Good stuff twinvl!! Sounds like your pretty handy with electronics. Maybe theres not enough oil pressure at idle to rotate the cam 20deg? Pretty sure the factory ECU dosn't switch it on until 1050 RPM anyway (then off at 4500). There is word that the bonnet won't close with the factory intake manifold. Have you tried this twinvl?

Quote: Originally Posted by twinvl I got it running! Just using a RB30E ecu and injectors, and i made a decoder to divide up the ignition pulse for the multi coils. Works perfectly! Could you please post up some details on this divider cct? I was looking at building a similar sort of thing useing the CAS as a refrence and then running it through the ignitor pack? Also does you system do the correct ignition advance or is it hardwired to fire the ignitors every 120 degrees?

Actually, did you wire it so your "divider" grabs the postion of the crankshaft from the CAS, and directs the power transistor output from the stock computer to the required coil packs for the dwell time? Just like the 24 valve DFI computer does, but your doing it externally! (I hope thats how you are doing it....) All you need is a cct that does that....erm....did you use a microprocessor based sytem or just a serries of transistors? sorry for another post, I just had a (dimm) light bulb go on in my head...... Some original photos have not been recovered yet.

Quote: Originally Posted by twinvl The belt viabrated on the slack side at particular revs but reved all the way without any probs. I took it off and checked if the valves could touch the piston. set the crank at TDC and i could turn both cams around and around! I'm abit less worried about it now. I put the belt back on and tentioned it up alittle more. Seemed better but not much. Sweet, its free running then meby joel can add this to his *.pdf file..... Some original photos have not been recovered yet.

I too am currently doing this conversion but into a VH comie. As my username says i'm looking for 650hp from a GT35R and Rb30/25head. You find alot of the finer details on the rb30 thread on skylines australia as Joel etc.. have mentioned before. http://www.skylinesaustralia.com/for...0&page=1&pp=25 (http://www.skylinesaustralia.com/forums/showthread.php?t=15420&page=1&pp=25) If you have the time have a read, it will take some time. The head i'm using has VCT but I won't be using it as RB25DET's use hydraulic followers and any cam over 256 duration and 9.2 lift will make the VCT useless. For 300rwkw's and more you would be better off with solid followers from a GTR and larger cams with adj cam gears and dont forget head porting...

Yeah my engine is going to be a lightly stressed Supercharged engine, I'm not after more than 160kw at the wheels, on a engine that just runs normal unleaded (no PULP) thats why I'm into water injection system and the like......a low 8.3:1 compression running 8-10psi of boost with manifold water injection on a VCT RB30 Twincam should do it.....my engine before was a RB30E with a SC14 (my old name was kaBOOMn....) The "toy" is a replica group B Lancia rally car If I can get Cams (pack of F*****.....) to let me run it in rally events at all, and getting the friggen Lancia Montecarlo center section out here... Some original photos have not been recovered yet.

