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Messages - twincharger

Engine Theory / Re: BOOST
May 30, 2015, 11:45:32 AM
Quote from: BigMike on May 29, 2015, 09:55:38 PM

Thank you for joining and for posting. Really cool stuff you've got going on! I will check out your build threads in a bit-

Mid 14-sec at > 13 psi? Need more rear tires? :headscratch:


No, it needs better breathing on the exhaust side.   A cheap header, crushed exhaust bends, 6 feet of pipe between the head and the turbo, a catalytic converter and a street muffler all add up to high exhaust backpressure.  I have already had to upgrade my valvesprings because backpressure was opening my exhaust valves.  HP peaks at 6000 rpm, instead of 7600 or so where the 20v should.  I'm convinced it's because of backpressure.  Midrange is pretty good. :)

I'm not going to upgrade it because it is quick enough, quiet and would just break parts with more power.
Engine Theory / Re: BOOST
May 26, 2015, 11:16:49 PM
Wow,  I think this thread was made just for me.

Here's a pic of my twincharged, 20 valve 4ag AE86,

and the build thread

Here's a pic or two of of my compound turbo 1JZ AE86.

and the build thread.

Yes, twincharging works...  I get boost in the white car as soon as the supercharger kicks on at 75% throttle, and then the turbo spools up extremely quickly when the supercharger is on.  The datalogs show 19 psi at 4000 rpm

It runs mid-14 second 1/4 mile times, and is only 1/2 second slower than the 1JZ car when it had stock turbos.

The blue car runs, but has not been to a track with the big turbos yet.  When the car was almost finished, both tracks by me closed.  I had nowhere to run it.  One has opened up again, so I'm working on it again.  More electronic stuff to do, eventually it will get to a track.

I'm hoping to get boost from the small turbo at low speeds, then both at high speed.

If that doesn't work, there's a nitrous bottle in the trunk.