Rb34 / 24U (Rb26 + 800Cc) - Project RB high deck engine (and related builds)

[Ryno]

Great read, though I'm hanging out for an open deck RB25!

Edited December 17, 2013 by Ryno

[GTRNUR]

Great read, though I'm hanging out for an open deck RB25!

In a Stagea block? The main reason for doing the open deck engines is to get better fitment than an RB30 block, but if you don't have to worry about retaining AWD, the RB30's are easier to work with.

The VCT can be transplanted to an Rb26 head too, although it also occurred to me that I could make the spacer plate to adapt between a 26 block and a RB25 neo head. Then plumb in the oil for the VCT to the side of the plate for VCT like I already do for head oil supply on this engine.

Then I guess there is only the matter of getting a side mount plenum and it would fit a GTR still.

[Raysboostin]

I'll test the stagea engine for ya if u wanna build me one

[Roy]

Reasoning for using Greddy plenum? I have always liked them...but guessing your reasoning may be more measured????

[GTRNUR]

Reasoning for using Greddy plenum? I have always liked them...but guessing your reasoning may be more measured????

Partly for more volume, partly for the second set of injector bosses, and also so I can balance the intake throttles independently using an old school airflow balance meter.

In hindsight I should have gone with a Nismo one, or gone stock. It was a pain in the ass to get it in there with the extra 10mm height this engine has (in its fitted position). Clutch master cylinder to plenum clearance was non existent until I lowered the engine a little.

[GTRNUR]

Second shake-down drive today. Performed flawlessly.

Still having to re-work the fuel map a bit, but I have the drive on load area's pretty good now. All going well and weather permitting I'll be going for a sunday drive to put a couple of hundred k's on it.

I was able to take a few photos outside of a garage today too.

[Weapon]

Lookin good Ian!

[XKLABA]

I had to read you post about your breather system again after looking at the photo, I thought it read you where trying to vacuum out of the cam covers, oh god no, then after looking at the photo and rereading it I see what you've done, should work very well, a great idea, in the baffling in the camber on the block have you got any gauss/foam/steel wool to "catch" fine air born oil particals

500rwkws is easily achieved with a 2.6 with this turbo and head setup, I would think the idea of this engine is to do it as low in the rev range with as wide as possible power band and least amount of stress on internals as possible

I am keeping a very close eye on this, like the last one, cause as I have nearly completed a RB30 based build and I am not entirely happy with fitment

I love the colour on your car, it is what I wanted but my BB one came up at a price I couldn't let go

[GTRNUR]

Thanks for the positive replies everyone.

I was able to go for a bit of a drive today, and have so far put about 300km on the new engine. It is awesome to drive, with amazing low end grunt. The only quirt I've noticed is that while it has enough torque to drive at 1700-1800 rpm in 5/6 gears, the roughness of the cams don't make it a smooth drive.

Keeping revs below 4000 is a challenge, as it seems to want to achieve wastegate boost at 3600. Ive had to lower 10 degrees of ignition out of the map so as to reduce torque should boost get to high.

I've got to do something about the noise too. Considering trying an Apexi slip in active silencer to try and curb the drone and bark of it a little.

Edited December 22, 2013 by GTRNUR

[GTRNUR]

I'm driving the car every day again now in order to clock up some KM and put the engine through some heat cycles. There is a little over 450km on the engine now and it is continuing to make me smile every time I drive it.

I've got the low end tune to about 80% to perfect, and as a result the throttle response is purely ballistic now. To give you an idea, it will chirp the wheels if you tap the throttle too quickly when idling along in a car park.

The boost response with the 6466 is extremely impressive. It actually achieves wastegate boost quicker than a stock turbo'd GTR does. With moderate loads and driving gently, it makes 0.3kg/cm at 2000 RPM. At 2400, its at about 0.5kg/cm and 1kg/cm at about 3000 RPM. Then you have to ease off the throttle or it will threaten to rev past 4 in the blink of an eye. The twin gates currently have 18lb springs installed, and both gates open at only 3400RPM!

Its going to be interesting to see what kind of top end the engine will deliver. It seems I could have gone with a 6766 or even larger, and still had ballistic response.

That's all for now..

[NYTSKY]

Mental numbers!

[niZmO_Man]

This is insane! Awesome stuff.

[GH05T]

videos are required

[KiwiRS4T]

Thanks for sharing not just what you are doing but why and how. Great stuff.

[colourclassic]

Comes on so quickly! Just wicked..

[GTRNUR]

Well it turns out that its even more responsive than I had thought.

The attached picture shows a screen shot of a drive I did today while data logging. 1.3kgcm is the 20K load scale. Full boost was achieved at 3200 rpm. This was the first time I have held it flat in 5th gear to properly load it up, other occasions had been about 3/4 throttle. As you can see from this screen shot, at 3200 its on.

I think it will be capable of pumping 25psi by 3500 from the looks of this, which means I will be very close to achieving my low end power goal of 300kw @ 4000 rpm.

I tried making a drive video today too but my camera it didn't turn out. I need to buy a go pro.

[NYTSKY]

Ian, I am literally blown away with how responsive the combo is for a 900hp capable turbo.

Can't wait for the end result.

[levinboy]

That is insane!!!

Great work can't wait to see the results when you get to push the engine harder

[Taiquri]

Nice!!

[Mitchee]

You'll shit in 300kw at 4000rpm. My setup makes slightly more than that at 4000, with 260 duration cams though.