There's plenty of oil pressure, cold oil and a RB25 pump, the gauge on the dash was maxed out. Yeah i think it must need a load to be notice the VCT. I've got a cut down manifold so no probs there. Quote: Originally Posted by Nizmodore Actually, did you wire it so your "divider" grabs the postion of the crankshaft from the CAS, and directs the power transistor output from the stock computer to the required coil packs for the dwell time? Just like the 24 valve DFI computer does, but your doing it externally! (I hope thats how you are doing it....) All you need is a cct that does that....erm....did you use a microprocessor based sytem or just a serries of transistors? sorry for another post, I just had a (dimm) light bulb go on in my head...... Thats exactly it, grabs the position from the CAS and directs the signal to the right coil. It doesn't matter where the crank is it picks up the signal in 120deg crank rotation max and is not processor based, just digital 4000 series IC counters and gates, and a few transistors. I don't want to give to much away with the ignition divider cos building these kind of devices is what i want to do for a living! So if any1 wants 1, i'll make it for a price, don't know how much yet. I will tell u how it works so if you're smart enough to make the circuit then u can! If you have a look at the pic of the Rb25 CAS you will see the slots on the outside of the disk are at 1 deg spacing and the inside of the disk the 6 slots are of vairing size starting at TDC for each piston. There are 4deg difference in each slot with the first slot 4 deg wide and the last 24deg wide. The divider simply counts the number of degrees using the 1deg signal while the 60deg signal is low (while there is metal between the sensor, not slot). The results are in binary 36 = 100100 40 = 101000 44 = 101100 48 = 110000 52 = 110100 56 = 111000 If you only read the middle digits, take the 1 off the front and the 00 off the end your left with 001 = 1 010 = 2 011 = 3 100 = 4 101 = 5 110 = 6 These 3 digits are latched and feed through a binary to 1-of-6 decoder. The outputs from the decoder are on for 120deg of each cycs compression stroke up to TDC and is conected to the base of 6 NPN transistors. The colectors of the transistors are conected the the ignition signal from the ECU and the emitters conected to the RB25 coil driver pack, 1 for each coil. The ign sig from the ECU only gets to the coil to be fired and is blocked to all the others by the transistors. I also convert the 60deg signal from wide slots to narrow slots so the RB30E ECU thinks its got a RB30 CAS. Does that make sense?? Any1??? Some original photos have not been recovered yet.

Yea, sorta makes sense. I have an electrical background (have a cert. in basic electronics and i'm an industrial sparky), but sounds like i'd have to sacrifice a few too many brain cells to nut it out myself. Think i'll just buy a Wolf3D!!

LOL Yeah only good for NA cos i used RB30E injectors aswell so i didn't have to stuff around with mixtures, there's not alot of fuel to go round. Still most cheaper aftermarket ECU's can only run multi coil with a waste spark and aftermarket coils, although new versions are better. My divider would work for that to, frees up a few outputs on the ECU aswell.

4000 serries, good 'ol CMOS Yeah from what you have written it shouldn't be too hard to build....don't worry I won't go selling them, you did all the hard work.... I'd prefer to use a RB30 ECU as they are much easier to reporgram then a RB25 one.....still......I should just buy a microtech..... Now all that stuff they taught me in trade school is paying off!!!!!! (electrotechnology...a cross betweem computers and electronics...we did a lot of binary and microprocessor work....and then I left the industry completely) Still, my boss is saying if I don't get my motor going soon he'll chuck 3 DCOE40's on the motor....aw gawd.....he wants the workshop space back! (I work with Alfa Romeos now....explains the webers everwhere....still a tripple carb RB30D would sound awesome under full load!) One of my (clueless) ricer mates suggested I wire the coilpacks to the injector signal......Oh yeah mate good one, fire the plug when the inlet valve is open and the injector is spraying fuel..... Some original photos have not been recovered yet.

Direct fire ignition is the way to go fellas, i decided to mount the coils under the dash, what ya think? Had them under the bonnet but the took up too much room. Some original photos have not been recovered yet.

Yeah like it very much. That looks like a serious setup RB30DET. Whats your running gear/ engine mods? Where are you located in QLD?

Quote: Yeah my engine is going to be a lightly stressed Supercharged engine, I'm not after more than 160kw at the wheels, on a engine that just runs normal unleaded (no PULP) thats why I'm into water injection system and the like......a low 8.3:1 compression running 8-10psi of boost with manifold water injection on a VCT RB30 Twincam should do it.....my engine before was a RB30E with a SC14 (my old name was kaBOOMn....) that blower setup looks pretty familiar! almost exactly the same as mine except for 45 degrees of blower rotation, my outlet is on the top near the dizzy, not underneath.

Up in sunny Hervey Bay

Quote: Originally Posted by StockyMcStock that blower setup looks pretty familiar! almost exactly the same as mine except for 45 degrees of blower rotation, my outlet is on the top near the dizzy, not underneath. Now I'm going twin cam, with a blower....upset some VLT owners in the process Some original photos have not been recovered yet.

