Sketch whipped up! I spent many hours with the head fully disassembled, blowing compressed air, running fuel through and poking thin wire through to figure out where all the galleries go and exactly how the VVT works to figure out the best way to set it up on a RB30. The oil drains to the crankcase area of the head, just near the front valve spring. Not sure if i've drawn the solinoid/valve setup corectly (cant remember exactly how it is) but u get the idea. Plunger pushed out by the solinoid blocking the oil drain causing oil pressure in the bearing. With the solinoid open, oil flows through the bearing with no pressure. Nismodore, i'm guessing u are suppling oil to around the plunger area?? Some original photos have not been recovered yet.

[Cue light bulb above head] Ah, so thats how it works. Cheers twinvl!

Quote: Originally Posted by twinvl Sketch whipped up! I spent many hours with the head fully disassembled, blowing compressed air, running fuel through and poking thin wire through to figure out where all the galleries go and exactly how the VVT works to figure out the best way to set it up on a RB30. The oil drains to the crankcase area of the head, just near the front valve spring. Not sure if i've drawn the solinoid/valve setup corectly (cant remember exactly how it is) but u get the idea. Plunger pushed out by the solinoid blocking the oil drain causing oil pressure in the bearing. With the solinoid open, oil flows through the bearing with no pressure. Nismodore, i'm guessing u are suppling oil to around the plunger area?? Hmmmmm......well this is how I worked it out..... I'll have to have another look.....I'm really not sure whats going on here....and I know if I'm wrong we'll have a flooded cam box......ala Alfa Romeo 105 mtor.... Some original photos have not been recovered yet.

The cam box wouldn't get flooded because the oil feed is restricted where it exits the RB25 block, i hope u put a restriction in? I'd check it out before doing to much more, some pics of the solinoid plunger and seat in the head would be good, see how good my memory is!

Quote: 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.... haha i see what you mean about the backfire! i'm currently using a water/meth sprayer nozzle before the blower, i find it cools down the intake charge noticeably, and gives a little bit more boost as the vanes seal a bit more. you can also advance the timing, and make more power out of the same engine with it. i have a steplessly variable controller that i built and a wiper washer motor pushing the water through an irrigation nozzle. if you want it a bit better than just a hobbs switch for on/off use, i can direct you on how to build the kit. only cost me about $100 too! runs seamlessly off the air flow meter output signal to vary the power going to the electric pump, and i have a potentiometer in the cabin which varies the load at which spraying begins. a very clean, good system.

phew, just read through this thread....i say dont use VVT, too much hassle!! good work on this though fellas, brilliant brain work happening. Some original photos have not been recovered yet.

I have a question for guys who have done the conversion. What diff ratio are you using?. I'll be using a r33 rb25det 5 speed, the diff ratios in r33's are 4.11 standard. It's not that hard to change the ratios to 4.11s in a borgwarner (use a pintara crown wheel) diff but I would like to hear from the ppl who have done it first.

I have a R33 rear end in my vl so has 4.11 gears and r33 manual also. Sits on 2700rpm at 100kmh. I much prefer the lower gears! But then i love shifting I must have changed abit cos now if i slow down and the engine is reving at 2000rpm i change down a gear where before 2100rpm was cruise and i'd change down at about 1800rpm? Also with the r33 box, 1st to 4th are slightly closer together and 5th is slightly taller than the MX7 box, so top gear compensates for low diff gears more than a MX7. Some original photos have not been recovered yet.

Quote: Also with the r33 box, 1st to 4th are slightly closer together and 5th is slightly taller than the MX7 box, so top gear compensates for low diff gears more than a MX7 I wasn't sure on the r33's gearbox ratios, thanks. The plan is to use a VL 6 diff add a tight LSD, VN centrewith 3.45 crown wheel and S3 silhouette axles or vlt axles or find a VLT diff. I'll see how it goes with the 3.45 crown wheel first, should be ok with the extra torque.

Is it possible to change the solinoid to a phase type if theres such a thing?

Well i raced on the weekend and i have to say i'm dissapointed with the power i'm getting from the RB30DE... It was slower that a stock RB30E, top speed of 180kmh... And i was down 5kmh at the end of the main straight... I stuffed around with the cam timing abit, retarded the ex cam 1 tooth (15deg) which brought me back up to the same top speed as the single cam. And i did 0.1 sec better lap time than last round... Any ideas any1?? I have a crap exhaust aswell, but the same as i had on the single cam.

Twinvl, how crap of an exhaust are we talking??? Twin cam supposed to breath more but if you've got the same restrictive exhaust on that's got to be restricting exhaust gasses and holding back peak power... Also what's the tune like? Might be worth getting it on a dyno to check the a/f ratios.

