This is too hot to handle! Great build so far, am ready for numbers and videos.

 

This build is really great. Thanks for sharing.

 

We had the idea of using the wastegate to put an upper limit on the boost and to change that limit based on the fuel we can get. I looked into it a bit more and found some people doing it on Honda as traction control. They use the weakest spring and a 4 port valve... so I just copied that. One guy tried running no spring and got his boost pressure down to 1 psi, but damaged the diaphragm doing it.

The filter is there to baffle the noise and keep oil from spraying out. And keeps thing from going back in that way, just in case. We will pull it off and see if it makes a difference.

We put the valve in the manifold... in a round about way. I was at Hytech talking to John about it. We were having issues about placement, supporting the weight, keeping it out of harm's way, and I mentioned that I really would want to control the pressure with the wastegate in the manifold. He mentioned that he had done that on Indy cars back in the day. He said it was no problem to do it right there on the back and we went for it.

Did not consider if it would impact the flow on #4. If you think about it we are not going to be getting rid of a lot of air. Right now Emilio is using all of it. My stockish setup will get more pressure (less flow) and I want to limit my power to non break things level (been there, don't like breaking.) I might be bleeding off 4 psi. We have are having a test header made to do cylinder trim. Might be fun to see if we can tell.

 

Let me elaborate on wastegate control of the Rotrex since I have done a LOT of research on the topic.

Centrifugal super chargers (Rotrex) build boost with RPM. Most motors are limited by fuel or stock internals so the SC must be geared towards those limits. The other approach (popular in the V8 muscle car world) is to gear the SC for max power and bleed off boost via wastegate to limit cylinder pressure. With wastegate control if your motor had a limit of 200tq you would be able to bleed off boost to cap power at that level. If your wastegate is controlled by your ECU you can further tailor the power curve for class restrictions or fuel limits. Think of the wastegate controlling power output not so much boost. With the MS3 you can have a funky boost curve to accomplish a flat torque or HP curve.

Another advantage is being able to dump boost (ecu controlled) after redline for those money shifts. This will give the intake valve springs some help by not having boost pressing against them.

Sorry to ramble on in your thread Mental but this is something that most people don't fully understand cause it's a relativity new approach with supercharging. I expect we will see more of it in the future.

 

 

Awesome.

 

Props, this is fantastic.

Sorry if I missed it, but what specifically was used for they gray coating on the tub/engine bay/sub frames etc?

 

Just paint from Home Depot. Meant to be easy to repair when scratched since it comes in spray and brush forms.

 

Not a major thing... but nothing major really left. Took me many months of thinking about how to execute it.

 

This thing is ****** beautiful.

+props.

 

Holy jesus. This is orgasmic levels of attention to detail. There are so many things you did that I would have done if I would have had a longer time to know more things about Miatas before rebuilding my car. Also if I would have had more funds to play with as well.

Major respect John, you just made me think my car was shoddy and dirty in comparison!

Dat engine bay!

 

Such a clean car. Inspires me to redo my lazy areas. Could you elaborate on your steering column? That looks like a sweet *** and big *******.

 

Small change to the look. I see I have not updated this thread in a while...

We blew the engine while tuning when the cam angle sensor decided to quit working for a split second at WOT. On to Rev B for the wiring, ECU, and engine. Since this forum has a 15 minute time out, I will break this up.

 

Redoing the engine harness for MS3Pro

















I decided to make an intermediate harness to go between the ECU and the engine. I will make all the final connections at the end of the PPF. This gives me 5 smaller harnesses to make later on. Figured it would be easier to repair and make changes to down the road. Also puts the bending and moving in the harness over a nice large section vs a hinge the way I had it before.

 

Modified heater core to use AN fittings since AN fittings are way cooler than whatever Mazda would do.





And now I know why Mazda did not use AN fittings. What a PITA. Many aluminum tubes were sacrificed to do this. Not sure it won't leak. I will fill the system with water and use a pressure tester before putting any anti-freeze in it. Probably use some stop leak in it too.

Added one of these.





Bring on the corn power!

Engine and transmission are back in. Upgraded to a 6 speed since we knew we would break the 5 even before the corn power. Thanks again to Emilio for donating one of the used race spares to the cause. More wiring to come soon.

 

The corn sensor works. 8% ethanol at 78°F. Some update pictures.

I can't paint. Serves it's purpose.





Is it properly or overly constrained?



Cheap bastard only bought black wire. I have a couple of wiring problems to sort out before it runs again.



I think that gets it back up to date. Just driving it NA, breaking it in, getting ready for tuning and hoping nothing else breaks in the mean time.

 

Good lord this thing is nice. Full on Miata hot rod build.

 

"Project Stupid"

Is that a Bosch style external igniter bolted to the PPF?

Amazing work as always sir. I wish I had your patience for wiring.

 

Yes it is. I am using the Fab 9 COP kit.

 

That makes sense. It looks like you are on a naked MS3 Pro (not a PnP) so you would need an external igniter anyway. The Fab9 cops are very minimalist, this goes well with your build