SKiT_R31

pfffttt VH41/45DE

Probably find the best info here; http://www.skylinesaustralia.com/forums/Sp...gs-t104405.html I've never worked with Nissan V6's, but I’d assume it would be the same story as the straight 6's. Pretty much run what the turbo boys run but a heat range higher. When you change your spark plugs, you can tell if you’re in the right heat range by the discolouration on the thread, if its past 3 thread lines, you probably want a colder plug (test after fitting your 5's) I used to have Indexed NGK BKR5EY-11's in my N/A RB25, had perfect burn and the plug wasn’t getting too hot. I generally think your best with standard nickels (what people call coppers, but they are nickel coated, and all plugs have a copper core) and would get the best performance & cost efficiency replacing them more often, than spending 6 x as much on an iridium and replacing it less often. This obviously changes if you have tom pay someone to change them for you, in which case it might be more efficient getting longer lasting plugs, as the labour would cost the difference.

The standard Nickel items are fine, NGK part number BCPR5ES-11 (or BKR5ES-11). The 5 is the heat range, 5 is most efficient on a stock engine, 6 is better for one that receives a regular thrashing and has mild mods (intake/exhaust). Power gain from different spark plugs is negligible. Platinum’s are less conductive than nickel (i.e. worse) iridium’s are slightly more conductive, but your unlikely to notice the gain, perhaps equally better off with V spark nickels or something, the most gain with spark plugs can be had by correctly indexing them, so they are all facing the intake ports (middle), you can do this by purchasing thin copper washers, to give you that half turn extra adjustment. some people have even managed it by buying a few packs of plugs and mixing and matching between holes (but copper would be best as it will squash as you tighten, so you can keep the correct tension). I run indexed BCPR7ES (gapped at 0.75mm with splitfires) on my RB25DE+T with water + meth spray.

eBay a BW78 Full Spool, better than minispool as your not spinning the heavy pos hemisphere. I have a welded diff in my R31, filled it using my mig, its done many skids and is faultless

Uh ok no worries. I just wanted a low boost (Daily) read out, and a high(er) boost (with water + methanol injection) read out, 10 sec job. Ta,

It says 3 dyno runs, are these consecutive? Can you make adjustments inbetween? (aka a low and high boost run)

sounds good, did you get the chance? Ta.

Nah, I've just done a lot of research whilst procrastinating with my engine build. As well as spoken to a lot of old school engine builders/mechanical engineers, the sort that squeeze 150whp out of 1.2L Datsuns, 1000p out of N/A big block V8's, etc. There is a lot of info on all sorts of things that you rarely hear about in the internet world (usually because its not relevant/necessary for FI). But the same can translate visa versa.

Hey all, does anyone have one of these spare? Possibly from a wreck? Cheers, -Dan

OK cool, that’s my bad. Right, questions on comparisons then Yes stock for stock, the SR20, especially SR20VE is miles ahead. But that’s because its been more worked from the factory, which means you wouldn’t be able to squeeze as much power out of it, compared to a rb20det, which lets face it, was pretty crap out of the factory. OK, so first I just want to ignore the obvious weight and size/overhang differences, just worry about power. The RB20DET has a shorter stroke and is a 6cyl, which is better for quicker engine acceleration and higher rpms. The SR20DET with its longer stroke will be more responsive at lower revs. The RB20DET has a 30mm inlet valve and 27 mm exhaust valve. Now yes, these are small when compared to the RB25/26's, but when you compare it to the SR20DET, they are actually bigger... If you calculate the total area of the SR20s 8x 34mm valves VS the RB20s 12 x 30mm valves, SR has 7263mm2, RB has 8482mm2, that’s 15% larger in the RB's favour. Its the same with the exhaust, 8x30mm on the SR vs 12x27mm on the RB = 5655mm2 & 7389mm2, That’s 24% larger once again in the RB20's favour. Now I don’t know how much you can get out of the SR's, but I would have thought, with access to RB25 valves etc, maybe again in RB20's favour? The SR20VE has an 11:1 compression ratio? Now I don’t know about their squash efficiency in comparison (which may ne negated if both had equal headwork anyway, to open the combustion chamber etc) but the RB20DE has 10:1 compression, so there's one reason to it being lower in power, so both engines should hit a similar compression limit on your chosen fuel, but the RB20 will have the bonus power (when compared to stock outputs) by having that extra 1 atmosphere on top. The SR20VE has 10.7mm lift, 264 duration. Stock this gives it a lot more power, obviously - compared tot he RB20's weak 7.8mm lift with 240duration (i know there is more to it than this, but I’m trying not to get too messy with complications). So once again, I see this as a limit on the SR, but in comparison a bonus for the RB, since there is only so far you can go, the RB can handle a massive upgrade over stock, where the SR can only make small improvements with after market (though the RB20 head would have to have a some headwork to support such extreme cams). I wont bring management into it, as both will become full after market (one would assume) so same kettle of fish there. Of course The SR20 has VCT, but with serious cams, could/would you keep it? They both have a lot of aftermarket support for water/oil pumps, etc (thanks to turbo boys) with the SR having more options with using pistons for compression (rather than block & head skimming) Also, there are a lot more people working N/A SR's, compared to RB's, so there is a lot more information out there. So really, as I see it, you should be able to get similar power from each motor, due to benefits on both sides. Really the only gain I see to using SR, is the less overhang & weight, but that comes at the cost of locating the engine, making it fit and wiring it in to the chassis loom/instrument cluster gauges etc. (so more time and money).

