gt-ahhh!

i love having a profec b boost controller. you clear it before you hand over the keys, and then when you pick the car up you can quickly see if they gave it some stick when they took it around the block. i caught a tyre bloke who obviously couldnt resist the urge to wind it out, but wasnt quite annoyed enough to get up them. my local mechanic who just does my servicing etc, seems pretty good. he only got up to 3psi. maybe because i work on the next corner... but you can hear my car in the next suburb. lol im going to give jem (ingleburn) a go next time. they seem very professional.

PROBLEM SOLVED! vacuum leak!

sorry, not much help. thats a very interesting idea though. not sure how you'll go seeing as the car is meant to be intercooled. but im assuming you cant be defected for an ic if you havent got one lol.

hhahaha thats effed. when i had my engine replaced, along with the turbz, the dickheads didnt even set the wastegate actuator. so basically it was wide open all the time and wouldnt make boost until about 5500rpm lol. took me months to figure that shit out. oh and then they installed the ebc wrong, so needless to say i dont go there anymore.

i was expecting a few of those.

so today i decided to play mechanic and troubleshoot a few idling, low rpm cruising problems ive been having. started by cleaning the afm. no worries there, though it was a waste of time since its only 10000km old. and then i thought id check for vac leaks. ive been convinced there has been one for a while now. im adamant the car is not as responsive or powerful as it should be, given the state of modification. so i blocked up the snorkel pipe with a can of beetroots lol and whacked an airgun on one of the manifold hoses. firstly, air came whoosing out everywhere from the u-shaped black pcv hose. turns out its split on the base about 2cm along. went down the st and got some hose, replaced that. then fed some air in again, heard a hissing coming from near the throttle body this time. had a look, found a strange hose coming out the base of the throttle body. i traced it across the engine bay to the charcoal cannister. i dont know much about them, but i figured its connected to the intake, so ill blast some air down it and see if its leaking at the cannister. this resulted in very loud hissing from the back of engine bay. obviously it was going to be very difficult to find/fix this. after some time i realised it was actually coming from under the car wtf! jacked it up, and lo and behold, there is a nice big hose wide open near the cat, and going nowhere!! seems the idiot caryard thought it would be a good idea to plumb the charcoal cannister into the atmosphere, which to my understanding, means the engine is sucking air from under the car while on vacuum, and blasting air out the same place when on boost. so basically my car has been nowhere near optimal performance since ive had it. i decided fk it, just block the charcoal cannister off. and retest the system for leaks. apparently it reached pressure rather quickly this time, and blew the snorkel off the turbo! great, probably the hardest hose to get to on the whole car. had to take off two other hoses, and it was still a bitch to get to. then when i was putting it back together, i lightly twisted a boost controller hose, which was apparently enough for it to fall apart in my hands! now i have to wait until tomorrow to buy some hose to replace that! WHO'D BE A MECHANIC?!

thanks i will take that on board. i just put in a z32 maybe 6 months ago, so itd be rather annoying if it was that.

i reset the ecu and it helped greatly, still did it once on the freeway. i have no idea, it seems totally random when it happens, the rest of the time the car goes hard. much better now though.

o2 sensor seemed to fix the problem, but it repeated randomly on the way home last night. guess i will have to throw it on a dyno and get them to have a good look see.

well thats a very good point. everyone rubbished kkr turbos a while back, many people still do, but they seem to go alright for people who actually tried them, inc. myself. the graph says splitfire vs "normal", engine is an rb26dett. so if theyre new factory coilpacks, 7ps is a pretty big gain. i didnt even consider the cost, i though splitfires were fkn expensive. but then again, genuine nissan is a total rip off for just about everything.

they must be stronger. i havent heard of anyone running new nissan coilpacks in heavily modified cars. splitfires are a common choice for racing applications. on my splitfire box it has a graph showing a dyno comparison, an RB making 323ps with regular coilpacks, and 330 with splitfires. theres also another graph which i assume is something to do with spark or volts or something (its in japanese) but the splitfires easily outperform the comparative product.

