Ok , I guess I'll start one ...

[California Jay]

Thanks guys

I assume there will be more time on the dyno b/c of these mods.. I'm not totally sure where the ramp in power will be. I've got too many changes to make a good guess. I'm asking our Garrett rep if one side of the housing will react differently at all than the other, if one side is shut. Who knows really.

Not much to update otherwise this w/e as its thanksgiving here... busy with the fam damily. More to come soon.

[Wizard-of-OD]

You need a dry sump on that engine Jay
Looking good ;)

[California Jay]

Heres a couple quick sketches I did this morning. It shows the flapper hinge b4 I got my dimensions figured out and ventured off to the CNC. I separated the sleeve so you can all see that it will assemble inside the housing. The transparent grey square is the outside wall of the turbo casting. The pin is the longest of the three items, it will use a cam idea to grab the sleeve that will have the flapper welded to it. To get the pin in the housing, the pin will have a dowel of sorts to sit in - the dowel is pressed and e-clipped in the housing from either side of the casting wall. this will prevent binding. After I see clearances are ok and the assembly is how I want it I will weld a tab for the actuator valve...







if this seems foggy let me know, I'll label and maybe re-explain.

[quattro16]

I feel like an idiot, and don't understand.

[t1demont1]

me too. From my understanding of this, your going to block off one of the ports on the twin scroll turbo. Then when the turbo hits full boost, youll slowly open the second port? Sounds like a pain in the ass to tune but a good idea to spool a large frame turbo on small displacement. If this is carried out well it would probably change the forced induction world.

[onemoremile]

I feel like an idiot, and don't understand.

The twin scroll housing has two turbine inlets. Rather than direct two cylinders to each inlet he is running all four together just like any single scroll turbo. The difference is that he is using a flapper to close off one inlet which forces all the exhaust gasses to run through one inlet. That halves the area of the inlet which double exhaust gas velocity which should help spool the turbo earlier. Once spooled the flapper opens so both inlets are fed equally.

[t1demont1]

wouldnt the turbo slow down as the flapper is being opened?

[onemoremile]

Potentially but it is already spinning faster than if it wasn't there.

[sean1.8t]

The twin scroll housing has two turbine inlets. Rather than direct two cylinders to each inlet he is running all four together just like any single scroll turbo. The difference is that he is using a flapper to close off one inlet which forces all the exhaust gasses to run through one inlet. That halves the area of the inlet which double exhaust gas velocity which should help spool the turbo earlier. Once spooled the flapper opens so both inlets are fed equally.

i think he understands that part. that's the easy part.

and i think he was refering to the sketches that Jay did. and im with him. i don't see how or what is going on with his design. yours is easy to see and comprehend.. but if we could get a lamens terms explanation of Jays sketches that would be awesome

[sean1.8t]

Potentially but it is already spinning faster than if it wasn't there.

exactly. and boost ramp up on larger framed turbo's like this is so rediculous that it shouldn't be too much of a problem

[luvin_the_rings]

hey Jay, what CAD program are you using?

I've had alotta experience with SolidWorks, looks like its from there.

Nice to see that there is some actual engineering going on on the forums
I think tuning is gonna b nutz, and honestly I dont think that the turbo will slow down much on the transition between single scroll and twin scroll.

What kind of actuator are you going to be using? maby a simple spring with the right spring rate will be able to pop open the flap when you hit 15psi, or 25, or 35... hehehe

[sean1.8t]

i don't see that much of a tuning issue.

what am i missing here?

just seems like it's going to be, more or less, a large turbo being spooled on a smaller than usual engine. the turbo is still going to act like it's supposed to.

am i wrong?

[California Jay]

hey Jay, what CAD program are you using?

I've had alotta experience with SolidWorks, looks like its from there.

Nice to see that there is some actual engineering going on on the forums
I think tuning is gonna b nutz, and honestly I dont think that the turbo will slow down much on the transition between single scroll and twin scroll.

What kind of actuator are you going to be using? maby a simple spring with the right spring rate will be able to pop open the flap when you hit 15psi, or 25, or 35... hehehe

The actuator is just going to be on a HKS internal gate. I use them a lot on the GT28 and GT3071 setups. They are pretty reliable and use a top/bottom push/pull boost reference.

