SKiT_R31

Ive got an RB25DE gearbox and it tends to whine through the first few gears, will a thicker oil help, what do people recommend? cheers

Hey people, Ive got an RB30DE with an adjustable Fuel Pressure Regulator. My problem is when i get into the high revs (after about 5000rpm) i start running really rich, blowing black smoke etc. I'm trying to troubleshoot the cause, at the moment my fuel pressure is on 28PSI at Idle, which is about 2PSI less than a stock RB30e, but I'm assuming the rb25de/t injectors would probably require a different pressure? Head is an S1 R33 RB25 with VVT also for arguments sake i'd like the fuel pressure for the RB25DET's if they are different to the RB25DE's cheers

I aggree with the above but it doesnt suit your " know everything thats happened to it.. I know how well it runs.. I know that everything is in perfect working order and of a high quality." argument. Essentially all you need is to remove all the turbo gear, and run some stock headers (or some extractors) But i would probably take it a bit further than that and revert to N/A Injectors and ECU, also up the compression to something similar to stock whether it be by some shaving/decking and/or NA different pistons - better for fuel economy. Cam etc is the same... But if i was you.. i would be selling it and buying a second hand RB25, something a little more drivable as an N/A and just as good economy

the relays etc are all wired up, they were already modified for an r31, im just trying to figure out what everything is for to aid my troubleshooting only the plugs in the first 2 pictures arent connected to anything so its them im most concerned about....

mmm both those plugs are in, the fuel pump primes and gives my fpr guage 37PSI what timing should an RB25 be at? its on 15 degs advanced atm added pictures to first post what are those plugs for

its getting spark and has perfect fuel pressure, i think for some reason the injectors wont fire... any idea's? the afm and everything is set up right even if it wasnt it would atleast fire and die in the arse or something - doesnt work without it plugged in also. What part of the wiring would stop the injectors from firing?

Hey all, Im having some trouble wiring up an RB25DE (S1 R33) wiring loom into an R31. Its all wired up but it wont fire, the car turns over but just wont fire. Ive checked the timing so its getting spark, theres definitely fuel feeding to the injectors it just wont fire at all, no splutters no nothing, it just lifelessly winds over. one thing i did notice is when i put the key on ignition, my safc fires up all happy and the ecu has a red light - but when i turn the key and it starts turning over, the light in the ecu goes out and it clicks... is this normal? the safc (2) stays on. Any idea's of what to check? im stumped... cheers EDIT: The first 3 plugs have no home, what are they for??? the blue relays, im just curious what they are for while im at it and the white plug up behind the ecu cheers, im just trying to get an idea of what everything is to help my troubleshooting ta

why...? personally i think keep it its normal thickness, you can run a fair bit of boost with the stock compression - which will be more efficient and make more power anyway, and if you want to run any more boost, you probably shouldnt have a dodgy "thicker" gasket, if you want to lower the compression - use pistons!!! RB30e ones would give an alright compression??

thats why if your running high compression, get a good tune so what exactly has happened? is it seized, have you shot a rod? f**ked a piston...? i aggree with above post

Does the car run any different?...

i wasnt having a go mate, but as said before yeah they have the same peak power output, BUT the rb30 has a good 100nm more torque, stock for stock it would easily just walk away, in take off and peak revs in its curve, then on shift etc. i cant imagine how f**ked it would have to be, and he must be retarded to not know there is something up, but anyway. that said you put a moron in a 150kw car and a good driver in a 100kw car and who's goign to win? that doesnt make the car faster, it makes a driver a retard anyway my intention isnt to get into an argument over this, but what you were saying is that a 20de is faster, this is not the case, a good 30e with those mods will walk away from a RB25de with the same gearing, you cant beat torque. alo people, dont forget your not talking about a newer engine, its not like the 20de and the 25de's etc which have been setup perfect from factory, to the point where most mods do SFA, with the rb30 simple things like exhaust and intake give it HEAPS as it is so restrictive from factory. example, a stock 30e gets around ~ 85rwkw? give it a 3" intake, bigger throttlebody, pod filter, extractors and high flowing exhaust and you can pull about 105-110rwkw on average, that is a very decent increase. also remember its not about peak kw, like yeah a 20de might pull 110rwkw too, but where? at 7500rpm? yay... below that its got nothing and no toque, remember kids, power outputs sell cars, torque and good power curves win races. 30e's dont rev and tend not to make a very high peak power, but they keep high power and torque through the revs which is where the difference is. anyway

