R33 S1 RB25DET ECU Upgrade

Hello everyone.

My name is Dejan and I am new to HPA forums. I would need your expert advice, if anyone is so kind to help me.

Firstly, my current setup R33 S1 rb25det: rebuilt engine with oem std rings, acl bearings, skimmed head, oem full gasket set, cosworth 87mm 1.5mm mls gasket, arp conrod bolts, arp head and main studs, arp flywheel bolts, n1 oil pump with crank collar, oem water pump and timing kit with gates racing belt, tomei poncams, apexi pfc with datalogit and fc edit, gt3076r turbo, aeroflow exhaust manifold, turbosmart wg50, 2.5" screamer, 3.5" downpipe running to generic middle silencer and reduced to 3" running to rear hks silencer, freddy skimmed inlet manifold but stock throttle body, thermatec inlet and throttle body gasket, nissan micra throttle cable, r8 cop with igniter delete, ngk bcpr7es spark plugs, hks evc7, walbro 255lph, torques fuel rail, bosch 550cc uscar from camaro, nismo adjustable fpr, oem fuel damper, bosch fuel filter from murcielago, generic 600x300x76 fmic, competition stage 4 flywheel and clutch kit, new oem lambda, new oem tps sensor, new oem coolant sensor, new oem z32 maf, new oem knock sensors, innovate lc2 kit, defi 10in1 dash, torques 1l catch can and head drain, boost doc splash plates. I think that is about it in my current setup. Car is running 454hp at the crank with ron100 pump fuel.

Of course that is not enough, so I bought cp 86mm pistons, tomei conrods, kelford valve springs and retainers for nvcs, tomei exhaust cam gear, aeroflow 8l sump, gtx3076r gen2, new oem r35 maf insert and apexi 80mm pipe, japspeed mvt intercooler, bosch 750cc injectors from some porsche, walbro 520lph fuel pump, I will re-use arp bolts (they can be re-used, right?), with new gaskets, bearings and belt.

I would like 600-650hp in my street car, I am not using my car for racing. I want good acceleration, not crazy top speed.

My questions for next stage of the build: should I stick with apexi pfc or go for link/haltech? Bear in mind that my budget is not unlimited.

Since my wiring harness looks good but is old, I am also considering of buying custom wiring specialties harness. If I go for link/haltech it would be wise, what do you think?

If possible, I would also like to retain nvcs and hydraulic tappets. My tappets and valves are still oem, working perfectly, but they are old. Would it be worth buying/upgrading them for my goal (rev limit is at 7500rpm)? What about CAS, I am still using the original one. Is a trigger kit hard to setup, or will buying a new (expensive) oem CAS do the job?

Will my new multivane fmic from japspeed do the job or should I go with stock r33 gtr fmic? Their claims in lowering intake temps are good, but gtr fmic is proven upgrade. On the other hand, my goal of 600+hp is pretty low nowadays where everyone is going for 1000+, so I don't know...

In my country there is no e85 fuel available at all, so I must stick with shell ron100 pump gas.

I also bought a serena r200 rear dif, which has shorter gear ratio 4.6. Anyone managed to mate it with r33 stock rear dif? I could not find a company that could drill and thread bigger bolts in the dif, because apparently the material is so tough... so they made me stainless sleeves for the bolts instead. R33 has m12 bolts, serena m10, if I remember correctly. I can't find anyone using 4.6 in r33 gtst, just to see how short gear ratios would work with gtx3076r/or similar turbo.

I know I wrote alot, I do apologize for such a long post...

Thank you in advance,

Dejan

Hi Dejan,

I'm just going to answer a few points to break it up a bit.

Are you going to be changing the fuel pump carrier and lines along with the 525lph pump? If it's all staying stock, the fuel pump is far too big for them and will cause high current draw and early fuel pump burnout.

The Z32 MAF will not support more than 450hp reliably; chances are you are already running it at the maximum value at the top end. You can get a larger MAF housing and use a Z33 or GTR MAF, but you will lose low-rpm drivability. The normal route to go down is a modern standalone such as a Link or Haltech as a minimum; this is where your tuner and budget come in. Are you going to tune it yourself? Or do you have a tuner? What ECU are they most comfortable with?

I usually fit NZ Wiring cam trigger kits for most builds, especially street builds on stock and mild cams.

If you are moving onto a modern standalone and are changing your loom, you could get a wire-in ECU and convert to drive-by-wire throttle, just an option, as it would save adding modules later to allow for this upgrade.

Intercoolers all depend on how much boost you're running and what size of turbo, will you be keeping the gt3076? Who made it and which generation is it?