Nissan 200SX Club - South Africa

Good day everyone, my name is Richard and I'm new to the forum.
I own a 1992 model s13 200SX fitted with a RB25DET motor and a Skyline GT 5speed gearbox.

The only modifications on the engine are forged Wiseco pistons, larger T3/T4 hybrid turbo and custom Stainless steel turbo manifold.
I'm running a 250lph Exco fuel pump and using a Go-Tech EFI management system and a large Proline intercooler.
Boost is set at 0.8bar (228 RWKW)

This is my first fuel injected forced induction car so I am new to the world of turbos and injectors.
My previous projects were all high powered large capacity N/A motors.

I have a few queries and questions that I hope you guys can shed some light on, regarding the RB25DET motor and also on the S13 suspension.

Here goes...

1) What is a safe maximum rev limit (rev range) for the RB25DET motor, the motor is currently wired to the stock rev counter of the CA18 motor so it over reeds with an unknown amount of RPM.
Plans are to fit a aftermarket tachometer and shift light.

2) Next up, what is a good grade and make of oil to use for high performance turbo application in both the RB25 engine and GT gearbox?

3) How much boost can a healthy otherwise stock besides the forged Wiseco pistons, RB25 motor handle?
Keeping drive ability and reliability in mind.

4) What is the best / correct way to connect up an oil catch can to the RB25 motor so that I maintain a positive crankcase vacuum?

5)Next one is a bit tricky, and diagnoses is unknown...Help please.
When i start up the RB25 motor in the morning, she starts up perfect and idles perfectly.
As she starts to heat up and the oil thins out, smoke starts to flow from the exhaust pipes.
Under load or at slightly higher RPM than idle the smoke disappears.
In driving conditions, she doesn't smoke until you stop at a traffic light and only after a few seconds of idling does the smoke appear.
Can this be a faulty oil seal in the exhaust housing of the turbo, or to much oil feed into the turbo?
The turbo does have a bit of end play but not much end float.

6) Suspension, I intend to use the car for multiple purposes.
Road, Drift and Drag, what is a good suspension upgrade that will offer me decent all round performance. Keeping in mind the added weight of the slightly heavier RB25 motor.

7) Lastly, does any one know how I can mate the stock speedometer cable to the GT 5 speed gearbox. Im currently running on a GPS and my highest speed recorded so far is 277km/h. Bloody scary with stock suspension and brakes! Also were can I source a set of R33 calipers and discs from?

Thank you for your time and input.
Regards
Richard

Hi Richard, welcome....would love an RB in my cabby.

I will answer what I can but there is more experienced guys with RB's that will help out better.

2) Next up, what is a good grade and make of oil to use for high performance turbo application in both the RB25 engine and GT gearbox?

I believe in Mobil 1, there is different opinions on whether synthetic or normal oil is best, most believe a good synthetic is the best for turbo and engine.
As for the gearbox, use a slightly thicker GB oil because of our heat(my opinion) ask your local part shop.

How much boost can a healthy otherwise stock besides the forged Wiseco pistons, RB25 motor handle?
Keeping drive ability and reliability in mind.

You will be safe with boosting 1 bar, the pistons will easely handle it and the mains and so forth should be ok, to be safe you can always add a water/meth kit. The question is how much fuel are you able to deliver....have you got standard injectors? If so you are close or on the limit of the fuel that can be delivered, you can sqeeze out a bit more by upping the fuel pressure but the best would be to install higher flow injectors.

BUT....228 RWKW is good on 0.8 bar....for normal driving who needs more.... on track days(drift and drag) ask your tuner to set up a map switch so that you can run higher boost on those days, obveously you need bits to do that, your tuner will help you out.

5)Next one is a bit tricky, and diagnoses is unknown...Help please.
When i start up the RB25 motor in the morning, she starts up perfect and idles perfectly.
As she starts to heat up and the oil thins out, smoke starts to flow from the exhaust pipes.
Under load or at slightly higher RPM than idle the smoke disappears.
In driving conditions, she doesn't smoke until you stop at a traffic light and only after a few seconds of idling does the smoke appear.
Can this be a faulty oil seal in the exhaust housing of the turbo, or to much oil feed into the turbo?
The turbo does have a bit of end play but not much end float.

This could be a few things, what colour is the smoke? Most propably the turbo seals(in most cases your boost pipes will be wet with oil) but it could be a breathing problem, question 4 might sort that, it may be valve stem seals.....to test for valve stem seals....drive the car hardish till about 4th gear, then take your foot off the gas with the car in gear....watch the mirror.....if you see smoke....valve stem seals....

6) Suspension, I intend to use the car for multiple purposes.
Road, Drift and Drag, what is a good suspension upgrade that will offer me decent all round performance. Keeping in mind the added weight of the slightly heavier RB25 motor.

There is some guys on the forum bringing in BC coilovers, this will go far on helping the suspension, then strut braces, poly bush kits for a start, then you can brace the bottom front and rear.....there is articles on the site that will explain all.

Also were can I source a set of R33 calipers and discs from?

You will most propably find it easier to import, but there is some companies in SA that will supply disks and pads for a S13 4 pot like powerbrake, Brembo and EBC.

Hope that helps.....the other guys will help more.

SX200-RB25DET wrote:6) Suspension, I intend to use the car for multiple purposes.
Road, Drift and Drag, what is a good suspension upgrade that will offer me decent all round performance. Keeping in mind the added weight of the slightly heavier RB25 motor.

The BC Coilovers work very well with the RB engines, seems like the 8kg springs in front is perfect for the extra weight. Good damping and wide range of adjustment.
Next order in Jan 2009 if u are interested.

1. 7500rpm

2. Castrol slx, shell helix ultra

3. as draco said 1 bar. injectors to fuel that will be the next step.

4. dont know, google?

5. sounds like turbo seals to me.

6. bushes and street spec coil overs and if you need you can do strut braces ect

7. the CA18 speed sensor will fit in a RB box to give you the right reading.

Brakes you going to have to import. Rezlo was selling a set of R33 calipers and 330mm disks

SX200-RB25DET wrote:. 4) What is the best / correct way to connect up an oil catch can to the RB25 motor so that I maintain a positive crankcase vacuum?

U dont need vacuum for the crankcase, all RB motors breath a bit. Just connect the breather pipes to a outside breather tank. Dont breath into the inlet pipe before turbo.

I've had the same "smoking" problem on my turbo'd corsa 1st thing to
do not use cheap oil, it will get too thin when hot loose its viscosity
and then cause smoking,

second thing The size of your Oil return pipe. if its not big enough (id =
inner diameter) it will also cause Smoking as it can not return the oil
to your sump quick enough.


The last thing, some aftermarket turbo's does not come with a
factory "restriction" on the oil feed, which causes problems if your return
is only be so big. I have resticted my oil feed before to fix the smoking
problem, whithout any problems, drove the car daily for more than a year
with no turbo failures. Oil flow should be around 500ml - 1 litre of oil at
idling per 60seconds of idling.

[/quote]