Looking good! I like how your Tach is already @ redline. lol

 

what gear box are you running again ?

 

i just had an idea...

early 12A twin dizzy front cover modified to accept 2 FC crank angle sensors. would allow you to run all 8 ignition circuits induvidually for poper leading/trailing including split.

i just happen to have one sitting here, the CAS fits fine but would need a timing lock tab welded on. i will have to check the depth but spacer rings could probably be made easy enough if it isn't just right.

figure this may be one option i use and just run 2 microtech units, treating the engine as 2 separate halves.

wish i had more time to work on the damn thing though!

 

Been lurking this thread for quite awhile. I must say the quality of work in here is outstanding!

 

bad idea, 2nd CAS blocks the water pump inlet/outlet. could run an electric water pump... hmm. sorry, just thinking out loud.

 

Vi-pec v88 runs 4 rotors.

 

Loving your build. Your a skilled man my friend.

 

Been watching this build on and off since the beginning. Wonderful stuff going on. I must say it's nice to see the chassis and body coming together now. Keep on it dude.

 

almost as excited to see this car finished as i am my own car!

 

While your at it, don't forget to put in useful cup holders!

 

S4 / S5 TII



Why go trough all the trouble adapting a second cas? Isn't it easier to just add an external triggerwheel, fabricate 2 brackets, and just fit 2 sensors? I'm also running an external triggerwheel. Anyway I don't see the need for running 2 ecu's, even if you really want to use split timing there are ecu's that can do it, Hell, I think even megasquirt can do it.



That's not such a bad idea really



Update

Today was a slow rainy sunday, so I locked myself up in the machine shop and started making shiny suspension parts
I started with the lower control arms, those flexy rubber bushings had to go, I'm going with bearings!




Couldn't finish it today though , the lower control arms themselves also need a little bit of machining, but they are a little bit too big for my lathe, it was really close though. Ah well, I'll take them over to my buddy who has a bigger lathe soon. In the meantime I'm drawing up more parts, in this case camberplates, since my coilovers don't have them. I could probably also get these from tein or somewhere but where's the fun in that

 

Simply amazing.

 

John, have you seen how Supernow approached that bushing? Are you just replacing the entire width of the original bearing?

Supernow Link

 

More beautiful results my friend, keep em coming

 

actually i think you could split the CAS signal, and run two ECU's on the single CAS, i think that's how the scoot 4 rotor is. stock FD CAS with 2 power FC's.

that white JC cosmo with the 20B PP engine is running THREE power FC's... the japanese LOVE that ecu...

 

Interesting, looks like they don't use needle bearings but spherical bearings. I've mocked up the control arm with the subframe today, and looks like it's not going to be ideal. The rear mounting point on the subframe isn't 100% flat and true, so it's going to be tricky to get the needle bearings perfectly aligned. Not aligning them will make them wear out fast and bind, I'm not really sure how AWR does this, maybe they modify the subframe too or something . Anyway I'm thinking about switching to spherical bearings, no problems with misaligning and it's proven to work well.


Wow, sounds like a horribly inefficient solution to a pretty simple problem , they must really love those ecu's.

 

it IS accurate, but yeah on a 4 rotor, two ecu's kind of make sense, but 3 ecu's on a three rotor is kind of silly

 

most ECUs haven't adopted the 4 rotor platform and don't have the capability to run all 8 ignition channels with the split. i was just thinking about it and figured it was an option. i don't see a problem running 2 ECUs though if it could be done with a single ECU that's great.

i'm just thrifty like that, having an LT8 already another would be cheaper than some of the pricey units that could do the job. i'd hate to be knee deep in and have some issues that required everything to go back to the drawing board while all the shiny bits collect dust.

 

two ECU's might actually be better, i ran an E6k on my 20B initially and it ran, but switching to sequential fuel and timing split with the E11 made a HUGE difference

 

nice drawing! actually the interior of the car turned out really nice too, its all business

we learned the hard way that the spherical bearing needs to be a pretty tight fit, any movement = clunking noises

 

I didn't mean that 3 ecu's wouldn't be accurate, just soo expensive and like you already said, silly . I wonder if they also used 3 programming laptops and 3 tuners to tune it

Ahh right, I didn't know you already had an LT8. Makes more sense now, if you were starting from scratch I would recommend you to get an ecu that can control a 4-rotor. it's just easier during tuning, because with multiple ecu's you have to switch programming each ecu all the time. Maybe it's a good idea to just get a standalone ignition controller? I think elektromotive makes them, msd probably also does. That way you can use your LT8 to controll the injection, and the leading sparks, and use the ignition controller for the trailing sparks. You would only need a 2-channel ignition controller because the trailing can be wasted spark. I think wasting sparking the trailings might also have a slight performance benefit too. Buying a 2-channel ignition controller is also way cheaper than buying a second ecu. If you really want to get fancy you can get a 4-channel ecu and modify the rotor housings for far trailing plugs, that would be a cool ignition setup... 20 sparks per revolution , maybe even something I can do on my engine!... dammit

Thanks , Yeah I know about the fit, I machine bearing holes all the time. If it's for something fancy or special I'll look up the required tolerances but most of the times I try to keep a +0 to +0.02mm tolerance, so for a 35mm bearing I machine the hole to be between 35.00mm and 35.02mm. 35.03mm or bigger get's scrapped or assembled with locktide depending on what it is.

 

actually having a different tuner for each rotor sounds like fun!

 

John, your car is already redlining. It's like the body wants the motor in it already. Give it what it wants, John.

 

a single CAS could be used if the rotor phasing was the same, but a 90* phased engine would require 2 separate inputs for TDC, a trigger wheel would probably be best but the microtech doesn't support it... i doubt i will use the microtech units given that the CAS idea was pitched out the window. as you said it would be much simpler to run a single ECU for making any adjustment.

if it were phased to fire 2 rotors at the same time it would be so much simpler but i don't want to go through the effort for that setup on the engine.

 

Microtech supports some trigger wheel functions, I think they started allowing use of the RX-8 trigger wheels in 13B's, and they sell crank trigger kits for different models. You could use dual 180* offset trigger wheels if you really wanted to use the 2 LT's, or ask them about programming for a custom one.

Once again John, build is looking great! If you decide to save yourself some labour, you could go with the ground control camber plates:



They seem to be a well-built unit, I have some for my FC.