Dream on mate... His car must be f**ked, and he must be a shit driver, also your car has shorter gearing and is probably lighter... anyways... Ok OP, What model is your car? GX/GXE? Is it a Manual? Ok you want > either an XF Throttlebody (68mm) or a KA24e (60mm) The latter is a direct bolt on but is obviously smaller, getting it enlarged to about ~ 64mm would be good, no use going any more as the AFM is only 63.5mm. There is a Guide on fitting the XF throttlebody at R31skylineclub.com, you also need to bore out your plenum, to match the throttlebody's. Add a 3" intake, heatwrap it, give it a good pod and a good heatproof enclosure, with some cold air feeds - unlike later model skylines this does actually make a big difference if its done properly. Another thing that gives just a bee's dick more power is (carefully) grinding off the heatsink inside the afm and taking off the mesh, just for less restriction and more flow. Run 98Ron fuel and advance the timing to 20degrees (if you dont do the next step) or around that, lower it if you hear pinging. Get a Darkhalf tuned ECU [cheap] they are the best, dont get ebay shit OR get a custom dyno tune (if you can afford it) Get a good set of extractors, if you want performance, go a good brand, like Geni/pacemakers etc, get a 2.1/4" or 2.5" MANDREL bent exhaust and a "highflow" CAT of somesort. Change the Diff gear ratio, from the stock 3.7 to maybe 3.9 (best compromise) or a pinny geared 4.1 if you dont mind high revving on the highway, and get an LSD for better takeoffs Lightened flywheel, singlepeice tailshaft, lighter rims, good grip tires, weight reduction... Suspension/handling mods to make the car funner ,and get better brakes. if you want to go internals, raise the compression to a nice ~ 10-10.5:1, maybe a P&P job if you can justify it, Maybe a Mild Cam - but if you intend to keep the car and want to go turbo later on, i would hold off... and of course theres always the old RB25 head on 30 block trick goodluck

I just got over a pretty painfull miss, which was a dog to find as it felt electrical, but anyway... to start with, find the cylender you think is missing, by removing your ignition leads, if the idle doesnt change thats probably your cylender... While your at it, see if one plug in particular is charfed up... and that the gaps are correct with no cracks etc... My miss turned out to be a bung injector (didnt have the pin thing in it!?) so it seemed to just poor petrol in, though it woudl and wouldnt intemittently fire, in mid-revs (2500-4000) the car ran smooth with all its power, then about ~ 4500rpm it just dropped a cylender completely and started pooring out black smoke... at the same time, one of my leads had a slight hole in it and was shorting out on the head to check/test/replace Plugs, Leads, Coil Packs/distributer+coil, Injectors the ticking is prob just your lifters, mine does/did it too from the area that my cylender wasnt firing, i dont know what made it louder though, i pulled the lifters and rails out because of it. i replaced Coil, Leads, 2 injectors (another looked dodgy), clean 02 sensor, replaced FPR, Distributer (cas), AFM, ECU, dizzy cap/rotor, probably other things, it was a hard miss to find as i had recently replaced the injector so i blindly denied thats what it was, but it was in the back of my head the whole time. this is on an RB30e

Yeah i was reffering to the RB30e, makes more torque and lower in the rev range than the 25de... Speaking of exausts though, drove my car without one this morning (just engine->extractors>nothing....) as extractors needed a flange welded on to be bolted to cat, and i wanted to fit them myself... and i did notice a few things, 1. it was f**king loud, and droned like buggery lower that ~ 2500rpm under accelleration. 2. it sounded sick as and lumpy on idle... anyway, main thing is i noticed i lost heaps of responce, the car just plodded along, hated the low revs, and it actually made the engine run a bit rough, but as soon as i hit the torque curve at around ~ 3000rpm everything smoothed out and it started to pull a fair bit harder than usual (sounding insane...) And another thing i noticed, that if i could put up with the vibration and deafening drone, full throttle @ low revs seemed about normal power (though it is hard to judge) but under mild acceleration the car was hopeless, had no low end go, you had to really give it some pedal in the lower revs... anyway, i'd assume that would be kind of similar to a bigger exhaust with the lack of vacuum etc, cheers aug for the info makes sense... if running a bigger exhaust causes something similar to no exhaust, i would assume you would use a fair bit more petrol also, as you need a fair bit more acceleration to move normally...

