AndrewD

i want to know how to make 455 rwkw from standard engine. what parts do i need to get. how much am i looking at? do i need a tune? can i run 2 bar?

Maybe your turbo oil seals are shagged, small amounts of oil are enough to cause white smoke, especially on quick on off throttle application which further encourages seapage. Also if you have a water cooled turbo that could explain the missing water

are those fan blades the right way around?

If your not sure, its probably not a wise idea then However, the tuning strategies remain the same, just your measuring the air quantity differently. AFM measure air volumetric flowrate MAP measures the air pressure, and given a temp sensor you can then convert this to speed-density tuning. Speed density if better for many reasons. Mainly now because you can include air temperature compensation if the PFC allows for this.

shouldnt make a difference, so long as the sensor, NOT SENDER, is located between the engine and radiator inlet.

most motorcycle engines rev this freely when there is no load on the engine. once there is load on the engine the ramp speed reduces. wow you must have one of those brains that magically measures shit and spits it out over the internet. and why ATDC? that would be counter productive. obviously f1 is into that shit too. maybe even the exhaust valves would be part open by this stage, meaning almost no charge to ignite, so they might have one of those magical spark plugs which follow the charge mixture? get my drift?

doesnt mean that increasing the pressure differential is a good thing. yes it helps 'spool' the turbo, however the pressure ratio may now be such that the turbine operates in an inefficient range.

lol have you considered the mass conservation principle? cause that statement is wrong. essentially in a closed system (e.g. a pipe without leakage) the mass of the substances remains constant. it follows then that the mass flow is also constant (i.e. now fuel or air is either injected or lost between the inlet and outlet of the turbo). hence: massflow at point 1 = massflow at point 2 also: massflow = density x velocity of gas x cross sectional area of pipe. so what actually happens when you increase the size of a pipe for the same mass flow is a REDUCTION is gas velocity, which is accompanied by a reduction in pressure drop for the same length of pipe in comparison to the smaller pipe. and as far as turbo blankets design for turbocharger performance is also crap. they limit at best the engine bay temperatures. cause increased temperatures within the bearing centre and oil coaking on shut down. WHICH is BAD! however if you have a water cooling circuit it will be ok, however take longer to cool.

Just to comment, it takes more power (rate of work) to accelerate a higher rotational inertia item than it does a lower one. so yes while it isnt directly related it has an effect. The excess power required to drive the fan no longer exists, and can now be used to accelerate the crank and gearbox assembly. I think you mean mechanical / accessory losses. friction losses would stay faily constant and only vary with changes in force.

air is classed as a fluid a fluid can take either gaseous or liquid form

Im still laughing. "Turbochargers cant cavitate" Any rotating machinery can cavitate, especially air systems. The type of cavitation you described was what is experienced in centrifugal water pumps. Doesnt mean it requires water. Btw those articles are by industry professionals. The same very people that design those turbocharger systems. Yes i understand there is an emissions, fueling related function of BOVs but its not their only function. Ive got logged data that proves the fluctuation in turbo speed, so maybe Simon is talking about a different situation.

I have few points to rebutt, -The physics do suggest it can happen. In applications where the throttle is POST compressor, when it is closed you increase the pressure between the compressor and the throttle. As pressure increases, pressure ratio sky rockets. Most compressors for road cars (not race cars especially F1) operate with a maximum pressure ratio of no greater than 2. Above this surge occurs (but not only under this condition). Surge also occurs when the throttle is closed, the compressor cannot 'push' the air any further and it reverts and flows over the tips of the blades. As JC Marhsall stated earlier this creates vibrations in the blades and coupled with high hydrodynamic pressure loadings on the blades (at a distance from the blade / wheel interface) this causes them to bend or shear. It happens, go to garrett they have plenty of compressor wheels on display that have failed due to surge. -Racecar engines that have not failed. I call dibs on this one. Lets define a racecar shall we. I think you will find that most racecars especially in the elite class, are often rebuilt after every race and the majority of their parts replaced. Not to mention that typical race cars with turbo applications run high boost (higher pressure ratios ie around 4 or 5) this means that compressor wheels are larger, and have a greater saftey against failure. However, I would like to point out that most of the earlier F1 cars had PRE compressor throttle. This means that while the the throttle is closed, still increasing pressure ratio, the engine is unhibited to breath the pressurised air. And this surge doesnt occur. Rather now you get cavitation. The need to run a recirculation valve to 'raise the inlet pressure' is not so pronounced and typically improved seals are all thats required. -Before you start complaining that people are getting all upset about falous claims, take the time to read many of Society of Automotive technical papers on this 'phenomenon' as you put it. Why do you think most compressor applications outside of automotive use are constant throttle / load? I'll leave you with something to think about, being as it is i have access to a race engine using a garrett GT15v (yes its small, but its also the very same kind used on the new porche engines) we have a shaft speed sensor and have clocked it at in excess of 200,000 rpm. Now consider that you have surge at a pressure ratio of 3. Almost instantaneously the shaft speed changes to 0. Now no matter how light that wheel is, there is a significant amount of inertia force on the blades which is tramsitted to the key and shaft. So before you go all internet mechanic on everyone, do some research. Peace out.

