Warpspeed

Thermal stress, or mechanical stress ? they are quite different. You can quite easily blow up a stock engine by leaning it out, as we all know. Thermal stress is probably the most dangerous with a mildly modified engine, if it is badly tuned or not tuned at all. Detonation damage is another very quick killer of turbo engines. None of this has anything to do with the basic strength or integrity of the engine itself. Mechanical stress is a completely different thing. Rpm and inertia forces are what most likely are going to break things and that has little to do with power output. If it is properly tuned and you stay within the factory redline it can make significantly more power without any additional MAXIMUM mechanical loading. The average loads will be up, and the torque be higher, but that will not break things, except maybe the clutch. Bigger cams and valve springs might be dangerous if you then expect to wind it out to 10,000 Rpm all the time, or buzz the engine by dropping back to second gear at 160 Kmh. An extreme and silly example, but you get the idea.

Metallurgy is definitely not my field, but from what I have read, parts that have already begun to suffer from metal fatigue and have microscopic cracks are not going to be restored to original strength or condition by heat treating or any other process. While cryo might be good on fresh new parts, at the very least I would get the old parts crack tested first. I have often wondered at the wisdom of specialist heat treatment of brake discs. You put the thing in an oven and very carefully control the temperature profile over hours or days to get some particular change in the metallurgical grain structure. You then bolt it onto a race car and put it through many more pretty extreme and uncontrolled heat cycles. I am just wondering how that disc can possibly remember that original "good" heat treatment, and how further "race track treatments" can have no possible further effect on it ? Yet people pay to have this done, and others are very willing to take their money to do it. It pays to be a bit cynical about some things. If some expert is selling some special secret treatment that he will not discuss, to make your race car parts better, I would be a bit skeptical, particularly if it is an expensive process. If it is something like extrude honing, where you can see the results, but do not really need to know about the exact secret process to do it, that is fair enough. But when the parts come back looking exactly the same, I would be a bit more curious as to the exact process. Shot peening is another "mystery", while it has some definite benefits if carried out properly on suitable parts in the correct controlled manner. But just hitting every steel part with the shop sand blaster and saying they have been shot peened, and must now be a lot stronger is not going to get you very far.

Ah yes, and there is the thing that you can install on the end of your exhaust pipe that costs $39.99 and increases power "UP TO" xx % Definitely true, as it was tested by a well known world famous racing driver, whose name now escapes me.

Ha-ha Carroll Smith the famous race car engineer once said, "you can tune any part of the car, but usually the most worthwhile part to tune is the drivers head". Also psyching out and demoralising the opposition is a big part of it too. Have you heard the rumor that a certain well known race team are now using some special paint that cuts air resistance by 90% ? All jolly good fun, but frowned upon by the professional engineer or scientist.

LOL, this could have been a really good thread.......................... But is strength the only criteria? how is hardness, and fatigue resistance effected ? Quite often something gained means something else lost. Yeah it is amazing how the motor racing fraternity continue to prove science and engineering totally wrong. No need for mathematics either, winning races is all that really matters.

I agree the Flashtac idea is brilliant, cheap, simple, easy, and effective.

That Flashtac stuff is good. It survives for years outside on corrugated roofing iron which can be in continuous direct tropical summer sun, and is supposed to be waterproof in winter. Should work well either under the font guard or in the engine compartment. Another way is sponge neoprene sheet, like the stuff wet suits are made from. Available from Clark Rubber in various thicknesses, glued directly on to the intercooler pipework with "Kwik Grip" contact adhesive. It stretches a lot, so is easy to wrap neatly around sharp mandrel bends.

Before they started having to crash test vehicles, you could do almost anything you liked, within reason..... These days to comply with ADRs the manufacturer needs to do front impact testing to prove that the design of the bonnet and hinges will not cause the bonnet to come through the windscreen and cut your head off. If you change the design, or fit non factory parts to your bonnet, catch, or hinges, the modifications would almost certainly be seen as illegal.

You can buy the exhaust heat wrap in coils from any decent car parts place, but it is horribly expensive for what it is SURPRISE ! Or you can get better stuff cheaper in a wider variety of sizes, but you have to hunt for it. It is called "fiberglass furnace tape" and it is used as a sort of gasket material and pipe wrapping for boilers, furnaces, kilns, pizza ovens and so on. It comes in rope or tape. The rope is used mainly for door seals, but the tape comes in a very wide range of widths and thicknesses. It looks a bit like fiberglass matting. Look in the yellow pages under furnace repairs, or something like that. For heat insulating intercooler pipes and induction systems, I have found black sponge neoprene sheet is easier to use, and looks a lot better. It is the same stuff they make wet suits out of, and makes superb pipe insulation. It stretches, and you glue it straight onto the pipework with contact adhesive like "quick grip". Petrol washes off any glue that ends up where it should not be. This neoprene wraps around sharp bends easily and neatly, and looks good in the engine compartment. Clark Rubber shops have it in various thicknesses. It is expensive if you buy yards of it, but you probably will not end up needing much. .