ok, to start with, 25de's are lacking in torque as it is if the volume doesnt effect you, then leave it, its fine. and the whole backpressure thing is bullshit, its not the fact that having a bit pipe doesnt have enoguh backpressure, its shit like the pipe being big makes the exaust cool down CREATING backpressure, and also some turbulence (the enemy of flow) since air shrinks as it cooles, then it goes bouncy bounce etc going to 2.5" will barely effect anything, except sound, yeah you might gaiun SFA low end, but nothing to write home about... you could save it for when you go turbo, or sell it to somebody who is turbo, or keep it and forget about it. for example, if you got some extractors, and say heatwrapped them and the entire piping (if you wanted to...) then and problem with that should be solved... i wouldnt worry about it, keep it if you like the sound, then if you want to, heat wrap the lot (paint first, rust bad) then paint over it again to protect it rotting etc, should give it a crisper note and any torque that you would have lost should almost be back... if you plan on pumping money into your na for some more power, you'd prob be better off to keep 3"... also make sure its 3" all the way, if its 3" till the rear muffler then its say 2.5", that will cause heaps more of a problem....

With the 4x50wrms amp can you bridge 2x50w and keep 2x50w seperate? ta

as written on r31 skyline club, VERY interested! Whats been done to the bottom end? also, are you using the factory RB30e fuel pump? That is pretty much the EXZACT engine ive been planning on building, its perfect...

nuh mate its 5 degrees, starting on zero (being red, the rest are white), so if its sitting on the forth notch its on 15 degs.

yeah stock timing is 15degs i knew he was talking about a HR31 you could have a gunked up cat also, if it doesnt like revving. I would go a 2.5" mandrel (or 2.25" if you have to...) with a highflow cat, a muffler and a resinator, with a nice set of extractors, that should make it pull a bit harder for a start. as for drone, its all in the mufflers...

Mate you shouldnt lose power from running lean, infact the opposite should occur. Stock pintara (CA20e) exausts are 1. 3/4" in diameter and stock R31 Skyline exhausts (RB30e) are 2" in diameter. 2.1/4" should be ok for an rb30, though you could lose a touch of power in the high revs, which doesnt matter too much as rb30's arent really made to rev. Once you start modding it though i would opt for a 2.5". Also if you'r running the stock exaust off a RB20DE you'll probably find the muffelrs in it wouldnt flow too well etc, your best getting a 2.5" system, with a brand spanking new muffler (go offset) and resinator. As for you problems, if its popping at idle, i'd check your TPS, could also be your air regulator etc, check your 02 sensor (maybe just give it a clean) and check your water temp sensor (clean it with a scourer until its shiny copper). When you rev it, like stomp it and keep it revving high, does it blow black smoke? And when you say its losing power, can you feel or hear it missing? Check for leaky fuel injectors, clean (with contact cleaner, and by scraping, also by bending pins so they sit tight) all your connectors, so that for each injector, the afm especially, 02 sensor, water temp sensor, tps, air regulator, CAS, etc. Check yourdizzy and rotor button, scrape off all the white powder build up, and blow it out of the cap, check the resistance on all the leads, clean and gap the plugs... after doing all this, your car should feel heaps smoother and should feel like its got a fair bit mroe power. Also check the timing, and maybe advance it to ~ 18-20degrees (depending on what fuel you want to feed it)

aggree'd, i went from a manual skyline to an auto skyline and its horrible... they obviusly have less power, but mine pulls just as hard if not harder than my old one (and its 100kg heavier, just a tidier engine), your getting the same acceleration, but its jst f**king boring, you lose the thrill, etc esp from the taller gearing... i find myself manual shifting constantly, and cracking the shits when the stupid f**king auto shifts into o/d at like 60kmph up a hill, so then i stomp it, shifts back to first & 5500rpm etc. it makes you want to abuse your car, i find it frustrating. needless to say, my auto tranny is shagged, she's getting a manual conversion, but if im going to go to the effort, she's going be be done properly (HD Clutch, Lightened f/w, single piece tailshaft, etc) You will regret it, dont start out on auto's, start out on manuals and then if you dont like them switch back. Its not hard to do your manual test (dont know about up there though) its just like a 15 min test where you drive around casually, find a hill, do a hill start and find a car to do a reverse park on, too easy. If you've got heaps of driving experience and are confident on the road, once you learn a manual you should ace it.

