Advise needed for power upgrade of RB25DET

[GTRM5]

My RB25DET engine is currently dyno at 217Whp & 27Nm torque ( at wheel ). The engine, intercooler (puny little one) and most stuffs are basically stock. I have the follow 'add-on' on it though.... 1) GReddy E-manage 2) GReddy Trust ProfecB SpecII boost controller (set to about 0.8bar boost) 3) Trust Airinx air filter.

I have been running on this setup for about 1.5 years now and is now thinking of uplifting the power a little. I do not want to go for big increase or extensive upgrade bcos this is my daily ride and reliability and ease of maintenance are still my main priority here.

Is there anyone out there who can share some advise and experience? I am aiming for 340-350Hp & 38-40Nm ( appro 270wHp & 31Nm ). Is this figure realistic for this engine? Which area of the upgrade shall I look at? Any workshop to recommend?

 

[akagilll3]

suggestion~~~

original ER34 RB25 already 0.9bar.
original turbine can't boost more that 1 bar, turbine fin not strong enough.
e-manage can't find good tuner here, prefer to put apexi power FC and FC commander, and upgrade clutch and fuel pump, easily get 300bhp on wheel.
maybe cheaper than e-manage with profec B.

 

[GTRM5]

Thanks akagilll3.

Mine is a 97' R33. Not R34, so the stock boost is only 0.5bar. I have heard from many skyline enthusiast, Apexi Power FC is much preferred when it comes to tuning RB engines. I bought the EManage and Profec more on impulse and without thinking of it's suitability. Anyway, I was new to Skyline back then.

 

[.S K A G E E.]

I assume you already have an exhaust system too right?I would agree to akagill3 suggestion of changing the fuel pump and I would advise you to get a bigger intercooler if you are looking for the power you mentioned (270whp).
Careful with the E manage as they have the tendency to eat up the coils.

akagill3: The stock Neo is pushing 0.9bar? How many bar could the standard Neo turbine take?

 

[kaminari]

Skagee share some ur experiencela~~hehe, RB25DET NEO 340whp!!

Basicly, boost up 0.9bar on NEO could manage 300whp over easily with add on NVCS & NICS system totally different feeling from R33 RB25DET low end range.

Share some minor mod, R33 RB25DET of mine 270whp wth 0.6bar.

Mod inside :
1. Front mount intercooler wth heat resistance piping bandage.
2. Straight 3 inch exhaust pipe, include front pipe, better response if have
outlet too.
3. Single plate racing clutch wth lighten flywheel for better power transfer
4. GTR fuel pump for consistance fuel delivery & sufficient petrol.
5. Iridium spark plug for better combustion (No.7).
6. SAFC or Power FC will do the A/F ratio adjustment.

Since u alrdy have boost controller, i believe 0.9bar could put arnd 290whp for ur car.:regular_smile:

 

[GTRM5]

Kaminari - Huh??? 0.9bar already give me 290wHp?? Why can't I get it from my car? Only 217whp. Then something must be wrong with my tuning method? I know everyone have their secrets to tuning their car but I am just impressed that sometime one can get good performance out of their engines with very little mod. Care to share with me which mech do the mod for you?

Skagee - Does that mean I have to throw away my E-manage?!!!! Hahaha...

I forgot to tell you i have upgraded the fuel pump to a 240l/hr too and my exhaust is a 2.5ins straight through. Forgot bcos I done see the pump and exhaust everyday...so immune to it...hahaha....

 

[akagilll3]

maximum boost for standard neo is 1 bar.

I assume you already have an exhaust system too right?I would agree to akagill3 suggestion of changing the fuel pump and I would advise you to get a bigger intercooler if you are looking for the power you mentioned (270whp).
Careful with the E manage as they have the tendency to eat up the coils.

akagill3: The stock Neo is pushing 0.9bar? How many bar could the standard Neo turbine take?

original turbine fin can't support more than 1 bar, over 1 bar turbine fin will break.

 

[DinNismo]

These are the only mods on my 25...soo I would suggest front mount intercooler,gtr fuel pump, and boost up to 0.8bar.

 

[kaminari]

Kaminari - Huh??? 0.9bar already give me 290wHp?? Why can't I get it from my car? Only 217whp. Then something must be wrong with my tuning method? I know everyone have their secrets to tuning their car but I am just impressed that sometime one can get good performance out of their engines with very little mod. Care to share with me which mech do the mod for you?

GTRM5, previously my car also like that and start mod from stock normal. Even you boost 0.9bar on stock intercooler, u wouldn`t get the result. Ur air intake too hot and low density of air will lead to lean combustion.This will harm ur engine, better change to big intercooler before boosting. Also recommend u change metal headgasket if u planning boost higher or turbo upgrade coz RB25DET is designed with high engine compression.

I always do at Onward Motorsports whch located at Puchong kinrara but i knw that there is lot other shop can do minor mod. Tuning must be done with proper A/F monitoring.

 

[space_cowboy]

Hie..

Busy body a bit. I'm running a RB20 on my cefiro. My dyno reads 218 horse power on wheel. And i didnt do much upgrade. All i did was....

1. SAFC 1 ..
2. GT-R Fuel pump
3. SARD Fuel Regulator
4. Boost Controller (boost up to 0.8 bar)
5. 3 inch straight piping exhaust system..

Hmm.. Furthermore, my engine is from a JDM A31 DET. Please bear, the turbine n ECU is not as advance as R32's RB20...

