GTRNUR

Nothing wrong with trying to make a better wheel. I've done that more than once before. Leaded fuels are illegal. ULP high octane is perfectly legal, as is running a fuel cell in the boot (at least it is in QLD). It requires a blue plate for the second tank, that is all. I live more than 2200km from the nearest E85, so it was never a consideration for me nor was I complaining about it. Frankly e85 is not a good option for duel fuel anyway as you use too much of the stuff to make power. I believe Piggaz told me his car drinks 10~14lt minute to make over 400kw. 3.7lt/minute of 98 octane ULP can produce the same power, and a high octane fuel would do it even easier. I estimate the average billet fuel rail wouldn't hold more than 60ml of fuel. At 3000 RPM/WOT/no boost my motor will empty that fuel rail in less than 2 seconds. Add a delay for the transition back to low octane when off boost and there is no problem there. That's not complex, its maths and a little engineering. There is no doubt that the NRE cars are utterly mental, but the point you should have taken from what they do is that it is possible. That is all. If there is any truth to predictions that fuel prices will exceed $2/litre in the not too distant future, duel fuel setups begin to make a lot more sense. Unless you'd rather be driving a hybrid.

Do you have an explanation to backup that opinion? Where is the problem? Everything is impossible until you put in some effort to making it work.

In theory a MAP tuned ECU would do it transparently with one map, so a D-jetro power fc would do. No crazy sensors or anything required. Using 2 fuels with similar calorific properties would make it easier to setup, and would make any transition a lot smoother and easier to tune for. The issue is that you have to use LOTS of e85 to make power so the tank has to be larger. Using a full blown race fuel makes sense as you can use a smaller tank. Evening using 98 in the second tank is worth considering, or 98 with 10-15% methanol perhaps...

The volume of the fuel rail would need to be consumed before making reasonable boost, but every turbo car has at least some lag initially. Once your into the boost zone, its not an issue. Using ULP low octane and a ULP race fuel has a very similar calorific value, so that transition back to low octane when getting off boost wouldn't cause too much of a glitch. Using ULP and switching to E85 is another story because it would go rich just as you got off the throttle for a moment when fuel mix switches back to ULP.

Perhaps if your using MAF sensors... but really who does these days. Any MAP sensor based setup could tune this.

I'll add, you could put a 2-3 second delay on the switch back to low octane easily enough to stop low/high octane fuels mixing during gear shifts too...

I'm sure many of you know about the Nelson racing engine cars from youtube. These guys setup their insane horsepower cars with a duel fuel system that allows them to cruise on low octane fuel, and then switch to race fuel when the power is needed. With rising fuel prices in mind, I just had an idea that might be useful for those of us driving thirsty skylines. You could leave the most of the fuel system standard in the car and just change to a billet twin entry rail and a set of 1000cc ID injectors. (Have a look at my diagram) Then install a 20lt fuel cell in the boot with external pumps and an under-car surge tank, with its own larger supply and return lines. The plumbing at the rail would use seperate fuel delivery from two regulators. Under boost a switch opens the race fuel solenoid valve (pressure switch), and the higher fuel pressure in the race fuel setup closes the back flow valve in the low octane fuel circuit so the engine is running on race fuel only. Low the low octane setup still runs, but returns all fuel to the main tank. Off boost, the race fuel solenoid is turned off. Fuel supply then flows through the low octane fuel reg to the rail. High octane fuel still circulates through the high octane reg, but it all returns to the high octane fuel cell. Considering how dam complex fuel systems are in most skylines these days, I don't see this as being any worse. Also, you could do away with the need to run really big injectors, multiple pumps and E85, and just go for a ULP race fuel like Martini 116 octane. You would use less fuel by volume, and have higher octane fuel and only be using the race fuel when your on boost. Any thoughts... ? Discuss...

Great! There is a need for a clutch in my immediate future. The rebuilt nismo gmax red cover that I have is starting to make some odd noises... plus its a prick to drive thanks to some modifications done to it by the rebuilders. Do you use the comp clutch Paul, or is the standard plenty?

Does he manage to get parts past customs and GST? I'm not a fan of unnecessarily paying tax and duty.

I'm more partial to a startup engine sound that induces a feeling of fear... Oh crap what have I built ! Instead of one that provokes a bunch of guys to get a semi... Fear is where its at! So no VCAM just yet... Are you still planning on using the Mines 10mm lift cams you were talking about at the nats?

+1 to what Rob has said. Granted there are a lot of faulty senders in R32's out there, but he did say "mechanical gauge" so thats not a factor. At idle with most engines, the oil pressure relief valve isn't even opening. Pressure in the system is entirely determined by flow at the pump, the clearences with the bearings and cams, (ie, the restrictions between the oil galleries and where it returns to the sump), AND the viscosity of the oil. Because oil viscosity varries with the weight of the oil and the oil temperature, then temperature is also a critical factor. Really, so long as there is some pressure at idle the bearings are safe, AT IDLE. A low idle will directly influence pressure too, so a 900-950 rpm idle is what to aim for. What matters is maintaining a pressure rise that is consistent with the RPM increase in order to maintain a lubricating oil film on the bearing and crank surfaces, so there is no abrasive contact. And as I said, 10psi / 1000 rpm is considered a minimum. If you have more than this at 2K,4K,6K and 7500K then you have nothing to worry about. Just don't go banging the rev limitor with the N1 pump, or expect a failure like Piggaz had...