What pistons are you using? Are you running the same static comp. as what you did with the Rb30E? ECU? What power did it make? If you are still running the sock ECU it will be leaning out causing a lack of power and loss of mid range. The RB's like to run that bit richer through the mid to make good torque. With turbo anyway. Its impossible for it to be slower if you have done it right. I remember years ago Turbo tune here in Adelaide did a SOHC -> DE conversion and picked up some where around 30rwkw. Top end didn't flatten out in fact there was quite a big jump in power above 5000rpm. That had a tuned ECU and apparently returned well under 10L/100km's when cruising.

Quote: Originally Posted by R32-Joel Its impossible for it to be slower if you have done it right. I remember years ago Turbo tune here in Adelaide did a SOHC -> DE conversion and picked up some where around 30rwkw. Top end didn't flatten out in fact there was quite a big jump in power above 5000rpm. That had a tuned ECU and apparently returned well under 10L/100km's when cruising. But that was useing a non VCT head.....whats your VCT soleniod doing TwinVL? I know your useing a std RB30E computer (well from your other posts) and the mob in Adelaide did use a std R32 computer.....Maybe the fuel/Ignition maps on a std RB30E (or ET?) are not upto the running the Hybrid motor well? I just bit the bullet and got hold of a RB25DE computer for my motor..... Also a lower compression ratio will do that...still......I'd assume your still useing std RB30E pistons for a compression of about 8.3:1? Also the divider cct you worked out is going on, in modded form on my Twincam CA20 Least on the RB30 you don'thave to drill out the headbolt holes and re-helicoil them >: Oh and man are those RB25 VCT head's are a prick to get off.....that last M6 bolt near the VCT solenoid (you know the one) In the end I took both the cam pullies and the cover plate off and used a "modded" 10mm spanner to get it off.......10min job I said..... Some original photos have not been recovered yet.

Nizmodore, Are you sure it was an untouched std RB25DE ecu? I'm sure it had been tuned or even piggy backed. I'll have to dig the mag out again.

Yeah it was a rb25 ecu and had extractors. my exhaust is just a 2in press bent job, stock off a VK... i cut it up to suit the IRS and was only ment to be a temp thing. Still it didn't hold the single camer back much. Rb30E pistons, i measured 8.06:1 comp ratio and can back it up with measuring the single cam head and getting figures of 8.97:1. Stock RB30E ecu. I ran the cam timing figures through Dyno 2000 (program for calculating engine power/torque, and calculated a stock RB30E perfectly) and it cam up with a best of 179hp. That was with ex cam timing set 2 teeth retarded from the stock timing.... Thats 30 deg... I measured stock cam timing at EVO 75 deg BBDC and EVC 15 deg BTDC??? how can that be right, the exhaust valve closes 15 degrees before the piston reaches TDC... I tried the ex cam retarded 2 teeth, it was 5hit... I'm gonna make an adjustable pully! I tried to find some cam timing specs for a Rb25de/t but couldn't. So what i measured was aprox EVO 75deg BBDC, EVC -15deg ATDC, IVO 5deg BTDC, IVC 55 deg ABDC. This adds up to 240deg duration which it's ment to be. Inlet valve timing is good according to dyno 2000. I measured the VVT adjustment, it's 20deg advance. There's a good low revs torque gain according to dyno 2000 again. I made a digital tacho/speedo/trip using a micro controller. A addad a couple of lines to the program to switch the VVT on at 1500rpm and off at 4800rpm. The VVT sure does work! I don't think the mixtures are too far out, it's very smooth, doesn't ping, and doesnt blow black smoke. A mate has a Autronic A/F meter i'll test it soon. The ign timing could be a prob but havent found a top end gain adjusting the base timing. The other thing that could be causing my prob might be my short runner manifold. Runners are aprox 100mm long only. has any1 had experience with very short runners, stock cams and exhaust?? It's giving me the 5hits, all this work for nothing... :/

Finally got mine up and running! Had a basic tune today so i can run it in. Made 162rwkw @5000rpm on 5psi. I can't wait to rev it out to 6000+, it feels like it's just starting to get angry at about 4500-5000rpm. The power delivery is very smooth, no lag to speak of, so overall i'm extreemly happy with the conversion.

What turbo are you running? Keep us posted if power does in fact keep being made over 5500rpm as from what I've seen the stocker RB25 cams tend to hit airflow limits around that rpm on the bigger 3ltr. :P Some original photos have not been recovered yet.

Turbo is a GT3040. Compressor is 0.70a/r and turbine is 0.86a/r. So power should improve quite a bit once it's run in and i can put 15psi into it.

umm yer it should just a little bit. :P It will be in the meat of the efficiency range.