4-Rotor FC Build
This 4 rotor build is such a detailed and well executed project! I'm stunned by the technical work and detail. Wish I had access to a machine shop and some mechanical aptitude to fabricate stuff.
Thread Starter
Joined: Oct 2010
Posts: 605
Likes: 13
From: The Netherlands
Sorry for the lack of updates about the 4-rotor by the way. I need the crappy beemer up and running so I can daily drive that, but the FC parts I put on there started to blow up. I ran it with about 1,2 bars of boost (wastegate set to 0.5 but stock s4 turbos creep like hell), and it was pretty quick but the turbo and headgasket blew. The project got a bit out hand after that. I don't know why I did it, but now I have a full equal length 4-2 header on there, ball bearing twin scroll titanium wheeled turbo (IHI VF38), a full 3" stainless steel exhaust and a welded, resurfaced and ported head with headstuds. Need to get the engine back together asap, and dyno it because I'm heading to the track next week. Hoping to get it sorted asap.
Thread Starter
Joined: Oct 2010
Posts: 605
Likes: 13
From: The Netherlands
Anyway, I actually did some work on the 4-rotor again
Nothing spectacular yet, lot's of small but time consuming stuff to do. First thing I did was finish the intake manifold, the TPS sensor was acting up. Got it to work though 
Also did some work on the exhaust, it was already mocked up, but I didn't have any gaskets in there. Normal gasket's don't fit because my exhaust port shape is so wierd. Took a sheet of copper, cut out some flanged and assembled it. There are cutting rings in the header flanges that dig into the copper to help it seal, kind off like an o-ringed head.
Currently messing with the ignition system. I was going to use cbr pencil coils, but now I found these bosch units that I like better. Just need to figure out how to mount them
Yup, I was surprised aswell! The subaru turbo had a better wastegate and didn't creep. Ran that turbo up to 18psi or so, but then that turbo also blew.
Anyway, I actually did some work on the 4-rotor again
Nothing spectacular yet, lot's of small but time consuming stuff to do. First thing I did was finish the intake manifold, the TPS sensor was acting up. Got it to work though 

Also did some work on the exhaust, it was already mocked up, but I didn't have any gaskets in there. Normal gasket's don't fit because my exhaust port shape is so wierd. Took a sheet of copper, cut out some flanged and assembled it. There are cutting rings in the header flanges that dig into the copper to help it seal, kind off like an o-ringed head.

Currently messing with the ignition system. I was going to use cbr pencil coils, but now I found these bosch units that I like better. Just need to figure out how to mount them

Anyway, I actually did some work on the 4-rotor again
Nothing spectacular yet, lot's of small but time consuming stuff to do. First thing I did was finish the intake manifold, the TPS sensor was acting up. Got it to work though 
Also did some work on the exhaust, it was already mocked up, but I didn't have any gaskets in there. Normal gasket's don't fit because my exhaust port shape is so wierd. Took a sheet of copper, cut out some flanged and assembled it. There are cutting rings in the header flanges that dig into the copper to help it seal, kind off like an o-ringed head.
Currently messing with the ignition system. I was going to use cbr pencil coils, but now I found these bosch units that I like better. Just need to figure out how to mount them
Thread Starter
Joined: Oct 2010
Posts: 605
Likes: 13
From: The Netherlands
What about them? Nice coils with an internal igniter, but hard to find over here so they need to be imported from the us which makes them reasonably expensive. But yes they will work on a PP engine. I did hear they can auto ignite when using a long dwell time which I believe is why some people prefer the IGN-1A coils.
Joined: Mar 2001
Posts: 31,835
Likes: 3,233
From: https://www2.mazda.com/en/100th/
https://www.rx7club.com/naturally-as...hread-1035364/
we did some coil testing and the D585's are ok, but they aren't good enough to go out ofyour way to get IMO...
oh and with my old 3 rotor car, i mounted the coils on the frame rail, it puts them really close to the engine, and if you have room, might work?
we did some coil testing and the D585's are ok, but they aren't good enough to go out ofyour way to get IMO...
oh and with my old 3 rotor car, i mounted the coils on the frame rail, it puts them really close to the engine, and if you have room, might work?
Thread Starter
Joined: Oct 2010
Posts: 605
Likes: 13
From: The Netherlands
They are used on a lot of mercedes benz engines 
Data sheet: http://www.bosch-motorsport.de/en-US...2778159755.pdf
3D Cad file: http://www.bosch-motorsport.de/pdf/c..._coils/2x1.zip
I've already seen that thread, some good info in there! I'm kind of hesistant of mounting the coils on the frame rails because my fuel surge tank and my bosch 044 fuel pump sit right on top of the frame rail. Any fuel leakage would end up all over the coils, probably not a good thing
. Plug I like the idea of mounting the coils on the engine, the mazda factory 3 and 4-rotor engines also had them mounted like that