Actually, can any RB25DET owners or Twin Cam RB30E owners (with VCT) tell me if at idle useing a stock computer, is there any power to the VCT soleniod or not? I pulled my VCT soleniod out of my RB25DE's head at work today, and its open when there is no power to it! A blast of compressed air confirmed this.....When I apply 12v DC to it it closes the soleniod..... I how does this VCT system actually work? I assume the cam system is on a spring of some sort? and the oil pressure retards it, and when there is no oil pressure, the cam advances? This has sorta got me miffed......(not to hard on a friday nite tho!) I'm not tapping a oil feed hole in the head, I'm latheing up a adapter that goes where the VCT soleniod fits, and the Solenoid fits into that and turns the VCT on and off.....Simple bolt up.....tho I still have to block off the oil feed in the head with a grub screw.....cant have it all my way can I now? Shoud be done by late next week......I post up some pics on how it goes.... Some original photos have not been recovered yet.

RB30DET - Good to see that red interior! Whats wrong with the standard coils, How much power is your engine making??? Well if you had to fit coils, under the dash is prob as good place as any. Nismodore, i'm not sure of the actual mechinism in the cam pully or which way it turns but i can tell you about the solinoid. There are 2 oil holes in the inlet cam bearing, 1 is connected to the oil feed directly and the other goes to solinoid. When the solinoid is open the oil flows into the cam bearing and out to the solinoid and drained off. When the solinoid closes in blocks the outlet and pressurises the bearing forcing oil into the cam pully and mechnisim. If you supply oil into the solinoid area the oil would just drain off when its off. I don't think much oil would get to the bearing cos it doesn't have to flow through. But would pressurise it when fine turned no. I've test drove my car! Seem to go well, power right to the limiter, But not as much as i hoped. VCT seems to make a difference but not much, i need to do more testing!

Twinvl, could you whip up a sketch to explain the diffent path the oil takes through the VCT setup? I'm a little confused. I thought the feed from the RB25 block went straight to the solenoid. Where in the head does the oil drain to? Nismodore, the VCT solenoid switches on at 1050rpm then off at 4500rpm according to several articles i've read. No first hand experience though.

Quote: Now I'm going twin cam, with a blower....upset some VLT owners in the process twin cam + blower = fun! out of interest, what size is your crank drive pulley? mine is 160mm diameter, and gives 4.5 psi max. you could expect this to drop on your engine, but make more power. i have heard that the teflon vanes in the SC-14 (and 12) disintegrate at 13,500 rpm, so i'm a bit cautious when taking the car toward redline. if you hit 7000 many times and the blower holds up, let me know.

Thanks for replies on the VCT system, like I said it had me a bit miffed Yeah I'll post up details of the brass adapter when its finished..... What I'll do with the VCT system, is I'll disconnect it from the computer, run the car up on the dyno, get a dyno graph, then I'll hard wire the VCT system on and run the car on the dyno again, and get another power graph.....put the graphs on top of each other, and I'll get a "Best" power graph, I'll then then wire the VCT soleniod to a RPM trigger....presto! Also what was the size of the oil feed line? 1/8BPT? I work with Alfa Romeo raceing engines, we had a SC14 putting out 14psi @ 1:1.4 drive ratio with a 7000rpm revlimit......why did it survive? Simple. We put the Carbie (I know, I'm EFI all the way, the boss is a Carbie diehard...) BEFORE the blower, the air fuel mixture cooled down the blower lobes...... Here the old motor with a Cavin Blower off some aircraft, with a 2-1/2 Inch SU.....the SC14 motor (don't have a pic of it on the computer) went bang in a big way, due to a lean out (stupid carbies!) and bent the SC14's drive shaft, ballooned out the inlet manifold.... damm..... Now a simple way to cool down the blower, would to be to run a extra fuel injector infront of the blower......but if we get a backfire......well.....just hope your inlet tract has some rubber joins in it..... So instead, I'm useing water injection, and keeping the spray fine enough, so not to hydraulic lock the motor....should cool down the lobes etc.... Some original photos have not been recovered yet.