StockyMcStock

the aac valve is used to control the idle under all conditions, not just on startup. it is vital.

nah you're not allowed in the dyno room for OH+S reasons, but you can sit upstairs and read the ricer magazines while your car is going mental on the dyno. the dudes in the office were complaining that they couldn't hear themselves think when my car was on the dyno - it was awesome.

yeah the XF TPS is a heap of junk, i'm not even sure if it gives a proportional output like the RB ones do. you need something that tells the ECU the approximate percentage opening of the valve, and also when it is shut for idle purposes. fitting the RB30 TPS fixes all these problems, as its output is almost identicle to the RB25 one. i measured em.

yeah mercury - even though they had NFI what my engine was they still did a good job with the powerFC tune.

jesus, the standard RB25 TPS opens THE WRONG WAY for use with an XF throttle body. unless you can bend the very fabric of reality and create some kind of backwards universe ruled by inverse laws of physics, then you will not get it to work with the standard TPS. go steal an RB30 TPS from a wrecker, it will cost nothing. the plug is even the same so there's no modification required.

dammit i must be posting in invisible letters again, hold on a sec let me fix that up.

XF throttle bodies open the opposite way to RB25 throttle bodies, so your TPS will be all out of whack. I use an XF body with an RB25 powerFC, i simply used the RB30 TPS which opens the correct way. the powerFC doesn't mind it one bit.

R324DR: it's a section of Tchaikovsky's 1812 Overture. a full concert recording of the piece is 17 minutes long. excellent piece of music that.

guys i just went and cut apart one of my N/A injectors here in the garage, took some photos but you can't really see anything properly so i'll just tell you what i found. the single pintle injector on the right is my 550cc injector, the one on the left is a factory RB25DE injector. they look the same and have the same casings etc, the only difference appears to be the little end cap which has the four tiny holes as per photos above. the cap is very thin steel but is spot welded to the tip of the injector in a very neat (and very strong) manner. i couldn't remove it easily, so i had to cut it off with a hacksaw until i could remove the whole piece in sections. unfortunately this resulted in the end of the injector being rooted as well, as the depth required to hacksaw to remove the cap was too great. it's hard to explain in words, i wish my close-up photos had tuned out but they didn't. it appears as if the single large pintle in the injector seats on the back of the cap. this would make sense because if it didn't, then there would be a small section of liquid fuel sitting between the two which would ruin the pressure differential and thus spray pattern. if the pintle seals against the cap with the 4 holes, then as it unseats off the back and the rear of the cap is exposed to full fuel rail pressure, the 4 holes would act to atomise the fuel fairly well. they are pretty tiny after all. what would be interesting would be to compare an RB25DE injector with an RB25DET injector, and see if the 4 holes in the end cap are larger. this may be the only difference, i'm not sure? anyway i hacked the rest of the thing apart just for kicks, it's all pressed together so i'm not sure how you would disassemble an injector if you ever felt the need. what i think has been done with mine is that the end cap has been removed with great precision, and then the tip of the injector pintle has been re-seated on the casing (again, hard to explain, easy to see). this might then allow the thing to have a decent spray pattern with the cap removed. i'll have the things flow tested in a couple of months i hope, so i will see what the results are like then. cheers

disco: a while back i bought some direct replacement 550cc injectors from the forums here, when they arrived i noticed that they were EXACTLY the same externally as the set of RB25DE 270cc injectors that i have here. i mean same colour, same markings, same numbers and everything. i was initially annoyed because i thought i'd been ripped off, but upon looking closer i found only one difference between the two injectors - the tips. the bigger flowing injectors have a single large pintle, whereas the N/A injectors have the four tiny holes as you described. i assumed that the guts of the injectors had been removed, and fitted with a single larger pintle. it does look to me now that you can remove the very end of the N/A injectors somehow - i will rip one apart tomorrow and see what i can find. it is very possible that this is what has happened, the 4-hole cap has been removed, but i'm not 100% sure yet. i'll let you know tomorrow if i remember to pull this injector apart.

post up both the dyno graphs man, it will help. could be valve bounce, or incorrect cam timing. did you check it with a dial guage and degree plate?

ok must be the RB30 and RB25/26 gears which are different. thanks for clearing that up.