Data sheet: http://www.bosch-motorsport.de/en-US...2778159755.pdf
3D Cad file: http://www.bosch-motorsport.de/pdf/c..._coils/2x1.zip
https://www.rx7club.com/naturally-as...hread-1035364/
we did some coil testing and the D585's are ok, but they aren't good enough to go out ofyour way to get IMO...
oh and with my old 3 rotor car, i mounted the coils on the frame rail, it puts them really close to the engine, and if you have room, might work?
we did some coil testing and the D585's are ok, but they aren't good enough to go out ofyour way to get IMO...
oh and with my old 3 rotor car, i mounted the coils on the frame rail, it puts them really close to the engine, and if you have room, might work?
I've already seen that thread, some good info in there! I'm kind of hesistant of mounting the coils on the frame rails because my fuel surge tank and my bosch 044 fuel pump sit right on top of the frame rail. Any fuel leakage would end up all over the coils, probably not a good thing
. Plug I like the idea of mounting the coils on the engine, the mazda factory 3 and 4-rotor engines also had them mounted like that
Joined: Mar 2001
Posts: 31,835
Likes: 3,233
From: https://www2.mazda.com/en/100th/
I'm kind of hesistant of mounting the coils on the frame rails because my fuel surge tank and my bosch 044 fuel pump sit right on top of the frame rail. Any fuel leakage would end up all over the coils, probably not a good thing
. Plug I like the idea of mounting the coils on the engine, the mazda factory 3 and 4-rotor engines also had them mounted like that 
. Plug I like the idea of mounting the coils on the engine, the mazda factory 3 and 4-rotor engines also had them mounted like that 
I just want to say, out of all the shiny toys and insane builds, this thread is by far my favorite to just sit and drool over. The amount of care and exactness being used is just crazy. Super, super kudos! Can't wait to see the final result, but thrilled to see the journey.
Thread Starter
Joined: Oct 2010
Posts: 605
Likes: 13
From: The Netherlands
Thanks everyone 
Well, not exactly. The casting part for the engine block is the same yes, but that's about it. Everything else is completely different!
Engine is holding together fine under boost though, it just likes destroying turbos for some reason
The subaru turbo also went after I upped the boost to 20+ psi. Oil pressure, oil temp, water temp, EGT temp and AFR ratio were all fine so I'm not sure why it went. Currently fitting a holset hx35 

This was filmed from the beemer on the track, subaru turbo running about 10psi. that popping sound is the revlimiter. I didn't have any grip anywhere, and I don't have any respect for the engine either, so I just kept it floored all the time

Engine is holding together fine under boost though, it just likes destroying turbos for some reason
The subaru turbo also went after I upped the boost to 20+ psi. Oil pressure, oil temp, water temp, EGT temp and AFR ratio were all fine so I'm not sure why it went. Currently fitting a holset hx35 
This was filmed from the beemer on the track, subaru turbo running about 10psi. that popping sound is the revlimiter. I didn't have any grip anywhere, and I don't have any respect for the engine either, so I just kept it floored all the time
Last edited by John Huijben; Dec 15, 2013 at 03:04 PM.