Coxy, cost of repair is not really an issue. You could use wooden wheels off an old stage coach on your car. They would be far better, because the narrow steel rim cannot get a puncture. This would save you the cost of repairing punctures. Seriously though...... Do not be fooled by certain "advantages". Turbo technology has advanced hugely over the last thirty five years. Using the old stuff just because it is cheap is not an advantage if you can afford something better. The modern turbos are far more durable in every way, with the notable exception of ceramic turbine wheels. The water cooled ball bearing units are far tougher. If you replaced both wheels, housing, bearings and seals, and balance it, I doubt if a whole new ball bearing centre will cost any more than a whole new sleeve bearing centre.

I suggest you find another workshop URGENTLY. Run as fast as you can away from that one, and do not look back over your shoulder ! I bet he just happened to have a crappy old turbo off a diesel farm tractor that has been fully reconditioned, for sale, a real bargain too. Did he also tell you it would be absolutely perfect for your engine ? Run for your life.......Hehehe

Hi guys, interesting discussion, lots of opinions here............... It all depends on what you want, how much time, effort and money you are prepared to put into it, and what you expect from the final results. There is no clear winner between supercharging and turbocharging, each has advantages and disadvantages, but turbos are much more widely understood than superchargers. There are even many quite different types of superchargers, so that makes it even more interesting, it is just not possible to generalise about superchargers. But there are a lot of urban myths and misconceptions that get passed on about supercharging. Superchargers have developed a lot in the last hundred years, as have turbochargers, but it would be quite unfair to compare a modern close tolerance screw compressor to a thirty five year old turbo with straight compressor blades and simple oil cooled sleeve bearings. It would also be quite unfair to compare a state of the art ball bearing turbo with todays computer designed blade profiles and low inertia rotors, to a fifty year old design GM roots blower straight off a diesel truck. How efficient it is going to be, and how well it works depends more on how it is engineered, and how well the controls work. Nobody today would think of using a turbo without a wastegate and intercooler. A supercharger also needs a bypass valve and an intercooler as well, and if it is properly set up it can give similar if not better results than a turbo on a similar engine. You get what you pay for. When people think of fitting a supercharger, they often think of the $300 Toyota blowers that came off a 160Kw two litre factory engine. This will certainly work, but it will not work well, particularly on a larger free breathing engine like the RB Nissan. It would probably work about as well as a $300 turbo that came off a two litre 160Kw engine would. Nobody would expect such a small turbo to perform on an RB30, but they expect mighty things from a similar sized supercharger. When you start to get really serious about either supercharging or turbocharging, the results can be very impressive either way, but what is most suitable depends on the use of the engine and the shape of the power curve. But there is a lot more to it than that. The biggest problem with positive displacement superchargers is just the sheer physical size of the thing, and mounting it in the engine compartment, but if you can manage that, there are a few real advantages. The first one is that boost can begin very low in the RPM range without lag, and airflow can be very high at the top end, provided the blower is physically large enough for the job. For a street engine another advantage is the vast improvement in detonation threshold of a supercharged engine. You can run much higher boost or lower octane fuel with a supercharger, because the heat can get out of the combustion chamber. At full power, boost pressure will be far higher than exhaust back pressure, and with sufficient valve overlap scavenging can be very efficient. The heat can get out. So there is relatively cooler mixture at the beginning of the compression stroke, and much less tendency towards detonation. At any given boost level and induction temperature the supercharged engine will run much further below the detonation threshold. A turbo engine running at similar boost and power will have significant exhaust back pressure to drive the turbine. Red hot glowing exhaust pipes on the dyno are not that uncommon. The exhaust is just as hot as those pipes, and a lot of it remains trapped in the combustion chamber when the exhaust valve closes. That hot trapped gas mixes with the incoming air undoing some of the good work your intercooler has done. Detonation is the number one killer of turbo engines. Another thing to think about is compressor efficiency. Turbos usually peak at about 75% on the flow map at one particular flow and boost pressure, and can be much lower everywhere else. A screw blower can be 75% EVERYWHERE throughout the flow range, and there is no surge line either. This not only means lower discharge temperatures, but less drive power required. Turbos are only efficient over a limited flow range, that is why there are so many sizes and different hybrid combinations. You pick your turbo for response, or maybe top end airflow, but you cannot have both. Show me a 500Kw turbo for a skyline that makes 15psi boost at 1500 RPM ? It is just not possible. But with a suitable screw blower you might just do it. But if all you want is sheer top end horsepower, a turbo will beat anything else, except maybe a centrifugal supercharger. Turbos are very good in other respects though. They are very small for a given airflow, and a lot easier to install. A turbo installation on an unblown engine is a lot easier than fitting a supercharger to an unblown engine. Turbos are great, I am not putting turbos down at all. But there are other ways that might or might not be better. If you want to drive flat out all the time and stay in the power-band, turbos are great. But for a street car, you will not keep your licence very long doing that. Standing starts are also more difficult with a high power turbo. You have to launch it at high RPM, or it just will not go. The higher up in the RPM range the power band is, the more difficult a turbo car becomes to drive. None of this is true with a well set up supercharger. It can pull from low RPM like an eight litre V8. But you do not get that surge of acceleration as the boost comes in that you get with a turbo. I think that is what is so appealing about high power turbo engines, they are just so much fun to drive. So where does that leave us ? It depends on what you want I suppose.

