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Twin charging an i5??

Posted: Wed Jan 14, 2015 12:31 pm
by Aktapod
I've had this crazy idea in my head that I can't shake, but I've never seen it done on our engines.

So the idea is, you have both a supercharger and turbo working together. The supercharger takes care of the of the low end torque, but as the revs rise, the large turbo starts to spool up in series with the supercharger. As it starts to build pressure, a valve slowly opens and allows the turbo to bypass the SC. Eventually SC is doing nothing and its clutch is disengaged, which leaves you with the turbo to do its thing and make MAD POWERRR!!

I know it would be very complicated, expensive, heavy, packaging and intercooling would be a pain, and it would be easier to just get a bigger displacement engine, but I am almost dead-set on trying this one day.

Anyone seen it done? Any hurdles I haven't considered? Is this just a pipe dream??

Re: Twin charging an i5??

Posted: Wed Jan 14, 2015 1:42 pm
by Midnight
The mk5 golf was available with a 1.4l Twincharged engine in Europe, maybe you could adapt that system to an 07k?

Re: Twin charging an i5??

Posted: Wed Jan 14, 2015 3:12 pm
by EDIGREG

Re: Twin charging an i5??

Posted: Wed Jan 14, 2015 3:14 pm
by ringbearer
Did he make it work?

Re: Twin charging an i5??

Posted: Wed Jan 14, 2015 6:02 pm
by Aktapod
Holy crap! That's awesome! I'm also interested in whether it worked or not.

Re: Twin charging an i5??

Posted: Wed Jan 14, 2015 6:44 pm
by Aktapod
Just kidding, I tracked him down to another forum. Looks like it works!! The thing seems mental! Uses a C32 AMG supercharger. Unfortunately, the forum doesn't let you see attached files and pics unless you're a paid member.

http://www.audiclubsa.org.za/cgi-bin/ya ... 1246870223

Re: Twin charging an i5??

Posted: Thu Jan 15, 2015 12:24 am
by loxxrider
I think you're better off trying a compound turbo setup...

Re: Twin charging an i5??

Posted: Thu Jan 15, 2015 12:30 pm
by scubagli
Compound the supercharger and turbo...air to water intercooler/aftercooler...if I could figure out the math I'd try this on something.

Sent from my KFSOWI using Tapatalk

Re: Twin charging an i5??

Posted: Thu Jan 15, 2015 1:35 pm
by Midnight
scubagli wrote:Compound the supercharger and turbo...air to water intercooler/aftercooler...if I could figure out the math I'd try this on something.

Sent from my KFSOWI using Tapatalk


Compound twin charging? :guns:

Re: Twin charging an i5??

Posted: Thu Jan 15, 2015 1:37 pm
by scubagli
Midnight wrote:
scubagli wrote:Compound the supercharger and turbo...air to water intercooler/aftercooler...if I could figure out the math I'd try this on something.

Sent from my KFSOWI using Tapatalk


Compound twin charging? :guns:

I'd call it hypercharging.

Re: Twin charging an i5??

Posted: Thu Jan 15, 2015 2:00 pm
by roortube
I spoke to Hank about compound turbos for my upcoming 07K ubild for the UrQ. Its a cool idea, but very much more complex. I got the feeling that he's a bigger fan of a properly sized EFR with a quick spool valve.

Re: Twin charging an i5??

Posted: Thu Jan 15, 2015 4:16 pm
by scubagli
Yeah properly sizing the turbos, wastegates, keeping track of boost,etgs,emps...but if you get the formula right you could have the potential for 5500 under the curve more or less....anyway it would make an interesting project.

Re: Twin charging an i5??

Posted: Thu Jan 15, 2015 6:30 pm
by Aktapod
IMO the key to getting something like this to work reliably is simplicity. The more variables you have to optimize, the more dimensionally complex the problem becomes.

From a control perspective, a twin charging setup would only require monitoring another MAP sensor between the turbo and SC, optimizing the time and rate the SC bypass valve opens, and when to disengage the supercharger clutch. Permanently having them in series would be even less complex, but has its own drawbacks.