GTRNUR

Wow its been a while since Ive signed in for sure. Time gets away... Good question. So much was different between the two designs. The RB315 was a test to see if I could do it. Limitations were for the most part due to local machining capability. Tolerances were an issue. The 3.15 used a single OD dry sleeve, and was almost the same as a kakimoto spacer plate engine, except I used a plate design similar to the OS Giken plate. I did not make the top flanges thick enough either. I can't be sure if it was machining tolerances, or thermal distortion of the sleeves, but the engine did produce quite a bit of blow by. The modified 87mm RB30 crank was also an issue, and was no where near as nicely balanced as the forged 90mm crank in the 3.4. The 34 was a next level build. The sleeves were stepped for max thickness, and were a semi-wet design breaking though into coolant completely in the block. Minimum thickness was 3.75mm and max was 5mm with the 90mm bore, and the new spacer plate also fully supported the tops of the sleeves closed deck style. This combined with far superior CNC machining, and a cylinder hone finish that the machinist does on 3000hp pro stock cars resulted in no noticeable blow by at all. In the end the 3.15 was removed to swap in the 3.4. I discovered the modified RB30 crank had partially sheared the woodruff key on the balancer. That was all that was wrong with it, but it did make the engine a paperweight at that stage. $1100 to make another crank for an engine with blow by issues was not worth it, considering I'd started playing with all Nitto forged internals instead. I hope you found this interesting. Cheers, Ian

I wonder what ever happened to this shell?

It has certainly softened the transition onto boost compared to the 6466 which was savage making 18lb at 3200 just rolling into it in 3rd. Now its around 5000 to 22lb. 1st and 2nd get to about 15lb max not reaching minimum boost unless launch control is used, but the car also struggles for traction in the low gears anyway just rolling into it. More boost isnt going to help that. I haven't maxed the turbo and don't really intend to. 28-30lb should see past 800kw, and it doesn't drop off in top end now like it was with the 6466.

Ah... No I changed to a 7275 Gen2 with a 1:0 hot side.

The 1.3 housing is for a 6466.

I've got a 1.3 housing new in box if anyone's interested? I decided against playing with housings and went with an overall larger upgrade.

Sorry I can't remember where I got it from.

Top and bottom like this pic. Also vertically each side of the core so that the rubber compresses when the shroud is bolted on. Finally that section behind the AC fan ALL needs to be sealed off. Don't worry about covering a little bit of the core with rubber. The surface area is still there, and ensuring COOL incoming airflow (and not bypassed or recirculating hot air) is far more important than a few square inches of core.

Absolutely put foam between the core and radiator. I sealed it to the core everywhere that was possible. Look at where the air is drawn out by the fan. There is huge sections where the shroud doesnt make contact with the core. That all needs to be sealed, behind the AC condensor fan especially, but all round the outside. I used a variety of different thickness rubber strips from a rubber shop. Everywhere the fan can draw air from that it a path of less resistance than drawing through the core, it will do just that. Worst, the air that bypasses the core is cooler than air that passes through the core. This cools the air that would be making your clutch fan work properly. I hope that makes sense.

Something is defiantly not right there. Your setup is almost identical to mine, radiator, greddy swirl pot etc. Im using an OEM 82 degree thermostat though, not the low temp one. My car will run between 84-86 on 34 degree (North Queensland) heat with the AC pumping when sitting in traffic. The clutch fan is absolutely roaring when its like this, as the viscous hub has probably locked up 100% at this stage. Have you tried another viscous hub? They don't last for ever. Its possible that the hub either isn't locking up because its leaked, or its not getting hot enough to cause it to lock up and begin that self regulation thing its designed to do. If its sucking cold air around the radiator core, there will not be sufficient heat to make the viscous hub work properly. When I installed my Koyo radiator, i put in a lot of effort to seal the shroud to the radiator, so the fan could ONLY draw air through the radiator core and not bypass it. Then a lot more effort was put into blocking air recirculation back around the radiator to the front of the car. More than anything when stationary, this helps stop temperature runaway. As the fan is only able to draw in COOL air in front of the HOT core. Consider a coolant air flow leak as being as bad as a coolant leak. It effects efficiency overall of the system. Something I learned from back in my air cooled VW days. If its sucking hot air or recirculating it, the engine isnt cooling.

