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Location:
Austria
Registered:
May 2004
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Location:
Northwestern Sydney
Registered:
August 2002
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Re: twincharger novel
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Sun, 23 May 2004 21:49
 
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The Charger is going to restrict flow to the turbo, which is giving you the waves in boost.
The way around that would be to place an alternative route for air flow around the charger that is valved to be directional so the turbo pulls air around the charger once the charger becomes restrictive.
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: twincharger novel
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Mon, 24 May 2004 00:42
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| Lambolica wrote on Mon, 24 May 2004 05:49 |
The Charger is going to restrict flow to the turbo, which is giving you the waves in boost.
The way around that would be to place an alternative route for air flow around the charger that is valved to be directional so the turbo pulls air around the charger once the charger becomes restrictive.
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This is a different twin-charger setup to the ones people usually describe, a centrifugal supercharger won't be getting restrictive at high revs, it'll just be starting to make full boost.
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Banned by his request
Location:
moved to tamworth
Registered:
July 2002
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Re: twincharger novel
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Mon, 24 May 2004 03:02
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i saw a supercharger/turbo setup thats all in one on a izusu deisel at the importers a few years ago the belt driven turbosupercharger used the belt till the turbo took over seems like the way to go for a twin turbo setup more compact and more efficent.
mick
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Location:
Canberra
Registered:
June 2003
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Re: twincharger novel
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Mon, 24 May 2004 03:24
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Why??? Is the question i'd be asking??
You go with an SC to get engine response on a big turboed engine when exhaust gas velocity is low. Obviously you are doing this to overcome lag from trying to spool up a large mass of turbine and comp wheel.
To achieve this you need a postive displacement turbo, most commonly a roots style. These provide boost largely independant of revs and hence can give good bottom end gains.
A centrifugal turbo has worse boost response than most turbos. Their boost curve is, at best, linear with revs so they still have a response hole at low revs. It makes no sense at all to use one of these in conjunction with a turbo setup. They generally have less efficiency than most turbo setups as well so there aren't going to be any top end gains either.
Again, why? What is your mate trying to achieve?
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Location:
Austria
Registered:
May 2004
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Re: twincharger novel
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Mon, 24 May 2004 10:37
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thanks for the response so far!
the mate actually is a 38year woman. she wanted to get a driveable setup. thats why she got what she has now. the "tuner" who made this is giving no information at all on what he has done. its a big tuners secret  after our meassurements i just can say he is a big bloke!
the torque band is pretty fat from 2000 to 5000 rpm. nearly constant 300NM.
we just had one hour on the dyno so we only made 3 runs.
we meassured the charger output pressure, turbo output pressure and the temperature of the last IC, inlet and outlet.
i do have some pictures of the setup. tomorrow i will also have small videos to show what happend at 4000 and 6000 rpm (both held for 10sec).
its very interesting - isnt there someone who knows how to put this on a webspace
would be far easier to explain with some pics and videos to show...
i also think that the flow will be restricted by the charger. but it had 0.2 bar left at 6000 rpm. so a turbo upgrade to suck these remaining 0.2bar out of the pipes would be possible i think. but how can i control the boost pulses???
there seems no way to get around a bypass. but with AFM thats no option for now....
hm?
cheers
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Location:
Canberra
Registered:
May 2002
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Re: twincharger novel
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Mon, 24 May 2004 22:44
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Is that 0.2 bar between the sc and turbo?
If so, watch the turbo inlet seals, they aren;t designed for a decent amount of vacuum on the inlet.
With some nifty plumbing, you could get a bypass to work with an AFM.
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Location:
Austria
Registered:
May 2004
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Location:
Austria
Registered:
May 2004
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Re: twincharger novel
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Mon, 07 June 2004 21:34
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ok. plans are getting more concrete. the lady is also willing to afford some helpfull stuff 
the plan is now to turn the setup around and make a bypass for the boosting turbo. water/air intercooler for the turbo. air/air for the charger.
the first thing to start will be a wolf3d v4 (i guess it is).
what ecu´s do other 3s-gte driver use?
anyone to share a hint?
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Location:
Austria
Registered:
May 2004
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Re: twincharger novel
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Sun, 27 June 2004 11:04
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hi again!
had some small repairs on the SW20 in the meanwhile. monday it´s on the road again. all mess of the so called tuner should now be eliminated, hope so. this was a good time on the car for thinking over the plans.
we also found out where to get some helpful parts like
bypass
http://www.hksusa.com/categories/?id=1062
autronic
http://member.newsguy.com/~gtfour/autronic/autroni c.html
now we think about a clutch for the albrex charger to disconnect in the turbo . anyone ideas or experience on this? where do you get such devices from? i wonder if a 4A_GZE charger clutch would do the job? just because i could sacrifice mine..
stupid idea???
cheers
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Location:
Sydney
Registered:
May 2002
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Re: twincharger novel
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Sun, 27 June 2004 13:32
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autronic is the way to go!!
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Location:
Austria
Registered:
May 2004
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Re: twincharger novel
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Mon, 28 June 2004 07:41
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| mx83toy wrote on Sun, 27 June 2004 23:32 |
autronic is the way to go!!
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i think so too! the autotune function will make it a way easier for the beginning 
the SMC has 4 outputs left so a clutch for the charger would be an option. a hint where to start searching would be nice...
now the albrex-charger is running fulltime. even at idle.
i think a clutch will give a lot of advantages. we could use a higher ratio for boost down low and declutch when the turbo builds boost. besides it extends the livespan of the charger as well if it is not driven all the time.
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Registered:
June 2004
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Re: twincharger novel
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Mon, 28 June 2004 09:13
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i was completely lost until someone suggested a clutch! i assumed it already had one! when does the turbo kick in, rpm wise? wouldn't it be better to use a certain size pulley that drives the sc to max boost just when the turbo would take over? that would save overworking the sc. i guess that would reduce the torque though, so maybe something in between.
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Location:
Austria
Registered:
May 2004
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Re: twincharger novel
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Tue, 29 June 2004 05:23
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the turbo and the whole setup in general is all stock. we just drove the car once in turbo only form. pretty smooth power delivery (stock turbo). think it makes boost pretty early like 2000 to 2500/min.
the only added parts are the albrex-centrifugal charger and another stock intercooler after the albrex-charger (the air-route after the charger -> intercooler is the original way)
all we found out about these centrifugal chargers is that they should have a internal variable ratio to make the best out of them. especially for low rpm. this is pretty logical if you think about the turbine style of these compressors. the pity is that this albrex unit seems to have a constant ratio - no variomatic stuff ...
it looks like we have to visit the maker/seller of albrex.
thats the company - www.motortuning.com
they made some fast porsches in the 1980s. now they do sheiks ferraris and rich mans lambos and such.
back to the clutch problem...
having a clutch would give us the option to find a better ratio to get some real boost up to lets say 3500 - 4000rpm. then we could look for a well sized turbo to take over at this rpm level 
isnt there any of the shelf clutch available for such operations ???
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