Sunday, April 11, 2021

BPU Stage 4+High flow CT20 GTX Hybrids by Skunkworks Customs

Want to keep stockish looking sleeper? or just a clean Supra and stay out of everyone else with big singles?
 
This mods was done after the car reached BPU stage 4.

Don't want to fucked up Toyota pristine working technique, and lose value of your car with other modifications that may ruin perfectly balanced engine?
    Then this is the right for you!


I will just show you a few shots and hints, but I will not drive you around with individual photos between steps, the rest is secret and you must found out by yourself like I did. So seat tight and stay tuned!

Everyone knows that mint stock Supra can be worth hundreeds of dollars with the right equipment. Such as TT, V160/V161 gearbox, hardtop, low mileage, Recaro Seats, LSD, tinted windows, sport floor mats, good overall condition, and a rare factory color can dractically increase in car's value. Such car can whitstand highly modified 1000HP beasts in price anyday and will give you advantage at selling it.



The mentioned setup include following modifications:

*Overhauled CT20 with all new gaskets, seals, lines, bearings and neccesary parts.


 

 
*Balanced turbo cores on very high rpms.

*HKS race induction kit was installed. I have polished those intake pipes as well. Remember air flow in a turbo car is pretty much like running river. Make sure to avoid rough surfaces and sharp edges! 

*Duralumin compressor wheels with larger diameter up to 48mm! I went with 46,02mm 11+0 compressor wheels with smaller center cone which gave additional 3mm of dia on each wheel. Also the wheels are polished and cropped between fins so they spool faster than the factory units. Aside from the shapes, a blades count has bigger influence on the performance. A 11+0 compressor wheel will spools faster than 5+5 or 6+6 blade wheel as it has 11 major blades and thus the air fills up the compressor housing faster, it boosts more efficiently but axes out sooner too.


 
*Inconel taller turbine wheels so boost and incresed heat producing by the turbines can be handled more easily and more efficiently.
 
 
Wheel is also taller than stock unit (after assembling the core)


*Ported and polished turbine housings


*Extensively ported exhaust manifold to matched the turbine housings. Sand blasted, polished and painted with high temp color.
I used titanium nuts on the head side.
 
 


*Ported wastegate ports to 30mm and enlarged between walls so the boost is easier to control.
If you go with 32mm DIA or larger, then different actuator flap is required! CT26 or ...


*Machined out compressor housings to matched the wheels. Slightly polished inside outlets too!
 
be4

after machining-out air inlets


*Slightly ported and polished manifold between two turbines.
 
 
 

*Ported and polished primary "H" turbine exhaust port without flap to matched the secundary port diameter with the flap&actuator which opens at about 4200rpm. Both holes needs to be exact the same diameter assuming that both turbos are the same size. From the factory, first turbo has straight open port that flows exhaust gasses all the time thru to the downpipe.. don't forget to polish primary port as well!
 
after porting both are same sized


*Ported and polished Y-pipe to matched the holes with previous part!
You can port-out single hole to 75mm at max!
 I don't recommend going any further as you may weakened the walls. Or you can use aftermarket alternative - Artec Y-pipe which has even larger ports. (The non-vvti and vvti is different pipe for both cases, so take note on that.
 
 
modified

stock 

*Uprated SMIC! This is a direct replacement for the standard unit with a 2 row 50mm bar and plate high flow core, capable of flowing enough to support 550bhp. The Whifbitz SMIC can be used for standard cars or anything up to small single turbo applications and the intercooler retains the Toyota ducting to insure all of the air is forced directly into the intercooler. You can go with FMIC, suit yourself.
 

 * Titanium "3" inch first decat pipe from GW is suitable for this mod.

*Titanium "3.5" inch midpipe by Tomei is suitable for this mod along with the rest 4 inched Ti exhaust (this ain't cheap!).
 


 

*At least 255lph fuel pump is needed for J-spec Supras!

*Good fuel is recommended. 102+ octane gasoline with O2 and additives is what I used for my lady. This type of gasoline is clear colored, very pure and doesn't smell/fume that bad as regular gas pump fuel. Drawback of this is it's cost at 3,3€/l !
     I ran on stock injectors, stock ECU without problems and keeping AFR in optimal numbers. All this is helped by two individual little piggiebacks. One for boost increasement and the other one for de-limiting speed blockade on ECU. Toyota factory ECU is hell and very conservative unit, that's why almost everypne end up with standalones or piggie backs. Good electronic EBC, and turbo timer is also recommended!

Now that you have all that, I assure you the car will be a rocket! Torque and power in spontaneous. The best thing is that the car is now noticeable faster than stock and still looks completely stock.

Don't forget to upgrade your diff, brakes and tires!

TRD 2-way mechanical LSD 200mm
You can pick OS-Giken, Kaaz or any other trusted brand as this item is long time discontinued by TRD and are very hard to find!
Solid diff mounts for the front ears
This is a 10 bolts ver. There are also 12 bolts.

Overhauled diff assembly
"Big" brake setup

brake bleeding process


 




 

 

Let's go for a little ride... 8)



                    

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