SKiT_R31

5 is a hotter plug, 6 is reccomended. 7 Is a colder plug and is more ideal if running more than stock boost imo. Also, a 1.1 gap is fine providing your coilpacks are in good shape, but 0.8 are what your supposed to run and will give you the least issues (especially if your coilpacks are getting old). It's common for a missfire to clear in the higher revs, its definitely your gap, i would down it to 0.8. If you still have issues you need to source some new coil packs - you can happily gap down to ~ 0.6 but any lower and you start to really hurt your idle and light throttle/off boost.

I think you should go RB30 with a stroker crank. Spool have a 3.4L option (or you could go custom) along with max oversize pistons. It will limit your revs to about 8000rpm but is a better option, and would sound tough. If people can and have hit 170's and 180's with relatively mild builds (mild in comparison to what is possible and how spastic you can go with cams, revs and even compression) 200kw with a 3.4 (or possibly 3.5 combined with max oversize??) should be similarly achievable providing you can get it to flow the air.

This is a pixture of the dyno graph and before/after tune (done on the street). The power curve would be a lot smoother now without the lean spot down low and not being that rich up top.

Hey All, I've decided to put my R33 up for sale because I want to go in a different direction. Not interested in swaps for bikes/4wd's/falcadors - may consider another skyline (GTR/R34) but mainly after cash. Car is serviced every 5000km with Mobil 1, recently changed spark plugs and did a compression test - car has perfect compression on all cylinders. Car is always warmed to temperature before driven, and idled for a minute before shut off RB25DE, stock internals R33 RB25DET ECU and Injectors Tuned Apexi AFC-Neo fuel controller R34 Turbo R34 SMIC Water + M/Ethanol spray injection (boost controlled) Splitfire Coilpacks Ball valve manual boost controller 17x8 & 17x9 jap rims R32 GTR Gearbox (with Redline Lightweight Shockproof oil) GTR ultra lightweight billet flywheel GTR Excedy HD clutch Rear Active-LSD ABS Tien super street coilovers in the front, lowered springs in the back Genuine Xenon headlamps Freshly regassed AC 4Ch JVC AMP, 12" sub, 6.5" Kevlar splits, pioneer CD player (great acoustics/treble, good midrange and bass) Alarm/Immobiliser & Remote central locking Car made 164kW on 9PSI at all 4 wheels on the GT Garage Dyno, fuel mixtures were out a fair bit (lean down low, excessively rich up top). That was with water + meth spray on 9PSI, it is now on stock boost (6.5-7PSI) with the water + Meth disconnected for safety and reliability (for the new owner). Car is mechanically in top shape, 195,000 km on the clock, looks to be genuine (no sign of tamper) and was N/A until 180,000 (so it’s had an easy life for an RB25). The body however has a few spots I'm not happy with, but it was used a daily driver - wouldn't drive a show car to the shops. I bought it of a uni-kid nip stock with an exhaust and a lot of rice/stickers, fixed it up as best I can, did the turbo conversion and tune myself. Car is on 15 Degree Ign timing (standard) with no detonation issues. It is incredibly snappy and responsive, with It's short gearing (4.36:1) and the turbo spooling at 2000rpm. After $10,900

Price drop $10,900 - Disconnected the water+meth, set it to stock boost and tuned the piggy back. Still pretty zippy, and great on fuel. Can refit it if required, but this is probably a safer option for most new owners, no risk of damaging the engine by running out of water/meth, plus cheaper to run. Because the engine is high compression, on stock boost its about the same as an RB25DET (with the same mods) on ~ 8-9PSI. dyno sheet, before and after tune attached (the curve would be a lot smoother now without the lean down low and rich up top) (BUMP)

