I have opened similar threads in different Subaru communities in the past. Some of you may bored my question already but this will be more spesific with the details. There is no actual problem but the performance of the car frustrating me.

Here is the mods I have so far;
Deadbolt Super16g Turbocharger
850cc Fuel Injectors
Perrin EBCS
3" Blitz Nur Spec R Exhaust
3" Invidia Downpipe
3" Mandrel Bent Midpipe
Green Panel Filter
STI8 TMIC/Scoop/Custom Splitter
Apexi PowerFC Standalone Ecu
Walbro 255 lph Fuel Pump
(PFR6G - 0.6mm gap, 100.000 mile stock internals)


According to deadbolt the Super16G supports 380 BHP. Big16G turbos known as capable of supporting 320-360BHP. Super16G(580CFM) uses the same TD05H turbine wheel used in the TD05H-18G, however it has a slightly smaller compressor wheel. This will allow spoolup that is quicker than the 18G, but it will also mean that this turbo will support about 15-20HP less than the 18G. This turbo comes standard with deadbolt heavy porting on the turbine housing, black ceramic coating on the turbine housing, and grey ceramic coating on the compressor housing.

I'm not expert nor a mapper but I'm trying to sort out things myself because in my country there are no reputable technicians. To me, my car is no where around 380BHP. In best case, it produce 300 BHP, 400 nm at 22 psi(1.5 bar) of boost.(Defi D) EGT climbs to 850c at WOTS.(Defi D)

Last week, have made a compression test and results were;

cylinder#1 = 121 psi
cylinder#2 = 121 psi
cylinder#3 = 120 psi
cylinder#4 = 121 psi

According to Subaru gurus it should be around 150 psi(?) but I never complained with the low results because I belive the engine works like a clock. I have checked all the pipes visually for any boost leaks nothing found. I have checked the whole exhaust system for a leak and again nothing found. I went to a Subaru dealer to check the coilpacks and the guy said me that the voltage is in normal range.(also visually checked)

So if its mapping? Yes it could be because I'm not a mapper but trying to work on it every weekend. Here is the PowerFC logs; Ignition, AFR, Boost







Some 3-4th gear WOT logs here.
http://www.hemenpaylas.com/download/.../logs.rar.html

Zeitronix Wideband is the simulator of the O2 sensor at the moment. PowerFC highlighted TPS sensor in the past for a few times so TPS is my replace list.(Max TPS voltage I have seen so far is 4.1v) I have changed the MAF sensor 4 months ago. Idles at 950-1000mv, max voltage 4.8v at 6000 rpm.

As I told earlier there is no problem with the car except the performance. No strugle, no hesitate, no knock etc. It revs pure untill the redline. My clutch is around 50K mile and it holds very well.(have a spare exedy organic in the garage)

Here is the latest dyno sheet. I have to have stop the run at 4600 rpm because the car has detonated slightly. There was no jetfans for TMIC cars at the dyno so cant feed the tmic.



DynoRun log
http://www.hemenpaylas.com/download/.../dyno.rar.html

BTW, in the past the car has always been diffucult to reach target boosts I set on PFC. I have never reached above 1.1 bar with TD04L with the stock solenoid. Changed the turbo to a Super16G(also wastegate) and the problem contunied. I changed the boost solenoid to the Perrin one, and now I'm able to reach 1.42 bar (1.51 for Defis) at the max boost duty cycle.

Sorry for the long post really need some technical advices. I have driven a MY97 with a VF34 yesterday and it was pulling much much more stronger. I know there is a bottleneck somewhere and I cant find it. It makes me sick! Any advices would be appriciated.

 

eeek

 

I have a customer car with similar problems. We changed to an 18g turbo, and it was an improvement but not what we were looking for. On the super16g we got to 326hp holding about 1.4 bar at 6000rpm. But after that the power dropped off like a stone. It is also a 98 car with similar mods but the addition of a FMIC and headers. When running a VF24 the car felt strong, and the intention was to bring it up to around 350hp, but this has so far proved illusive. In contrast, newer cars with fewer mods we are able to make similar power with ease..

 

is there an issue with MY98 cars? as my MY98 type R had similar mods and struggled to make power went for a 20G to see if that helped things just need it mapped now to see

 

I think UK/Euro cars in paticular can be troublesome. i've had no real problems with STI versions.

 

This is really interesting. We have no GC8 STI cars here so the question if they have AVCS?

 

Sonica


Do you know what your compression ratio is? 8.0:1 or 8.5:1 ? I pressume it would be closer to 8.5:1
what is the model number in the vin plate?

Koji

 

Koji
EJ20G / 8.0:1

So we sum up with not to use big TD series turbo on UK/EU MY97-98 cars? Anyone willing to make a technical explanation/comparing different years?