As far as programs, I'll use Solidworks for sketches/ideas and prototyping with the dimension printer at work. Most of my CNC stuff I'll run Mastercam X2. If it has to be brought over from SW I'll convert it into a Parasolid first. It seems to break down the drawing better for me to pick up dimensions and make changes. Most of my exhaust manis items I use Catiav5.. I'm still learing it, I picked up on it while working in the UK for a bit.

[t1demont1]

The reason why i thought there might be a tuning issue, is the drop in boost as the flapper opens.I could think of this thing till im brain dead but well never know till he puts it to use.

Ideas:
1) it would be cool if you could use something similar to a wastegate that opens when the desired boost is reached. This would allow the flow to be disrupted as little as possible. Just like a wastegate, this spring would release air keeping the turbo at a desired psi, but instead of it being vented to air it would be redirected to the secondary scroll to make more power.

2) probably impossible, but a dump tube from the wastegate to the second scroll taht shoots the air into the second scroll when the wastegate opens.

Concerns:
1) How is this development going to be sturdy enough to no fall apart and demolish the turbo
2) A slow opening flap: Im not too sure on how twin scroll turbos work, but id imagine each scroll spins the same wheel in the end. What if the secondary scroll when opened slowly doesnt have enough velocity to help speed up the wheel until its fully open?
3) A fast opening flap: Would more than likely cause a disruption in air flow and choke the turbo momentarily
4) Tuning: With a fpr, they are rising rate aka as boost goes up, fuel pressure goes up. However the problem with opening more turbo up is that the car will be seeing the same amount of fuel as if it were at 20psi with the secondary scroll closed but waay more air causing the car to go super lean and kill itself. This could be eliminated through running secondary injectors tuned to the pressure of the spring on the flapper possibly?
5) The design of a flapper twin scroll is like switching from a 28rs to a 35r smoothly after the 28rs spools. I dont know if that helps you see what i mean? but you cant run a 35r on a 28rs tune because the 35r requires way more fuel

I dont know if any of my ideas or concerns are relevant but i like thinking out loud. I know little about tuning so i may be incorrect on a few of my concerns.

[AudiA4_20T]

The reason why i thought there might be a tuning issue, is the drop in boost as the flapper opens.I could think of this thing till im brain dead but well never know till he puts it to use.

Ideas:
1) it would be cool if you could use something similar to a wastegate that opens when the desired boost is reached. This would allow the flow to be disrupted as little as possible. Just like a wastegate, this spring would release air keeping the turbo at a desired psi, but instead of it being vented to air it would be redirected to the secondary scroll to make more power.

2) probably impossible, but a dump tube from the wastegate to the second scroll taht shoots the air into the second scroll when the wastegate opens.

#1 and #2 sound BADASS, especially #2, I could see that, but I think that might cause some SERIOUS surging problems, because the wastegate would not be a wastegate anymore

[California Jay]

The reason why i thought there might be a tuning issue, is the drop in boost as the flapper opens.I could think of this thing till im brain dead but well never know till he puts it to use.

Ideas:
1) it would be cool if you could use something similar to a wastegate that opens when the desired boost is reached. This would allow the flow to be disrupted as little as possible. Just like a wastegate, this spring would release air keeping the turbo at a desired psi, but instead of it being vented to air it would be redirected to the secondary scroll to make more power.

2) probably impossible, but a dump tube from the wastegate to the second scroll taht shoots the air into the second scroll when the wastegate opens.

Concerns:
1) How is this development going to be sturdy enough to no fall apart and demolish the turbo
2) A slow opening flap: Im not too sure on how twin scroll turbos work, but id imagine each scroll spins the same wheel in the end. What if the secondary scroll when opened slowly doesnt have enough velocity to help speed up the wheel until its fully open?
3) A fast opening flap: Would more than likely cause a disruption in air flow and choke the turbo momentarily
4) Tuning: With a fpr, they are rising rate aka as boost goes up, fuel pressure goes up. However the problem with opening more turbo up is that the car will be seeing the same amount of fuel as if it were at 20psi with the secondary scroll closed but waay more air causing the car to go super lean and kill itself. This could be eliminated through running secondary injectors tuned to the pressure of the spring on the flapper possibly?
5) The design of a flapper twin scroll is like switching from a 28rs to a 35r smoothly after the 28rs spools. I dont know if that helps you see what i mean? but you cant run a 35r on a 28rs tune because the 35r requires way more fuel

I dont know if any of my ideas or concerns are relevant but i like thinking out loud. I know little about tuning so i may be incorrect on a few of my concerns.

