Sydneykid

Invisible rice, it's going where I don't have to look at it all the time. :angel:

Personally, no I have never achieved over 220 rwkw out of standard RB25DET injectors and that was with a small increase in fuel pressure. Others have though, Steve-SST seems to be able to do it, but he is a better tuner than me.

It doesn't need engineering :headspin: , the "new" block will have the same engine number as the "old" block. Because it gets stamped on there by the machine shop when they rebuild the "new" bottom end. If you want to sell the "old" block, you have to have the numbers machine off, because there can't be 2 engines around with the same numbers. I wonder if he will get it this time? :bonk:

Cams or no cams, did I say 250 rwkw out of standard injectors anywhere in this thread?

I thought that too, until I added it up, the RB26 top end is much cheaper to get to the same power levels than an RB25. For example solid lifters, larger diameter head studs, stronger standard valve springs, 6 throttle bodies, plenum, RB26 cams are cheaper and easier to get second hand, better oil return to the sump, top feed injectors and rail are much cheaper to upgrade than side feed, coil packs, ignitor etc etc the list is long and expensive.

The old scourer in the stocking trick, works well every time. :wavey:

An 8 degree celsius increase in air temp cost 5% in horsepower. So if it's 25 degrees admbient and the under bonnet temp is 60 degrees, then you would loose ............... I am sure you can work it out for your self.

Hi JimX, in the "machine" costs is included drill and tap the block for cambelt pulley (the idler is already done), drill and tap for oil return to the sump (there is a cast flat there for it), oil supply and water supply are easily unblocked. Exhaust manifold clearance (water gallery) takes 5/10 minutes with the die grinder, it's not included as most guys use aftermarket manifolds that seem to fit without it. Better add $30 for that. You probably would need a spacer (between the dump and the engine pipe) to clear the foot well, although some exhausts have plenty of clearance. Each car is different. Better add $20 for that. I forgot the long cambelt, the're $40 or so. The trick is to never mention "SKYLINE", it's for an "old VL Commondoor". As soon as you mention the "SKYLINE" word, the price of everything seems to double. The real problem with the budget is people keep adding things as they go along and they quickly spend that extra $1K you were talking about. You know what I mean, there is the gap between the cambelt covers, it would be nice to have it covered. It would be nice to have the VVT working. Then there is some nice VHT paint or HPC of the block, and an adj camshaft pulley, the cam covers need polishing, and the cross over pipe, should I put better bearings in it, what about a brand name head gasket etc etc. With some self control, you could do it on that budget, most people choose not to, that's all.

There are many reasons, let's try 2.. #1. When you put your foot down quickly, the ecu adds extra fuel momentarily to help accelerate the engine. This is called acceleration enrichment, if you don't have it the engine won't accelerate. If you are already at 100% duty cycle, then there is no capacity in the injectors to do acceleration enrichment. Generally acceleration enrichment is expressed as a percentage, ie; current fuel requirements plus X%. Commonly X is around 14%. #2. The ecu has bult in safety measures, one of them is richening up the mixture when the inlet air temp gets too high, another is when the water temp gets too high. If you are already at 100% duty cycle there is no capacity in the injectors to add some fuel to protect your engine. :Bang: I am sure others (smarter than me) can add some more.

The SAFC doesn't control anything! The ECU does that, the SAFC just bends the input signals to the ECU. So the question should be ................ Has anyone tried to control bigger injectors with the standard ECU? Yes, and it doesn't work too well, cruise and idle are the problem, as is hot start.

Hi JimX, those injectors will be ready next week. The boys made up some tricky stuff (mechanical and electrical) to check them, very accurate flow tests results now. I will PM you. On RB30 costs... used RB30E short $200 new rings, bearings and seals $650 machine, o'ring, presure test, tunnel, bore, hone $750 assemble $500 Total $2,100 One of these made 475 bhp on the engine dyno with an R32 RB25DE top end, almost 4 years, still running strong. I don't think a used, $2K RB25DET is gunna make anywhere near the average power that it did either. RIPS in NZ has used this same philosophy a few times and ended up with good results for little money. Just because some people get carried away with mega RB30's, doesn't mean you have to. PS; ABuSD, you are not going to have the car for long enough to enjoy the RB30, so my recommendation is the same as the other guys, get a used RB25 and sell yours.

He missed it, didn't he? :headspin:

If you are going to replace everything then I'd start with an RB30.

Hi Mark, there is around 20 kw difference on our dyno for the R32 GTR between 2wd and 4wd. It is representative for the power losses of the front diff and drive shafts, since total rwd power loss is ~60 kw.

Yes, but keep in mind that a good tuner will work around this as best he can. You sneak up on the problem rpm range, watch the AFM voltage on the multimeter (before and after SAFC), move the boost up and down, advance and retard the CAS timing, a little more fuel correction on the SAFC, a little less correction etc etc. Eventually you end up with the best settings you can get, but it is still a COMPROMISE. The reality is that all this fiddling takes much longer to do properly than doing a full tune on a Power FC. You keep having to go back and change things that you had already set. That's why I am not looking forward to doing it on the Stagea, I just know it is going to drive me crazy. Stick with it though, it is worth it in the end.

