Cosworth supercharger for the NC

greenMachine · Postby **greenMachine** » Thu Jan 27, 2011 11:44 pm

zombie wrote:
Yes, the Mazda ECU controls everything except ignition and fuel. ABS, DCS/TCS, Cruise control etc work great.

I have long believed this 'PEMS' or parallel EMS is the way to go for the NC. The only reservation I held was the Mazda EMS throwing a wobbly when some of the sensors it expects were off-line, or data outside its expected(required) parameters. Was this an issue for you?

:mrgreen:

zombie · Postby **zombie** » Sat Jan 29, 2011 12:08 am

I had roadstersport headers installed at the same time, and as a result my O2 sensors are currently not connected - giving me 3 codes.

P0037 O2 bank 1 sensor 2 low voltage - this one results in a MIL (Malfunction Indicator Lamp / check engine light)
P0031 O2 bank 1 sensor 1 low voltage
P0140 bank 1 sensor 2 no activity

If I clear the codes with my OBD2 reader the engine light does not come back on until I next start the car. If I don't clear the codes the car does not behave any different anyway, so for short trips I don't bother.

The roadstersport instructions suggest relocating the O2 sensors into the midpipe to avoid these codes - and I was going to do that, but I have this suspicion that if I do so, the Mazda ECU is going to attempt to adjust the short and long term "fuel trims" to account for the difference between the AFR it expects to see, and the AFR it actually sees - because it is no longer in control.

This would most likely result in having it throw codes anyway, so I may as well leave it as it is, it's not doing any harm.

Sailor · Postby **Sailor** » Sun Jan 30, 2011 11:23 am

Hi Matt, Don´t quite get how the mixture is being controlled without feedback from the O2 sensors. Is your addon ECU actually a piggyback type with the std ECU nowrunning in closed loop?
If so you´ll need the sensors installed in the exhaust before you try running the engine hard or you´ll end up with schrapnel even with the most desirable internals.

zombie · Postby **zombie** » Sun Jan 30, 2011 1:49 pm

Hi Rob

The Adaptronic runs open loop only, ie using maps of throttle position vs RPM vs load vs temperature etc

The factory Mazda ECU runs open loop when under full throttle - and even the XEDE forces the Mazda ECU to go into open loop sooner so that it is more predictable - and using a single map, so I'm not sure what you mean.

Closed loop is normally used only to fine tune at part throttle and cruise, mostly to minimise emissions and maximise economy. At open throttle things are happening too fast for any ECU to keep up.

Perhaps in a few more years we will see more powerful ECUs that can keep the perfect mixture settings at all times by using all the sensors, until that happens all ECUs use lookup tables.

Sailor · Postby **Sailor** » Fri Feb 04, 2011 8:56 pm

Awwwww....me bad....Too many margheritas before posting.
Still I'm home now..back to the grind..

Sailor · Postby **Sailor** » Fri Mar 04, 2011 5:06 pm

Had that thing tuned yet Matt?

zombie · Postby **zombie** » Sat Mar 05, 2011 1:30 am

Hell Yes!

and I am stoked with the result.

Finally got some new tyres yesterday so I can actually get the power to the ground in every gear now. The old tyres were fairly shagged and first gear was smoke gear...

Looking forward to the MX-5 Club Sprint on Monday...

Sailor · Postby **Sailor** » Sat Mar 05, 2011 2:26 pm

Whoa!!!!
That IS impressive....

zombie · Postby **zombie** » Mon Mar 07, 2011 11:06 pm

And... I got video :mrgreen:

See this thread for details

Is this giving you inspiration to get yours installed?

Sailor · Postby **Sailor** » Thu Mar 10, 2011 11:15 am

Inspired I am...though I need to complete our bathroom and front verandah renovation first.
BTW, some discussion here
http://forum.miata.net/vb/showthread.php?t=411974
re installing a catch can to reduce oiling of the intercooler.

Postby **orx626** » Mon Mar 21, 2011 6:50 pm

Hi Zombie, did you change out the standard crankshaft for Cosworth's forged item with a keyway machined for the crankshaft pulley and drive sprocket (rather than the friction joint)?

Cheers,
Danny