: Impractical but awesome..
11-22-2008, 09:17 PM
So I am gonna open up a debate on twin-charger applications for the zetec motor specifically. Besides it being expensive and impractical to a point. I want to open a discussion on why everyone thinks its so hard or near impossible as they would have it. To be specific I am talking about a turbo feeding a supercharger.. I mean besides a solution to efficiently cooling the intake charge and the added stress on the blower.. why is there all this need for a clutched pulley on the blower and these one-way valve ideas, etc.. etc.. I mean the blower is a direct drive unit.. your not going to over-spin the blower and as far as it being a restriction in the top-end of the power band.. I really can't see that either. A roots-style supercharger for example is a positive displacement motor.. what it is going to do is multiply the boost pressure being fed by the turbocharger.. say the turbo is supplying 8 psi through a blower with a pulley making 10 psi... the end result would be say 25-30 psi.. this is just an example.. not calculated by any formula, etc.. I just don't understand there being a restriction problem, etc.. which is why I'm throwing this out there again.. because I am about to embark on this project soon as my focus is already supercharged and the turbo and other parts needed for fabrication are being supplied.. I just want to get people's unbiased opinions or facts I am over-looking to make this as "painless" as possible.. [wrenchin]
11-22-2008, 10:57 PM
i guess the price.. you can do the hp you want with a built engine anda turbo... no need of the supercharger... i guess thats one of the big reasons
11-22-2008, 11:01 PM
yeah. i always thought about the idea of using a turbo and supercharger... and if it even was possible. if it is ever done i would LOVE to see pics of this. and vids of it in action.
11-23-2008, 12:45 AM
wouldnt it be a supercharger helping spool the turbo and not the turbo boosting the s/c. ussualy twin charging works with the first method
11-23-2008, 01:56 AM
price is gonna be a huge restriction here, and for the power gains to be made price per the gains most likely be cost effictive. buy the time you get a set up like this to work on a focus, you could have done a v8 conversion......
11-23-2008, 02:14 AM
Thought yall might like this article. Its not about a turbo feeding a super tho, its about using the super to get low end boost, and then the piping switches over to take feed from the turbo once it spools up to a good boost level for higher rpms.
11-23-2008, 12:03 PM
the super to feed (spool) the turbo is the way GTP Grand Prix's go about it and the way RL's and SS's tried. The later, from what I remember, couldn't get the tunning right.
11-23-2008, 02:23 PM
This has actually been tried on a focus already, Its the tuning. They were unable to tune and have the car run correctly
11-23-2008, 02:35 PM
hahn racecraft makes a turbo kit for the cobalt SS's that leaves the factory supercharger. twin charging was how alot of airplane engines were back in the day.
11-23-2008, 04:01 PM
^^yeah, that twincharge setup on the cobalt costs less than a Powerworks kit for us and nets crazy powa!
11-23-2008, 06:17 PM
aircraft engines back in the day ran or they didnt...they didnt have to worry about ecu tuning crap...lol
11-23-2008, 07:04 PM
^^^ your right just helping them lead into some good research on the set-ups. knowing the start of things always helps the end of things
11-23-2008, 07:17 PM
what about using the centripital superchargers like the vortec and a turbo? then u could just do a 2 into 1 intake setup and have it run similar to a twin turbo set-up. then u'd have the supercharger "covering" for the turbo lag. anyone know if that would work?
11-23-2008, 10:49 PM
Right so besides the cost being impractical, and the tuning being more difficult.. why do so many of these cars that are twin-charged have clutched pulleys?.. at the point that the pulley disengages the blower is then no more than an intake manifold.. its no longer making compound boost.. if the blower was still driving at higher rpm it seems like it would be making even more power making compound boost pressure.. heat is an obvious problem.. but was that the only reasoning?
11-24-2008, 10:51 AM
i dont see a turbo feeding a roots style blower making much sense. The amount of air going to the roots blower is still going to be limited by the amount of air that the turbo can supply the blower with. so you are still moving the same volume of air. If the turbo is forcing air into the blower then the pressure from the turbo would have to be higher then the blower in which case why even have the blower there? if the blower is pulling the air from the turbo then it isnt being supplied with enough air in which case why bother with the turbo.
now if it was the other way around i can understand using a blower to overcome lag because it is pulley driven, then once the turbo spools thats where that clutched pulley would come into place, it would disengage the blower pulley and allow the turbo to work on its own.
but i really dont know a whole lot about this stuff.... so dont mind me
11-24-2008, 11:16 AM
Reguardless if the SC is turning or not, if you dont have a switchable pipe going from SC to turbo then the SC is still just a restriction.
11-24-2008, 12:35 PM
I have considered this as well myself, but always thought of it as using a procharger because of where it mounts under the A/c compressor. You could get an intercooler that has dual endtanks on the passenger side, one for the procharger, and one from the turbocharger of choice, and then a single outlet on the otherside (like how the APS twin turbo kit has the intercooler for 350z's). In this scenario it wouldnt be all that difficult to set up, but def. would require a multistage boost controller to keep the boost level in check and keep it from having strange spikes everywhere.
11-24-2008, 02:44 PM
It can be done.... but I could kick its ASS with a single turbo set up.
11-24-2008, 09:12 PM
I don't really see the point unless you have AWD, all the power is just going to spin the tires..
But it would look cool