If E85 is available for you, then that would be a great option. With the increased compression ratio with higher octane and higher oxygen content in the fuel your goal should be a lot easier to achieve. It would be a good option for you to not shave the head at all, and if possible even use lower compression pistons (flat/dished pistons are actually better than dome anyway) Then increase the compression by shaving the block/bringing the piston height up. This way the piston could pass the head gasket so the peak of the compression would be between the head and the block, this will reduce detonation (by minimalising hot spots in cyl wall and head gasket ring) AND means you can safely decomp the engine at a later stage (using a decomp plate) without altering the factory squash or adding hot spots. Also if a good fuel isn’t an option, there are other alternatives, like a smoothed and polished combustion chamber and smoothed and polished pistons. Running a good lean tune straight out of the box with a good fuel (my pick would be an E10 fuel, like boost 98 if E85 isn’t available) to reduce carbon deposits by having rich mixtures or using gypsy detergent fuels (carbon deposits cause hotspots and detonation). You could also ceramic coat your pistons and chamber to further cool things down. At the end of the day, to keep the car drivable, you really want the best management you can find and the highest compression ratio practical on the fuel available. This is how you'll get usable power from your N/A, the only other way is to increase revs but pushing your peak power up (using cams and inlet runners) which will then make it a pig down low (which you may or may not care about, if you don’t care then BAM even more power). And as cool as they are (and the beautiful sound of induction!) I would only recommend ITB's if you keep the factory GTR plenum and use an AFM. Otherwise a short runner length inlet manifold with a single throttle body would be the better option, using MAP & Air Temperature sensors for the best performance and drivability. Tuning EFI cars with ITB's and trumpets with cams/high compression at light throttle and idle is a nightmare and you would never get decent daily drivability from it, the only benefit would be high rpm response - the power difference would be negligible (infact having a sealed plenum would mean you could have a ram air CAI, which would net more power and gain response at higher speeds anyway). In summary; pretty much what I would do is shave the block(or raise the piston) as much as possible, if more compression is required I would change the pistons, shaving the head as last resort. If funds were available (otherwise I wouldn’t touch the head at all) I would do a full port and polish (full radius cut valve seats does sound like a good option) as well as general smooth over on the head, and at least get the piston smoothed and ceramic coated (once again skip pending funds). I would match the cams, inlet runners (make customs) and exhaust runners to suit the same rpm peak power & torque (This is what will make good power), I’d probably aim for a peak of around 7000rpm with the limiter on power drop off (or within harmonic/oiling limits), ECU would be MAP based, being able to tune when the engine is in vacuum will give you great part throttle response and economy especially with a high compression motor.

What condition is the suspension? No leaks etc? Dont suppose you'll be venturing to hobart any time soon?

It's something I’ve observed from oil pressure & temp gauges. When cold it sits perfectly on 3/4, at temp on idle it’s at 1/4 and with revs/load it’s just under halfway. And as the temps climb those pressures remain constant, only lowers once the oil is due for replacement (~ 5000k's). Mineral oils are pathetic, consistently get thinner with heat, and I’ve found nulon 10w/50 '100% synthetic' and another synthetic I’ve used (19=0w/40) is far too thick on startup (nearly max on the gauge) and way too thin with any heat (~1/8th on gauge at idle, 1/4 with load/revs). Oil in an N/A will get hotter than in a det though, as they don’t have the water flowing through the filter point, among other reasons. So yeah a 40w might be a good option, I’m just quite pedantic (having done bearings before) and like my pressures perfect (and watch them closely). BMW M series engines for example run 10w60 (Castrol RS), for the same reasons I run the thicker oil. I have noticed no performance drop, and it’s worth it for peace of mind. Anyway, not an oil thread If you check ngk's website they do say a nickel alloy for there standard plugs http://ngk.com.au/sparkplug.php.

Nickels just get called coppers, all spark plugs have a copper core but copper its self cannot handle the combustion temperature and pressure's - if it did, then it would be BY FAR the most superior conducting spark plug type. http://environmentalchemistry.com/yogi/per...electrical.html (read bottom up) Oil is a personal preference. If your car is ever driven hard, you are stupid to have anything but a full synthetic oil. I am very particular with oils and monitor my oil gauge pressures and temperatures carefully. While yes, on an N/A 50w might be a bit excessive (with 40w being better) I would never run any thinner than a 50w, even with a decent full synthetic 50w oil (Mobil1) after a thrash my oil gets dangerously thin. Oils any thinner or any lower quality (nulon 100% synthetic for example, even in a 50w, once hot is pathetic). My engine is turbo though, but is in a cooler climate. The oil still got very thin on long run summer days (when N/A). I would never go a 10w40, would rather Mobil1 0w/40 (but at a zillion dollars), why would you want a thicker cold start... It’s already off the charts in pressure at my 5w.

Spot on Neg, Standard plug is nickel - the ix in the code above stands for iridium. A nickel plug would be BKR6E-11 or BKR6ES-11 (S is for standrard) the BK is thread type and is the same as BCPR6ES-11. There is no performance gain, usually better off with normal nickels unless you are after less frequent plug changes (which isn’t recommended for performance anyway). The plugs on RB's are easy to get to, so there is no reason you wouldn’t want frequent changes, but each to their own. Your better off spending your money on higher quality oil, like fully synthetic 5w-50 (if you dont already) or saving it for actual performance mods.

What are the specs of the cam, and what is your engine?

I would like to do that, but combine it with candle wax mmmmmm smells good

Hey Mate, replied to your PM, cheers

What are you going to do about your throttle control? Assuming your not using the GTR's ITB's?