You could possibly get one s/h off R31skylineclub forums, otherwise you can get your current cam reground to GTS2 specs at somwhere liek surecams/crowcams etc. You could also get it ground to different specs, maybe a bit better but i'm not sure if nistune can tune them off the shelf (i.e. not custom tuning on the dyno) if you sent matt @ nistune an email, he could probably tell you the specs of the cams he has already got maps to suit.

wtf, like you are going to get EPA'd. It could make a f**kload more than a factory turbo, the reason I said otherwise was because of the things you would have to do to keep it looking stock (exhaust, manifolds, throttle, intake pipe, mild cams/compression), sounding stock and street drivable would dampen the power ALOT. I have 4 cars, a built RB30DET, an RB30DE, an RB25DE+T, and an RB30E+T. All are completely different, and have their places. Not everything is about the most power possible, the 30e+t does a good skid, but its lazy and wont rev. The RB25D+T is incredibly responsive, great on fuel, and is just a great daily car. The RB30DE is just heaps of fun - especially in the twisties (so is the 25de+t though), makes a mean sound, gets up and goes, pulls beautifully linear (With a great surge up top) and just screams. While the RB30DET is good for making people shit their pants in a straight line or going sideways. If you’re a P plater, have heaps of money to blow for shits and giggles, and want to make more power without anyone finding out, that’s the sort of thing you can do. The car will drive well, pull hard and will make decent power. Once you’re off your P's you can let it breath again, put on some visible bolt ons and make a fair lump more power. People have spent a lot of time and/or money on a lot worse cars & engines to make less power. I can’t see why it couldn’t make a fair amount of power, somewhere between 160-200kW at the wheels depending on how much you push it with cams and compression (talking about the 3.4L). That’s a car happily in the 13's, with a suitable amount of power for it to be quick on the street and for some fun around the track/through the hills/twisties. Too much power is not always a good thing, it takes the fun out of things, its good on occasion to test yourself out, but I’d much rather drive my lower powered 25DE+T & RB30DE (both have equal power - around 160WkW) than the RB30DET on anything but a straight line. Everyone keeps forgetting we are in the N/A section. Also, just like everyone making power with a turbo doesn’t have forgies and 10g’s worth of supporting mods, you don’t have to N/A either. Yes you can have a nice wish list, but at the end of the day if you don’t f**k it up, you can still make good numbers. Just like you can strap a GT30 on a stock RB25DET, run 1 bar, add supporting mods such as injectors & management. You can get an N/A motor, and spend just as much by bumping up the compression, running some meaty cams. With a turbo motor, you can get a stock RB30e bottom end, throw an rb25 head on it, a bigger turbo and you’ve got an rb30det. Just like you can get an RB30 block, give it a buzz, drop your rb25de slugs in it, new ring and bearings, once again cams, and your making some bloody decent numbers. Yes you can spend thousands balancing it, putting lightweight pistons and rods, headwork etc – just like you can with a turbo motor. But at the end of the day, with just the simple 3L, cams, compression and management, with breathing mods, somewhere around 150kW at the wheels is where you’re going to start. Obviously if you’re trying to make the most power humanly possible from a certain base engine, FI is the way to go, but that’s not always what everybody wants.