My recommendation would be to check everything else before going that route. Air/steam pockets, shrouding the radiator so it doesn't recirculate hot air. Bleed the air and/or add an air separation tank. Radiator thickness if aftermarket can be an issue. Too thick is not good for airflow. Above 45mm in traffic and expect issues, as you can't move air through it fast enough unless you have 80km/h of air pressure in front of it. Then, try get an old steel VG30 pully first. Ebay or a wrecker from a nissan pathfinder, maxima or 300zx. It will be cheap because they can't give those things away. Keep in mind it will increase your clutch fan speed too. My current setup, I went back to an OEM pump, with the RB26 sized large pully supplied with the ATI balancer. My 3.4lt's maintains 84 degrees even on hot days. In winter, it rides the thermostat at 82, and oil is the same thanks to my 96 row earls oil cooler.

Nope... They look the same from the outside.

Should be fine if its just an RB26. Only taller blocks have issues. I have a greddy ITB intake on my RB34 high deck, and have had to shave the back off the master cylinder to get it to clear. I still use the booster and an OEM clutch master. The OEM plenum fit with plenty of room by comparison for an engine with the same deck height. Your plenum will be 20mm lower than my setup.

I'm just about to get on the EFR train and get a 9280/1.45 for my RB34. Any recommendations as to where the best place is to source one?

My RB34 with the 6466 Gen1 1.0 opens the gates at 18lb (boost controller off) at 3400 rpm. I've still got a 1.3 housing here... One day I'll get around to fitting it, with the hopes of stopping the kw drop off around 7500 rpm.

My setup has the same issue with the 1.00 6466 choking the 3.4lt. 705whp at 5500 rpm till redline. It seemed the hot side was just completely maxed out, at 30psi. I've got 1.3 housing here to go on the car which should really liven it up in top end and make it a little less savage in mid range.

No, you don’t need to torque plat the block when gapping rings. The way I do it, which is probably a little over cautious, is to measure the height of the first and second ring lands on the piston with a vernier. Then measure your ring gap with the ring positioned in the block at that height. You will notice that the ring is in the area of the block which is still the upper deck. This area will not distort with a torque plate installed and studs are tensioned.

Low boost, 18lb so I guess around 400kw. Not the 30lb 500+kw tune. I only mentioned it in case that was going to be someone's next question. I suspect with my crappy driving and new tyres I could probably do a low 10. Also I have a 3 hr return drive to the nearest track, and it wasn't trailered. I didn't want to risk breaking a diff or something. The point I was trying to get across is that 98 octane will knock limit you to around 400kw even on a very stout engine build.

I don't see the 6466 getting even close to 500kw on 98 octane. My 8.9:1 cr RB34 with the 6466 managed 385 kw on 98 octane at gate pressure of 12lb. Tuned on a 30+ degree high humidity day. Alice springs has much drier air. Turned up to 18 it was able to make more low and mid range but was knock limited at around 400 ish kw. E85 solved that but the turbo still runs out of puff and maxed at 525kw. I don't have any real drag times that count as I've only had one clean pass on low boost, that was also a soft start. 11.6 @ 125mph. The options are either to have a race fuel tune, low compression/high boost or add a WMI kit. You have to keep that knock under control, and the only way you'll get past 500kw is to get that cylinder pressure up.

My first drag launch in 16 years. Gentle off the line. I was surprised it hooked up as using a mild launch control setting and 4500 RPM limit is useless on the street and results in uncontrollable traction loss. https://www.youtube.com/watch?v=6xeQ7IT1vxo I'll upload the second video soon.

