Galois

probably want a smaller gap with 16psi, the higher the pressure, the more potential to "blow out" the spark, or at least create an environment where spark generation is difficult

interesting... thanks for the awesome replies guys so the blackness comes from exhaust sooty crap getting out of the cylinder chamber into the oil? what would it mean then if the oil came out black every 1000 or 2500kms every time? should it ever come out looking new consistently? just trying to gauge the situation. the sougi is very good at cleaning the engine, though not in the detrimental methods that engine flushes are. so at equilibrium, with no carbon buildup being removed, so only blackness produced by degradation and exhaust blowby, how black would that make the oil? the degradation wouldn't be much on a group V after 5000kms, so pretty much all the dark material would be from exhaust material, is that very much over 5000km? and for a poor detergent oil, does it just allow carbon buildup? didnt realise magnatec was so crap, was just buying a cheap mineral oil as suggested several pages ago to simply "wash" the system. haha it'll prob come out clean! might be looking for sougi pretty soon then. i have done 2 nulon's and an 8100, and now the magnatec. krazykong, thats insane about the oil having black parts after 1 day!! i get your point tho, change slightly less often and use better stuff, and it makes sense here cos sougi is so cheap.

ps: holy sh$t rolls, your sig is awesome haha

haha, really? lucky guess. i only thought of that while i was typing the question hahaha mines a series 1 (1999) r34 neo, but i didnt think much changed from 1-2 engine bay wise. can anyone confirm/correct this? yeah, our actuators are definitely different, which is weird lol. i'll have a close feel of the hose leading to the actuator and see what happens. i have to track down another boost gauge, cos that would be an embarrassing thing not to have checked!!! btw ill post a couple of pics up tonight

to the thread starter: given what you said about jumping in the car and red-lining it to avoid a truck, you probably want a lighter oil such as a 0w or 5w. as for hot weight, go for 40 as these engines are getting older now and it is warmer here than in japan (where they use the 7.5w30 stock). use a full synthetic, not a mineral synthetic, as it'll be better for your aged performance engine. i'd recommend motul xcess 8100 5w40 as you seem keen on the lighter weight (quicker oil through the engine). you can pick it up for $75 and it has so very many great reviews. it is a good group 5 oil. or, you could do what more and more people are doing, and start using gulf western sougi s 6000, which is a group 5 oil. it isn't sold in places like supercheap or autopro, but autobarn can get it in for about $80. or you could, like most do, just call gulf western and find your nearest distributor and buy it from them for ~$60. that's the best type of oil you can get for only $60. ALL of this stuff is covered in the oil sticky at the top of the general maintenance forum, well worth a read even if you only go through the first few and last few pages.

hey maddowse, that is an interesting day haha. i have found when i tested it (not on public roads) that my speed limiter came in at ~190km/h if that helps. i took the actuator off yesterday (many scuffed knuckles haha) and took some pics. it had the number 99629 on it ind was unmodified as far as i could tell. i took some pics but don't have them with me today, will post them tonight. it had the piping in the center of the round piece, not on the side like yours. i also had a good listen and test of all the pipes but didn't notice any fatigue, they actually seemed in surprisingly good shape lol can someone please explain how exactly the actuator works? im guessing that when the pressure gets too high it moved a plate in the actuator, which moves the rod it's connected to which opens the wastegate? lol that could be way off. i have to find another pressure gauge to check mine is running properly. what else could be causing the high boost if the actuator is unmodified and the hoses are fine?

how do you mean carbon intensive birds? what exactly is it that makes the engine oil go black? i understand its the breaking down of oil due to the temp, but what else? just the plain castrol magnatec stuff. 1000km changes come every second weekend so ive started using the cheaper crap now. as for how long, not really sure. it was more brown-black yesterday than it has been before, the last changes looked like the oil had served 20000km, really black, horrid stuff. so hopefully only one or two more to go before i can get on to 5000km changes. i guess if its still black after 2 or 3 more ill have to start considering an engine flush, but i really would rather not do that. it'd take a long time for the engine to recover from that (ie: re build the carbon layers that actually help the engine)

glad to hear about the good results krazykong. just bought 10w40 castrol today to use for the next 1000kms (1000km changeovers, old oil, poor prev owner, told this story too many times lol). but there was also a valvoline, several shell's and mobil, so there are other 10w40 options, just none worth considering haha looking forward to some sougi goodness!

covered in the last page of posts mate. call and ask for your nearest distributer. also autobarn will get some in for you but its $80-ish instead of $60-ish yes, but you can never put oil in that classifies as too good not everyone using it is turbo. its probably not necessary to use a grade 5 oil for a non-turbo, but this is grade 5 oil for grade 3 price, so you can't go wrong. 10w50 is probably too thick when hot. most people use something-w40 (5w40 or 10w40). its more flexible since you're not smashing the cylinders with a turbocharger, but you can never take too much care of your car read through the last 5-10 pages. it doesn't take that long and it answers so many questions, lol and causes so many more questions.