This thread almost seems like a troll... Anyway, If I was a P plater, and had some drug money to blow on my natro skyline and didn’t want popo attention + wanted a perfectly tame street car; I'd go an RB30 Bottom end, SPOOL 3.4L stroker kit. Deck the block so the pistons rose flush to the thickness of the compressed stock head gasket, aiming for a compression of around 10.5:1 (assuming its your daily, this is to keep it 10.5-11:1 Compression ratio Porting/polishing/oversize valves/enlarged ports Mild cams, something between 255-260 range, with adjustable exhaust cam gear, and VCT controller (if the ecu cant do it) Stock Headers (maybe some internal work), stock Heat shields/covers/brackets, Stock GTS-T Exhaust, Stock Air box with high flow filter Stock intake manifold, but modified somehow to get more air in it, maybe machine out the throttle body and fit a slimmer knife edged butterfly. Tuned with aftermarket management of your choice (sneakier the better, retaining stock loom/sensors etc would be smarter) And would probably have power somewhere in the vicinity of a stock GTST, with a car that just as streetable, with no one knowing any different. Keeping the rest of the looking as standard/low key as possible (stockish ride height with stiffer springs/shocks, stock/non flashy rims, lsd, quiet car, stock interior bits etc) and the car would actually be something worth having.

Yes, but he has said it multiple times that he isnt going to change his mind, so none of this is contructive.

wtf people his chosen his engine.

Extractors will change the note, make it a bit more raw and rough/throaghty, and generally give you a bit more mid range (if they are properly designed to scavenge) as well as give you more flow up top when matched by a full 2.5" exhaust with straight through mufflers/'highflow' 2.5" cat/decat. The more generic extractors probably wont give that much of an improvement to mid range, and yeah like 2-3kW of top end performance loss (on an otherwise unrestrictave exhaust) but will still be better than stock manifold. A GTS2 cam is a good idea, makes the RB30 a lot happier in higher revs (but can be a little doey down low without remap), I'd get an XF throttlebody and fit it to your intake manifold (remember to port match the plenum) then a Z32 AFM, 3" mandrel intake pipe (with a think a 60 degree bend is ideal) with enclosed pod filter, and finish it off with a Nistune chip (like $90 to get fitted to your ECU on exchange) To suit the Cam, AFM and 98RON fuel, and the old RB30 will be quite lively, usually >110rwkW at like 5500rpm on a healthy motor. Which is good power for a P plater and such a torquey engine, and is about 20-25rwkW more than they get bog stock. I miss the good old days, with basic easy mods... (http://wiki.r31skylineclub.com/index.php?title=XF_Throttle_body)

Of course full management is the best way to go, but SAFC's are quick and easy. Of course your not altering injector timing, ugh. Also once you go leaner than 14.7:1 temps start cooling down again, they don’t just keep getting hotter and hotter. Heat is a good thing; you want it, more expansion, better burn, more power etc. Stock tunes are rich for emissions and reliability, so you can run hotter spark plugs for low load/rpm emissions testing (they then richen the mixture to stop plugs from melting etc) also as mentioned before, they don’t know how your going to drive the car, prolonged heavy load and high rpm will stress components, not only internally, it could damage your CAT and O2 sensors etc, these are the reasons manufacturers tune things so rich. Also, they don’t know what other variables could change. Older Japanese cars are tuned stupidly rich for these plus other reasons, different manufacturers/newer/older cars are not all like this. My base timing was 20degree's on a factory turbo ecu (because they have more ignition timing up top + I ran turbo injectors) I also had an AFC neo with a Q45 Y piecing twin throttle body’s. I now run MAP through a Microtech LTX12s, altering fuel mixes/ignition timing via vacuum and revs with air temp adjustment (using 550cc injectors and enjoying sequential injection to alter the injector timing for more efficiency. The idea of getting power out of an engine is to have the peak pressure of the explosion as close to TDC as possible, with the burn lasting the full stroke providing it is complete by the time the combustion stroke has finished and the exhaust stroke starts. Regardless of anything else that’s your goal, you adjust your ignition timing and fuel mixtures to make this the most efficient as possible, if your EGT's spike, you have either prolonged the burn too much, OR your combustion is too intense. Likewise with detonation, the engine is combusting too quickly, you need to slow it down, either by igniting further away from the peak pressure (when the piston is further down the combustion stroke), by dulling with too much fuel or some other method (less compression/boost).

