Question on max boost with a stock rb26dett

[NismoS-tune]

Both my GTRs run stock turbines at 1bar. One has seen nearly 30,000km in my hands (the way it's meant to be driven) and the other only 2000km so far. Anyways .7bar is less than the .8 factory boost setpoint which I don't even think your stock actuators could function below .8 (don't quote that). Most will say 450hp is the limit on the internals however there has been many stock blocks with razor sharp tuning to seen 800hp, Auto style's mine replica, dsport's editor R33 for example. This subject has been brought up too many times. Use the search function. I'm sure mcfly posted a 100 things about that. He has a 1000hp gtr in edmonton and seems to know a fair bit.

The hks 2530 and nismo gt/lemans are tough competitors in the 600hp range.

[Skym]

Turbo's can fail due to high oiltemps when running higher boost levels. Air to air engine oilcooler is a must have mod. Also higher exhaust temps (engine running lean) is another cause of ceramic turbo failure. Upgraded fuel system, Z32AFM x 2, 600cc injectors, fuelpump upgrade, retuned ECU or aftermarket ECU is a must have when boosting engine up with stock turbo's. Also ECU tune must produce no knock if you want engine to last. Also need a boost controller. Also add full exhaust, podfilters.

Should be able to extract around 430ps with a basic boost up on R32 GTR with stock turbo's and the above mods.

For 460hp with stock bottomend -

Tomei Poncams Type B (260 duration)
Tomei valve springs (depends on engine km)
2x Z32 AFM + 2x Z32 plugs
Apexi airfilters
Boost controller
Full exhaust (from turbo's, which includes dumpipes).
Apexi Podfilters x 2
Nismo 600cc injectors
Nismo fuelpump
ARP headbolts, ARP grease
Tomei metal gasket kit (includes metal intake gaskets, metal headgasket, etc)
RB26 repair gasket kit (new valveseals, etc)
Tomei oilrestrictors
N1 turbo's (or rebuilt stock turbo's)
Nismo baffle plate (sump)
Stock ECU retune or aftermarket ECU
Twin plate clutch + upgraded slave cylinder, braided clutch hose.

Then add cooling mods like thicker radiator, lowtemp thermostat, N1 waterpump, engine oilcooler with built in thermostat.

That's the full on boost up list for stock RB26 bottomend.

Then next stage can be a 700hp (at engine) capable bottomend on the cheap (without N1 shortblock) -

Forged pistons
ARP rod bolts
N1 oilpump
ACL bearings or Nismo bearings

Note: Make sure you check for cracks on top (deck) of stock shortblock.

Not on the cheap bottomend -

Forged pistons
Forged H beam conrods (includes ARP rod bolts)
JUN oilpump
ACL bearings or Nismo bearings
N1 shortblock

Probably be looking at a triple plate clutch, ATI pully upgrade, HKS 25/30 turbo's (or similar), etc.

But in my opinion, it's better to rebuild the whole engine and do it all in one go.

[Nismo BKK]

Yup, 27psi IIRC. Water/Meth can work wonders. It popped at 27 but Andrew ran 22 psi for a very long time with Water/Meth. Ran 11.70's at 122mph IIRC. Stock turbos can produce the goods.




Jon.

Yeah I guess that works too, just make sure you get a good kit that has a boost safe system should the tank runs out or fail to inject the mixture.

[Dragon Humper]

Yup, 27psi IIRC. Water/Meth can work wonders. It popped at 27 but Andrew ran 22 psi for a very long time with Water/Meth. Ran 11.70's at 122mph IIRC. Stock turbos can produce the goods.




Jon.

[Nismo BKK]

You can bump the boost a bit up but its best to keep it at under 1.0 bar cause anything higher than 14 psi, you risk shortening the life of the stock turbos. If you want to run more boost, you have to upgrade the turbos. If you plan to run high hp, its recommended you do a compression test to find out how strong your motor is and whether or not a rebuild is in order.

[kneacsu]

Stock turbos can go well over 7psi. A certain person on here was dyno'd at 487whp? with stock turbos.

[DougTaylor]

I'll try and share what I've learned over the past few months since no one else has responded and hope the gear heads don't flame me too much.. First - do your reading - that's the fun part! Stock r32 turbos can't go past .7 because the ceramic wheels disintegrate and make a big mess. The stock internals, provided everything tests OK (compression, leakdown) have been known to hold 600hp, but I'm not taking mine that high. I am doing a build right now with Garrett 2860r-5 turbos, from what I've read they are about the best match for 500-600hp. I am using 1000cc hks injectors and an appropriately sized fuel rail (hks) and pump (sard) but each cc is approximately equivalent to one HP, so 600cc injectors would be fine. I am also upgrading to Tomei Poncam Bs and replacing the exhaust manifold (Tomei Expreme), downpipes (Tomei), coils (Splitfire - my r32 coils weren't generating spark at boost higher than .7) and ignition (hks twin power), and an rps max clutch and flywheel (because the stock one won't hold the torque) to complete the picture.. Good luck!

[maximus140]

I just have a question on what kind of boost could you run with a rb26dett. If I had a goal of getting around 500-600 hp. While still running the dual turbo set-up. I have heard the stock turbos should not be pushed passed .7 bar....

Is the stock long block capable of this(obviously I would upgrade the oil pump)?

By going to larger turbos-what would recommend? or definately not use?

as well- an idea on injector size...750cc?

thanx for your help