Discussion About Rb20det Using Rb25det Turbine

[stormlcc]

what is needed for the engine to support it? Let's leave the suspension and brakes from this discussion...

1) Larger intercooler (must)
2) Larger piping (3" at least?)
3) Injectors???
4) remapped ECU or Engine Management???
5) Better air intake??? (suggestions?)
6)
7)
8)

Guys, let's do this on a budgeted scale, no hard core or very expensive items that cost a fortune to install.....
And I heard from someone that the turbo lag is a bit annoying even after installing a mines ECU, larger intercooler, bigger piping and K&N air filter....is bigger injectors a MUST HAVE item?

Thanks all Sifus :rolleyes:

 

[[PIMPIN]]

well.. depends on how far you really wanna go.. if you're planning on keeping it stock, then just swap over turbo and you wont need any other mods such as injectors and stuff.. its when you start pushing the car that you need the support systems such as injectors, fuel pump, cooler, etc etc..

i used to have an RB25DET for 3 yrs and then play RB20DET for just over a year.. i miss the effortless cruising in the torquey 25.. the 32 is somewhat sluggish and 'dead' under 4k rpm.. such as going uphill and stuff you need to drop gear for better acceleration..

what i did to my RB20 was that instead of dropping in an RB25 turbo i instead got a HKS2510 turbo.. i'm currently running stock boost with the stock intercooler in place.. in winter it seems fine but in summer u can tell that a FMIC is really needed.. response wise its awesome, around town and cutting through traffic it pulls a lot harder than the stock RB20 turbo.. the reason why the RB20 lacks the response of the 25 is obviously the lack of displacement but what also is a factor is the lower compression ratio of the engine.. although it feels sluggish off boost, you can run higher boost safely.. i have mates who have run 1.3 bar or so on stock internals for 1-2 years, even running at the track and things seem to be going fine.. (as long as fuel and cooling systems in place)

 

[a31gtst]

If your budget is tight then its just basic stuff.
The oil and water lines may not be the same but this is just minor, your mech should be able to mod it pretty easy. Just make sure tht when u swap the turbine, take out the actuator from the rb20 one and fit onto the 25 turbine.
Stock 25 one if i'm not mistaken is only 0.4 bar in comparison wth the rb20 one which is 0.6 bar....so if you do the swap without swapping the actuator...the car will feel like a real lemon!!

Do the swap first, when you have the cash you may consider doing your piping, dump pipe, afc/ safc(good upgrade), etc etc...
Just dont boost the bugger to high, i think 0.9 and below should be fine but then again just dont risk blowing the bugger.
Another thing to look out for is the pipe from the turbine to i/c....the 25 one is bigger than the rb20 one...you may need to swap this.

Having done a similar project before, i find the engine now very torquey at low rpm and the turbine spools very quickly...could be my setup but if your interested to find out more just ctc me at 012-3344044

All the best in your project.

cheers!

 

[[PIMPIN]]

yeah from memory the RB20 runs 10psi and the RB25 runs abt 7psi..

i could be off by a bit tho..

 

[zephuros]

I've done that swap too... it's sweet! Real sweet but there were a couple of things that kinda kill the fun. Firstly, LAG!!!!! YOu'll get a lot more of it right up till a tad below 4000 revs. Be prepared for this. It's a pain when you come off boost so nowadays i'm always in the lower gears around town, and that definitely keeps the bosses at Shell and Esso happy! I think the turbine upgrade is worth the time/effort if you proceed with a 3" exhaust system and a pod filter. I think that this made a significant difference in my case. Once you let the engine breathe a little more you'll also notice that the boost climbs a little faster. Am just using a simple bleed valve to control boost at the moment and even that helps keep it at around 0.6. With the exhaust and filter the other thing you'll notice is that when you pile on the revs there's no letting up in torque near redline unlike the stock 20 turbine which basically rruns out of steam at 5500. This is perhaps the nicest of the benefits that you'll get. I do recommend that you get an AFC and a decent fuel pump since you'll be running the stock injectors pretty hard. Any detonation at these revs will result in a bent conrod or spun bearing (i know this from experience as my last engine suffered this very fate! haha)

keep the injectors stock for now. They're good for around 270bhp when running high duty. Again just make sure you have some decent engine management and you should be just fine... there's a lot of fun to be had in the upper rev range!


Yo Pimpin, what car are you running that setup in?

 

[stormlcc]

zephuros, u said to use a decent fuel pump, what do u suggest?