I had earlier explained that the system uses another gate (internal)... so thats clear.

A wastegate cannot be routed into the scroll, by this time you have already reached your desired psi to open the gate. Plus that would require another gate to disperse of the excess gas... ie another dump that controls the total desired boost. I understand what you are getting at... we are essentially already doing this

There is never an actual drop in boost.

Answers to above....

1 The materials used are of the same grade of my manifolds... they are either low sulfur rate stainless or high grade steel. Considering the size and thermal expansion rate by mass or fatigue rate of the material used in these conditions, there would have to be a tremendous amount of heat for a quite a long time for it to bend/warp... I can't simulate the forces at the moment, but I know from experience these materials will not fatigue in this situation. I could tell from the last run of tuning the car was running quite well. EGT at WOT was always under 1300 deg unless under extreme load. Far below any warning signs I need to worry about. The flapper itself 1/8" stainless.

2/3 The time that will be between a closed flap and open flap will be literally under a second. not enough to worry about... remember for every mm I close one side off I'm opening the other to be equal. As rpm under load increases so does velocity to compensate.

4/5 The boost will still rise equally between each wg...internal and external. The internal gate will just ramp and hold at "x"psi through till desired redline to hold the flapper even between the ports in the twin scroll. Your concern of killing the car and going lean I don't see as being an issue. Yes you are basically overlapping a k04 tune and a gt3x tune. The tune just needs to have a high resolution of cells to be effecitve, and it has to be logged to monitor where the ramp of power is and the transition. This is much like tuning a compound or vnt turbo. Its all in the tune, its half the battle.

[t1demont1]

cool, thanks for answering. I cant wait to see a working concept

[dougyfresh]

Nice to see that there is some actual engineering going on on the forums. I think tuning is gonna b nutz, and honestly I dont think that the turbo will slow down much on the transition between single scroll and twin scroll.

Lot of guys use 3D modeling to help with prototyping. APR, ASP, Jay, etc....
Even better is taking those 3D models and making stereo lithography prototypes to see what your design looks like before you put it in metal.

As far as programs, I'll use Solidworks for sketches/ideas and prototyping with the dimension printer at work. Most of my CNC stuff I'll run Mastercam X2. If it has to be brought over from SW I'll convert it into a Parasolid first. It seems to break down the drawing better for me to pick up dimensions and make changes. Most of my exhaust manis items I use Catiav5.. I'm still learing it, I picked up on it while working in the UK for a bit.

Jay,
Do you run into problems losing actual sizing when you create a parasolid? Sometimes, with large complex models, I have to export my Unigraphics solid as a parasolid in order to successfully import into my ANSYS FE software. In doing that the scaling can get messed up and I lose critical dimensioning (even after I've verified the scale factors are correct). I use this as a last resort and have found other ways to clean up the UG models since the ANSYS importer and pre-processor are crude and do not like complex geometry.

Then again, with the work I do, I'm concerned about things as small as 0.001" and 0.0005".

[California Jay]

Heres a more detailed explanation of how the hinge works.

Item 1 is the center rod that the flapper pivots on. It sits parallel to the dividing wall in the housing. The rounded end of it also sits itself to the original part of the casting, in location b

Item 2 is the sleeve that that is welded to the flapper, and is "keyed" to grab the center rod when the center rod is being turned by the internal gate or actuator at a given psi. I separated them in the photo on purpose, item 2 slides over top of item 1

Item 3 is basically a bulk head/bushing that will aid in support for item 1 and will be scored to fit two e-clips. It will sit in location "a" . The location of the e-clips take up any side to side slack that is left between the "keyed" area and the swing arm. The swing arm will be welded to the pin (1) on the outside of the turbine. Again the swing arm is attached to the actuator/int wg.

[California Jay]

Lot of guys use 3D modeling to help with prototyping. APR, ASP, Jay, etc....
Even better is taking those 3D models and making stereo lithography prototypes to see what your design looks like before you put it in metal.

Jay,
Do you run into problems losing actual sizing when you create a parasolid? Sometimes, with large complex models, I have to export my Unigraphics solid as a parasolid in order to successfully import into my ANSYS FE software. In doing that the scaling can get messed up and I lose critical dimensioning (even after I've verified the scale factors are correct). I use this as a last resort and have found other ways to clean up the UG models since the ANSYS importer and pre-processor are crude and do not like complex geometry.