Anyone following the political situation in Arabia and Iraq ? I doubt if we will see petrol prices below $1.00 ever again. Get ready for $1.50 per litre fuel, it will be here soon enough.

What sticks to the magnets looks like a sort of grey sludge, not like metal at all. But obviously it must be either microscopic steel or cast iron particles or it would not have stuck to the magnet. It is easy to do and there are no disadvantages. A lot of good quality production cars and trucks actually have magnetic oil drain plugs fitted from the factory. This is nothing new at all. It is probably of more value in the gearbox and diff than in the engine. That last missed gear change probably chipped away a few microscopic particles of super hard steel. Those chips are going to circulate around and around in the oil, being squeezed between the gear teeth perhaps breaking off more fragments. Not very nice. At least the engine has a filter and the oil gets changed, but what about the diff ?

The part I used on all my sump plugs was the 12mm x 5mm size (part number 3140). This easily fits in the middle of the drain plug which probably has about a 16mm thread, not really sure of the exact thread size. I have been using these for a very long time. The magnets are very light in weight and strong, and will never move once stuck to a steel sump plug.

I have been running magnets on ALL my oil drain plugs for over twenty years, they work great. Every time you change the oil there is a big fuzzy blob of steel crap sticking to the magnet. I would much rather have it there than going through the bearings and gears, or having it clog up the oil filter. Do it yourself ! The strongest magnets available these days are the Neodymium Iron Boron rare earth magnets, and you can get small disc ones for around a couple of dollars each, that stick by themselves to the steel drain plugs. These things stick so hard to the drain plug you need pliers to get them off. I have five on my car, sump, gearbox, transfer case, front diff, and rear diff. Check out: http://www.aussiemagnets.com.au/rare_earth.html

I seem to recall reading that nitromethane is extremely destructive to engine oil, it causes it to break down somehow. This is no problem in an AA fueler because the oil gets changed very frequently, but it may cause some problems if you expect 5,000 Km oil change intervals in a road car. I may be completely wrong about this, but it may be worth looking into. A very interesting idea to be sure. Maybe some additional injectors with nitro/petrol mixture could just be switched on or off. They could be driven at the same duty cycle as the main injectors when turned on ? It would then be a case of adjusting the nitro/petrol ratio and injector size to give the required power increase at the correct air/nitro/fuel ratio on a dyno.

Hehehe, that's a trick question....... Both cams turn clockwise, so if you move the camshaft itself more clockwise, things will happen sooner, which is advanced. BUT to do that, you have to move the gear on the end of the cam anticlockwise with respect to the cam. Hope that makes sense.

You are right, the gearboxes are absolutely identical, ratios and all. The R32 GTS4 with the RB20 has the different lower gear ratios. The R33 GTS4 is the same as all the GTRs. I looked at this GTS4 vs GTR thing myself a while back, it is a tough decision. At the end I suppose it depends on what you really want. If you want a GTR, only the real thing is going to satisfy that...... But if you want a great sleeper, a GTS4 with stock four stud wheels and stock on the outside would make a great street sleeper. You are a lot less likely to have it vandalised or stolen as well.