That's smart of the EVO's for sure. Faster ECU processors, faster ADC's and another 10 yrs of ecu development make a difference. Allows false positive noise detection to be reduced too, like when the engine moves around under accel/decel.

Knock sensors are basically microphones. Detonation when it occurs in a cylinder induces a specific sound at a specific frequency within the cylinder block. This frequency is determined by the bore size and block design/material. The knock sensors pickup this sound, along with all other engine noise, and pass it along to a band-pass filter which filters out all but the frequency in which detonation has occurred. The signal is then sampled with an analogue to digital converter, where it produces value that the ECU can make use of. In the case of an FC, it is a byte value (0-255). The ECU can then act on that data based on thresholds you define relating to knock. Different ecu's have different capabilities here of course. The nature of how the Power FC does this internallly is anyone's guess. But on an RB as there are two sensors, I would say that the sensors sample an averaged signal amplitude every 3 ignition pulses from the front and rear cylinder banks. 6khz is an audable frequency, so knock sensor signals can also be fed into an amplifier and listened too. This is basically how the knock box systems works. You mount the knock sensor on the intake manifold and it will pickup noise reflected back past the intake valve when detonation occurs.

Anything you aim to do with 2.6lt can be more easily achieved, be more reliable, and will be less stressed overall when its done with more displacement.

I believe he meant he was already using an after market gauge, not the factory one. Bad choice of words on my part using the word 'jump' too.. I meant increase, and gradually like you have seen is normal.

Super cheap auto have a MAF/airflow sensor cleaner spray. Use that to hose out the sensors. Before you go buying coil packs, I'd suggest pressure testing the intake system from the twin turbo pipe to the intake manifold. If you have a lose clamp or split hose somewhere you'll find it. The miss could be simple over-fueling as a result of an air leak.

Im keen to see your results for this. I created an autocad drawing a couple of months ago to do just this, after seeing what was done on the powertune GTRB28 car. I took a little inspration from the ARC ones as well to make it a little more racey looking. Should be interesting to see what yours turns out like.

It all depends on many factors which you have left out. Oil temp Oil viscosity Crank and rod clearences Head type and restrictor Remote filter. But to cut a long story short, minimum you want 10psi/1000 rpm. 1kg/cm = 14.5psi, which is fine for idle when your oil temps are at ~90+ degrees I believe you will see it immediatly jump up to at least 3kg/cm or more at 2000 rpm. This is where it matters, when the engine is actually carrying some load on its bearings.

Yes absolutely. Pre-heating allows the weld to take to the steel without the engine block acting as a huge heatsync, pulling heat out of the metal pool as the weld is performed. It also allows less heat to be used to achieve the weld. Probably the most important thing is that it reduces the thermal differental between the two materials. Consider the length of a block being about 600mm long, and factor in the thermal expansion of iron/steel at 1000 degrees. The block will grow about 7mm in length. Heating allows less thermal variation at the point of the weld between the two materials, and therefore less stresses will be formed in the block when it cools to room temperature again. Ideally the whole block would be heated in a gas oven, and welded in stages where the block is returned to re-heat and stabilise the block's temperature. It should also be cooled in an oven after the welding is done over 6 hrs or so. One of the engineering shops I work for does this soft of thing all the time. Not with engine blocks, but with other heavy industrial and mining equipment. They also often heat cycle the welded item many times to stress relieve it after welding. You can liken the induced material stresses to that of a spring or a rubber band stretched to its limit. Or even better, an ARP fastener. Compared to an un-welded item it will take less force exerted to push past the point of elasticity into yield and eventual failure. Please don't take this as criticism with your project. I take my hat off to anyone willing to have a go but since your posting this publicly expect a few differing opinions.

+1 I've not measured a standard block and seen all the mains measure up the same, let alone a welded one. For the extra few hundred dollars its worth the piece of mind. Personally I hate the idea of pulling an engine out of a car to fix something I could have done better if I'd just paid a tiny bit more. While you might 'get away' with it in a lowish power situation combined with big 2.8+ thou clearences, why would you set an engine up like that if you can do better. Especially in a GTR.

I'd like that but won't be making it to the Nats this year. At the moment I have a choice... go to the nats or finish my next engine. Only if work picks up a lot over the next 2 months can I consider doing both.

Great looking R-tune's you have there. I'll be interested to hear how streetable they are compared to the S-tunes. I want that adjustability of the Rtunes, without added harshness. Ie... no rougher to drive than the s-tunes.

Hmmm. What I think the Zeeeb is saying is that your air intake is drawing air from behind the hottest part of your radiator... You could go a long way to improve your setup by just moving the air intake. Perhaps to behind the left headlight. Or even box the filter in close to the left guard and duct air from behind the headlight to the filter. You might have to move the radiator overflow to where the filter is, but there will be room. You can only "get away' with that kind of intake setup if you happen to live in an area that has typically <10 degree C ambient temps, because your thermostat will barely be opening and as a result your radiator core temps (and exhaust air) will be much lower. Designing an optimal setup in conversions is always a challange because the cars were never designed for that kind of setup.

Interesting stuff Ash, its amazing how much climate can effect things. What RPM does this happen for you with an Rb26?

I like it! Nearly looks like an RB26. The only suggestion I'd make would make would be to haven an align bore done on the mains. Shave 1 thou off your cradle, install your main studs, and then re-align bore the main bearing saddles to make sure everything is straight. Then do the rest of your block machining.