ↑ons dec 29, 2021 11:33 am RX engines are restricted as well so they don't need boost control in the same way, they do need to make sure that the turbo doesn't over rev though.
It's also a matter of reliability in racing, using complexity at the right places, like 3D printing or machining the collector for perfect shape, that's expensive but they can avoid the internal valve.

"In short, the Borg Warner setup has a special valve that can apportion airflow from the vehicle's exhaust between either a single scroll or twin scroll. Each offers its own advantages, depending on the engine and how hard it needs to work to motivate a vehicle.

The overall advantage here is that the valve allows automakers to utilize less exotic materials for a variable geometry turbocharger to work in a gas engine, where exhaust temperatures can be very high. This means that variable twin-scroll turbochargers could be feasible for use in a wide range of vehicles at a reasonable price point."

This is a quote from; https://www.motorauthority.com/news/110 ... -of-turbos

This solution seems too have less complexity

Stefan Ingi Jonsson skrev: ↑ons dec 29, 2021 2:11 pm

psa skrev: ↑ons dec 29, 2021 11:33 am RX engines are restricted as well so they don't need boost control in the same way, they do need to make sure that the turbo doesn't over rev though.
It's also a matter of reliability in racing, using complexity at the right places, like 3D printing or machining the collector for perfect shape, that's expensive but they can avoid the internal valve.

"In short, the Borg Warner setup has a special valve that can apportion airflow from the vehicle's exhaust between either a single scroll or twin scroll. Each offers its own advantages, depending on the engine and how hard it needs to work to motivate a vehicle.

The overall advantage here is that the valve allows automakers to utilize less exotic materials for a variable geometry turbocharger to work in a gas engine, where exhaust temperatures can be very high. This means that variable twin-scroll turbochargers could be feasible for use in a wide range of vehicles at a reasonable price point."

This is a quote from; https://www.motorauthority.com/news/110 ... -of-turbos

This solution seems too have less complexity

The article pointed out what I said, and in the end it's still for two different purposes/markets.
But if you want to be a dick and roll your eyes then please do so.

psa skrev: ↑ons dec 29, 2021 5:12 pm

Stefan Ingi Jonsson skrev: ↑ons dec 29, 2021 2:11 pm

"In short, the Borg Warner setup has a special valve that can apportion airflow from the vehicle's exhaust between either a single scroll or twin scroll. Each offers its own advantages, depending on the engine and how hard it needs to work to motivate a vehicle.

The overall advantage here is that the valve allows automakers to utilize less exotic materials for a variable geometry turbocharger to work in a gas engine, where exhaust temperatures can be very high. This means that variable twin-scroll turbochargers could be feasible for use in a wide range of vehicles at a reasonable price point."

This is a quote from; https://www.motorauthority.com/news/110 ... -of-turbos

This solution seems too have less complexity

The article pointed out what I said, and in the end it's still for two different purposes/markets.
But if you want to be a dick and roll your eyes then please do so.

psa I'm not being a dick (you are misunderstanding my emoji which might be my mistake) I'm speaking to you about this topic and trying too understand your point.

Why avoid the internal valve? That's probably what I want to know the answer to mainly.

This is a quote from Elmerracing;

"The ultimate part for making exhaust manifolds for maximum performance. Featuring smooth transitions, and exact dimensions for the best flow possible. This translates into less back pressure, and means more power with the same boost, or the same power with lower boost (and less lag)!"

As you see, they are looking at the same areas as I am.
We are talking about two different purposes/markets.
However, with the same goals regarding combustion engines. Less back pressure, more power and less lag.

On this forum, most of us don't like being called a dick.
These are bad manners.

What about building a manifold with the collector going in to the "Low rpm scroll" and a wastegate from the collector leading in to the "high rpm scroll"? Sort of having the "flap" before the turbo flange and not in the housing.

Have seen a build of this but cant remember from where.

Allx skrev: ↑tor dec 30, 2021 10:36 pm What about building a manifold with the collector going in to the "Low rpm scroll" and a wastegate from the collector leading in to the "high rpm scroll"? Sort of having the "flap" before the turbo flange and not in the housing.

Have seen a build of this but cant remember from where.

Are you talking about something like this?
https://shop.elmerracing.com/billet-mer ... in-wg.html

Yep! You were talking about that in the thread but I didnt know it was called a spoolvalve