thats it, the rev's you lose wont matter, as you may lose the ability to rev that extra 1000rpm or whatever, but the power you would make that 1000rpm later, you will be making more of it with more than 1000rpm lower... besides... get it all balenced and set up properly, sacrifice the $$$ and get the RB30 block to rev just as high and make HEAPS more power .

true that n/a's sounds raspy with normal mufflers, but throw in a bit resonator and they deepen right up. Extractors > offset mufler > resonator = Deep throbbing throaghty exaust, sounds tough Yeah i was thinking about an RB26 head, but i think the extra money that would cost, would be best spent elsewhere/maybe doing up the RB25 a bit more, whats the flow differences? Its hard building a motor, as you've gotta find a happy medium between power, drivability, economy, power and cost.... i was thinking about a Q45 90mm afm & Throttlebody... have you got any info/links on the "hypereuric" pistions...?

it is easy possible to even get more than that... for instance, i know of a few bloody buick V67's (hardly a performance engine) that are pushin around 180RWKW... look at engines like the L28 etc... or for example what im looking at building up (after new job and loan clears). I dont know hows its going to turn out, but im aiming for ~ 150-160RWKW... wont go into too much of the details of it, but im aiming for ~ 11.5:1/12:1 CR (depending on what 98ron BP ultimate can handle) RB25 VVT head on RB30 Block, maximum head porting and polish, matched intake plenum/runners, custom exaust/extractors, Stock cam, and aftermarket ECU with custom dyno tune. Usual lightweight gear (not sure how far ill go) Flywheel, lightweight single piece tailshaft, dont know about pistons - not keen on the rattle, etc. i mean there will be a bit more to it than that, but thats the gist of things... if it doesnt make 150RWKW ill be surprised and its not really that serious of a build, heaps of daily drivability and response, nice economy when driven mild etc... Though im not soo much aiming for peak power, more for heaps of power/torque through the rev range, dont want to have to rev it too hard to make power (after reliability). - the point is, if i was to expand on that, i could easily pull a few more kw's out of it... imo anything under 200RWKW isnt unrealistic when it comes to an N/A 6 cyl, it can be done and has been done many times, you just need the time, patiency, low blood pressure and $$$. Once you start getting over 200RWKW you are dreaming a bit, or you are one rich muf*kr

That is true, turbo's will respond to exhausts more, with increases in power and with less lag etc. But an exhaust is one of the best things you can do for a lot of N/A cars (maybe not the supra then, though I wouldn’t know). I know on my skyline, from the factory 2" exhaust with 1 muffler (other one previously cut off) to a 2.5" PRESS BENT (though its a f**king good job) with a muffler and a resonator, my car (auto) was completely different to drive, rev's quicker, gained a little low-midrange, and heaps of top end (where before it died in the arse after ~ 5000rpm) it loves it to the limiter. Maybe a compromise, with the stock exhaust with mufflers changed?? You could always paint your exhaust black (or charcoal mixed with brown ha-ha) as long as you have a standard muffler on it (i.e. no f**king cannon) cops wont notice or care. Its quiet, it looks normal, be it a little oversize but they wont know that, and if they do, its the same difference between putting a stock turbo exhaust onto it, its still bigger... really though, they cant stop you from replacing your exhaust, exhausts don’t last forever, they need to be done, it was already on the care and since its sound you assumed it was stock!? I really can’t see 99.999% of cops caring about a stock looking exhaust, esp. one without a tip (not that they can do anything about that) Its really up to the driver, rules are meant to be broken, it's just up to you to decide if its worth the risk, and at the same time, if your cars quiet and you drive sensibly (esp. in a stockish looking car) I cant see you getting pulled over or harassed at all... though I am in Tassie and its different than some of your police states, we're still fairly strict, I have a LOUD throaty exhaust (but you only hear it when the foot goes down) way darker than legal tint, lowered, with stock wheels, polished to a mirror, I keep my car clean, and im constantly on the lookout for anything and generally drive fairly softly (but we all have our days/moments). And even when they see my car cruise past with nothing but a throb (I always spot them first and easy off) I never get any attention. But at the same time, if I got caught being stupid, im sure I would be pretty f**ked...