RB30-POWER

Not really, i had to modify a lead to suit the application really, but now i have it, i can rip the coil off and use the lead to get my timing light working anytime i have too. You will suss it all out im sure. With a bit of luck your light will work connected to the factory loop, but if it doesn't you know where to head. Catchya...

You don't want all fancy iridium, platinum plugs and crap.... They cost money and do nothing. Stick with standard copper plugs, for the price you can change them as often as you want and copper provides better spark anyway.

Yeah connect your timing light clamp around the loop wire first and see it work succesfully. If it doesn't work with your timing light, the only way you will get it to work, is remove the plastic coil cover (in between the cam covers), remove coil on cylinder one and use a normal spark plug lead (like on a dizzy car) to connect from the spark plug to the coil. All this lead does is allow you to hook your timing light clamp around it, so it gets the correct signal to fire the timing light. Hope that make sense? It will make sense when you realise that stupid loop at the rear of the head doesn't work properly

When you set the timing make sure its up to full operating temp. Disconnect the TPS with the car off, just to be safe. Make sure the idle is @ approx 650rpm to set the timing. Timing should be at 15deg btdc (middle mark) Don't advance it to much over the factory, its already tuned for high octane jap fuel. At the back of the head there is a white wire in a loop, just near the coil pack plastic connector. This is the wire to use for the timing light. I've typically found that with alot of timing guns, this wire, allows the light to pick up all pulses, therfore not giving a light as it should from cylinder 1. I usually have to use an old ignition lead between the coil and the spark plug to attach the timing light too.

You have to disconnect the TPS sensor on the RB25DET to stop the feedback. The timing will jump all over the place even on idle if you don't disconnect it. As per the manual.

If you put a plug in that is to cold (for NGK plugs, the higher the number the colder it will run) it will foul up when your driving around the street when its under light loads, and not under big boost. The car will do anything from run rough, misfire, stall, hesitate, you name it if they foul. This is because the cooler plug isn't hot enough to burn off the carbon deposits. I would go no lower than a 7 on the street. This will allow extra headroom over the 6 rated plug, but shouldn't foul. Realistically, if you go to the drags or have the car on the dyno, go to a 8 *if needed* for those conditions. But if its a street car, I don't think it ever going to see sustained high power output requiring a cold plug.

Looking at the graph, about 5850rpm on that boost anyway. What management does it run? Is it running forgies in the bottom end?

If you want to wire a Series 1 (4 wire style) plug to a Series 2 Loom, you just have to add the extra earth wire for the power supply side of the AFM. The factory Series 1 earth that the series 2 doesn't have is wired to the front of the plenum with the rest of the earths. If that helps.

Sorry guys, I haven't even put a picture up yet. Here is what im craping on about.

I have only played with it a few hours last weekend. I put it into my brothers R31. Anyway he has been driving it the last week, and i wont have time to play with it again until the weekend. Because its only running 5psi i don't think im upsetting it yet, bit more air flow and might have trouble. I actually really retarted the static timing, to see if the VCT would make a difference, or mayeb allow me to see a difference, but still couldn't notice anything. I have the factory 25det ECU at a static timing of 25deg BTDC, with 15 it lost response a bit, haven't tried any more than this at the moment. Doesn't ping at all. With the 8.3:1 comp ratio it should take an extra 10deg or so almost everywhere, because it was setup for the timing of the 9.0:1 25det motor.

On another note, if i remove the factory O2 sensor to fit a Wide Band while i setup the jaycar interceptor. Will this throw the ecu into any limp home modes, or will it just run open loop maps under light load instead of closed loop. What i mean is it will not effect the high load open loop fuel maps, while i trim them up a bit with the interceptor? It will save me welding an extra thread nut into the pipe, if i can jam it into the factory location just while tuning. I don't think that tuning with the Wideband in the tailpipe after the Cat will give accurate figures will it?

Yeah, I can not see any difference at all with it on/off. i think maybe the oil supply volume is inadequate. I used a 1.2mm restrictor hole. The depth of the restrictor is probally around 8mm though, i think the restrictor in the block was only around 3-4mm. Wether that will effect it or not, im not sure. Out of interest, can yoi hear the VCT camgear mechanism engage or is it silent. I can hear the solonoid click with the power, but thats all.