If your tuning on a dyno, you only need a $300-$500 gauge and sensor

No its not, lean is good. Lean is better for your engine, better for your power and better for your economy/efficiency. What is bad for your engine is excessive heat and/or detonation/too quick combustion. I hate tuners that tune from A/F mixes without monitoring EGT's. Your running an N/A RB, your not going to melt valves or pistons running too lean, esp on a stock motor, all its going to do is cause flat spots in acceleration/lose power if too lean. My RB30DE used to run at flat 14.0:1 until 4500rpm where it richened up, I had amazing economy, no issues with detonation, and i had cool EGT's on NGK 5 range spark plugs. On an N/A Engine you should definitely be able tune it no richer than 12.5:1 at WOT in peak rpm without any issues, with it a lot leaner at light throttle/lower rpms. Everyone has issues with economy on their N/A's, this should definitely help. I would never tune a car richer than 12:1 (including my DE+T), if my EGT's are too high, over fuelling is just a bandaid solution - and a bad one at that (too rich can actually cause the same issues as too lean). The issue should be fixed elsewhere. (high octane fuel,water+alc/meth injection, colder spark plugs, less compression, less boost, change injector size, fix spray pattern, injector timing, ignition timing, cyl wall temp inc oil temp and water temp, under piston oil squirters, the list goes on) In summary, if everything is functioning correctly and setup properly - i.e. you want clean flow tested (and matched) injectors, identical spark plugs in an appropriate heat range (7's are my preference for daily) preferably all indexed, equal cylinder pressures, you can lean your car out into the ideal range (12.5 - 13.2). You need to monitor EGT's and AFR's, then just push it as close to the 13.2 as possible for the best power under acceleration, richening at higher rpm with full throttle as required (once again watching your EGT's) with some leeway of course, then tweak your ignition timing to suit. SAFC's are ideal for this reason, as you have part throttle and full throttle rev based mapping, you can squeeze a fair bit more efficiency out of your engine, just make sure its done with the O2 sensor unplugged and with your coolant temp sensor functioning correctly and your car at operating temp.

GTS1/2 are good, plus you can heat heatsheild them, Genie/Pacemaker are good. Really just go for any that are mandrel bent, and a more decent performance based brand. Some of the cheaper ones (aka wilcat) are really just for stock manifold repl;acement (when it cracks) and have pretty bad flow, I've deconstructed them before, they usually just have the pipes stuck in randomly with welds around them, look OK from outside (excluding press bends) but ont he inside, soo much turbulence and uneven cyl restrictions. That said, its not really going to make too much difference on an unopened engine.

In which case, it should be built anyway.

My N/A+T goes great, only running 7psi at the moment through an R34 sidemount, and its about on par with a lighter GTST, with FMIC and 10psi, but has far better delivery.

Just buy a turbo ecu, turbo injecotrs, exhaust manifold, turbo, oil and water lines, crossover pipe, turbo inlet pipe (inc plumb back and breatherpipes), bov and FMIC kit, and bolt it all to your current car, set your ignition timing to 15 degree's and away you go, on stock management you will make heaps of power- more than a turbo model would, just run like 9-10psi, which is all you should be running on stock turbop and management anyway. Else, if you must buy the full new engine, sell me you N/A engine, so i can put it in the R33 with a blown TURBO engine, thats sitting in my driveway.... (and i'll just bolt all the turbo gear onto it, and make more power than it did before it died)

A piggy back like an SAFC will give you some power and economy improvements and fix up all your fuel mixes to the right amount, but full aftermarket management will net you more power due to being able to alter the ignition timing maps. But with an SAFc you can somtimes get some extra benefits from the ecu seeing less airflow, therefore pushing you onto slightly more aggressive maps (especially if you have a couple modifications, so your car is breathing mroe than standard).

Nah in hobart, how much?