KE25 running gear

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4a-gzte 20v in the build...
 
The Plan : 20v 4age twincharger  

*20v silvertop block
*rear position knock sensor drilled/tapped into block
*8.0:1 aw11 4agze pistons
*2nd gen 4age/4agze rods
*7afe oil pump with VR sensor + custom lower cam belt/timing pulley
*7afe alloy sump with winged/baffled pan, possibly w/ external wet pump
*oil cooler
*20v blacktop head and quad throttles
*exhaust porting, deburring and harder valve springs
*3 layer metal head gasket (7afe?) , genuine 20v gasket set fitted elsewhere
*custom alloy inlet plenum
*custom water manifold off back of head (for firewall clearance)
*custom water outlet at front of head
*ae92 remote thermostat mounted under intake plenum behind S/C
*Turbo - Garrett GT3076 or similar
*External wastegate 44mm?
*Steam pipe turbo exhaust manifold (6boost?)
*3" exhaust system
*Front mount intercooler w/ 2.5" piping
*SC14 roots supercharger (2tz-fze Estima), custom mounts and tensioner, custom manifolds
*2tz-fze S/C recirculation valve - stepper motor type (if i can find suitable controller)
*Alternator low mounted under turbo with custom tensioner to suit
*AE92 reduction starter - from smallport 4age (exhaust side).
*diaphragm operated butterfly bypass valve (for testing efficiency differences)
*noise dampening butterfly upstream of SC
*ECU - considering a Link G4 (4D mapping suit quad throttles + many features)
*Cam angle sensor - front mounted off exhaust cam
*coil on plug sequential ignition (CDI?)
*water/ethanol injection system?
*wide band oxy for tuning purposes
*W57 gearbox w/ USA truck front shifter position. aftermarket gearset if won't hold together.
*9" custom chromoly flywheel and 6-puck ceramic h/d clutch (if it holds) otherwise twinplate + custom fly
*more saving moneys + sell kidney

Note: I'd like to try out both compound and sequential systems for comparison. The following setup should allow me to test both. It could also allow me to bypass a controlled amount of air to reduce the S/C pressure ratio at higher rpm, allowing more flow from the turbo, but controlled to keep inlet boost pressure higher than exhaust back pressure for obvious cylinder scavenging and knock prevention benefits.
There's many other ways of setup, and the following looks to be the least intrusive. All piping is low in the engine bay which will keep engine bay clean looking.

Pro's
* low end torque
* top end power
*instant boost
*more power than either charger can produce alone (compound boost)
*no/little parasitic drag at higher rpm
*turn s/c off for fuel economy cruise
*its nuts

Con's
*complexity
*cost
*added weight
*cramped engine bay
*heat
*increased failure rate
*build/tune time

twincharger setup
Engine : 20V 4A-GZ(T)E
 Since this car no longer needs to be daily driven, lets why not boost the crap out of it!
The idea here is to use all the best parts the generations of 4age have to offer, and build them into one ripper engine. The plan is to use the 20v silvertop bottom which has the larger crank journals and bigger gudgeons (compared to bluetop bigport 16v 4age). A silvertop 20v bottom end is apparently pretty much the same as ae101 4agze but much cheaper to purchase.. so have scored one for $75. I've now sourced a black-top 20v engine that had run a big-end bearing from which the head and 45mm quad throttles will be used. Turbo will sit on a custom turbo manifold, feeding a front mounted intercooler, custom intake plenum made for the quad throttles with associated intercooler piping and controlled by an aftermarket Link G4 or similar ecu which also gives me the option of installing sequential coil-on-plug ignition so the distributor can be ditched rather than cutting the firewall. A custom water manifold off the back of the head needs to be sorted amongst other things. Some ideas for that here. The water system i plan to run is this.

Gearbox : W57 close ratio 5speed
For Supra W57 box, need to sort out a suitable bellhousing, either by modifying std bell housings, ie cut/weld the A series engine side flange on the front of a km36 5k/G52 bellhousing, or could make an adapter plate on the back of a T50 bellhousing or splash out on a custom bellhousing (Niteparts), or make own custom A-W bell, to mount a supra gearbox to the 4age to keep things strong & reliable. Then a custom driveshaft and gearbox crossmember made up to suit. This then will fit the 4a-gze sized 9" flywheel/clutch without contact. Also on the search for the US spec truck shifter position which is even more further forwards than the ta63/ma61 shifter which apparently is not quite forward enough to come through the factory ke25 shifter hole. Conversion Components shifter is another option.

Fuel delivery:  Must add a surge tank to counter the fuel surge problem at anything less than a 1/4 tank.  Either make a baffled fuel pickup inside the tank or use an external lift pump feeding an anti-surge tank positioned beside the main tank.  From there a boot mounted high pressure pump feeds fuel to the high pressure fuel filter in the engine bay... which then feeds through the fuel rail, then rising rate fpr and back into the surge tank.  The surge tank has an overflow line at the top to drain fuel back into the main tank.  A larger fuel delivery line and a fuel tank vent is also required.   The std fuel line is pretty good size for 4age n/a.  There are two types of factory fuel tank venting, one running from top of tank to front chassis rail which I have in the SR, the other from the fuel filler pipe to the rear chassis rail.  combining the two, i can run the tank vent as fuel return and filler vent as the tank vent.

Electronics: Wire in ecu. Alarm installed with super trick anti-theft death inducing devices. battery relocated to boot to make room for turbo and cold air intake system.

Exhaust:   Going for a stainless 3" mandrel bent exhaust, possibly a high flow cat if new smog laws come into effect.. and a dumpy muffler hanging off the rear.  I like a quiet exhaust but having a turbo also reduces noise somewhat compared to n/a so here's hoping a straight through exhaust with resonators and cannon muffler will do the trick. Gearbox xmember needs to be sectioned to clear the exhaust.

Cooling:  More custom bits.. alloy radiator or something similar + electric fans.   Intercooler sits in front of radiator and oil cooler off to one side all tucked behind an unmodified bumper (hopefully).. super sleeper styles. valence will likely need some mods for clearance.

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