Sydneykid

RB25 head bolts are 11mm RB26 head bolts are 12 mm We use 12.5 mm in RB31's

OK, I am still confused.....more help required........ I can lean mine off as much as I like with the DFA, as soon as it goes closed loop (idle and cruise) it goes to 14.7. My understanding is that is the target in the aim table in the standard ECU. I haven't seen the Stagea closed loop aim table, but the R32 and R33's have no limit. The ECU can turn the injectors right off if necessary in an attempt to reach the target. I don't think that matters anyway, if the target is 14.7 it will richen it up (also unlimited) if necessary to reach that target. As for idle, I unplug the AFM (zero voltage) and mine will still idle and start fine, hot or cold. I don't believe the ECU uses AFM signals at idle at all, it use engine rpm, water temp, throttle position, road speed and lambda when in closed loop. It is only when I attempt to get off idle that there is an issue, basically it stalls when I apply load. Since you have had some success, I must test lowering the voltage with the DFA to see whether that makes any difference on mine. Over 15.5 there is a general warning about its effect on exhaust valve seats. Plus there is an argument that says you need more throttle opening to hold the cruise speed, so there may not in fact be any benefit. The test is injector duration (which can be read off the IEBC input), if the injector duration is longer (regardless of the lambda) then it is using more fuel. Verrrrry interesting, sparked my interest to do some more fiddling, as if I don't already have enough to do. Ps, even with a power FC and Datalogit software on the R32's and R33's, I can't change the closed loop aim table.

Replacing tweeters, I have them mounted and wired (at the tweeter) but not at the head unit. I ran out of time on the day I was doing the install and I haven't gotten back to it yet. I was hoping someone had worked out the wiring codes to save me a poking around with the multimeter.

Mine has standard tweeters in the A pillars:cheers:

Ah, the old antenna amplifier. There's a job for me tonight, connect up the blue wire. You haven't by chance worked out the colour coding for the factory tweeter wiring harness?

OK I'm confused, at idle and crusie mine runs closed loop, so it doesn't matter what the DFA is set to. The ECU will always aim for its target A/F ratio (ie; lambda voltage), changing the AFM voltage has no effect of the closed loop aim table. The standard ECU has water temp compensation (ie; when cold go richer X%) and it doesn't run closed loop until the engine gets up to normal operating temperature. So if I lean it off at light throttle (open loop) then it will lean it out a bit at cold run, but I doubt that would be enough to cause it to run rough. It certainly wouldn't cause any damage as it is still in a rich running state. If I am merely compensatiing for increased efficiency (eg; exhaust) then it won't, in fact, be any leaner at cold run than it was standard. So remain confused :confused:

Sorry, but I simply don't have the time to write a long explanation on the workings of a trailing arm rear suspension. Simplistically, the idea is to change the wheel's movement arc by repositioning the mounting points. Offset bushes are a good place to start, effective and cheap. The next step is redrilling the mounting holes. By moving the inner mounting points upwards in the chassis you can lessen the dynamic camber change. By changing the realtionship between the front and rear mounting points you can affect the squat, hence lessensing the need for excessively high spring rates. By moving the top mounting point you can lessen the static camber, this is helpfull as it can be diffcult to achieve the balance by only using the lower inner mounting points. The Nissan trailing arm rear suspension has been popular since 1969, so plenty of people know what is necessary to be done. There are a number of books on the subject, the one written by Peter Brock (no, not that Peter Brock) on 1600's is a good place to start.

RB30ET suffers from 2 diseases; 1. Insufficient camshafts 2. Insufficient valves

The cheap RB25 upgrade is JDM manual S15 side feed high impedance injectors, good for around 450 bhp. Spray pattern :confused: I am getting a bit peed off with some of the crap written about spray patterns on forums. I have tried about 20 different injector styles/brands/flow rates in all sizes of RB's over the last 5 years or so, and I will be buggered if I can find stuff all difference in power, economy or emmisions. Tuning makes more difference than injector spray paterns, if you are going to spend more money, then spend it on getting the tune right.

Lots of questions...... The cost is because it utilises a brand new ball bearing core, not plain bearing. A lot of the hi flows rebuild the standard core with plain bearings. Plus it is micro balanced on the latest Schenk and only brand new parts are used. The best part is it works, I have used them on many cars, so have plenty of others and they NEVER fail to perform, I have seen plenty of others that don't. So they aren't expensive, they are cheap. Depending on load, full boost of 1.2 bar at 3,200 rpm all the way to 8,200 rpm. The turbo will efficiently make more boost than that, but the engine is old and I needed it to last. Well at least until the new RB31DET is finished. Mods for 225 rwkw ........... combo spilt dump, engine pipe and cat replacement (all in one piece) and 3.25" exhaust. Power FC with Boost Control Kit, RX7 injectors, POD, substantial air feed, heat shield, GTR fuel pump, PWR radiator, electric fan, oil cooler with ducting, remote oil filter, GTR intercooler, my own intercooler pipework, Jun adj camshaft pulleys and tuning. Lots of tuning, for response, I don't care about max power at one rpm point, we went for the best average power. Hope that clarifies:cheers:

I don't find the RB25DET GCG ball bearing hi flow at all laggy on the RB20DET. The throtle response is very good, but it does have an excellent exhaust (split dump, 3.52" exhaust, no cat) and is tuned for response via a Power FC.