Well i have come to the conclusion that the VCT is not working. Im going to remove the restrictor and see if there is any change. If not i will upgrade the diameter of the oil supply line as well. Its difficult to tell if it works because the 3L has so much torque as it is. Maybe im expecting to see to much from it, I mean its not VTEC after all. I can't see/hear feel any difference off idle when it engages or when it disengages at 4500rpm, so i think it has a problem.

Ok back to this thread, can anyone help with the following, i know alot of you are using the non-vct heads, but anyway. How do i tell if the VCT is working, i can't see/feel any difference with it on or off. Also if i supply 12V to the solonoid on idle, the sound/idle doesn't change in anyway what so ever? Shouldn't I be seeing something with the extra 10deg advance on the inlet cam, or will 10deg be neglible on the 3L. i may need to get it on the dyno to prove if its working or not. Its got a copper feed line from the standard rb30 oil pressure sender hole. The copper line is small diameter, like boost guage line size in diameter, but this diameter is still bigger than the restrictor hole in the head, which i made 1.2mm from memory, like the restrictor in the rb25 head. Do i need to get bigger line, maybe a bigger restrictor hole? Stupid VCT, causes more trouble then its worth, grr........

Sounds like he is preety switched on then. He works for the performance shop obviously that you chose to do your tuning, or you know him personally?

Thankyou for the response SK, appreciate your time to share some knowledge. Cheers! It sounds like what i already know, im going to be fighting an uphill battle with the stock ecu. I have set myself a target of atleast 200rwkw with the stocker setup, which im sure it should do with some persaverance. Will just try to minimise the dips in the power curve as much as possible. As for managment Cubes, I will be getting PowerFC without a doubt, I love the accuracy of AFM tunes, the PowerFC logic, and its plug and play ability, plus having a base map will help alot more again, if i have a go myself with the Wideband Lamda, but if i can acheive 200rw without the extra cost of the PowerFc, it will keep me out of trouble in the mean time. While i built the motor, just to serve my own curiosity about the benefits of twin cam, if you asked me again would i do it, I would say no, for the money involved it could be invested into the SOHC and have way more bang for my buck. But hey, maybe once i get further down the track and have the major bolt on goodies it will offer benefits. Ill get some injector duty cycle measurements up here soon, and also see how much extra boost until i trip the 5V mark. Once im happy with it, i will throw it onto the dyno and just see what it is making at the treads.

Great result considering that turbo must be causing heaps of back pressure on the 3L, with the tiny turbo housing.

Could be a cracked/broken solder joint inside the unit or dodgy wiring job.

Ok i understand about the injector time that more is needed at higher rpm if that where the maximum VE and power points occur. I think i should do well over 200 at the wheels on the stock injectors as long as i leave the stock cams in the head, if i go bigger cams it will move the max VE and power points higher in the rev range requiring more injector "on time" with less time between cycles so to speak. Now, does the 25ECU pull timing when it sees 5.1V (or is that complete fuel cut?) or does it see AFM voltage/load vs RPM being off the map and retards the timing. Like if the standard map only has good timing values up to a certain AFM voltage/load point at each RPM point and if you add more boost/more air at the same rpm point it will go to a higher map point where the ECU has a lower timing value, because the factory ecu knows that a standard motor would never be at that higher value air flow at that rpm. Or is the timing just 5.1V related? Also SK, after looking at numerous dyno charts from other factory ecu engines, the ecu doesn't actually seem to dump more fuel in, it just pulls the timing. You may measure more richer on the O2 simply because of the retarted timing isn't allowing the motor to burn the fuel that goes in. Also with regards to the AFM mesh thing, i've read and beleive from experience on other motors that it does effect the AFM readings and leans the mixtures from the extra air that gets passed without being measured from the lower restriction. I will test this myself and see what results i get. I don't see how it can effect idle as on idle the static timing is set and the ecu uses closed loop mode and keeps the air fuel right. So it should be just as solid idle as with the mesh. I'll ask more questions later Regards Mick