Because you only have 2000rpm of stall up in your torque convertor, this is a good thing because it makes your car more responsive in gear above those revs. If you want more you would need to buy a higher rpm stall convertor, you can get them as high as you want - 3500rpm etc, but they make the car a lazy pig to drive and bad on fuel. You are stuck with the 2000rpm to launch from, unless you want to do the neutral drop into drive trick (I used to do it a lot when I was ‘a wee lad’ trying to kill my gearbox before manual conversion). This is not a good option for your box as it will misalign the selectors, and could f**k the box all together. That said, my box loved it, every now and then the selectors would stuff up, I'd just have to put it in park and hold it on the throttle (it would stall up like it was in gear) until it would clunk then free rev, meaning it was then fixed. If you want a car you can 'launch' and still drive everyday, you really want it to be a manual. An SR20 S13 with a 5 speed behind it and a couple mild modifications would actually be quite zippy. Manual conversion will cost <$1k and is relatively easy to do if you have a weekend spare and a handy mate.

Compression is the winner for N/A imo; it’s like upping the boost on a boosted car. I wouldn't have minded having the P platers laws (Tas doesn't have it) I think it'd be a bit of fun to get some sneaky power. If I was in that position I'd go an RB25DE coupe, opt for a 2.5" mandrel exhaust, high flow cat, 2 x quality straight through centre offset fibre packed mufflers (keeping the volume down well below legal, nearly stock - no cannon, just a simple 2.5" outlet with discrete or no tip). Then I would pull the head off, get it shaved and fit a slimmer head gasket aiming to bump the compression up around 11.0-11.5:1, lightweight flywheel and HD GTST clutch and fit 255/8.5 tomeii cams & adj gears. Leave the stock air box and piping, stock heat shields and everything else in the bay looking completely standard. The last thing I would change would be the ECU, I would fit a Z32 (or stock if R32 RB25DE) nistune ecu, and spend good time tuning it, the most aggressive fuel mixture & ignition timing setting at each RPM point (without knock), also tuning leaner and equally as aggressive at part throttle. I would be really interested to see what power you'd end up with, I would definitely expect it to match that of a factory turbo, the car would be amazing fun (esp for hills and track) response would be great, police couldn't find anything (as long as your exhaust looks factory, none of the other changes are visible, those cams are mild and wont effect your idle). On top of this, it would be an incredibly responsive daily and the economy from it would be great, even N/A's are tuned excessively rich from the factory, tuning it - even with cams should return a healthy 10-11L/100 (I get this from my NA+T with just a mild SAFC tune). The real winners would be those with the RB25 R32's, nice and light, with the above mods should easily net more than a stock RB20DET and with that weight advantage it would be quite zippy. I'd leave the car 4 stud, but buy turbo callipers and blank discs (and get them drilled), Auto GTST factory LSD, aftermarket suspension (as you would with a turbo anyway) some F5 R4 spring rate adj damper coilovers set at standardish height on the street (you could get away with a bit lower), aftermarket sways and finally some tame rims. It would be an amazing package imo. Then when P plate time is over, either sell it and get a turbo OR if your attached to the chassis, just build up a turbo block with some lower compression forgies (to compensate shave, as you wouldn’t be able to NA+T this) and drop it under. The car would be an amazing base to start with as you already have all the supporting mods, and then you can just skip the stock turbo/intercooler route and go straight for FMIC and high flow/aftermarket. The only things left holding you back would probably be holding you back in your factory turbo car anyway.

Problem solved, looks like it was just my water+meth setup confusing things. Had to wind a little boost out of it though but these are the results.

Exactly the same power as mine, have you got the graph?

pics?

I really hope not, can’t really fork out for full management. Everything is fine I just need to correct these fuel mixtures. There must be a reason for this issue... Its not like I can’t adjust it any further, its simply just not making any difference to mixtures (even if I +50% it).

My R33 GTS4, It's turbo now but used to be N/A

Setting it to 4 & 4 didn’t make a difference. I randomly set one to 1 and one to 4 to test it and the car spluttered like expected, so it is working... Here's a picture of my wideband log, RPM vs AFR, you can see the lean spot which i am trying to iron out....

Yeah that’s set right, low throttle comes in at 0% and high throttle is at 40%. I've tried moving the threshold higher to run of low throttle maps, but it doesn’t make a difference. Regardless it runs increasingly rich until around 45% throttle, then it leans right out.

I think I've found the issue (though not sure if it would cause my symptoms...?); I installed this based off this guide: http://www.skylinesaustralia.com/forums/Sa...3-G-t85232.html Where is says set AFM IN and AFM OUT both to 1 But reading here: (Page 24) http://www.scribd.com/doc/19576441/Apexi-I...-Wiring-Diagram It says set both to 4. I'm not sure if the AFC is different, or if it is wrong, or even if it will make any difference - I'll have to wait until I get home tonight. Please still post if you have any other insights...

This did cross my mind, but it clears up top, to the point where it gets excessively rich...