Warpspeed

They probably figured it was going to be a financial loss right from the start, but worth it from the PR and product exposure point of view. Advertising is horribly expensive any way you go about it. Probably now, they realize we are entering into another long term worldwide depression, and the car makers are fighting for survival. It is not now a question of how much profit they will make, but how long they can go on re-financing their debts before they go bankrupt for the last time. In the 1920's there were over two thousand public companies listed in USA that declared their main business activity as "automobiles, or automobile parts manufacture". After the 1929 to 1935 stock-market crash, only THREE out of the two thousand survived. (Ford GM and Chrysler). Back then the boom technologies were wireless, aviation, and automobiles. Now it is computers, software and the internet, and it is all crashing into a great heap just as it did last time. In recent times we have seen one-tel, ansett, HIH, and other large companies just cease to exist. There will be many more.

There are going to be fifty wealthy Holden fanatics out there, that are going to be mighty pissed off at GMH I am thinking. If the idea was to really get the blood stirring amongst the Holden fraternity, they have certainly done that, but not in the way they intended. I think it is called shooting yourself in the foot. Duh.

This does not make sense. They say they are only prepared to build fifty units, and they have fifty firm orders, so what is the problem?

I have been thinking about this plenum/runner flow business a fair bit myself lately. Testing the static flow of each runner on a flow-bench individually means nothing really, because you are flowing only one runner at a time, although getting them all the same is probably a good start. What you need to do is flow all the runners together at the same time, so that for example, cylinder number one sees five cylinders worth of air passing right across in front of it. The runner and plenum flows should be something like what happens in the car. To make it even more real, you might have to drive the inlet cam with an electric motor, so the runners pulse in turn. I have not done it yet, but how about blowing air into the plenum under pressure, turning the inlet cam with a motor, then measuring the flow out from each combustion chamber with six identical orifice plates ? The turbulent air into the plenum would approximate pretty much what comes out of the intercooler I would think. You could drive the inlet cam at any speed you really want as well. The only thing missing is piston action and exhaust reversion, but I think this would be as close to measuring reality as you could get. Probably an ideal tool for plenum design testing. I will definitely try this when my new larger flow-bench is completed, I should finally have enough airflow to do it.

Hi Inasnt. If you plan to run 1.0 bar boost, looking at that compressor map, that is going to be at about 90,000 compressor RPM. Now, what you need is an exhaust turbine and housing a/r combination that will spin up the compressor to the required RPM. The tip speed of the exhaust turbine is just about the same as the exhaust gas velocity inside the exhaust housing scroll. Now comes the compromise part. You can reach the required exhaust velocity by forcing the exhaust through a small exhaust housing, BUT the exhaust back pressure is going to be very high. So a small a/r is going to boost early, but it will have high back pressure. Once it reaches 1.0 Bar, the wastegate will open and hold the shaft speed close to that required 90,000 RPM. It will also hold the exhaust back pressure at about the same level required to reach that 90,000 RPM right up to redline. Or you can run a larger a/r and reach the required exhaust velocity at a higher engine RPM with less exhaust back pressure. The lower back pressure will produce more engine power at the same boost level. So you get a choice, lots of low RPM boost and reduced top end power, or lots of lag, and huge top end power. Take your pick. One factor though, if that special exhaust housing you have, turns out to be not what you want, you might be stuffed finding another one with a T3 flange and more suitable a/r. The cams you run depend mostly on exhaust back pressure. Small cams with small exhaust turbine housing, big cams with big exhaust turbine housing. Try to keep some proportionality between valve overlap and exhaust back pressure for best results. It really all depends on how peaky you want it to be.

Yes. You supply the beer. PM me.

No, the RB20 has smaller cylinder bore, and water passages will not line up with other larger RB motors. RB25, RB26, and RB30 all have the same bore size, and blocks and heads all interchange. There is a slight problem with mixing VVT heads with non VVT blocks, but it can be overcome fairly easily. Best combination is RB30 block with RB26 head, or early non VVT RB25 head. Later RB25 VVT head can be made to fit though. RB20 head only fits RB20 block, no other combinations possible.

Sounds like an interesting project. If you start on the basis that the stock RB25DE already makes pretty good specific power, you need to really think very carefully about what you want to change. Do you just want more top end power, or more midrange grunt from it ? For an everyday road-car 20% more midrange torque and no more extra power might liven up the on road performance quite a bit. But if you just want to drag race it, more top end power is going to be a lot better. But it will be slower in traffic, and frustrating sometimes to drive. For a road-car I would fit an RB30 bottom end, with some mild head porting,and some mild aftermarket cams. And strip out as much weight as you can as well. The RB26 six throttle body setup is going to lose you a lot of midrange torque because of the short runner length. With large cams it will really start to haul over 6,000 RPM though, but be slower down low.

