Twincharging

[dbh86]

Does anyone know how the hilmersson racing did their twincharging? Or have any ideas of how to set this up so that it works well?

[stillspoolin]

no, I dont.
but I wanted to say whats the damn deal from san antonio

[Two 87s]

If you really want to do it, you can probably figure out what's needed...

I asked for a translation in this thread:

http://forums.turbobricks.com/showthread.php?t=73889&highlight=hilmersson

I think the hardest part is figuring out how to switch from one boost source to another. I don't know if he made those huge one-way valves or if he somehow found them somewhere. It'd be nice to know. I seem to remember e-mailing him and never hearing back.

Aaron

[adrianpike]

no, I dont.
but I wanted to say whats the damn deal from san antonio

Uh, this isn't OT. On-topic, capn.

I don't know exactly how he did it, except I know it involves diverter valve black magic.

From what I can gather, the supercharger and turbocharger inlet systems are separate, and join up right upstream of the intercooler.

[Two 87s]

Hey, as long as we're talking theory...

I believe Adrianpike is right. I think the idea is to pipe both boost sources through the same intercooler, and into the same throttle body. The split occurs on the hot side intercooler piping. Each boost source (turbo or supercharger) has its own filter and outlet. Each outlet has a one-way or check valve on it. That means, in theory, that if the turbo is pushing 1 psi and the supercharger is pushing 7 psi, the pressurized air won't be able to fight its way back out the turbo, because the check valve will prevent it.

But we're talking about HUGE check valves. These things need to be at least 2 inches in diameter. Those are a pain to source commercially.

Also, the check valves really shouldn't be doing the entire job. I think Hilmersson worked out a way that the supercharger bleeds off to the atmosphere once the turbo reaches a certain pressure. That way the supercharger's check valve is seeing 0 psi on the back side. I guess no bleed is needed for the turbo, since down low, the supercharger is building boost, but the turbo isn't. Once the turbo spools, the supercharger cuts out and the turbo takes over.

To do the supercharger bleed, I think he hooked a wastegate actuator to a throttle body. The boost source is the turbo outlet. When it reaches the set level, the actuator opens the throttle body and bleeds off the supercharger's output.

A diagram would probably help. But say that the supercharger has a 7 psi pulley, and the turbo pushes 25 psi, but doesn't spool until 4000 rpm. (I'm just making up numbers here.) From idle, the supercharger is making boost and feeding the intercooler. Its boost can't exit through the turbo, because the check valve is pushed back by the 7 psi, and the turbo isn't making enough boost to overcome that. As the turbo starts to spool, the pressure against the back of the check valve will build. When it reaches 7 psi, it equalizes, obviously. Right around there, the actuator opens the modified throttle body at the supercharger and vents its boost. With no backpressure, the check valve at the turbo opens and allows the turbo's 7psi through. The turbo's 7psi flows into the intercooler and continues to feed the engine. It also slams closed the supercharger outlet check valve, since there's now 7 psi pushing that closed, and no pressure on the back side because the supercharger is being bled off. The turbo continues to spool up the its max boost (25 psi in this scenario).

That's how I believe, from everything I've seen and read, that Hilmersson's setup works. I don't know if the crossover is smooth, or if that would cause a bog at the point where the turbo reaches 7 psi. There could be more to it, honestly. But it sounds, in theory, like it would work okay.

Aaron

[volvo740t]

I see VW has designed one these "twincharged" motors
http://www.autoblog.com/2006/05/10/volkswagen-twincharger-tsi-voted-best-new-engine-of-2006/

[Poik]

two inlet one outlet box with a flapper. don't think too hard.

[Two 87s]

two inlet one outlet box with a flapper. don't think too hard.

I'm afraid I have to think a little harder to understand what you mean. How exactly do you mean for this flapper to operate?

And what happens when you completely shut out one side (either supercharger or turbo) and it's building boost against the flapper? Compressor surge?

Aaron

[Alex Buchka]

See attachment, it's in Swedish but you get the idea.

The Hilmersson setup is on the left, what Poik is talking about is on the right

[adrianpike]

don't think too hard.

You don't let that stop you too often, do you?

[dbh86]

But making it nice and hard is what's cool, right?
I'm thinking about using some pressure sensors, electronic vents (to release pressure), and some way to switch from super to turbo, and maybe even a electric clutch for the supercharger all controlled by a basic stamp that uses the pressure inputs.