I'm using RB25det fuel pump now, is it the same as RB20det pump or better compared to it? and is it sufficient to support 260 HP, since I'm planning on using RB25 turbine boosting it to 0.9 bar, but using basic mods only and using the stock injectors. Planning to use SAFC also.

If RB25 fuel pump is not enough, then Bosch 910 fuel pump should do the job, but it's damn expensive...

 

[[PIMPIN]]

i dont know abt the prices in Msia, but Walbro pumps are pretty cheap here.. the 255l/ph

GSS 341 is the part number or somthing along those lines.. i have to look it up..

 

[zephuros]

yea, those walbro pumps are nice and small and can fit in any tank man! not like the stnadard unisia pumps!

 

[cmng]

Get Walbro pump
RM500-600

 

[a31gtst]

hey stromlcc,

the rb25det fuel pump churns out abt the same as the rb20det one. What you want to look for is either a gtr pump or a fairlady(300z) one. This can cost you anywhere btwn rm250 to rm350. Source these from potong shops or if you want one i can source one for you.

As for the lag, this is very subjective...both me and zephuros have similar setups but i would say his mods are superior to mine...yet the power that we are getting is very close but i dont get much lag. So it is vey hard to tell, what you should make sure is that your i/c is not leaking and there must be enough air flowing thru it...if your bumper restricts the air flow you will feel lag and lack of power.

What size is your exhaust piping?

 

[zephuros]

a31gtst....

that's coz your engine is not really a 2.0 is it? heheh... perhaps some extra ccs have grown inside of the cylinders! :lol:

 

[[PIMPIN]]

just get the walbro i listed above.. should support 250rwkw easily and is bolt on

 

[cmng]

yea walbro. buy from US

or buy from me
i have 3 unit GTR 32 and 3 unit Z32 Turbo fuel pump
kekeke

 

[a31gtst]

[quote ]
yea walbro. buy from US

or buy from me
i have 3 unit GTR 32 and 3 unit Z32 Turbo fuel pump
kekeke
[/quote]

:P heheh, cmng...u really got everything ler
forget oredi ler but how much does both pump flow per/hr arr?


cheers

 

[cmng]

GTR 32 = 192
Z32 = 210

 

[a31gtst]

Originally posted by cmng@Apr 22 2005, 11:11
GTR 32 = 192
Z32 = 210

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cool...thnx for the info
haih...kena con so many times wth fuel pump...
thankfully now i got the right one :lol:


cheers

 

[stormlcc]

a31gtst, my piping size is 2.5" at front, 3" at the back to the muffler...but i'm using stock RB20det only lah, haven't mod yet...'cause no money, I even don't have sport rims that can fit in my gts-t disc brakes and calipers...now ony using WAJA rims... :P .....

I'm planning to do this kind of mod in the near future, now most important is to find a set of sport rims first!!!

 

[a31gtst]

:o waja rims?

wow, btw you didnt mention what car ur rb20 is in...is it a cefiro a31?

For your piping, tht should be ok for now...once you put in the rb25 turbine you would probably want to upgrade the exhaust too. heheh...and brakes are also a very important upgrade... gts-t, are those the 298mm ones?

rims are aplenty nowadays so dun worry too much abt tht but you should upgrade the brakes for sure. try looking for rims that are slightly wider like 7inch or above...otherwise your tyres will look really narrow and traction wont be so good as well. I myself am going to put in the r32 gts rims but they are 16x6.5 so i'm afraid my car will look really funny..plus tyre size would be very limited...max i think shud be 215 or 225.

all the best in your project.


cheers

 

[cmng]

32 GTS Rim look funny on A31 if your car ride is high or standard
if your car ride is low.. then it is cun..

did you know wai car all the while is running GTS 32 Rim before
he put the GTR 32 rim ?

 

[a31gtst]

Originally posted by cmng@Apr 25 2005, 10:07
32 GTS Rim look funny on A31 if your car ride is high or standard
if your car ride is low.. then it is cun..

did you know wai car all the while is running GTS 32 Rim before
he put the GTR 32 rim ?

[snapback]924854[/snapback]​

waaah, really arr....damn means i gotta slam my car to the ground ler :P
but i really love the look of the rim... do you have any spacer arr cmng?

coz wth the gts rim the wheels are very very inside the wheel arch...wanna put spacer to bring it out a little...otwise look funny ler :lol:


cheers

btw, saw the white ''car'' at wai's......droool :rolleyes: