Warpspeed

Yeah, just make the hole so it knocks the edge off the noise. If you make it too small, the exhaust will just hiss, and the guy doing the test will know you have done something shifty, and start looking underneath. So don't be greedy, just enough to pass.

RB26 crank rods and pistons drop straight into RB25 block, also get the oil pump as well if you can. RB30 crank will not fit, RB30 block is MUCH taller than RB25 block.

CrazyGTR is spot on, get a piece of thin sheetmetal and put a single smallish hole in the middle, maybe 15mm diameter and put this between the cat and the pipe flange. If you are clever, it will not be seen, especially if you spray it with black muffler paint around the bright cut edge, before you fit it .

Yes, use the good stuff. But actual daily running costs will have more to do with the mileage you do, and how and where you drive as well.

Yeah they were bought out by Ford and are now the luxury car division of Ford. But as an independent company they ain't around no more.

No, my instincts right now tell me to remain totally debt free, and not sink money into non performing assets. A GTR is definitely a non performing asset. It might perform on the street, but is not going to make you money over the next few years. If we do sink into the worst depression in history, the secret is to be cashed up and then buy assets for cents in the dollar right at the lowest point, in maybe three to five years after the initial crash. Some of the now wealthiest families in the world did exactly that last time around. It will be the complete end of the middle class everywhere. In America companies that made wonderful high performance cars went broke, Cord, Packard, Lincon, just to name three. The survivors Ford, GM, and Chrysler built cheap crap cars for the masses. If Nissan stays in business, they will probably be making de-optioned Pulsars, available in three colours only.

Just about all the big car manufacturers are technically bankrupt, and have been for many years. It all depends on being able to roll over the massive debt and stay in business. The Japanese banks are also bankrupt. During the 80's property boom they loaned out unimaginable wealth to speculators. When the property market crashed they now hold property deeds at the face value of the loan. These paper assets are all the banks hold against depositors money. If there is a run on the banks the system collapses. The whole system worldwide is drowning in debt, and phony worthless paper assets. The accountants can "prove" net paper worth exists, but actually there is nothing there. Even in Australia the average yuppie has a mortgage on his overpriced house, shares in the stock-market, and otherwise is in debt up to his eyeballs, with zero net savings. If the property market and stock market both crash, and he loses his job, he is finished. Your millionaire yuppie is broke. It could happen at any time. The whole thing is based on an illusion and is on a knife edge. These days, all the wealth is actually a promise to pay by someone else. It is NOT conspiracy theory, it is FACT. This is miles off topic though, but it is a subject I have a deep interest in.

Yes, Japan is an economic basket case, but at least they still have considerable export volume. If the US folds there will be mass unemployment in Japan, and it is not going to be pretty. In the US, before the great depression radio, aviation, and automobiles were all in a boom, just like personal computers and the internet are now. Before 1929 there were over 2,000 public companies listed as being in the automobile or automobile parts manufacturing business in the US. Only three survived, GM, Ford, and Chrysler. Things are far worse now then they were back then just before the economic crash. This is going to be real bad. If Nissan are smart they are not going to be spending zillions of dollars developing an expensive new car which no longer has a market big enough to recover the development cost. So I believe they are delaying the release date, they know what is coming.............

Maybe Nissan have lost the plot................ Or they are really smart. We are due for a worldwide economic collapse and depression any time now, especially in Japan. If it happens, there will be no GTR.

Car companies are run by the bean counters these days, not by young engineers with a vision. Also the economic situation is looking very bleak indeed, especially in the car industry. I believe they will come up with a 4WD system that will generate public interest and hopefully a greater market share. But they will try to keep costs to an absolute minimum. That is why I expect a basic solution, not a high tech solution. And I will also like to bet it is marketed as a safety feature for the family man that does not want to drive a two ton SUV truck. The twenty year old hoons will all lust after a 300Kw 4WD Monaro, but the reality is that the people buying them will be wealthy middle aged yuppies that only want to pose in them.

If you run a straight pipe through the centre of your cat no one will know. But there will be no measurable performance difference, there might be a bit more noise, and there will be more black crap at the back of your car which will discolour the paintwork and bumper. If your cat has disintegrated and is rattling or blocking the pipe, get it replaced.

Sydneykid is spot on, I have been buying individual RB26 bits, and will probably have spent around four grand by the time I have everything. At least it has the advantage that you can see the condition of each part as you buy it. If I ever do it again I would just get a whole complete RB26DETT, they go for about Three grand, but you need to be quick. I will put it all into an RB25 block to keep the same engine number, and stock sump. Saves a lot of trouble. You will have no difficulty selling your complete RB25DET either, especially while it is still in the car and running. As far as flow testing goes, I will be able to test at 56 inches (2psi) , as my blower goes to just over sixty, but my latest (largest so far) flowbench is not yet completed. I have done extensive tests on the bare blower though. It has a 7.5 Hp three phase motor, and needs every bit of it. But I would not expect the results to be any different to testing at 28 inches. A DIY flowbench need not be expensive or complicated, but it requires a fair bit of work and research to get the best results. It is an ideal home project, this one will be my third, and will allow me to reach 600CFM, and be easier to operate.

Just because it is 4WD does not mean it is going to be any good ! ! ! What sort of 4WD system are we talking about ? Is it a constant 4WD like a WRX or a Range Rover ? Or is it going to be something a bit more sophisticated like ATESSA ? Is it is going to be a front beam axle mounted on leaf springs, I assume it will be independent..... So many questions. It might actually be pretty good, or it might not. Lets wait and see. Should add 120Kg and about thirty grand to the price I reckon.

Hello again Sydneykid. On my flowbench I do most of my testing at 28 inches of water pressure drop, which is pretty close to 1 psi. The induction system is measured at 28 inches vacuum, and the exhaust side at 28 inches of positive pressure. It is generally recognised that the flow figures that you get normally aspirated come pretty close to what you would get on an engine dyno, which is why that particular pressure differential is so popular. Also, induction flow ends up near 1.5 CFM per BHP, and exhaust flow 2.2 CFM per BHP when doing flowbench work. So when you say your cylinder head flows 380 BHP, that would equate to 380 x 1.5 = 570 CFM flow (total) at 28 inches of water pressure differential. That would be 95 CFM per inlet port on a six cylinder engine. It does not really matter if you suck or blow, as long as the flow direction is correct, the exception being right at the beginning of the induction system, which may sits in (almost) still air. So if you have individual tuned n/a trumpets, you must suck. But a turbo inlet plenum is going to see some pretty turbulent air coming down the intercooler pipe, so blowing into the plenum with your flowbench is quite valid, probably even better. The same goes with testing intercoolers. You must blow. If you try to suck, the incoming air has to see a sharp edged pipe on the upstream intercooler tank, and you get a false reading. You could fit a very efficient bellmouth to the end tank, but it is probably still better to blow. But getting back to plenums, and air distribution, it would be pretty difficult to create similar flow conditions on a flowbench with steady flow. You really need the intake runners to pulse in the correct sequence, otherwise I think any flow distribution figures would be pretty meaningless. Another thing people forget, it is actually fairly difficult to measure static pressure in a fast moving airstream. If you had a hose with a very sensitive pressure gauge on the end, and stuck it out of the window of your car at high speed, you could measure a positive or negative pressure depending which way the end of the hose faced. It is not realised how high the air velocities get in a turbo engine, maybe half the speed of sound is high, but not all that unusual coming right out of a turbo. So the air is going maybe 500 Kmh, and the boost you measure might change rather more than you think depending on where and how the sensing line is fitted. The fact that the poor old plenum struggles a bit to distribute the air evenly is not really surprising.

Just fit a Brock energy polariser, and all your problems will be solved. Or you can send me a hundred dollars, and I will supply a device that is money back guaranteed to cut your fuel bill in half. (You will receive a pair of cheap plastic scissors). Go ahead, make me rich...................

I am a bit skeptical about all of this, how were the measurements made, and at what test pressure? Is each runner flowed individually, or was there 1712 CFM flowing through the throttle body when these readings were taken? I cannot see how flowing one runner at a time with a steady airflow is going to behave anything like six runners pulsing on a running engine. I am not trying to put anyone down, please do not misunderstand me. Just trying to get my head around what it all actually means. The only way I can see of doing this might be to blow high pressure air into the plenum, about the same amount as the engine would use, around 1.5 CFM per horsepower. And it should come through a similar pipe to the intercooler outlet pipe. Fit six identical orifice plates to the head face of the manifold, and measure the static upstream pressure at each orifice through the injector holes. A better way might be to do a similar thing with a cylinder head fitted and rotate the inlet cam with an electric motor. You could measure the airflow coming out of each combustion chamber either with an orifice plate or an anemometer. This would be as close as you could really get to having similar conditions in the induction system to a running engine. I would really like to try this myself someday, and probably will once my latest and largest flowbench is completed.