Then again, with the work I do, I'm concerned about things as small as 0.001" and 0.0005".

We have a Dimension SST 1200 on site here to do models b4 casting and machine.. I love it.. makes it easy for customers to acutally see the idea in their hands. I'm sure you know. I don't have the time or budget left with this customer to do that... we are over $40k on this build now. I used the SST to make the gauge pods for the TT.





I do have issues with transfering/converting files for certain ppl in my area. Everyone likes to take files differently or set them up a bit different for machining. I'm still leaning this area of the modeling world. I'm great at getting the idea on paper/screen and making it work... but the one's and zeros of it to adapt to certain cncs' or other programs I struggle with at times. In direct, i don't seem to have lose detail or accuracy with my items in converting to parasolid. But I don't think I run with as much detail as you.

[dougyfresh]

We have a Dimension SST 1200 on site here to do models b4 casting and machine.. I love it.. makes it easy for customers to acutally see the idea in their hands. I'm sure you know. I don't have the time or budget left with this customer to do that... we are over $40k on this build now. I used the SST to make the gauge pods for the TT.

Looks great and I'm sure your customers greatly appreciate it .

I work in the aerospace industry (design jet aircraft engines) and we have 3D stereo lith models made in 1x, 2x and 3x sizing for our design reviews. Various sizing primarily because of the size of our parts and the features within. Its easier to see things at 3x when you've got features in the 0.020" range and smaller on a part that is probably only 3" tall. Helps our discipline experts and everyone else in the review better understand what we're presenting and how it converts into real life. A valuable tool.

I do have issues with transfering/converting files for certain ppl in my area. Everyone likes to take files differently or set them up a bit different for machining. I'm still leaning this area of the modeling world. I'm great at getting the idea on paper/screen and making it work... but the one's and zeros of it to adapt to certain cncs' or other programs I struggle with at times. In direct, i don't seem to have lose detail or accuracy with my items in converting to parasolid. But I don't think I run with as much detail as you.

Those issues you are faced with are just the differences between all the different CNC machines and how they accept the code. As you stated, its a format issue (like all issues of this stature) because there is no 'industry standard'. The secrets and work-arounds will come with time. Its just hard to juggle those nuances while also running a shop, fabricating things and bringing in money to keep things afloat.

[California Jay]

True .. I even get a few guys who still request a draft sheet in addition to my model on some simpler parts.

Back to my own build for a bit.. I got started on the bottom end a bit today. I installed a bit more beef into the main caps. I used a set of ARP small block Chevy studs, they are a bit bigger ...and theres plenty of casting to hold the studs in after machining..
I'll be putting in a scraper and squared crank for this bottom end.. It will help lighten the reciprocating mass. The stock A4 pan has to be shaved at the rear main seal for it to clear the studs.

[dougyfresh]

Is that an 058 block?

[onemoremile]

Cool stuff.

Most 3D cad systems will use Parasolid, Acis, Step, or IGES. Parasolid is the kernel that SolidWorks runs so it is generally the best for it. Step AP214 is the next best. Most CAM software like IGES but things always go goofy with IGES.

I just took a contact gig turning scanned cad data (point clouds) and turning them into life size concept models. The shop is full of cool toys and the projects are even better. Multibody CNC carved molds for fiberglass and carbon fiber, vac forming, embedded electronics, and plenty more.

[California Jay]

The block combo is ABA/AEB

Cool stuff.

Most 3D cad systems will use Parasolid, Acis, Step, or IGES. Parasolid is the kernel that SolidWorks runs so it is generally the best for it. Step AP214 is the next best. Most CAM software like IGES but things always go goofy with IGES.

I just took a contact gig turning scanned cad data (point clouds) and turning them into life size concept models. The shop is full of cool toys and the projects are even better. Multibody CNC carved molds for fiberglass and carbon fiber, vac forming, embedded electronics, and plenty more.

Everytime I run a IGES in Mastercam from Solidworks I can never grab any dims or surfaces/faces. I kinda went through this with you b4. I would like to get into more use and info with Minolta infrared scanners, Faro arm etc etc. My imagination would go off the deep end.