hahaha outstanding

whoa, i had no idea it worked like that. makes sense about the cat tho, using the extra fuel to lower emmissions. fascinating, what like of thought did the designers go down to come up with that design conclusion, clearly in a time of cheap fuel lol. thanks for the info, i get it now. i'll have to look up some numbers but im guessing the engine never actually reaches stoichiometric combustion ratios (sorry to go all chemical lol) ok, some explanation for the above questions: no cat means soot and crap that would have been combusted in the cat instead is fired out of your tail pipe. a high flow cat is effectively a shitty cat, not doing its job properly, because to do it properly the cat needs a large surface area of exposure for the exhaust air, but large surface area means tiny thin piping, which impedes exhaust flow. hence us performance minded people go for larger arrangements for higher/free-er exhaust flow, which means more sooty crap coming out the back, ie: more staining. with no cat at all, none of the carbon left over from the engine is combusted in the exhaust system and it goes straight out of the exhaust pipe.

ok, easy here, and i mean real easy... what exactly is oiling the seal? i will cry if i have missed a crucial step in all the oil changes ive done and reaped the happiness of a job well done *ducks for cover*

hey mate, as you said the gauge is pretty inaccurate. i notice a HUGE difference in oil pressure behaviour during hot/cold/idle/load driving. im doing 1000km changes of oil+filter cos my oil keeps coming out black (thanks previous owner for not taking care of the engine) and i don't want to use a flush for various reasons. each filter/oil has different resting points. now with that nulon "synthetic" stuff and a drift filter it's sitting just below 2 on idle, maybe at 1.7-1.8, but im changing this weekend. 700kms ago idle was at 2.5. if you're concerned, do another oil change at 1000km. as suggested above, it might take a few oil changes to level out. maybe the sensor just needs new oil washing over it...

if you want to see if its working, drop the clutch on some grass and see if the front tyres spun as well. either the grass will be flat, beaten and ripped a bit, or it'll be dug up. or do the same on some dirt or something. but if the car flys off into the distance instead of just sitting there burning out its probably working...

+1. the oil thread is packed full of info. that said, when birds says something about oil people listen

hmm, interesting, so that fuel is effectively wasted, or only reacted to produce carbon monoxide instead of dioxide, until it reaches the cat? and fuel that isn't reacted combusts in the exhaust? or leaves the exhaust? sorry for all the questions, just interested in how the combustion works exactly. also, i read somewhere else that adding a bit of water to the airflow keeps the temps down, so would it be more efficient to do that and lean the engine out instead of wasting petrol energy with incomplete combustion? thanks for the info

thanks mad082 ok, so leaning out the afr increases the rate of reaction, so bigger bang over shorter time, or more importantly, bigger bang at top dead center, which means there is more gas volume produced in the small tdc space which produces more power. does that affect the engine temperature that much? the vast majority of the fuel is going to combust anyway right? which means all that heat is released during the combustion anyways, so why is it hotter if its leaner? cos if there is a significant difference between the amount of complete combustion between lean and a normal run that's an efficiency loss...

lol, i was so very close to forgetting to put the new oil filter on before filling 2 weeks ago. was doing a coolant flush at the same time and got a bit mixed up, could have been bad if id started her up :$ where abouts is the oil pressure sensor, does anyone know?

sorry to ask, how does the t piece work?

from what ive read it'll increase your lag, not your boost. but your air temp will be lower, which means higher density, which means more O2, which means bigger bang... so is that an r32 actuator above?

can someone explain why there's a power gain from leaning out? is it just because the combustion reaction is more complete (for the same amount of fuel pumped in) when you force more air into the engine, ie simple equilibrium and kinetics? cheers

which on gravel isn't always a good thing, at slow speed on some lose surfaces its a quicker stop to lock the wheels and dig in instead of trying to keep perfect traction. my r34 applies the abs on the rough grassy crap downhill outside my house and it scarily doesnt stop! but thats the tradeoff for not hitting that truck or not skidding out under brakes in the rain

isn't much of the heat generated due to the friction between involved in a bearing moving at ~130000rpm? lol i like the way you think maddowse

wait, is an ebc illegal? or does it just beg for further inspection? thanks

correct me if im wrong, but with free flowing exhaust, the pressure in the exhaust is lower for the same pressure on the other side of the exhaust turbine, higher pressure difference = higher spin speed of the exhaust turbine, higher spin speed at turbine = higher compressor speed = higher intake pressure. isn't it a solenoid that electronic boost controllers use to increase boost? how can we tell if the ecu has been modified? my actuator looks different to yours maddowse, it has a hose leaving from the center of it. i'll have to take it out (prob on friday or weekend) to have a look at the numbers. my boost holds nicely at 13-14 psi, increasing evenly till about 4000rpm. to check: take the actuator apart check vacuum hoses will get back to you. btw, repeating maddowse's question, do we have to adhere to the exact pipe sizes used when replacing them? because i have a fair few smillar pipes leating into bigger pipes leading back into smaller pipes. not sure if the larger pipe is just there for protection sheath type arrangement, but if its using 3 pipes instead of one thats pretty poor