The GTR and GTS4 4WD system is unique to Nissan. There is no centre diff as in most other 4WD systems. The way it works is that it behaves like a normal RWD most of the time, and under certain conditions, there is a clutch that will feed torque to the front wheels. I believe the computer that controls the 4WD clutch looks at throttle position, as well as lateral and longitudinal accelerometers, and relative front/rear wheel speeds, and decides how much torque to feed to the front wheels. It combines awsome straight line traction, but has none of the corner entry understeer of a full time 4WD. It is a very good highly developed system far better than full time 4WD. Full time 4WD is probably better in mud, dirt, or snow, but the GTR system is more suited to driving on wet or dry sealed roads. It was made to win races, not drive around paddocks.

A real sharp shifty used car salesman will know all about winding back or replacing the speedo, and all about wear on the steering wheel, carpet, drivers seat, drivers door, and pedal pads. What the bugger will not change though, is the brake discs. They may even have been reground by the previous owner, but they will be always be thin on a very high mileage car.

Yea, I wonder if you could register a slingshot dragster as a special purpose "commerial" vehicle ?

Another thought, taxis are classed as commercial vehicles, not passenger cars. Now commercial vehicles can get away with all sorts of special requirements, things like garbage trucks and road sweepers with left hand drive, mobile cranes with all sorts of crap hanging right in front of the drivers face for example. There are not the same limitations with engine swaps either. You can even register a fork lift, and a lot of people do. So things like ground clearance, windscreens, and lighting do not apply either. It may well be that taxis are exempt from some of the restrictions about mounting stuff inside the car, because it is "required" for a specific commercial purpose?

Yeah, come to think of it you are right. I have seen large clip boards and all sorts of crap mounted all over the place.

A dash mounted taxi meter is only going to limit your view of the bonnet. A pillar mounted gauge will reduce your vision of the road. As far as I can see there is no double standard.

This is really serious stuff. Maybe we can turn it into an election issue, you know............ street marches, petitions, bumper stickers, politicians giving interviews on TV, all that stuff. This could be the really BIG issue at the next Federal election horsepower or Kw, let the people decide.

He he Ronin, I like you style............. Yes if you want to call joules per second watts that is strictly true if you are a lawyer minded type of person, but as a working engineer I have never seen it used that way before. Its a bit like asking how far it is to get to some place, and being told 30KMH per hour is the distance, when what you really mean it is 30 Km away. You can prove this is correct with a bit of algebra, as you have done, but people might still think you have a screw loose somewhere. Why not just call watts watts, and kilometers kilometers. In either case time does not really come into it. And I also agree with you that quoting energy units in non relevant terms is not strictly wrong, but just a bit weird. I have no idea how mechanical power ever ended up being defined in electrical units though ? ? ? I wonder if it was some dork government bureaucrat somewhere, I just cannot imagine an engineer doing that. Horsepower is a far more direct and useful unit if you are dealing with shafts, gears, pulleys, weights, and other mechanical engineering problems. Just as amps, volts, watts and ohms are all tied together very elegantly for solving electrical problems. Next time someone asks me about engine power, I might express a number in calories, that should confuse plenty of people eh !

One electrical watt is generated or dissipated when one amp of current flows with a potential difference of one volt in a resistive load. A watt is true electrical power, it cannot be anything else. As you say it may be equivalent to other types of power such as heat energy or mechanical energy. There is also reactive power measured in volt amps (VA), but that is another story. But a watt is not mechanical power, or heat energy. After thirty five years of using these units every day as an electronic design engineer, I can assure you that this is correct. Another example of this, if you look at your gas bill, (in Australia anyhow) you have been charged for the number of megajoules of energy you have used. Your gas meter measures cubic metres of gas, and you are charged for the energy content. Megajoules of energy are millions of watts per second. Take it from me, watts of electrical energy do not come out of your gas pipe. Likewise your engine dynamometer might calculate kilowatts of energy equivalent. But volts and amps do not flow out of your flywheel. Also, a Joule is one watt second. RPM is revolutions per minute, and KMH is kilometers per hour. You cannot have RPM per minute, or KMH per hour. Likewise joules per second do not exist. (That would be watt seconds per second). The point I am making is that it is a common conversion to multiply Kw by 1.34 to convert to horsepower. So ten one hundred watt light bulbs equals 1Kw, and this is equal to 1.34 horsepower. But calling a 100 watt light bulb a 0.134 horsepower light bulb is silly, because there is no mechanical power involved at all. Equally silly is saying that a rotating engine driving a rotating mechanical load is developing so many kilowatts of (electrical) power, when it may not be doing anything of the sort. If my electric jug is rated at 2.4Kw and requires 240 volts at ten amps, can I test it on your dyno ? Hey Ronin, don't take it all so seriously, I am only stirring the pot. Cheers.