The Quest for 450hp on the RB25DET

[geno8r]

Hi

I'm just about to get my tax return & am thinking this will be good money to do the next stage of mods to my car, or atleast a stash for when i have enough to do a whole lot at once.

My car is currently putting out 309 rwhp (230 rwkw) @ 12psi which im guessing is around 370 hp (275kw) @ the engine.... My goal is to get my engine towards 450 hp (335 kw), by the time its at the wheels, maybe 260 - 270 rwkw? Please correct me if you have better estimations.

This is my car & current performance mods:

r33 GTS25T 95' Series 1.5

GTR Front Mount Intercooler

GTR Fuel Pump

T3/T4 HighFlow VL Turbo *internal wastegate

Apexi S-AFCII

GReddy Profec B Boost Controller

Blitz Dual Turbo Timer

Blitz Open-Atmosphere BOV

3" Exhaust Turbo Back

HighFlow Cat

MegaFlow Twin 2" Tip Muffler

K & N Pod Filter

Iridium Spark Plugs

Brass Button Clutch

Locked Diff

Works Rims

10" Wide Rear Tires

Aftermarket shocks

Front Strut Brace

Always run 98 Octane BP Ultimate

Stock RB25DET engine.

Stock Headgasket, Injectors, Cams, ECU.

Stock AFM, Throttle body, Plenum.

Current Max Power

309 rwhp (230 rwkw) @ 12 psi

This is all I can think off, might be another 1 or 2 small things… Anyway.

So i've been thinking a bit about my next mods & would really like some information & prices about the following mod subjects

Total mod prices are estimations / guesses, could be 2nd hand or brand new, prices should include installation.

Next Mod 1: Power FC

Total Mod Price: estimated $1600

Now I'm not sure whether to get a 2nd hand one or brand new, im thinking i'd like to get a 2nd hand one with hand controller for around $900 - $1000.

Once i have this i'll need a full on tune which will cost around $500 i believe, but! i wont get a power FC installed or tuned before i get the next mods installed @ the same time i think.

Next Mod 2: 550 cc Injectors or 440 cc GTR Injectors?

Total Mod Price: Anywhere from $400 - $1000

Ok so to make 450 hp im going to need some better injectors, i'm planning to run max boost of 18 - 19 Psi. What injectors could do this for me, could the GTR ones cut it? & are 2nd hand injectors acceptable after being cleaned.

Next Mod 3: z32 AFM

Total Mod Price: $300 - $500

From what i've read the stock AFM is getting maxed out at around 230 - 240 rwkw. I know im going to need one of these.

Next mod 4: Misc parts, Fuel Rail?,Oil Catch can, any suggestions what else i'll need?

Total Mod Price: $200 - $500?

Depenind on what injectors i'll need, might need certain fuel rail, with this power *450hp* do i need a oil catch can... please suggest other parts i should get.

Ok so whats the plan?? I think i'll save & buy all these parts @ once & get them all installed at the same time, get everything set up & done once. With all the part installed I'll get a full dyno tune & see how much power we can make @ 18 - 19 psi. Posibly might need new Headgaskets too. another $800 right there. Running 18 psi i'd like to make around 255 rwkw. I'd really like to see how much power my turbo can make... in good time it'll happen.

Now this is my simple understanding of what to do next, Any feedback with people who have went through this stage of modding, "Stage 2, Stage 3?" your feed back would be greatly appreciated, & for all the people who simply know what parts work well with what, your suggestions / comments would be great too!

Why am i trying to max out my gtst? Well if i end up making 450 hp one day i know i cant make any more power on stock internals and i think this may satisfy me 'I'll probably then just spend my money on body kits & making it look phat hahah".... If i can have one of the fastest 33 gtst's going around on a stock engine & internals I'll be very happy, its not how fast your car is, its how fast your car is in comparison & for the situation. While my long term goal is to get that r34 GTR, then with the 34 GTR its not about comparison no more coz the things are king of the mountain anyway! hahah.

Cheers!

[aybee]

before you do anything, make sure your exhaust is at least 3inches all the way through. so get rid of the twin 2inch muffler and get something with a larger diameter (a single 3inch tip is larger than two 2inch tips). even better to go for a 3.5inch cat back exhaust.

[geno8r]

before you do anything, make sure your exhaust is at least 3inches all the way through. so get rid of the twin 2inch muffler and get something with a larger diameter (a single 3inch tip is larger than two 2inch tips). even better to go for a 3.5inch cat back exhaust.

I've actually got a dirty big HKS Hyper muffler but arnt using it because its WAY too loud... the drone that thing makes... It's just asking for cops to bust yo ass... The twin tip works great with cops... looks stock, but yeh, i know its going to be restrictive... if only i could get that big f*$ka tail pipe engineered, wouldnt that be heavenly.

[Pandaemonaeon]

Correct me if I'm wrong, but isn't twin 2" roughly 6.282" area compared to a single 3" being around 4.7115"?

[geno8r]

Think its just because it has to break the flow more is why its restrictive. My hyper tailpipe is 3" inlet 6" muffler, 4.5" tip. It's quite large.... It would flow better.

[Robo's]

Its (2*3.142)square = 39.48 * 2 = 78.97

(3*3.142)square = 88.84

So 3 inch is bigger!!

[Pandaemonaeon]

Yeah. It was a bad day yesterday. About 3 hours later my brain started working again and I realised what I had done. Always helps to square the number. :bonk:

[geno8r]

Your doing better than me... i've forgot all maths i learnt in school... & i was only @ school last year... lol Maths... Pffffff who needs it, done nothing for no body *dont take this literally and reply with some bs :wassup:* If you were listening to JJJ this morning Adam & Will had a pretty funny fight about Maths being useless with Adam obviously being Pro Maths... hahahah