What mods to do on a rb25det for around 400hp?

[cosmicgate]

As the topic implies, can i get some rough idea what to completely modify for a stock rb25det in order to get around 400hp?

i currently only have 3inch piping, afm upgrade,intercooler, fuel pump and exedy single racing clutch.

 

[gtr_vspec]

simple step
change hks turbo gt28
ecu apexi fc
fuel rail hks
oil cooler hks
internal all std
cost 18k+

can get around 420 whp

mod 1 yr ago on my r34gtt

 

[cosmicgate]

thanks, i can afford 18k but is 18k inclusive of all labour charges and tuning?

this one can safely be done on stock internals bro? stock injectors only go 330cc i thnk for my case so i think need to upgrade that as well?

and btw how many bar u boosting?

 

[khoyos]

i dont have much to say about r33 rb25 stock engine internals cos i blew mine 1 month after installation of aftermarket turbo etc. and that's on a very conservative fuelling n ignition maps, main objective to prolong engine life, power comes second. maybe the halfcut engine that i got was already dying. the R34s that i hang out with (none of them running stock turbo) dont seem to face any problem with their stock internals so i guess r34 rb25 neo is significantly stronger.

anyway if u choose to do it (plus u said rm18k no prob for u) then at least install a metal head gasket n n1 oil pump during the aftermarket turbo installation.

u can get bigger turbo that is capable of more flow at a fraction of the price of garrett gt turbo. i used garrett T3/T04E and it was amazing! but most people nowadays (especially those who start playing cars after introduction of garrett gt) would not believe that conventional turbos are also capable of achieving high power.

injectors MUST change. minimum is s15 480cc injectors. i used 740cc nismo injectors last time. the rest should be okay. just remember the rule of thumb for minimum injector size selection for RB/JZ engine: 1 hp = 1 injector cc. if u plan to run 400bhp, then u need at least 400cc injectors. thats for on crank hp to be safe. so meaning if u target 400hp on wheel, then roughly on engine is 450-460bhp, so injector cc should be 450-460cc MINIMUM. go 1 step bigger just to be safe.

 

[JaHaX]

400 whp ... huhuhu ...

im still chasing that elusive figure

 

[gtr_vspec]

i m currently boost for 1.2 bar
u can set higher 1.5 bar using fc

 

[cosmicgate]

i m currently boost for 1.2 bar
u can set higher 1.5 bar using fc

i see. I think i will only boost with accordance with the ratio of my metal gasket.

Bump: some other question:

1)just what is the difference btween procam and poncam?

2)lets say u put either poncam or procam will this cancel the vtc?I heard its very hard to tune then?

3)cam pulleys necessary for the quest of 400hp with poncam/procam?

Bump: some other question:

1)just what is the difference btween procam and poncam?

2)lets say u put either poncam or procam will this cancel the vtc?I heard its very hard to tune then?

3)cam pulleys necessary for the quest of 400hp with poncam/procam?

Bump: wtf is wrong with the reply?

i keep reply it keeps quoting and "bump-ing" my post.

 

[GTS500]

400hp on wheels or fly?

Bump: to use procams on rb25det, u will need to convert to solid lifters and purchase the correct set of valve springs.

poncams are plug n play.

 

[cosmicgate]

is anything above 260 considered procams already?

im targeting 400 otw.

 

[GTS500]

400whp is possible.
You will need
1. TOMEI Solid Lifters
2. TOMEI Valve Springs
3. TOMEI PROcams 260 10.25mm for intake and exhaust
4. TOMEI Cam Pulleys
5. TOMEI Shims
6. GT35R Turbo
7. JUN Oil Pump
8. ACL Bearings
9. Pistons of your choice
10. Least 550cc Injectors
11. Fuel Pump
12. Apexi PFC

Get ready 35-40k to achieve 400whp on a RB25DET. Thats what i paid and gain.
Parts may be cheap but labour to build and to convert your cyl. head to solid lifters application comes with a price.

