R34 RB26 questions, differences between 90's versions and 99+ versions.

[sidewinder]

I have a few general questions regarding the 99+ years of the rb26, specifically what the changes in the turbos were and what psi they can reliably handle. I'm in the process of purchasing a 34 and will use this thread to ask general questions as I go through the build with it. I'm a bit New to this site still so if there are links to questions on current other threads just post a link or tell me where to go that would be appreciated.

[bobbo]

34 turbos are good up to around 15psi however higher boost means less life. They are a BB turbo so they spool noticeably sooner than an early RB26.
With a proper tune and a couple typical bolt ons you can expect about 375whp comfortably.

Coincidently I'm in the Calgary airport on my way to Kelowna.

[sidewinder]

Right on! Appreciate the reply, my plan is to do a full build like I did with my gts type M; not just turn the boost up and call it good. Would 375whp be maximum for the stock twins even with supporting modifications like IC,
,full fuel system, exhaust etc

[bobbo]

With stock injectors, intercooler, R34 snails, HKS exhaust, A'Pexi intakes on 91 octane on a DynaPak I made 367 whp.
You may see a little more response with a good A/M I/C and 93 octane but the general concensus is the I/C upgrade isn't essential until you're over the 500hp mark.
Depending on your hp goals you may not have to get into the short block at all.
I'm at 427 whp on stock internals and has proven to be more than reliable. The only thing I'd like to do is play with cams to improve response.
Again, what you're going to have to spend is very dependent on what you're goals are. IMO quite a number of people tune improperly causing engine failure vs underbuilding.

[sidewinder]

Excellent! So the internals could be said to be good up to 450-500 approx? I'd like to see 500 at the wheels. And I agree I plan on over building all of the supporting modifications for the motor before having to touch internals so that we can see what it makes before deciding to either bore out or install pistons rods etc, also the motor will be under as little stress as possible.

[bobbo]

There are cars making over 500whp with stock internals. Are you racing the car? How competent is your tuner? How healthy is the engine to begin with. These are some questions you'll have to consider.
I track my car frequently and the only issue I have is oil temps. If you track your car buy a good oil cooler.

[sidewinder]

The car will see the drag strip and potentially circuit. As for tuning that's yet to be decided, would like to research who's reputable in Vancouver area. The cars in transit from Japan atm so I'll have to see once it's here as for the status of the motor. From what I understand it's healthy only 94km's. And yeah even with my gts oil temps and pressure are some of the things I'm constantly looking st. Any recommendations for oil coolers? Mishimoto greddy?

[Skym]

100,000km is the recommended rebuild km, so the engine and other parts around it (auxilaries, gearbox, diffheads, etc) are close to needing a refresh. Usually when rebuild engine for more hp, the older auxilaries can fail not long after, so just be aware of that.

It's recommended to sell the engine, buy new N1 block, N1 head from Nissan and fill it up with aftermarket parts. Start with new parts as stock short block could be cracked (common) and need new N1 block anyway, head warped (overheating), etc.

With boost up mods, around 460hp at engine is possible with stock R34GTR engine. The R34 stock turbo's are close to N1 turbo spec, camtiming is different, stock intercooler is slightly larger, better flowing than R33 GTR, R32 GTR stock intercoolers (R34 stock intercooler is a cheap upgrade for R33, R32 GTR's). The key to extracting hp with a stock R34 engine is in the size of exhaust (free flowing exhaust). A 3.5" or 4" catback, but make sure the transistion from front pipe to catback isn't too big or it can cause turbulance that can restrict exhaust flow (max of 0.5 inch difference between front pipe, catback exhaust).

General rule of thumb is stock forged I beam GTR conrods are good to 550hp with stock conrod bolts, cast pistons to 600hp (100 hp per cylinder).

Can push stock forged I beam GTR conrods to 700hp with upgraded conrod bolts, forged pistons (Tomei or similar), but is not recommended if you thrash car (H beam conrods, forged pistons are used after 550hp for reliability). Around 700hp with stock conrods is more dyno only, run lower boost levels on track, etc for reliability.

With Nurburgring N1 engine they could extract 640hp, but found 500hp to be the reliable hp limit for a 24 hour race.

This is what a 500hp N1 RB26 R34GTR engine performs like (Falken Nurburgring 24 hour racecar) -

https://www.youtube.com/watch?v=xkoZ5sOnQTg

ECU tune plays a big role in if the engine stays together. Some tuners can extract alot of hp, but the engine won't last as long as a tuner who tunes conservatively.

Oilcooler, Setrab or Mocal oilcooler cores, Greedy or HKS sandwich plates with hoses, fittings to suit. Setrab oilcooler cores are used on Lamborghini's, etc, so one of the top of the range oilcooler cores for a good price and come in many different sizes. Also are reinforced, have optional mounting brackets with rubber insulators to prevent the oil cooler core twisting when car corners.

Or buy a Nismo oilcooler kit that comes with ducting, hoses, mounting brackets, etc (more expensive).

[sidewinder]

WoW! Thanks for the input and info, much appreciated! I have to go over the planned build now and see of there is anything else that I am un decided on or could use some help. I'll post pictures of the car once it's in town.