RB20DET Max Boost?

[LordFly]

My car is completely stock (except for a BOV and air filter), and I like it that way. But I would like to squeeze a bit more power out of it. I believe stock boost is about 10 PSI, which is rated for about 215 HP. I was hoping to up it just a bit, maybe 250 HP. Could I just away with just a boost controller?

I'm guessing 250 HP could be accomplished with about 13 - 15 PSI. Just wondering if the stock turbo and stock injectors could handle it, or would I need to start changing out parts and doing mods?

How much boost have other squeezed out of the stock system with just a boost controller?

[S13Jordie]

stock ceramic turbos wont withstand high boost for very long. upgrade to a steel wheeled turbo or the slightly bigger RB25 turbo

[frankydodo]

like jordie said. mine was dynoed at 254 hp @ 15 psi. with intake/exhaust/fmic. stock injector and maf but 255 lph fuel pump. but the turbo last 1 summer. so depends on what you want to do

Envoyé de mon SGH-I747M en utilisant Tapatalk

[Skym]

Stock is around 7-8psi. With podfilter, BOV it would be roughly 1-2psi higher.

With podfilter (+0.1bar / +1.47psi or around +11hp), 3" exhaust from dumppipe / outlet pipe back (+0.2bar / +2.94psi or around +24hp), BOV you can achieve around 12psi which is as far as I would push the stock turbo. That should produce around 250hp at engine. But I would use stock airbox and aftermarket airfilter, as the hp gains with podfilter are only noticed with the hood up (no heat soak).

Add a tune with Nistune for stock ECU (updates stock ECU so it can be reflashed / retuned via consult / diagnostic plug under dash on drivers side of car and laptop, consult cable, etc). Diagnostic plug is the grey plug next to fuse box under dash and have to remove access cover under dash on drivers side to see the grey plug. This plug is used by Nissan's handheld diagnostic tool (Consult) to check for sensor error codes. Basically it's like the same way most new car stock ECU's are retuned / reflashed. Tune can be from +15hp for safe tune with stock side mount intercooler to +30hp if you push the tune with FMIC (with FMIC there's +1-1.5psi and up to +27hp).

Can run 1 bar / 14.7psi for 330hp at engine with a 3" exhaust from stock turbo, boost controller, FMIC installed and 550cc injectors, 255-300lph fuel pump (hardwired for 13.5+ volts), Z32 AFM, Z32 AFM plug + ECU tune to suit, upgraded clutch, upgrade sparkplugs but longevity of stock turbo might be in question due to the age of turbo (wear and tear on the bearings). Stock turbo might go out of balance due to the higher shaft speeds / higher boost level with worn bearings. Usually results in the ceramic exhaust wheel going off balance, hitting exhaust housing, shattering and taking a walk down exhaust under full throttle.

The key with longevity and the ceramic exhaust wheel is keep exhaust temps low (run engine richer), boost level low. Supposedly the glue holding the ceramic exhaust wheel on the shaft fails under higher exhaust temps, but never seen that type of failure. Usually the shaft snaps due to it being out of balance (worn bearings). Stock turbo commonly fails on intake / compressor side of turbo due to high oil temps, bearing failure.

I would recommend you fit a air to oil engine oil cooler, as RB20DET doesn't have a stock coolant to oil oil cooler like RB26DETT, RB25DET have to prevent oil temp related failures with turbo's or engine bearings. Also the oil would be changed from the factory 5w30 to at least 10w40 (street use) or 10w50 (higher oil temps when thrashing car on racetrack).

After 1 bar / 14.7psi it's recommended to change headgasket to a metal headgasket, as stock headgaskets are known to fail when engine is used on a racetrack.

Change the sparkplugs to heat range 6 (NGK PFR6A-11) with a 0.8mm gap to prevent missfiring at higher rpm, boost levels. Stock sparkplug is NGK PFR5A-11. Be careful when regapping the sparkplugs (don't damage the tips).

[LordFly]

Great info guys, thanks! I definitely want it to last longer than 1 summer. I don't want to push it real hard, just a little extra umph Is the bigger turbo off the RB25 a ceramic as well, or is it steel?

[cozmosland]

its ceramic and i believe the 34's were even nylon. one option would be getting an op6 housing which is bigger and was on the r34 rb25 turbo ( someone correct me if im wrong) and get it rebuilt with better internals and steel.

[Skym]

You're welcome (from all of us).

All exhaust wheels on GTS model turbo's are ceramic. From what I understand, it helps with turbo spool, transient response and is suited to street use.

R31 GTS-R (RB20DET-R with T3/TO4E turbo), N1 GTR (R33, R34) have steel exhaust wheeled turbo's.

R34 stock turbo has a compressor wheel made of nylon, exhaust wheel is ceramic.

Only stock turbo's I know of that were said to have steel exhaust wheels, were from the VG family (VG30ET and VG30DET).

Hybrid stock turbo has steel exhaust wheel (uses the same CHRA as fitted to stock VG30ET turbo, similar size wheels to VG30ET turbo in bored out stock RB20DET turbo housings, hence why it's called a hybrid turbo, as uses parts from different turbo's) -

http://www.cherryturbos.com/Hybrids.html

Combine that hybrid stock RB20 turbo with stock RB20DET engine, ECU tune to suit and have a very responsive engine on or off throttle on the motorway if in a lower gear (feels smooth, normal on the street). That's using stock exhaust, stock airbox, stock BOV, stock SMIC, etc. It looks stock but has more hp (sleeper).

[LordFly]

It sounds like more work that I feel it's worth on a GTS. If I could get away with just a boost controller, it would be fun. But it sounds like that is not very advisable. I like the car the way it is, so I'll just leave it alone and drive it until I find a deal on a GT-R that is too good to pass up.

[Skym]

If you want hp, torque RB25, RB26, RB30 are the engines to have.

[Dragon Humper]

Exhaust.....

The quickest way to pooch a stock turbo is to up the power (even a little bit) and leave the stock exhaust on it. A decent 3" catback (Ebay is fine) and you will relieve at least 200*c of exhaust temp. Heat kills the turbo...not boost pressure. You could run 20psi with the stock turbo on E85 and water injection as long as the temps are kept under 700*c.



Jon.