Bump: Other minor parts will be your
Wastegate
Oil cooler
Clutch
Intercooler
Tyres

 

[rajie]

if i got 45k i will buy over my mechanic skyline engine 8++whp with t88 turbine
but sadly no money

 

[derrickho]

seem very interesting topic

 

[GTS500]

researching and puchasing your own parts then pay someone to build your engine
and paying for a ready made engine is totally a different contentment.

 

[rajie]

true bro ...u build ur self with what u want is the best

 

[derrickho]

just replace RB30 engine lor..... hehehe JK

 

[cosmicgate]

400whp is possible.
You will need
1. TOMEI Solid Lifters
2. TOMEI Valve Springs
3. TOMEI PROcams 260 10.25mm for intake and exhaust
4. TOMEI Cam Pulleys
5. TOMEI Shims
6. GT35R Turbo
7. JUN Oil Pump
8. ACL Bearings
9. Pistons of your choice
10. Least 550cc Injectors
11. Fuel Pump
12. Apexi PFC

Get ready 35-40k to achieve 400whp on a RB25DET. Thats what i paid and gain.
Parts may be cheap but labour to build and to convert your cyl. head to solid lifters application comes with a price.

Bump: Other minor parts will be your
Wastegate
Oil cooler
Clutch
Intercooler
Tyres

for the price of 35k-40k i think i top up abit i can slot in a 2.8L stroker kit already. Pretty much a newbie engineer here when it comes to engines but i've always wanted to do the top overhauling myself,well hell, if i screw up its only around 4-5k for a new rb25 anyway, its suffice to say, i really do enjoy building it up myself instead of sending it to the garage.unfortunately don't really have time for it and my peeps are all profesionals, they don't get the idea that its pretty fun to open up things and put `em back, they are more towards those kind of wuss that don't wanan get their hands dirty lol.

well i don't know,at the moment i'm buying just these and those parts seperately, i am really tempted to take a long leave like say 3-6 months just to do both the top and bot ends at my backyard but since this is my first ambitious quest i think i'd just take time comtemplate until i get enough ppl with the know hows to guide me around. It ain't funny when you have to open up a whole can of nuts and bolts just to get lost half way i reckon lol.(fyi i've been living somewhat a good life, i can't even change a tyre what more a god damn engine.Hmm, i resent that, so i'm here for improvement lol)

Any friendly mechanic wanna be my friend?

 

[kaminari]

Good luck!And dun forget to post ur progress here,u can do it.hee.

I`m sure Mechanic is pretty bz at their own shop.....No times to surfing~heheehe

 

[RyDeL]

What is the actual bhp of stock RB25det? anyone had tested it before?

 

[mj_23]

As the topic implies, can i get some rough idea what to completely modify for a stock rb25det in order to get around 400hp?

i currently only have 3inch piping, afm upgrade,intercooler, fuel pump and exedy single racing clutch.

For on Crank 400HP,

All u need is:
Bigger turbo
After Market ECU and a good tuner
Front Mount Intercooler
Oil Cooler
Bigger Fuel Pump
After Marke Fuel Regulator
Bigger Injector (Nismo got plug and play 480CC)
Better Air Intake
Bigger Exhaust System

That's all.

Will be good to throw in Coilover for better handling and bigger braking system (You will need it).

For On wheel 400HP
A even bigger turbo
Forge engine interior (Whatever u can find, forge it)
2.8L Stroker Kit prefered
A much stronger clutches
Even bigger Injectors and Fuel Rail (You need min 600CC injectors)

Hope these help.

Cheers
MJ

 

[Driftmeister]

I reckon if you can afford to mod ur RB25 (ER34) at a budget range of 40-50k then my advice is to sell ur car and buy the 34GTR. You get that kind of power & maybe more with just EBC, ECU and Exhaust. Your future roadmap for tuning is limitless from here...depending how deep your pocket is. Just my 2 cents comments.

Reason because i have seen many ppl done all those on RB25 yet crave for the GTR engine in the end....