I've been told by some muscle guys that a electric clutch on a supercharger won't work, but I don't believe them. Any possible clutches for a eaton?

[adrianpike]

Guys, is the Avlastningsventil just an oversized bypass valve, or is it a throttle plate?

[dbh86]

I would say it's a bypass valve. Spjall looks like it's the TB.

[comingmonarch]

I've been told by some muscle guys that a electric clutch on a supercharger won't work, but I don't believe them. Any possible clutches for a eaton?

I don't really know about the big superchargers on v8's, but i know a clutch can work on a four clyinder engine seeing as how toyota used one from the factory. I'm not sure what years it was, but maybe 87-89? MR2 supercharged, had a 1.6L engine with a factory electorinc clutch on it. and it was toyota reliable, unlike their turbo 3L motor (supra, about the same time) which had serious head bolt problems. I think the main problem with it would be the massive amounts of torque reqired to turn a V8 supercharger.

[dbh86]

I don't really know about the big superchargers on v8's, but i know a clutch can work on a four clyinder engine seeing as how toyota used one from the factory. I'm not sure what years it was, but maybe 87-89? MR2 supercharged, had a 1.6L engine with a factory electorinc clutch on it. and it was toyota reliable, unlike their turbo 3L motor (supra, about the same time) which had serious head bolt problems. I think the main problem with it would be the massive amounts of torque reqired to turn a V8 supercharger.

I'm pretty sure blown240 used a clutch on his car, if I can remember correctly, but it wasn't turning an M62 or M45, which is what I would like to use.

// edit "Toyota SC14 Supercharger with clutch"

[aibast]

how about setting up thinkg like this airfilter -> MAF ->turbo -> charger -> intercooler -> intake manifold = no more need for weird flaps in it. Been done on volvo 480 engine. Result was stock 120hp changed to 235hp :D

[adrianpike]

how about setting up thinkg like this airfilter -> MAF ->turbo -> charger -> intercooler -> intake manifold = no more need for weird flaps in it. Been done on volvo 480 engine. Result was stock 120hp changed to 235hp :D

That's a pretty low power gain for so much shindiggery.

[riderJones]

I've always thought compound forced induction is very interesting, but at the end of the day I just can't justify the high price of a $upercharger, or the extra complexity. I would rather get a b.b. turbo and spend the extra $1000 on fried chicken and porno (actually more performance parts). Although, if money was no object B21FT+SC would be one the 1st projects on my list.

[scottstephen111]

That's a pretty low power gain for so much shindiggery.


Dunno, from a Renault derived 1.7 engine and in a car that weighs the same as a 740's bonnet, its worth the grief i would have thought?

[crandandall]

how about setting up thinkg like this airfilter -> MAF ->turbo -> charger -> intercooler -> intake manifold = no more need for weird flaps in it. Been done on volvo 480 engine. Result was stock 120hp changed to 235hp :D

This sounds like the least complex way to do it. You use a SC with a magnetic clutch that turns off at say 5psi then after that the turbo takes over. This way, you don't have to deal with the SC trying to force air into the outlet of the compressor on the turbo or vice versa. When the SC is off the turbo just blows through it and into the intercooler. It may be more work than it's worth, but it would be sweet to see.

[Lucky the Smiling Pirate]

something I've wondered about SC clutches. is it an on/off kind of thing? or more of a "get up to speed and then maintain that speed" kind of thing?

it would be neat if there were some way to keep the SC spinning at final speed X, regardless of how much past the target rpm for X you went.

doesnt matter of course, 1 big honkin turbo seems to be the old faithful of the go fast world. twin charge is definitely sexy but...meh.

[nederzweed]

A dutch cartuner; (Van Kronenburg)

CLICK HERE (http://www.youtube.com/watch?v=YdF0H-16OO0)

not one but TWO superchargers and a big-ass turbo :wtf: :-D :omg: :oogle:

[Fuse]

I don't know if you guys have seen this, but it's twin charged 245 from Finland. It boosts 0.5bar from the idle and 1bar at ~2500rpm

vid: http://s19.photobucket.com/albums/b176/turbo245/?action=view&current=245072.flv

http://s19.photobucket.com/albums/b176/turbo245/

It's his daily driver.