What's this engineeered crap? :wassup: When you buy a new engine block from Nissan it has no engine numbers on it. The idea is, if you are replacing your old engine block then it must be damaged, so you transfer (stamp) your old engine number onto the new block. RB30 blocks are 30 mm taller than RB25/26/20 blocks, but they are hard for an inexperienced person to tell the difference. Get my drift

RB20/25 AFM's are 80 mm.

Hi guys, a quick, simplistic explanation of how an SAFC works might help... As the airflow into the engine increase, the AFM records this as increased voltage that the ECU sees. What an SAFC does is sit in between the AFM and the ECU and take the voltages from the AFM and either increase or decrease them depending on what you have programmed the SAFC to do. By increasing the voltage, this tricks the ecu into pumping in more fuel, you do this when the engine is running lean. By decreasing the voltage, this tricks the ecu into pumping in less fuel, you do this when the engine is running rich. The next bit is hard to understand unless you remember that the standard ecu does not supply fuel in direct proportion to the afm voltage ie; 4 volts is not twice as much fuel as 2 volts. Engine rpm, boost and throttle position also help the ecu determine how much fuel to add. It has been my experience that RB25's run a little lean down low in the rpm range (Nissan do this for fuel economy and emissions) and a lot rich up high (Nissan do this to protect the engine). So I have to increase the voltage (using the SAFC) up to around 3,000 rpm and decrease the voltage over 5,000 rpm. The real problem is in the 3,000 to 5,000 rpm range as the engine comes on boost. They really need lots of fuel very quickly in this area. This can mean that you need to increase the voltage (that the ecu sees) over 5.1 volts to get the right A/F ratios. The ecu then goes into engine protection mode, rich and retarded. Past that rpm you can start leaning it out as it runs too rich, so the voltage needs to be turned down under 5.1 volts. The ecu sees this as the engine not needing protection mode any more, no more rich and retarded. So you get good performance up to 3,000 rpm, then sluggish from 3,000 rpm to 5,000 rpm and then good performance from 5,000 rpm and over. The SAFC may not help this, in fact as explained above, it can in fact make it worse if the tuner is not switched on to this stuff. With bent afm voltages, the ecu (tricked by the SAFC) also fires the ignition to suite the airflow it THINKS the engine is getting. This is not a good thing as you generally end up with ignition that is too far advanced in some rpm ranges. The poor tuner has to juggle the SAFC settings, so that the A/F ratios are OK, the ecu doesn't get into rich and retard (engine protection) mode and the ignition timing is not too far advanced so as to cause detonation. My experience (I am not a good tuner) has been that this is full of compromises, sometimes you just can't win and have to reduce the boost level a bit to get even a reasonable compromise. Keep in mind that this explanation is very simplified to make it fit in a reasonable space, the rpm's used are rough guides only and every car is different. Hope it helps (and makes some sense).

We have one on the GTR, one on the GTST and one on the GTT. But the Stagea is an auto so it gets an SAFC, better than nothing.

HiChris, the 120 degree bend design saves over 1 metre in pipe, which is 3 litres less air. So definitely worth doing in my opinion.

Oh yes Jay, the R34 GTT has a full bolt on kit (no internal mods though); Tomei 260 Poncams Split dump Hi Flow Cat (very hi flow) 3.5" exhaust Pod filter Heat shield CAI (big one) R33 GTR standard intercooler Tomei injectors Tomei fuel pump Power FC with boost controller Low/rear mount exhaust manifold (like an R31 GTSR) Electric fan OS Giken twin plate (very light chrome molly flywheel) Oil cooler It runs 1.3 bar (all the time, none of this hi/low boost crap) Fitted 2 years ago, done 45,000 k's and still going strong. Did an 11.9 on Goodyear Drag Slicks last winter, might have a go again this winter.

Hi Chris, I don't like it, wouldn't do it to my car, not worth the effort. Do a search, I have written pages on why.

SInce you binned the Wolf, can I assume you are using the standard ECU?

Hi guys, currently we have 2 X GCG 450 bhp ball bearing hi flows, one is on an RB20DET that makes 220 rwkw and the other is on an R34 GTT that makes 265 rwkw. On the RB20 that is around the same power as a 2530 but on the RB25 it is 30 rwkw more than we have been able to get out of a 2530. It is about the same as what we get out of a 2540 on an RB25, but it has way less lag. Note that the RB20 is very old and tired (170,000 k's), we could probably get more out of it if it was fresher. The RB25 is probably more of an indication of what is possible out of a GCG 450 bhp ball bearing hi flow. We have not had as good success with the 500 bhp version, they run very close to the compressor surge line on a standard internals RB25. I would not consider one for an RB20, where a 2530 is very hard to beat for all round performance. We have a Stagea coming and it is getting the GCG turbo off the RB20, I have several other choices. But I believe that is the best all round turbo for that application. It is getting an SAFC (it's an auto), FMIC, Jamex panel filter, CAI, Autospeed (Norgren valve based) boost controller, split dump, (very) hi flow cat and a 3" exhaust. So it will be fairly typical of mild tune RB25. The bottom line for me is, I don't believe that I can find a better turbo for that level of tune. Hope that helps

Dymo labellers are cheap