i highly doubt the small potential to improve mileage makes it worth it. its likely to start misfiring, and why on earth would you want that?

i have some of those symptoms. and i've narrowed it down to what i suspect is the O2 sensor. i completely unplugged it and it made no difference (better or worse) so im assuming that means it farked! have a read of this: http://www.skylinesaustralia.com/forums/O2...sor-t43095.html have you noticed poor fuel economy? that would normally be a good sign of the 02 sensor being rooted. i dare say it would be the original part still in there, god knows japs dont look after their cars. i believe theyre recommended to be replaced every 40000. theyre only $80-100 so its probably worth replacing anyway, otherwise id advise getting a diagnosis performed on a dyno. theyre quite useful. good luck!

gut those power thieves! there could be numerous reasons for your boost curve, one of which is exhaust restriction. it might interest you to know... when i got my new turbo etc fitted, the mechanics in their infinite wisdom decided not to adjust the wastegate actuator, so the wastegate was open nearly 100% of the time, and the poor turbo was still huffing out 13psi by about 5000rpm lol! might be something to consider. or small boost leak? bov? whatever boost control you have?

problem has re-emerged as soon as i got on the fway. hoping its the O2 sensor, and hoping i can actually get the one i need instead of a fkn vl one.

replacing the fuel filter made a massive improvement! wasnt overly difficult to do either, so ill def be doing that every 20k or so. the old one was filthy, no idea how old it was... potentially 100 000km. still to change the plugs, cant locally source anything in a 7 heat range ffs!

edit: car also seems to respond to quickly backing off and then getting back on throttle.

hello yes i have searched the forums .33 gtst rb25det .modified to ~220rwkw, 18psi. .all supporting mods inc. toshi remap last night the car developed a strange problem hesitating, stuttering, coughing low down in the range (up to 4000rpm). it felt similar to the car running out of fuel, or an air leak. checked both these things, cant rule out a small boost leak, but i am puzzled because once the turbo comes on boost the car runs fine, and still swallows the tarmac like it always has. even downshifting and booting again, the car works great as long as you keep it on boost. it seems that whatever the problem is, boost fixes it. to my understanding, that rules out ignition problems, since i figure they would get worse under high boost. (though im about to change the plugs). same goes with a boost leak, which would probably get much worse under high boost. my old man seems to think it might be the fuel filter, a blockage of some sort. i guess maybe when it comes on boost it overcomes this blockage? another theory i have is the o2 sensor, though i have little understanding of them, it seems to be a common problem in my various searches through the forums. any ideas? i figure a fuel filter would be about $20, and an o2 sensor <$100 so ill prob change them if i cant figure it out soon. cheers, mitch

oh well dont go berserk, the standard internals are good for maybe 250rwkw to be safe. 16psi is porobably a good bet. im pretty sure with an ebc, the actuator doesnt matter so much. you can set whatever boost you like.

do you have forged internals? if you wind it up to 16-18psi you will see a massive increase in power, and yeh a tune would be required to maximise potential and keep it safe. profec b goes for like $380, plus maybe $100 to install. try slidingperformance.com, or look for SLIDE on here. they were quite cheap and deliver fast. or just jap in syd.

yes it would be advisable to tune for it.

my understanding is that a kkr480 refers to 480hp or 355kw (~300rwkw) and kkr430, 430hp or 318kw (~260rwkw). i could be wrong. id be impressed if a kkr430 made 260rwkw.

that would be at 192kw at the wheels for sure, about 250kw at the flywheel. wind that puppy up to 14-15psi and you should see more like 230kw.

have you thought about other associated expenses? fuel system, intercooler, exhaust, engine management? much besides, here is a massive topic http://www.skylinesaustralia.com/forums/Rb...tml&hl=rb20 all about turbo upgrades on rb20s. you can learn a lot about the power figures, and other mods you might require.

the car is registered as a turbo, and will still be considered illegal to drive. if you want to risk it, well it will probably cost a bit of coin to do the work, not sure if its worth it for 9 months to be honest.