i randomly get a knock of 32 every know and again when i'm hammering it, don't worry it's just engine noise. mine is particularly high because i have a 50mm wastegate which is air-vented and a supercharger in the engine bay as well. nothing to worry about.

i am skeptical that it will idle or drive at all. give it a try, if it doesn't work then get it towed there for like 50 bucks.

i was under the impression that the RB25 and RB26 have different cam gear offsets, thus you cannot interchange the two gearsets. can anyone confirm this at all?

wow that's the first car i've seen idling for ages. thank you so much for sharing your idling prowess with the world.

could be wheelspin mate.

that could also be PARTLY due to the RPM at which the run was begun. if you have the car idling in 4th on the dyno and put your foot down to log the run, it will reach full boost sooner than if you start at 3000rpm and put your foot down. just a thought - the first run starts at 90km/h and the 2nd starts at 60km/h or so. the cams certainly did make a large difference though, i'm not detracting from the gains which you have found. the difference is quite marked. it is one of those "all or nothing" power curves in which camshaft selection is critical as well. top stuff.

jesus, what a nightmare! just make sure you don't mix up any of the scavenge and feed lines in that mess haha. did you get rid of that viscous clutch fan yet? thermos FTW!

the variations in cambelt tension and stretch over time are easily enough to throw your cam timing out by as much as 5 degrees when measured properly with a degree wheel and dial guage to measure the lift. for example, if you over tension the cam belt using the swinging tensioner bearing by a small amount it will totally muck up your "factory" cam timing. moral of the story is, leave it on zero and install your belt, then run the engine for a while. after this, get someone who knows what they're doing to check your cam timing with a dial guage and degree plate the proper way. it will be way off the factory settings. you can play around with it on the dyno as much as you like once you know where you're actually starting from. an engine simulator program will help you decide whereabouts to set the real cam timing if you can get your hands on one.

i bought the blower from USA ebay for $300 AUD delivered, they came standard on a heap of cars over there and are hence much cheaper than here in australia. the later model ones also have improved internal design which is nice. after purchase price, i had to have the drive snout shortened by a machinist which was $200. i bought some steel for 20 bucks and made the brackets myself. tensioner bearing was maybe another 30 bucks. the other main cost is in the billet pulleys you can see in the drive system. i used a pair of cam gears and had a toolmaker lathe up some billet pieces for them to bolt to. there is a cam gear bolted to the crank, and another on the end of the power steering pump shaft. this is then bolted to the billet 8PK drive pulley, and the whole lot has a single retaining nut on the power steering pump shaft. it's a very neat system and allows for clearance to the radiator and other things which i won't go into. this was $500 for all the machining work. you could certainly do it cheaper, but i wanted this setup to be very reliable and well balanced, which it is. running the blower only is great, until you get the revs up. the lack of top end power will only be disappointing to your average punter. it drives a whole heap better on the street though, with bulk low-end power. fitting the turbo only was the opposite, massive top-end power but nothing below 4000rpm. with the two combined, and the multiplying effect of the two compressors, you have a very nice end result - as seen in the power delivery on the dyno. an almost ideal power curve of that shape, with that peak power on that boost level is just not able to be replicated on any 25/30 i've ever seen. the torque delivery is flat as a tack, so no matter what RPM you're doing you have the same torque at the wheels. this makes the car much easier to drive, and stay on the edge of wheelspin by controlling the throttle.

yep i payed - thanks for the bargain gents!

my twincharge is basically a supercharged RB25/30 with a turbo added, so all the principles are very similar to running just a supercharger - except this is vastly better: there's more info here: http://www.calaisturbo.com.au/showthread.php?t=79101 http://www.calaisturbo.com.au/showthread.p...ight=dyno+today http://www.performanceforums.com/forums/sh...ight=twincharge cheers

i have a supercharged 25/30 but it also has a turbo, so i'm not really sure if it fits the bill?

Nemini90: that looks good, shouldn't be any issues. there are, as you have found, a number of different ways to go about it. you just need to make sure you don't drill and tap through into a bore or water jacket or something, it's pretty simple stuff. so long as the cam timing appears to be spot on, it will run OK. obviously adjustable cam gears with proper dialling in will help to locate the camshafts exactly where you want them. remember with non-OEM belt setups like we all have, the cam timing could really be just about anywhere. while you can alter belt tension on the two swinging tensioners to move the cams, it is not ideal. cheers