thats because your both idiots you dont need to do anything. if you've got compressor surge you can hear it. one way to get it is to block off your recirculation valve. asides from people already suggesting that compressor surge, flutter chatter whatever you call it does not harm turbocharger function and componentry its well documented in the engineering realm that it does. there are too many gits and internet mechanics that speel shit on here that its just so funny. im not saying dont do it, its your choice. just be prepared to spend the money for reconditioning or potential engine rebuilds from destroyed compressor wheels.

You could get a competant welder to block those tubes off, however you may have punctured the surrounding tubes by removing the fins off of them. Best thing is to get it done, take it to a radiator shop and get them to pressure test it. If it passes the test, remember to block off the hole so air will not flow through that section of the core. Ive done it before, however i removed the tanks and seamed it from the top of the tank flange other than the bottom as you have done there. Proved reliable. Just need to pressure test it before you put it on.

HAAHAHAHAHAHA this topic is such a farce so many idiots

I cant believe you think your going to get an increase in power from the lower rotational inertia just by removing the mechanical fan. The rotational inertia would equate to maybe a couple hundred Watts, not kW. electric fans are better than mechanical purely from a control perspective. They flow less, but transfer the energy required from the crank to the alternator. Its not a power gaining mod. More an engine saving one! Think of it this way, at start stop traffic engine speed is slow. Fan speed is proportional to engine speed (hence so is flow, so long as cavitation isnt present). Electric fans arent related to engine speed, rather engine temp.

Maybe you should read yours again. It was nothing special either.

AHAHAHAHAHAHAHAHAHAHAHA there is no way the exhaust flow at any stage is laminar

Its funny how this discussion has almost become about how big your d!ck is Im an engineering graduate, and i have not worked on XR6T or RB26TT engines before, not that it makes any difference the principles are the same (you cant tell me an XR6T works on a different cycle than an RB26TT now can you) Its elementary fluid mechanics. He should have atleast learnt that by 2nd year. And if hes is only on around 55 he is like said previously most likely a recent graduate. Like myself. That or he has no aspirations. Unlike myself Fact is the damage could be caused by many reasons, and just because the turbine is post cylinder doesnt mean it can be excused. Engines are not steady state machines at even any far reach of the meaning. Especially the gas flow throughout them. And as far as small particles not damaging pistons you can think that again, the acceleration of the piston itself throughout the cycle is enough to make minute particles worthy of doing damage. Why do you think most pistons fail at TDC? High inertia forces resulting from high acceleration! Even though they weigh very little. 100's to 1000s of gs can do that.

I have to disagree. That engineer can say what he likes, however you still have either an internal or external wastegate which limits the exhaust manifold pressure. Although this pressure would be higher than previous. You can still get cermaic wheel pieces or dust swept back into the cylinder. Especially during valve overlap when your exhaust manifold pressures are much higher than your intake (increased if your turbo is broken: greater pressure differential). While your engineer is correct that increases in EMAP will increase residuals during the next cycle, its unlikely due to the fact your wastegate would still relieve the EMAP close to normal operation and the compensation by your ECU is still most likely within its limits assuming your lambda sensor is in and working for feedback control. I can think of plenty of other reasons why a turbocharger would damage your engine. Mechanical contact from compressor pieces. Hydraulic compression of fuel from running too rich and incomplete combustion outside of ecu compensation (which is limited)....

What about the internal pressure relief? (that would return excess oil to the sump before being sent up to the head) Is there not one?

Sorry for point 4 i meant decreases after restriction. i left bit out Are all 4 of your scavenge stages from the sump? or do you use some for the return oil from the head? any of the stages used for scavenging turbocharger routed oil? What type of pump is the standard internal pressure pump and the external scavenges? gerotor or roots style?

has anyone who has done this modification of restricting oil flow and lowering oil pressure to the cam journal bearings noticed increased wear? the problem seems like its an oil return, not a supply problem. if you restrict the flowrate the cylinder head doesnt recieve enough cooling. also the pressure drops because of the restriction and you now have issues with maintaining the hydrodynamic lubrication of the journal bearings. this leads to increased mechanical contact between the bearing surfaces. why not do as is already suggested and improve return oil flow? increasing oil gallery size and added external lines are perfectly fine.

Thats hilarious. Was that supposed to offend? I dont care if beer or anyone else on here wants advice because they wont get it. Maybe i should dish out crap. You tend to agree with that.

Nah its ok, im just having a bit of fun. They can give it back if they want Im just annoyed at the advice people give thats falous. I guess my approach wasnt warranted. Next time i'll bring the flowers rather than the boxing gloves