Hi Benster, an RB30DE is an interesting project, around 250 bhp is quite possible for a mild road engine and close to 400 bhp for a race engine. The VVT from an RB25DET cylinder head would be an advantage, but the multiple throttle bodies from an RB26DETT would be a bigger one, in my opinion anyway. There are plenty of camshafts available that would do the N/A job quite nicely, the RB26DETT would be the pick again due ot its higher lift and solid followers. The standard RB25DET injectors (370cc for 370 bhp) or RB26DETT injectors (444cc's for 444 bhp) would be fine for the task. So there is very little that would stop the project from succeeding using standard parts, hence easy and fairly cheap. Well compared to a mega power turbo build up anyway. You have correctly indentified compression ratio as the main problem, for a good road N/A engine you need at least 10 to 1 and for a good race engine 13.5 to1 is the current target. An RB30E bottom end will get you around 8.3 to 1 using any of the DOHC clinder heads as their combustion chamber volume is much larger than the old SOHC. You could sneak that up to 9 to 1 with a bit of judicious cylinder head machining, maybe a light block skim and a thin head gasket. ACL make RB30 pistons locally so you should be able to pick up a set that will boost the compression ratio, or you could use JE's 87.5 mm VG30DE (non turbo) pistons. They will give a bit over 10 to 1 compression ratio and at the same time be suitable for mild boost later on. As usual it all depends on your budget which way you choose to go. Hope that was of some help:cheers:

Ouch, did it fail to proceed Brad? Or did the rear diff drive it on one wheel?

That places the teeth on the belt too close to the other teeth going in the opposite direction. Even the slightest whip in the belt will mean they touch. At high rpm it wouldn't take much touching to rip the teeth off the belt, very ugly. My suggestion, stick with what has worked on hundreds of of RB30 DOHC conversions.

That's a contest on who can buy the parts the cheapest.

What are you getting done to the engine? A bit of extra capacity will help the poor old 2540's. As would some more compression, a set of mild cams, gapless rings, ceramic coating the combustion chambers, exhaust ports and the piston crowns. Maybe power port the exhaust manifolds and a set of split dumps are a must (not those short ones, the combined dump and engine pipe style). Basically anything that makes more exhaust flow:cheers:

Shoot J, you might have hit on it. Our Stagea had to have the LHS rear door replaced (compliance blah blah blah) and it went to our race team panel beater to have the door repainted (it was white, not blue). So that's it, the panel beaters stuff up the radio reception when working on the LHS. Oh and that's the side I get worst reception on. It all adds up (where is that X Files music?) :werd:

Please, a severe interrogation of their knowledge would be appreciated:cheers:

Could be, seems coincidental that the gauge stopped working and now the light is on. If it truly had zero oil pressure at idle, then the hydraulic lifters would be rattling their heads off. Since you haven't mentioned that, the most likely suspect is the sender, so time to replace it. When the gauge is working you will have a better idea of what the oil pressure really is. PS; if you want to check that it does indeed have oil pressure, take the oil filler cap off while it is running and make sure there is some oil moving around the cams.

Get a new oil pressure sender and call us back in the morning:cheers:

Both have GCG's, one is R33 and one is R34. Rule of thumb, 300rwkw is a reasonable limit.

I have no personal experience with either turbo, we find the GCG ball bearing high flow to be a great all round turbo, suitable for road, drag or circuit. We have a couple of RB25's with 260/265rwkw and both have more power everywhere than standard. That's makes a great package for circuit work.

My 20 cents.... There is a huge difference between a 250 rwkw turbo and a 350 rwkw turbo. You could stick the 350 rwkw turbo on and keep the boost low for 250 rwkw, but it will be as laggy as hell. People tolerate laggy when they have 350 rwkw, but you will have laggy and only 250 rwkw, not so appealing. So choose, it's either a 250 rwkw turbo or a 350 rwkw turbo and they are not the same turbo.

Not a lot, that's why they are such a good idea and popular.

I'm with the Snowman on this one, the Gibson GTR's were built to restrictive Group A regulations and you can't compare them with cars built with total freedom. I have this discusion from time to time with John from UAS about his Zed. He brags his Zed is faster than the race GTR's, but they are built to regs and his Zed is free of any restrictions. Whatever he wants and can afford to do, he has the freedom to do it. If the cars are not built to the same regulations then it is simply a contest of which workshop has the richest customers. What separates a good race shop from the rest is the ability to make a car faster using the same equipment, with the same limitations on mods. PS; Techonolgy marches on, for example stick todays race tyres and shock absorbers in the Gibson GTR's and they would be heaps faster. Take out the ballast they had to carry and they would be faster again.