Whats a Z32 90mm?, So its up to 4V and your pushing stuff all boost through it as well, maybe i should get a bigger one again? With a Q45 meter its 100mm?, will i lose resolution down low in the maps that will effect drivability. Surely I don't need that unless im making massive power? Im just suprised to see such high voltage with stuff all boost, maybe another 5psi or so won't push it over the 5.1V mark, as you say they aren't really a full linear scale. Its deffinately not near 200rwkw, i would estimate maybe 150rwkw. On another note, how do i tell if the VCT is working, i cant see/feel any difference with it on or off. Also if i supply 12V to the solonoid on idle, the sound/idle doesn't change in anyway what so ever? Shouldn't i be seeing something with the extra 10deg advance on the inlet cam, or will 10deg be neglible on the 3L. I mean honestly they are tractor motors, they haul arse with timing or without, the capacity is great. I will measure injector duty cycle as well, just to see whats going on. Why is it my VLT can make over 200rwkw on the stock 250cc injectors while the 340-370cc on the 25 can only make similar power, is it something to do with the suqential/batch mode injection difference, with how the ecu actually use the injectors. I mean i dont really want to upgrade the factory injectors just to make a little over 200 at the treads, i know 250cc can do it on a rb30et. And they say the twin cam is more efficient, I wonder, more fuel and less power, but maybe i missed something.

Ideally you want to go to about a maximum of 80% or so, at maximum power/boost for your motor. Its not a good idea to run injectors close to 99% all the time as they weren't really intended to be pushed that far, and could shortern their life considerbly. Therfore when choosing injectors for a certain motor, you want them to be at a maximum of 80%. This will allow safety margin, if you need a bit more injector on time, maybe when its a cold night or such. Another thing, if you get massive injectors that you only run up to say 40% at full power, it makes it very difficult for the tuner to control them as acurately. In fact microcraps and other cheap ecu arent the best for massive injectors if outright accuracy is wanted in the tune at low loads and light throttle. Autronic and Motecs are much better at controlling very large injectors at low duty cycle.

SK or others that could offer some real advice can you offer some ideas or suggestions on the following. I have just completed an RB25/30 running factory managment so far, now I only have a small stocker type turbo on it at the moment. Now before i boost it up to much, knowing that the ecu will pull the timing (RICH AND RETARD) if i trip the 5.1V mark on the AFM, I done some measurements. At around 4500 it peaks at around 4.7V @ 4-5PSI boost pressure. I gather that this is the point of greatest VE, hence it breathing most Air. Now what i want to know is how much more boost do you think it would take to trip the 5.1V mark. (I guess only a few PSI extra and a cold night will allow it to measure that sort of voltage) What is the best work around for the time being? Should I work the boost curve so that it drops a few PSI at that point keeping it all below 5.1V or Should i get an interceptor and just lower the Voltage from the AFM that the ECU sees. (I guess it will get lean preety quick, or is the mapping preety rich anyway at that point, that i could drop it under the 5.1V and still have ok mixtures? Now lastly, even if i got a PowerFC, with this small turbo and more boost its going to measure way over 5.1V, so the only way around it will be to get a bigger Air Flow Meter correct, one that reads less voltage for the given air flow. Im thinking i may also be able to fool the 25 AFM a bit by removing the mesh elements/screens, allowing a tiny bit (maybe 10%, i've heard) more flow through the meter, without the meter measuring it. Also one other thing, on the AFM i have an adapter and pod, but the adapter steps from 80mm to 70mm, do you think this could be causing the meter to measure a bit high as well, or it shouldn't effect it to much? Thankyou for any ideas, sorry about the long post, but i feel i should give all details. Mick

If your rich just throw a wideband O2 into each runner. Can't get any better accuracy then that. But it looks as though even SK isn't that rich Out of interest, how do they tune V8 supercars, or are the manifolds flowing that equal flow anyway?

Put some more boost through the server that runs the forums, sometimes its so laggy, if the pages don't load fast, it doesn't matter what is on them. Sorry, just my 2c.....

Congrats mate a i said in the 31 forums. Will impress im sure