Rolls

it is heat and peak cylinder torque that will destroy head gaskets not rpm imo, though rpm will contribute to heat.

If you changed nothing else but went from single scroll to twin scroll (both with good aftermarket manifolds) would the twin scroll make more peak power as well? or does it primarily only assist with low down/midrange power when coming onto boost?

Upgrade the fuel tank to 120L ?

I have no doubt that you can hear the difference of certain things especially when they break, I'm just doubting that you can hear the difference between two oils that are performing perfectly well without issue. I am sure that you guys are more than capable of diagnosing faults by ear, it is just when you have two oils that have no issue, but one 'feels' better, it just sounds wishy washy and inexact to me. This is exactly why I brought up the blind test example, eg get someone else to change the oil to a really crap one and see if they can tell the difference.

I definitely agree you can hear the difference in lifter noise between some oils.

I bet if someone changed the oil for you and didn't tell you what oil they used you would not consistently get these feelings, if you don't believe me get someone to do it, get your normal oil and a 25-50w and get them to not tell you which oil is in the car. Drive it up and down the street a few times and I guarantee you won't be able to guess, if they've put the shit oil in then change it afterwards.

They are both connected, they will read the same pressure surely?

After a NEO RB25DET, doesn't matter if it is a bare block, don't need the manifolds or injectors/loom etc. Preferably in SA but if shipping can be arranged will consider interstate. PM me on here or call <removed> if you have anything, looking to buy within a month. Cheers Roland

Anecdotal evidence is it just as important as factual evidence? Well if thats what you think then sure, I don't think you'll find many people that agree with you though. Neither, if I was trying to compare a difference I would do it on the dyno before, then compare it on the dyno after. That is like an engine getting a big end knock from using a certain oil (lets say water lol), that is something that you certainly can hear the difference, a minute difference between two engines that are both running fine is not going to be something you can tell by ear though.

What I was trying to say is he probably doesn't actually know which oil was better because there is so little in it and without proper testing equipment there is no way in hell you would know by just sound. Car manufacturers don't just try a bunch of oils and decide based on feel what they will recommend, they do lots of very expensive extended testing.

I'm an engineer, I only believe in real and measurable things. If we designed bridges by 'feel' half of them would fall down.

How do you gauge which one performs better? Point I'm getting at is there are basically no metrics to compare them with, the only thing worth checking is what oil has more or less bearing material in it, or if one makes the lifters noisy, how good a job it does at cleaning your motor, everything else pretty much doesn't matter.

How does an oil 'feel' better?

He doesn't have to do any of this, regency will inspect the vehicle and if they can't find the boost controller then they have to clear it. Make sure he does all his bushes and fixes everything else up though as they will always find something to pick on.

s1/2 r33 rb25det head for sale, rebuilt 7000kms ago have receipts, motor has done rings so replacing it with a neo 6 and selling off the bits. Head is very clean, turns over by hand fine, all valves look fine. call Roland on <removed> or PM me on here.

Why are you selling a brand new motor at a massive loss? Is there something wrong with it?

I have an R33 series 1/2 (not sure) rb25det head for sale, it has no accessories, just the head with rocker covers, cams etc. Came off motor a few weeks ago due to the motor blowing, only runs on 4 cylinders so thinking rings. Valves all look fine on the head, turns over by hand with no issues, very clean no oil gunk, was re conditioned 7000kms ago, have receipts. Going to replace the motor with a NEO six so selling off the bits. Can get pictures tomorrow but it looks like any other rb25 head, clean with motul 8100 oil used, changed twice in its lifetime. Location: Adelaide Contact: Call me on <removed> or PM me here.

it is a thicker oil, you need a thicker oil if it is a really old engine with poor tolerances due to its age (old holden 202s etc) or it is burning oil due to worn rings, or it runs really hot so the oil is thinner than normal. Lets say you get 400km to a tank and use say 50L thats 12.5L/100km, if you suddenly get 14L/100km it is not the oil that has changed this, it is either your driving style, your car has broken something, or you filled up when you had 5L more in the tank the second time. It is almost certainly the last option being as you have about 10L left when the empty light comes on. The only wage to gauge fuel economy is to fill the tank to brim, reset odo, drive until its empty, fill to brim and divide your litres used by kilometres travelled/100, this should be averaged over multiple trips to account for highway driving and city driving etc. Trust me there is no way changing from 30 to 40 uses an extra 1.5L/100km.

if its burning oil go the 10-60w, or if it see extended high temps on the track

eg variable vane with a simple to program controller, om nom nom

Can you jam the wastegate shut? Be careful when you do this as you will have no boost control at all.

won't it just suck harder through the smaller hole? edit: actually you are right, it will drop

Airflow cut due to the higher boost at low revs than the standard tune expects. You need to have the ECU replaced or remapped, personally I would opt for an RB20DET ECU with a nistune and an aftermarket controller for the VCT, other option is Z32 ecu which can control the VCT on its own. It is unlikely you are actually maxing the AFM out, if you are (need to look at the actual volts it is outputting) then a Z32 AFM is required, if you do this you have to upgrade the ECU to aftermarket or a nistune. Simple solution for now, remove the boost controller until you can fix the above problem.