[onemoremile]

I've got friends at all the major metrology companies so just send me a pm or email with your questions and I'll try to answer them or get answers. Got friends at Romer/CimCore, Cognitens, Metrologic, Faro, Capture 3D, and a few others. See the guy with the face fuzz in the blue shirt? That is me 4 or 5 years ago talking to the Germans about the super secret Veyron project. Well, it was a secret then.

[dougyfresh]

For white light scan data we use a piece of software called GeoMagic. That is all I know about it. My life is spent on the FEM side trying to make sure our designs actually work. My favorite aspect is when I get to go into the lab and run vibration and other such tests to fail parts. Oh, and cover engine strain gauge tests. The F135 JSF motor is pretty amazing to see operate in person.

Point cloud data from a CMM is just inputted into UG (our primary CAD program).

Did not realize you have a healthy background in this, Jim. Good to know !

[AudiA4_20T]

I've got friends at all the major metrology companies so just send me a pm or email with your questions and I'll try to answer them or get answers. Got friends at Romer/CimCore, Cognitens, Metrologic, Faro, Capture 3D, and a few others. See the guy with the face fuzz in the blue shirt? That is me 4 or 5 years ago talking to the Germans about the super secret Veyron project. Well, it was a secret then.

lol people are never how u expect them to look

[blkb6a4]

subscribed, looking forward to seeing more of this project, could revolutionize forced induction! and I love all the engineering going on here! I'm a sophmore in college for mech engineering and this thread alone is making me want to get into the "real world" even more now...even more than my tech aid job at 3m is...seeing how I'm at work right now suposed to be working but I'm on the zine :/ o well what can you do keep up the good work guys!

[California Jay]

lol... good

I'll have the finished hinge done very shortly...

[Kyle H]

This thread reminded me why I'm a mechanical engineering student.

[AudiA4_20T]

This thread reminded me why I'm a mechanical engineering student.

that makes 3 of us now

[dougyfresh]

This thread reminded me why I am a mechanical engineer.

Edited for 'me'

[California Jay]

More progress.. some bottom end work...

I'm still going forward with a crank scraper but backing out on the sqared crank idea.. I got looking at the cranks lack of material after balancing and I fear I would be left with too little material after squaring and re-balancing. So, I'm going to leave well enough alone. I also refitted my frost plugs, I forgot to put sealant during install b4.







I also got my pistons... pretty nice and the dish I wanted for 9:1. But my rods interfere with the gap of the piston for the top of the rod.. so CNCing we go. I've got to spread things out by almost .09" for my desired slack





And... I had found my idlershaft to be a bit tight for my liking, I have a few small honing bits that work wonders for fixing this... now its like butta.

[Kyle H]

I almost forgot that this thread was an engine build-- i thought it was a turbo development thread

[California Jay]

It will be a full car assembly thread... this is just my current point in the build..
The turbo piece is an added extra.. we all got on the topic of the divided housing in advance. I'm also doing it for a customer.

[AudiA4_20T]

lol... if this thing spools a gt40r before 5k count me in

[Toyotatech]

Sounds like a great idea, my only question is if your trying to push such a large volume of air on the cold side will the volume on the hot side have enough to push it before the flapper opens. I understand there is greater velocity but wouldn't there be greater resistance on the cold side due to the greater volume of air being pushed and not allow it to spool any faster without an equal volume on the hot side?

I would love to see this work, if it does I want one. I am rooting for you.

[AudiA4_20T]

Sounds like a great idea, my only question is if your trying to push such a large volume of air on the cold side will the volume on the hot side have enough to push it before the flapper opens. I understand there is greater velocity but wouldn't there be greater resistance on the cold side due to the greater volume of air being pushed and not allow it to spool any faster without an equal volume on the hot side?

I would love to see this work, if it does I want one. I am rooting for you.

I think the point is that when the flap is closed, the engine won't have to push as hard to get that exhaust wheel going.... think about blowing through a smaller straw and a big straw, its easier/faster to get that small straw full... But it cant flow as much, however, as long as he gets the 40r compressor wheel spinning at least like 10psi, when that flapper opens it should be enough to make that thing fly

[sean1.8t]

no think of it as putting a 25 series turbine with a 40r coldside.

it would spool like crazy, but that's about all it would do. it would choke just like a k04 does up top.

this is the reason for the flapper