Rolls

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Yes this is completely true, sorry my point was more that people should realise that above 90-95% they aren't going to get more fuel. The reason I say this is if say you mapped everything at 90% and it is running fine you might go to yourself "Oh I still have 10% to play with so if we get an extra cold day it will be fine" However as seen from the graph it is a false sense of security, you should be treating 90% as the absolute maximum. Yes that is all it is, a very simplistic estimated flow vs PWM output. If you know the open and close time for the injector along with the frequency of the PWM signal I could generate an accurate graph for you. Personally I think the allow 10-20% is a good rule, whilst you may have tuned your car so that it correctly mapped, you still are guessing for changes in boost and air temp. What if you tuned the car in 10c weather and maxed out the injectors? (lets say a very cold day) and then you go out for a drive in the rain in the hills where the air temp is say 4c and the rain on the intercooler causes it to work far more efficiently? You are almost certainly going to need that 10% of headroom.

there is no way they will be able to tell the difference, I don't think it will be an issue.

The problem is above around 90-95% the injector will be static and completely open anyway. Sure it'll be getting a 0.9 pulse to the injector, but the injector is mechanical and physically can't open and close in the time of the off pulse so anything around 90-95% technically is maxing it out. Depending on the injector you might get some more flow at 100% but it wont be a linear increase, it will drop drop off severely around 90%. Here is an image to demonstrate what you are likely to see. So as most people have said, you should always aim for not much more than 80% duty cycle.

Castor rod and camber arms are as far as I know. Mech 2 way is also, but I have known people to get through with one even with it chirping away in front of the inspectors. Sway bars should be fine. What does the tension rod do? Is it like a rear strut brace or something?

You get permission from regency park to get a permit, take the proof of permission to the transport office and get a 1 day permit then drive it there. Or you could just trailer it. $50 for a permit. I wouldn't be surprised if they read this thread, and your car is fairly stand out being those colours in your pics so you might want to edit out calling them f**k-heads.

It is funny because I've owned 2 fast skylines and 1 very fast skyline yet ALL of my traffic offences have been in my mums 1.5L non VTEC civic which I drive about 20 times a year. I sometimes just say nissan because I am embarrassed of the stereotype.

haha good call, cant imagine Castrol would be too pleased reading that though lol.

With an AFM I imagine the car would just run super rich and you'd notice straight away, unless of course the car was tuned from scratch with the boost leak. I wanted to get a better idea of whether the situation was possible with a MAP, I'm still not 100% convinced but I think it is quite likely, to what extent though? I do not know. Only way to tell is as you said, with a turbo tacho and a controlled environment.

Oh the car isn't defected, I just bought it from interstate so it has to go through for a full inspection. But thanks for the tip anyway, will have a play in a day or so and pull it out.

Without a doubt there are, this is more just for some interesting debate, I'm running an AFM in my skyline now so it is not even a possible issue, I am just curious of the physics and whether it can occur. I agree that we need a variable sized hole and a turbo tacho to ever prove this one way or the other, still I think it is interesting to discuss.

Thanks for that, I will just remove the amps as they are mounted poorly (and refit them correctly at a later stage) and leave the sub box in place.

I agree with what you proposed if there is a very large leak. However if you decrease the size of the leak so that a decent amount of the air is going into the engine (remember a stock turbo can hold full boost at 3000rpm with half throttle, let alone redline on full) so let us say half the air is going in and half is leaking out. Now being as a stock turbo can run full boost at 3k with half throttle surely there would be enough exhaust gas to allow the turbo to keep increasing in speed to some point? edit: I've made the same thread over on performance forums to get a wide range of opinions and GTSboy has explained why he thinks it would overspeed with the aid of a compressor map. I guess the only thing to argue now is whether or not you have enough exhaust gas to keep the turbo spinning faster, personally I think with a small undersized (stock) turbo you would have no trouble doing this. http://www.performanceforums.com/forums/sh...php?p=840645505

It is just a theoretical question, I would hope that the average Joe would hear it and notice as well but that is not the point of this thread.

Obviously not forever but until it started to get out of its efficiency range I believe it would.

Do you mean turbo speed/air flow? Because once the pressure reaches say the set limit (eg 10psi) it will open the gate and stop increasing. If you did mean turbo speed then yeah that is my question I guess, how much faster it will spin. Do you agree that it would spin faster though? Because any increase in speed would make this a problem big enough to look into, as any increase in speed will wear your turbo faster. I agree that with a large leak even with the wastegate closed all the way to redline that it won't be able to make more a few psi, and that because of that there wouldn't be enough exhaust gas to spin the turbo fast. However if we had say a medium sized leak which is large enough that the boost will never reach 10psi (lets say 8psi for example is the max it can reach) would 8psi (with the wastegate closed) be enough to create enough exhaust gas to overspin the turbo? Assuming that if it spins faster trying to reach the 10psi and all the extra air is going out the leak it will just keep spinning faster and faster until it reaches the limit that 8psi can spin it to. Gah this is doing my head in trying to understand it and explain it. I think the only real way to test would be to use a turbo tacho and a variable sized hole on the intake.

I have a question. Lets say you have a turbo with an ecu that runs a MAP sensor opposed to the stock AFM and a boost leak. What I propose will happen is the air will leak out of the pipes causing the boost to never reach the set level (say 10psi) because of this the turbo keeps spinning harder and harder trying to reach the 10psi however due to the leak it cannot. As the ECU is reading the correct pressure (and temp) in the pipes it injects the correct amount of fuel allowing the car to drive properly. Now would the turbo just keep spinning harder and harder or at least as hard as it has to to reach the boost pressure with the leak, this would cause far more wear and may even destroy it instantly if the leak is bad enough? If so how would you protect against this? I know with an AFM car the AFM will read more air than is really going into the engine, so the engine massively overfuels causing it to barely run, you then go 'oh shit I have a boost leak' and fix it immediately. Anyway I am curious as to if my thinking is correct and what you people think about this. As if correct, this could be the source for a lot of turbo failures or accelerated wear on MAP tuned cars. I guess ultimately it comes down to how much harder the turbo has to spin to overcome the boost leak, if it is 10% it probably doesn't matter, if it is 100% then it would. However if the boost leak has to be so large to make it spin 100% harder, then there probably wouldn't be enough exhaust gas to spin it this hard. I imagine the problem would be more pronounced with smaller (stock) turbos.

What are regency like with having subs in your boot etc? Mine is firmly fitted to a wooden sub box that sits under the rear seat and is all bolted in. It is fairly easy to remove however. What are peoples experiences with going through regency with things like this? yey or ney?

They aren't even in slightly the same class lol.

I would buy it.

I cannot believe I just found this. http://forum.jdmstyletuning.com/ roflmayo.

Only when they are totally abused to the point they have no meaning anymore. Mag wheels generally refer to any alloy rim but it is hardly ever used and definitely not in the same wanky way that JDM is, so no it does not make me upset

I actually saw some guys in a non turbo VL driving down the bay a while ago with one of their mates going 'TUTUTUTUTUUUUUUTUTUT' every time he throttled off, it was actually hilarious.

This is the proper use of the term, I was mainly questioning the other random usage.

But that is the whole point, it doesn't mean anything at all like that! It means jap domestic market, each every single car that was marketed and sold in japan is JDM. It is nothing special at all.