Quick Update. I finally got a weekend off work and was able to visit a Springmount Raceway, which is a new drag strip that was built and 1.5 hrs drive from Cairns. I only ended up doing two passes on low boost. (1.3kg/cm). First pass was an 11.6 @ 125mph 1.8 60' with a soft launch. Second pass was a mess. Launched the card harder and was hit with the ashtray part way through first gear. Accidently pulled it out of 1st early and then slow shifted to 2nd. 11.9 @ 124mph. I'm pretty happy considering my tyres are nearly 3 years old, and the suspension setup is for corners not straights. Plus I basically drove the car there and back, and only pulled out the silencer to race. I'd like to go back and try again some time but need to invest in a tilt trailer so I can trailer the car there and some shade. I've got some video which I'll upload to youtube later. No in-car though as my go-pro had died and wouldn't hold a charge anymore. Cheers!

Late is how everyone does business these days.... You'll have to get an Albins after you try this sequential out, so you can report on which is the best for the rest of us.

Update time – The End. I am sure many of you are aware that a few weeks ago Mercury Motorsport closed the doors to their workshop permanently. This was a bit of a surprise to me, as I had been hoping the AWD S15 was going to make an appearance at the Flying 500 event at WTAC. My RB33 engine is being freighted back to me this week. This change of circumstances for Mercury has essentially bought my project to a standstill. While it was my intention to develop the engine design further (and conduct testing with Trent @ Mercury), at this stage I have decided to not tip more money into the project and jump into a new arrangement with another workshop. Personally, not being able to take the project further with Mercury is only a little disappointing. It is also a relief and a huge weight off my shoulders as my time is now able to be greatly freed up for other projects and work commitments that will make instead of costing money. The current status of things are that my R34 GTR still has the v3 RB34 engine installed, and it is still going strong. I do intend on running the car at Springmount Dragway (new track near where I live) next year when the season starts again. I also intend on updating the engine next year with my new full-circle firings, and adding a platinum block brace, and a Quaife front diff next year. May also need a gearbox upgrade as I am not sure the getrag will survive. The RB32 that is currently 90% assembled will be completed, sealed up and filled with oil for long term storage. The RB33 engine that is coming back from Mercury will also get the same updates, and then have the same storage treatment applied to it as the RB32. I have no plans to restart work on the project for at least a year (if ever), and no intention to sell either of these two engines (unless someone offers me an absurd amount of money). I will consider selling both engines and the developed IP for the project to someone that wants to take the project further. Looking back to when I started this project, I built the first RB26 based 3.1lt just to see if I could do it. That was the main reason. I love designing and building things, especially engines. It was not my intention to go into business selling engines, or to even develop a product for sale. (The project started to head that way though all by itself.) At the end of the project I not only proved that I could build an RB26, but I developed the largest displacement version of the engine in existence. Not bad for a guy that works on computer networks for a living! Here are two parting videos. The first one is of my car with the RB34 and in its current configuration, and the second is of Mercury’s “Nitto”, “First Startup” video of the RB33 (where it was initially intended to go). That is all. IMG_1973.MOV video-1476672019_rotated.mp4

Pete, I think "better" is a relative and an opinionated term. It comes down to what you want from the car in terms of the power curve. Different people have differing opinions on what is desirable in a power curve. For me, I think that what it comes down to now is that while I have mad low end and mid range power, I do miss that rush feeling you get above 7000 RPM from power that continues to climb. That and traction was the lure of a GTR in the first place. While still currently part of the Precision crowd, I do also plan to go 9180/1.45 on my 3.4. Perhaps next year the 9180 will deliver close to both.

Pressure/leak down test your lines to your wastegate. Use an air compressor set to 12lb on the gate, disconnect the hose from the intake pipe and pump it up. If you can do this with the manifold off, all the better as you can see the gate open. I suspect either a leak in your wastegate line(s), boost control valve, or a hole in the wastegate diaphragm.