[nederzweed]

looks nice, but dumpvalve isn't working correct ?? stays open quite long...

and i hope/ think he has some kind of valve between the inlet of the turbo and the air filter, or else al the compressed air would go out through the filter..

[Alex Buchka]

Guys, is the Avlastningsventil just an oversized bypass valve, or is it a throttle plate?

It's literally just a throttle body with an actuator on it that opens when the turbo boost rises above the supercharger boost and bleeds off all the air from the supercharger.

[nederzweed]

http://www.autozine.org/strange_car/strange_pic_lancia_s4_charge.jpg

Above pic is voor Lancia Delta S4... also a nice example of twincharging....

[Two 87s]

So where do you get the right size backventils?

[coldfusion21]

why couldnt you have the SC clutch cut out right above its max boost pressure? and then use a throttle body normally closed to cut off the turbo under that pressure and another normally open to cut off the sc over that?

[TestShoot]

In hindsight you'd wonder if using a s/c to evacuate the cylinders like a big diesel truck would be a good idea instead of blowing air in. I just would figure melting the s/c would be an issue if you went cheap.

[frostburner]

mercedes blowers have electronic clutches on them a well, i have an m45 from one

[Hank Scorpio]

use a 70mm tial external gate for the "flapper" valve?

[benfer]

I would think a staged turbo system would work far better. allthough it looks quite complicated to plumb and mount to a manifold. anything is possible :cool: like such:

http://cgi.ebay.com/ebaymotors/New-Borg-Warner-Prats-2-Stage-Turbo-s-K16-K27-2-R2S_W0QQitemZ170132938646QQihZ007QQcategoryZ33742Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem

[Two 87s]

use a 70mm tial external gate for the "flapper" valve?

I only see 60mm valves on their site (the V60 model). At $600 per wastegate, that's a lot of money to spend on a small part of the system. Well, at least to me.

I'm also not sure if a wastegate is the design you really want. Would you give it a boost signal, as you would if it were set up as a wastegate? Or is there some way to "tune" it with just a spring to open at certain pressures?

I think a "flapper" style would be superior to a piston style. I wonder if Hilmersson just machined something custom?

Aaron

[Forg]

Can you get one-way valves, ie. with the sort of functionality in a force-fed car's brake-booster, but with the amount of flow you want/need to feed an engine?
'Cos what if you set-up a Y-shaped join into the intake of the intercooler, and feed the blower & turbo into the two 'ears' of the Y through two one-way valves? Then you could clutch & declutch the supercharger approximately near where it needed to be done, and you could wastegate the turbo approximately near where it needed to be done, and the one-way valves would maintain boost (& stop it going back the wrong way) at the highest level of the two ... ?

[coldfusion21]

Can you get one-way valves, ie. with the sort of functionality in a force-fed car's brake-booster, but with the amount of flow you want/need to feed an engine?


Throttle bodies with actuators on them. or even as said before, throttle bodies hooked up to internal wastegate actuators.


if you wanted to be fancy you could machine/weld a custom "y" with a flapper in one side and machine a plate and then hook that up to your desired method of acuation.

[Two 87s]

That's the big question, Forg! Where do you get LARGE one-way valves? They should be self-contained units, as opposed to opening and closing based on some signal. They should open or close based on pressure differential across them.

Hilmersson uses two large one-way valves of some design for the turbo and the supercharger, exactly like you suggest.

And then he uses a throttle body with a wastegate actuator to open up and bleed off the supercharger's feed above a certain psi. All that does is put less pressure on the back of one of the one-way valves. The turbo doesn't need a bleed-off UNDER a certain psi, since it takes a while for it to build boost. While it is building boost, the pressure differential across its one-way valve is maintained by the supercharger's boost.

It'd just be nice if someone could point to a commercially available, sub-$100 one-way or check valve in approx. 2 inch diameter that would work for this application.

Aaron

[coldfusion21]

It'd just be nice if someone could point to a commercially available, sub-$100 one-way or check valve in approx. 2 inch diameter that would work for this application.

Aaron


I can find a few, but none i would want to put on a vehicle. go to mcmaster.com and search for swing check valves. you should find a page or two. Possibly buy the cheapest brass or bronze valve and then have a nice housing machined to fit.