A very great deal depends on how the cams are timed in the engine when they are installed. Each cam could be either advanced or retarded and the resulting valve overlap could be set either narrow or be quite wide. Factory cams have very little or no valve overlap to keep idle emissions within legal limits. How much overlap you can get away with on a turbo engine depends mainly on total exhaust back pressure, which in turn depends on turbine size and a/r and how much noise you want to make. It is all relative, and it is not really possible to give advice. I think you are going to have a lot of other problems long before the idle goes really lumpy on a turbo engine. If you overcam it, it is not going to run well unless you really uncork the exhaust side, then it will be very noisy. So decide what you want. Do you want just a bit more on road performance, but still keep it reasonably quiet ? or do you want balls to the wall top end horsepower only, and noise is of absolutely no no concern. Too many guys fit bigger cams then find out it is laggy and unresponsive. They then fit a huge exhaust and find it then runs really well, but is cop bait. The usual conclusion is that the original exhaust was limiting performance and had to go. Nobody ever thinks that the engine did not go because it was overcammed, it is always the exhaust that is the problem not the cams. Everyone has their own ideas about all of this, and what is acceptable and what is not.

Another factor is, what is the car actually going to be used for ? If it is a street car, anything much over 100Kmh can be pretty lethal to your driving licence these days. You can even get nailed at half that speed. A pretty quick 0-100Kmh car does not need 1,000 BHP with a narrow power band. In fact, a very highly tuned turbo engine can be quite slow and difficult to drive except absolutely flat out at high speeds. With something like that it would either totally bog, or break into uncontrollable wheelspin. Only fast in the hands of an expert driver, definitely not a good everyday car. If you want fast and reliable, something like an HRT427 would be nice, but they do not make them. I hate V8s, but I cannot deny they make quick easy to drive and reliable road cars. Maybe not that fast down a dragstrip, but easier to drive, and probably actually quicker at legal road speeds. If you have ever been caught off boost in the wrong gear, you know what I mean. Having something that accelerates really hard at over 250Kmh is pointless on the street.

There is a bit more to it than that. When you start running very large amounts of valve lift and cams with very fast rates of opening and closing, with super strong valve springs, as you must with a really serious engine. It can rip the hell out of the rest of the valve train pretty quickly. So you might drive your engine that has a power band between 9,000 and 11,000 Revs like a granny. It might cough and splutter and be totally gutless off boost below seven grand and be no fun at all to drive. The whole valve train will be rooted pretty quickly, a return Sydney to Melbourne trip would probably do it at a steady 100 Kmh. The glossy magazine editors love those engines. A feature story about how some dork buys a forty grand car and spends another eighty grand modifying it to destruction. It sells a lot of magazines. Some wide eyed pimply eighteen year old reads that, and thinks he can make his rusted out twenty year old bomb go just as hard if he fitted all the same parts. It is all pure fantasy for the gullible. Go and buy a five dollar magazine and dream................... On the other hand if you might have a multi million dollar aftermarket parts, or tuning business, you can afford to build a project car as a publicity machine, and tax write-off. You win horsepower heroes with it, or get it into the hot car magazines as a promotion. It will bring in lots of business from the dreamers. So you might have some car that cost well over a hundred grand to modify, with the company name all over it and it dynos at 1000 BHP+ Maybe it appears as a promotional exercise a few times a year at car shows and so on, with lots of publicity. People go......oooh....ahhhh, and talk about it on the Forums............. If the same car is still there five years later, people seem to think it must be driven to work every day, and must be some guys personal transport. Hardly likely.

Yeah, if you do a complete engine rebuild every couple of months it should be completely reliable, no worries at all. Even a 6,000 BHP+ slingshot dragster could be completely reliable and probably run for years if it has a complete total tear-down and inspection after every few runs. A new set of plugs and valve springs and an oil change after EVERY run would definitely be required. You just cannot build a high power highly tuned engine and thrash the crap out of it for hundreds of thousands of kilometers and expect it to be reliable. 20K's that is almost exactly 50 quarter mile passes, without checking or changing anything, pretty optimistic for a 1,000 BHP Skyline without something bustin.

Mate.... It is all there in previous threads. It is just that you are too slack to do the work of looking for it. You want some poor bugger to spend an hour typing how to do it because you cannot be stuffed spending five minutes looking for the information for yourself. Then you flame someone.... If you want people to help you, at lest be a bit more gracious.

I had never thought about upstream water injection with this setup. Thinking about it, it may very well cause some problems. Best ask one of the heating ventilation and air-conditioning engineers (HVAC) about this, any of you guys out there ? How does sensible cooling vary with changes in humidity ? If for example, you blow 50C relatively dry air, as compared to blowing 50C 100% relative humidity air over a hot dry object, how does that effect the heat transfer into the cooler airstream ? ? ? Warpspeed who knows nothing, is always eager to learn something new......... ! My gut tells me that water has a far higher specific heat than dry air, and more of it is going to suck out more heat, but I would like to hear from someone that really knows about this stuff. And if it's true, how does a standard hot wire AFM cope with large changes in relative humidity ?