I would be very cautious about doing anything with the electronics. The relationship between the two hot-wires (or hot-wire plus thermistor) is critical. It would be very easy to really upset the zero flow calibration point, and also make the flowmeter highly dependant on ambient temperature. This would be a disaster. While the design looks simple, it is something that has been developed with a great deal of care and testing for mass production (at minimal cost). Much safer to leave it completely stock and simply increase the airflow path cross sectional slightly. I would also be worried about putting anything upstream in the airflow path that might cause cause wake turbulence. The hot-wire is a very fine wire that responds rapidly to air velocity changes. If the air is turbulent, the flowmeter output signal will be up, down, and all over the place. The EFI computer will probably freak out. You must have a smooth airflow, to get a smooth flowmeter output signal. It is absolutely vital.

O/k guys, there seems to be some confusion here about how these things actually work. The proper name for one of these devices is "a hot wire anemometer" and they measure air velocity. There are actually two hot wires, but you can only see one. One is mounted near the middle of the moving air-stream, and a second one is mounted within the mounting stalk. The second hot-wire is immersed in the air-stream, but is located in still air. An electric heating current flows through both wires, and this current heats both wires. Now as the wires become hot the electrical resistance of the wire changes. If there is zero airflow, both wires will reach equal temperatures, and the voltages and currents in both wires will be identical. The electronics senses this, and outputs a zero flow signal voltage. Because there are two wires, they will always be at the same temperature, even though the ambient temperature may vary very widely. That is why there two wires to cancel changes in ambient air temperature. Now when there is air movement through the flow-meter, the wire in the air-stream cools down slightly, because the moving air carries away some heat. This causes the electrical resistance of the wires to be different (because one is now hotter than the other). The electronics senses the difference, and feeds more heating current into the colder wire to force the temperatures back to being the same. The amount of extra power fed to the cooler wire (located in the moving air-stream) is the actual flow-meter output signal. There is a very sensitive amplifier to detect even minute differences in the wire temperatures, so air velocities over a very wide range can rapidly bring the wire temperatures back to equilibrium. Now if you place the hot wire anemometer in a tube of known cross sectional area, it becomes a flow-meter. A known flow will create a known flow velocity, which equates to a certain signal output voltage. However an individual hot-wire flow-meter can be calibrated for any reasonable maximum flow range. Now this is very important. There is no real fixed relationship between flow-meter size and calibrated maximum flow. A 60mm diameter flow-meter could quite easily be set up to measure a higher maximum flow than a 100mm flow-meter, simply by changing the sensitivity of the electronics to the air VELOCITY. So you cannot just say I am replacing my 60mm flow-meter with a 100mm flow-meter because it tops out in flow calibration. A better approach in my opinion, is to remove the stalk and electronics from your existing flow-meter, and mount it in a tube of larger cross sectional area. You will then know that the calibrated flow will have increased by the area change in the tube. Also the plug will still fit, and the connections be correct ! There are some pitfalls though. The hot-wire anemometer measures flow velocity at one point only in the airflow duct. That flow needs to be representative of flow across the whole cross section of the duct. It may not be, if there is a sharp bend or discontinuity upstream of the flow-meter. Also the air can flutter (vortex shedding). This is the same effect that causes flags to wave in the breeze. The best way to fix it is to have a smooth straight pipe section upstream, and also to fit a wire mesh into the air-stream. It breaks up big vortexes into little vortexes and helps calm things down. Sometimes the mesh can be removed without any obvious problem. Other times people that have tried it, end up having to replace the mesh. So take any pipework changes upstream of the flow-meter very seriously. Another interesting characteristic of these things, is that they are sensitive to air density. At high altitude where the air is thinner, less heat will be removed by the flowing air from the hot wire. So the flow-meter automatically shows less airflow when the air is thinner. A useful characteristic. I have not actually tried it, but it should be fairly easy to make a larger flowmeter body out of PVC pipe or something, and simply fit your existing hotwire internals. If it does not work, you can always put it back together again. The cost would be zero, and you can make it as big as you think you need !

It seems to be a standard belief that high power motors need big oil pumps. I have never understood this logic. The larger capacity oil pumps are only needed to maintain oil pressure at idle. Think about it. If you have an RB30E, you only need a certain sized pump to stop the oil light coming on at idle. Now if you have an RB30ET the turbo oil flow bleeds off a lot of oil from the engine, so they fit a larger displacement pump. Same thing with the RB25DE, extra camshaft = more oil needed. RB25DET, bigger again, extra cam plus turbo. RB26DETT, has two turbos, extra cam, plus oil squirters, so you need a really big oil pump, but only really at slow idle. Now oil pump flow is proportional to engine RPM, so at say 2,500 RPM even a small oil pump is going to easily provide enough flow and pressure for any situation. The problem really only exists at idle RPM. So the theory that you need a massive high volume oil pump for that 9,000 RPM racing engine is simply not true, quite the reverse in fact. But if you are building a street RB30DETT, a big pump would be a very good idea, no matter what the final power rating.

