Possible Turbo Upgrades for RB25 GTT Auto?

[weihan76]

Hi Guys,

Need some advice or suggestions on this matter. Wat are the possible turbo upgrades that a RB25 GTT can do? Let's say within a budget of 5k. Can an existing RB26 Twin Turbo work on the RB25 Engine? Appreciate a feedback. Thanks.

Regards,
Wei-han

 

[skyther]

Stock 25 turbo will do 12psi+ easily, I'd spend that 5k on a PowerFC and a boost controller. 25 Neo ECUs are hardly tuner friendly. :confused_smile:

 

[kaminari]

How much hp u aiming?But within rm5k budget, buy a Power FC n boost controller shuld be enuf alrdy to do 320hp on wheels. Changing turbo means u have to change metal headgasket + fuel pump as well :regular_smile:

 

[RERider]

Power FC only released for manual transmission. Unfair to tiptronic. :sad_smile:
Double the budget u can get a 3037 turbine.

 

[red_line]

complain complain !!!

 

[Driftmeister]

Somehow you still need an standalone ECU before you can up your boost whether it is standard or aftermarket turbo as a safety net. Plus if your tuner is good he can tune them for Power and Economy (highway/cruise) mode.

Heard the standard Turbo is good up to .8bar. Pretty fast actually..

 

[red_line]

so wats the recommended aftermarket ecu on the market?

 

[kaminari]

Hmmm, if tiptronic.... have to use piggyback kind of aftermarket ECU. Myb
e-manage can help but i dun reckon,haha. F CON SZ would be better but who can tune in Malaysia?

 

[weihan76]

Hi, I have previously installed the E-Manage and HKS EVC and upgraded to a GTR intercooler and N1 has tuned my Triptronic GTT upto a max of 1.0 Bar but has recently created some problems of misfiring and over boosting. Not sure its due to settings or turbo limitations. Went back to N1 and got the EVC to tune down my high boost settings to 0.9bar but the lag has increased tremendously.

A thought just came into my mind, can the 2.5GTT be converted into a Twin Turbo (meaning using GTR stock turbos) ? Maybe the manifold has to be changed i guess. Appreciate some comments :) ?

Wei-han

 

[kaminari]

weihan76:

I believe N1 shuld know tht stock ECU skyline come wth boost cut feature at 0.9 bar.No boost allow beyond tht. Go refine the tuning especially ignition timing to reduce misfiring. Overboost?Mind explain detail?EVC comes wth boost limitter, go set ur boost limit to prevent overshoot boost n unintend damaging turbo.

I think got discuss abt twin turbo before. U must run full com ECU comes wth D-Jetro feature to run it airflow less. RB25DET using single AFM, u need twin AFM for twin turbo.I never comes see yet twin AFM wiring into RB25.It`s complicated wiring to divide single AFM voltage 5V to 2.5V.Twin manifold is a must, flange bolt also different position.Custom adapter needed.

 

[Driftmeister]

why you need the complication of a twin when you can go for a bigger turbo like HKS 2835 Pro, 2540, or a responsive onve like the GT-SS or GT-RS. end of the day you need a proper tune with after market ecu, fuel pump upgrade, injectors and Cams can be useful too. ECU maybe you can go for F-Con Vpro as a piggyback and retain your standard ECU for the auto to still work. But nothing beat changing to manual gearbox then your deep pocket is only the limit...hehehe

 

[red_line]

kaminari: F con SZ so bloody expensive wei....

anyway thanks for so muc information, kaminari....



:p

 

[cmng]

allo
triptronic.. what to do
FCON V PRO it lo
dunno got harness or not..
maybe custom harness from japan

 

[sakakida]

weihan

I know what you thinking.... heheh you want to make that 4 rear pipe to split fire is it.... hahaha

since everyone is talking about ECU... anyone know anything about Mine's Aftermarket ECU?

 

[weihan76]

yeah lo, then u guys can use my pipes as ciggie lighter mer :) hahaha

 

[sakakida]

i will be the first one to test it out bro.... but don't boost too high, it will burn our face...

i think you should go for HKS 2835 Pro and maybe get mines to tune your car in japan.... it will look stock standard but it smoke everyone else....

 

[fcruz3r]

stock ecu boost cuts at around 11-12psi...so getting a bigger turbo and running higher psi is only half the equation...u could go cheapo method of safc + hks fcd and save additional cash for high flowing ur existing turbo...that way u can use standard oil and water lines back...and will bolt on to your existing exhaust manifold without any modifications.

 

[satigue]

11-12 psi? r u sure?

 

[fcruz3r]

yupp....higher boost and ur cars goes into rich n retard...really sucks the fun out of the rb series engines

 

[fcruz3r]

well the correct explanation is skylines dont have boost cuts in the sense that it measures boost and cuts beyond a specific psi...what happens is the stock ecu measures airflow...when boost reaches around 12psi...airflow exceeds a preset ecu limit...therefore the ecu dumps shit loads of fuel and retards the timing to prevent detonation and therefore results in loss of power.