Sensible power target for RB20 project

[Sydneykid]

Hi browny, we have a GCG hi flowed RB25DET turbo on an RB20DET running at 1.1 bar that makes 210 rwkw, good boost at 3,000 rpm, flat torque curve from 4,000 rpm to 7,250 rpm.

Turn the boost up to 1.5 bar and it's over 250 rwkw, gets bit of intercooler heat soak during a longer race, but the new intercooler will fix that (standard R33 GTR one). Also less restriction, so should make 1.5 bar (at the engine) with lower boost at the turbo, less heat generated there as well.

We are going to upgrade the compressor cover when we go to the larger capacity engine so there is still plenty left in the R33 turbo yet. According to the flow maps 500 bhp is not out of the question.

Hope that helps.

[browny]

So the turbo you have is one of these....

XTRGTST-STG1 450hp rated $2250.00

XTRGTST-STG2 500hp rated $2450.00

Which one?

Is there any use in upgrading injectors, afm and management at this level?

[BOOSTMEISTER]

Clint....how can you make that power on stock injectors? Even the cleanest set will only flow enough for 220rwkw, I am not doubting you its just that I am curious.

Browny, here are the specs to my old RB20DET

215rwkw (220rwkw with special fuel)

ARE front mount intercooler (500x300x75)

VG30 non ball bearing turbo with ceramic exh. wheel @ 14psi

HKS Cam gears

3.5" exhaust from turbo including dump

APEXi S-AFC

Blitz Access ecu (any tuned rom is fine)

HKS Air filter

Other things to take into consideration:

Oil catch can

Clutch

I drove the car every day and it was fine, the vg30 doesn't change the power point too much in fact I rathered it as most times around town I was only just on boost so fuel economy was great. You can also read the thread I started about 250rwkw from a RB20 to get another idea

[Sydneykid]

Hi browny, currently spec'd same as XTRGTST-STG1 450hp rated, and upgrade the necessary bits to XTRGTST-STG2 spec, 500hp rated for the next engine.

The RB20DET injectors are supposed to be 270 cc's, if so would be good for 300 bhp (170 rwkw) max. But we have an RB20DET that makes 210 rwkw on the standard injectors and there are a number of others with the same hp or even more.

I have never flow tested a standard set, we just automatically replace them (with RX7 Series V turbo ones 550 cc's) if more than 300 bhp is needed. When I take this set out I am going to stick them on the injector flow tester and confirm the 270 cc's.

Standard AFM is OK to around 400 bhp, then we go to Z32 AFM, doesn't flow any more but has resolution at higher airflow.

An ECU upgrade is essential, we use an Apexi Power FC.

Hope that helps.

[browny]

cool, thanks

[Clint32]

Boostmeister it made the power without any special trics, and the dyno is not magic one either, same dyno same car with the normal mods (14psi, dump back 3", large FMIC, pod) 136rwkw. Add one TO4 turbo and wastegate, 16psi and a decent tune and 234rwkw. The 044 pump does help as unlike some big pumps they will flow a lot more with a high pressure. And they were cleanded the day before so it has to help.

The fact that people say they are 270cc is very suss as they would be lucky to make 170rwkw as sydneykid says so they have to bigger. Someone will have to have one flow tested to be sure then we can have some info to argue over.