An aftermarket steel flywheel will be more like $600, but it is a worthwhile improvement. Whatever you do do not try to lighten the stock flywheel, you cannot remove enough material to make any difference without seriously weakening the thing. Also you will need to balance it afterwards. Either get a new steel one, or leave it stock.

I can understand that. If you piss onto something that is at a very high voltage, it could ruin your love life.

Yeah, its really interesting. Some of those early cars with DOHC engines, had wheels made from wood, and only had tiny little drum brakes on the rear wheels only. If you could see the skinny round section tyres they put on those wooden wheels you would just freak out. The early cars may only have been capable of 80Kmh flat out, but on a rutted and potholed dirt road, you would still need balls of steel to drive at that speed I would think.

Have to agree. A proper dyno tune with a programmable ECU is always going to be better than a one size fits all "chip".

Golly ! He does not sound like a happy man. It is a good story though, must file it under "pedder files" with all those other nasty people.

Hey 2rismo, I was not trying to have a go at you or anyone else. When I said YOU, I was not referring to your good self. YOU know it is, YOU leave home in a hurry, YOU leave your wallet behind, and YOU run out of petrol miles from anywhere. That sort of thing. Sorry if I offended you, it was not intended to read that way.

You are absolutely right about age discrimination, no argument there. But.............. younger people do things that an old fart like me used to do once, but would not even think of doing now, Think about it. This is just an example, but the people that vandalise trains, and do spray can graffiti, and go chroming, are not 20 year olds are they? So its reasonable to assume the cops trying to reduce train vandalism, chroming, and spray can graffiti are not going to stop and search adults walking down the street looking for spray cans. But they probably will give a group of younger teenagers just hanging around the area A REAL HARD TIME. That sure is age discrimination, and probably a good thing. It is a similar situation on the roads. It is younger people that joy ride other peoples cars, carry weapons, drive unlicenced and underage (obviously), and mostly have unroadworththy vehicles. Terrible isnt it. I am not saying the police are all heroes, they sure have given me hell when I was younger. But as soon as they lay eyes on you they will form an instant opinion as to your age, social standing, education, and general attitude. They are very good at this, they do it every day. If you look like a punk loser, and then you tell the cop he is a cnut and wouldnt know his ass from his elbow, look out.

2rismo, it is you that are missing the point. When they have you on the side of the road, with the bonnet up, and the notepad out, you are stuffed. You need to reduce the chances of being pulled over before it actually happens. It is not the slightest bit of use arguing with the copper about road traffic regulations. Even if you have a law degree, you are still stuffed. Usually they hide behind a bush somewhere, waiting for something UNUSUAL to drive by, maybe a bit noisy, or low looking, or a bit fast, just DIFFERENT to the normal traffic flow. Then on go the lights and siren, AND YOU ARE STUFFED.

A lot of very valid and interesting points raised there ! You are right about age being a very large factor, I am a retired engineer probably three times the age of a lot of you guys. So you have sprung me on that one. Age changes quite a lot of things. you DO slow down when you become older, and you gain a lot more patience as well. Also you become a bit more sneaky and devious in your old age. And lastly, some pimply young constable is less likely to be a smart ass, because I might just happen to be a good mate of his chief inspector, or an out of town magistrate, for all he knows. But I was your age once, and understand how you can be passionate about cars. Early on I lost my licence twice, and was on P plates for years. I also once ran off the road and wrote my car off. Recently I had another car stolen by joy riders and written off. So these days I try to keep my head down and stay out of trouble. But I still enjoy driving cars, with decent power and handling. I cannot see myself ever fitting purple neons to my car though...... Cheers.

Yeah, modding your car, and attracting attention are two completely different things. To some people how a car LOOKS and SOUNDS is far more important than how it actually goes. This can lead to trouble. But other people (me) are more interested in how it goes, and are deeply into engineering mods, but want to keep a stock external sleeper appearance. As a result the cops ignore me totally, and so do the thieves, vandals, and joy riders. Suits me just fine.

I think TOny has summed it all up rather well.

Absolutely ! ! !

But thats the whole point. If you drive a quiet fairly stock LOOKING car, and drive sensibly, the plod will ignore you. But if you drive a noisy riced up shitbox, and you give the cops the finger..................... expect trouble.

Thats the problem. The cops may not be that smart, but they are a heck of a lot smarter than a lot of Cool Dudes that post on the Forums. Who wants to be known as a nerd ? Being dumb is the in thing.