All of this, i did it at GT Auto in Sunway......



cheers'

 

[Johnyblze]

These are the only mods on my 25...soo I would suggest front mount intercooler,gtr fuel pump, and boost up to 0.8bar.

mr.din using rb25 yeah..nw i know..ehheheh

 

[GTRM5]

Thanks so much guys..... I need a bigger intercooler, I need to check if my 240L/hr fuel pump is sufficient, I need to get the Air Fuel ratio right on the entire RPM band right. I may want to stick to max 0.8bar boost for the time being cos I want to see if I can acheive my target power with mostly stock. Let me start this 'project' first and I shall come back with the result for you all. Hmmmmm... need to go hunting for an intercooler. ( Problem is I don't usually see big I/C with inlet/outlet on the same side) Which intercooler you guys use?

Question : How will the fuel regulator as recommended by space cowboy help in my case?

 

[gti88]

GTRM5,

on my ECR33 last time, when it was fairly stock,
I got 252.2hp at the wheels (194kw). Dynoed on ART's dyno dynamics machine.

stock boost, 0.6 bar
stock turbo
SAFC 2
HKS type-S intercooler
MINE's pod filter
Bosch 910 fuel pump
Aftermarket 3" downpipe
3" JUN exhaust + decat

Get a Jap intercooler kit and do keep us updated on your progress. :_:

 

[kaminari]

I got tested GTR32 fuel pump before wth 400whp on RB25DET almost 100% cycles, dyno proved.So no need worry abt that if ranging <400hp.

The fuel regulator help u to maintain the fuel press for injectors since changing fuel pump and power upgrade.But it`s not necessary for RB25DET coz still sufficient (have 2 fuel regulator)<--Go check it keke.RB20DET only 1 regulator.

Intercooler I use ARC brand, but other brand like Blitz and greddy is same piping like u stated.HKS I/C is like GTR piping.

Do monitoring the A/F ratio all range but pay more on 4000~6500rpm coz fat torque for RB25DET is 4800rpm and peak power 6400rpm.Need more fuel on that range.

Let us know the progress~~

 

[arhstr2]

hi,
ok, 4 me, i suggest
1. exhaust system (trust,hks,apexi n other) by spec.
2. big intercooler by spec
3. gtr fuel pump aftermarket (hks,apexi)
4. metal gasket
5. upgrade turbo bolt-on
6. oil cooler kit
7. downpipe n outlet
8. hks pro-v n tuner
9. upgrade brake n rotor
10. exhaust temp
11. fuel pressure
12. lsd n single hyper clutch
13. camshaft 270in 270 ex apexi n adjus pulley
14. injecter 555cc to 740cc
that all may be u can get more than 300hp to 350hp in 1.2bar

 

[fcruz3r]

depends on what ur budget is like...u could go fmic..but that will involve cutting a hole under ur battery for the piping...unless u get the return feed pipe running back to the stock position.

stock turbo has a ceramic exhaust wheel...too much boost and heat ...and the bonding between the ceramic wheel and the steel shaft becomes unstable...and the wheel detaches from the shaft and grinds against the housing...better to keep it at 0.8 bar

that being said...mods that proven to work

1. high flow exhaust
2. sell the emanage get a power fc...much more tuning capabilities and proven on so many skylines
3. get rid of ur pod filter...if u dont have a fully enclosed heat shield for it...its been proven to lose power ....use the stock airbox but get a drop in filter replacement...K&N, airinx, hks...all works fine
4. r34 smic is 1.5 times larger...has 19 rows compared to 16 on the r33 smic..is 8 cm thick ..r33 is 6.5cm ...we have a couple of skylines running the r34 cooler running 200rwkw...which is around 268 rwhp

wont talk about clutch n stuff...that doesnt add power but is just common sense that u will need to upgrade to handle more power.

with regards to the sparkplugs..i dont see why so many ppl thinks it adds power...iridium is less of a conductor compared to copper...so u get better sparks from just normal copper...only reason to go iridium is that it will last u longer...but no hp increase.

and last of all...have a sticker of all the jap shopping list on ur door..hks, apexi, greddy, tomei..etc...each sticker will add 5hp at least :tongwink:

 

[a31gtst]

GTRM5

The stock side mount cooler is not sufficient for the level of power you are aiming for, it just wont cope. Upgrade to a Front mount, Garage_r has some good deals.
You also have to look at your exhaust, have you changed your dump pipe? The stock one is very restrictive as well. Changing the dump pipe and upgrading from down pipe onwards to 3" will make the difference. Once you have done this your engine will be breathing much better and you will notice better boost and power response. All the best in your project.

P.S. if you are looking for a dump pipe i have what you need.

Cheers

 

[highboostin' 36]

With a newly rebuild RB25det with stock internals, ive pushed 259kw/336.7hp@1bar

- HKS 3.5" to a 4" pipe
- HKS GT2540
- HKS Intercooler
- HKS Oil Cooler
- HKS Pod Filter
- Apexi Power FC
- Walbro 255L Fuel Pump
- Sard 550cc Injectors
- Tomei 1.2mm Metal Gasket
- OS Giken Twin Plate
- Nismo N1 Oil Pump
- Nismo Fuel Regulator
- Greddy Profec B Spec II Boost Controller

Here are some mods ive done. You can take it as a guide if you want to achieve the power you are looking for. Most importantly is the tuning. Right tuning = good response and power. Try to get an aftermarket oil pump as it will save your main bearings from wearing out. E-mange wont get you far and stay away from HKS SSQVs as it will bring down the longetivity of your turbine if you are goin for an aftermarket turbo.
Cheers!