RB25 powered SX200

[200SX-RB25DET]

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.RegardsRichard

[l0nestar]

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.RegardsRichard

Ok, this will take some time..1. did you change head-gaskets when you installed the pistons? What cams and valvetrain? All Stock? keep it under 8k.2. Please search. Any good quality synthetic oil. I do not know what brands are availible in SA.3. Again, stock HG? stock head studs? What exact turbo are you using?4. zerothread?id=4038975. 6. That's up to you. A lot of people prefer coilovers to a good strut-spring setup. 7. You will have to do a conversion. There are companies here in the US who will do it, one of the RB moderators (Carl H) does them on the side as well. You can also look into a converter box from Dakota Digital.

[200SX-RB25DET]

Hi there, thanx for the reply.

As far as i know all other parts on the motor are stock RB25 bits.The turbo is a T3/T4 unit. Not sure off the compressor wheel and housing sizes.Head gasket is stock too.

Regards

[RustspecS13]

Let me throw in my two cents....

1) 7500-8K is what Ive always heard. Since your stock tach works, its reading 1.5X the actual rpm. You can calibrate it with a resistor but I'm not sure exactly what ohm reading. I'm going to do with with my stock tach when i get around to it. Until then I'm using a 89-94 maxima tach. J30/Z32's work as well, since they are all made for 6cyl engines.

2) Anything that is NOT GL5 compatable. GL5 fluids have additives that eat our older brass type synchronizers. I use Penzoil Syncromesh made for GM tranmissions. Redline MT 90 works as well and most after market high performance fluids are compatable just make sure they aren't for GL5.

3) A completely stock RB25 is good to 500WHP pretty reliably, and the weak point is the piston ringlands. With your pistons upgraded the rods will likely go next in the 600-700whp range but that's a grey area that depends on tuning and rpm's. But over all the 600WHP and under 8K range will keep your motor reliable.

4) covered

5) It kinda sounds like your valve stem seals are bad. Under vacuum they suck oil through the seals, but once boost hits it pushes back through the seals and stops burning. If it was a bad turbo it would only smoke when the turbo is working hard making boost, at least if it started slow. A bad turbo can leak all the time.

6) Any decent quality set of coilovers could do that. I would try to get something that has adjustable rebound/compression so when you go dragging you can soften it up, and vice versa for drift.

7) I believe you need a z32 NA speed sensor. Since it basically is a z32 transmission with rb bell housing

~Alex

[MoogLe]

i was going to say maybe valves about the smoking as well,

definately not the turbo as it would be the opposite, no smoke or little smoke on idle and allot more smoke under boost