I have an M45 s/c for my Me-Otter and part of the plan was to stick an aftermarket ECU on the car (most likely MSPNP, currently don't feel flush enough for an FM Link). I know that I'd be paying for the famous FM customer service with the Link, but I'm not sure I can justify the expense at the moment.
I think I should be able to do a reasonable job mapping the car using a wideband and appropriate software - I massively improved the map on the Talon that the "egg spurt" who built the car put on it.
Plus Miata engines are cheap 
.
Anyway, given that at some point I haz the boosts I probably want a knock sensor. The Internet is full of complaints about aftermarket knock sensors, any recommendation for one that will work with an MSPNP and does a decent job?
Also, the car is currently N/A - would you throw the ECU on it, map it without the S/C and then repeat the exercise with the S/C bolted on, or just go whole hog, bolt the S/C on and then map the whole thing in one go?
Of course the other option is to just get an FM Voodoo Box (I have an MSD timing controller already), throw the s/c on the car and be done with it, but I personally am not a big fan of cutting up the wiring loom for that. But it's probably the quicker way to get the car running.
There's no factory knock sensor on that car?
I'd probably personally go with the "whole hog" option, as your n/a timing map isn't going to be REAL useful to you once boosted.
BoxheadTim wrote:
Anyway, given that at some point I haz the boosts I probably want a knock sensor. The Internet is full of complaints about aftermarket knock sensors, any recommendation for one that will work with an MSPNP and does a decent job?
We used a Bosch 0 261 231 008 sensor for developing the MSPNP's knock circuit.
One word of caution: Do not use a knock sensor on the Miata as a primary tuning tool. Miatas start losing power with timing advance well before they start knocking. Also, the MSPNP knock circuit is better than the one in the MS/Extra manual, but it's not as good as your ears (that's why it has a headphone output, so you can listen to the sensor).
Also, the car is currently N/A - would you throw the ECU on it, map it without the S/C and then repeat the exercise with the S/C bolted on, or just go whole hog, bolt the S/C on and then map the whole thing in one go?
I'd put the MSPNP on there first; even if you don't fully map it, it would be good to be sure everything is working as it should.
BoxheadTim wrote:
Of course the other option is to just get an FM Voodoo Box (I have an MSD timing controller already), throw the s/c on the car and be done with it, but I personally am not a big fan of cutting up the wiring loom for that. But it's probably the quicker way to get the car running.
If you want to avoid cutting the wiring harness, AEM makes ECU extension harnesses that go between the ECU and the factory harness. That lets you cut the extension harness, rather than the factory one.
You're better off with the MSPNP than the Voodoo though. Yes, it's more work, but it's safer and you'll make more power.
codrus wrote:
BoxheadTim wrote:
Of course the other option is to just get an FM Voodoo Box (I have an MSD timing controller already), throw the s/c on the car and be done with it, but I personally am not a big fan of cutting up the wiring loom for that. But it's probably the quicker way to get the car running.
If you want to avoid cutting the wiring harness, AEM makes ECU extension harnesses that go between the ECU and the factory harness. That lets you cut the extension harness, rather than the factory one.
I was aware of the extension harness for the CPU, but I'd also need to cut into the cam sensor wiring harness to use the MSD timing controller. IIRC there is no extension harness available for that one.
codrus wrote:
You're better off with the MSPNP than the Voodoo though. Yes, it's more work, but it's safer and you'll make more power.
My understanding is:
MSPNP > Voodoo Box > Powercard (which is what I have now)
I'm not a big fan of piggyback ECUs so my general preference would be for the MSPNP anyway. I guess that's going to be the way to go then.
MadScientistMatt wrote:
BoxheadTim wrote:
Anyway, given that at some point I haz the boosts I probably want a knock sensor. The Internet is full of complaints about aftermarket knock sensors, any recommendation for one that will work with an MSPNP and does a decent job?
We used a Bosch 0 261 231 008 sensor for developing the MSPNP's knock circuit.
One word of caution: Do not use a knock sensor on the Miata as a primary tuning tool. Miatas start losing power with timing advance well before they start knocking. Also, the MSPNP knock circuit is better than the one in the MS/Extra manual, but it's not as good as your ears (that's why it has a headphone output, so you can listen to the sensor).
Just "for dummies", I assume that I have to have the knock sensor mounted to use the headphone output, correct?
MadScientistMatt wrote:
Also, the car is currently N/A - would you throw the ECU on it, map it without the S/C and then repeat the exercise with the S/C bolted on, or just go whole hog, bolt the S/C on and then map the whole thing in one go?
I'd put the MSPNP on there first; even if you don't fully map it, it would be good to be sure everything is working as it should.
Thanks Matt, that was my thinking but I wasn't sure if what was intuitive to me actually made sense in the real world.
Right, the knock sensor has to be wired up.
Swank Force One wrote:
There's no factory knock sensor on that car?
My understanding is that NAs don't have factory knock sensors.
BoxheadTim wrote:
I was aware of the extension harness for the CPU, but I'd also need to cut into the cam sensor wiring harness to use the MSD timing controller. IIRC there is no extension harness available for that one.
Theoretically you could make one. Buy a broken CAS and cut off the end of the harness from a junkyard, dremel the connector off the broken CAS and solder it to the other end of the dremelled connector. I did this to make a coolant temp sensor wiring harness extension when I installed the M-tuned coolant reroute kit.
Not worth the effort though, MSPNP is better.
Additional question - my understanding is that the MSPNP can't/doesn't drive the EGR valve, is that still correct?
As I mentioned in my latest post in my build thread, the Maxim Works header I have and the cat are having a bit of a co-spatial event. I have two options, get another header (Jackson Racing, that one is CARB legal and has an EGR fitting) or get the cat modified and fitted with a new flange, which would result in an automatic EGR delete as the Maxim Works doesn't have a provision for the EGR anyway.
FYI, the Link has been out of production for some time now. We sell the Hydra these days.
The knock sensors we use are OE Subaru parts, if memory serves. They don't seem to have any reliability concerns.
The Voodoo is a legitimate option. The nice thing about it is that you're still driving a stock car when out of boost. You're not responsible for cold start, idle, cruise, AC compensation, etc. You also retain OBD-II codes if you have a 1996-97. A programmable ECU will give you the ability to do something about the idle problems you'll likely encounter with the M45, though. As for ultimate power, expect about another 20 hp due to the larger injectors you'd be able to run with it, but the M45 isn't a high power option regardless.
I don't think any of them control EGR.
Thanks Keith, for some reason I always get Link and Hydra mixed up.
The car is a 95 so OBD-II codes aren't an issue, cold start, idle, cruise etc might be. One of the advantages of throwing a known solution like the Voodoo box at this would be that I can get the car up and running quicker compared to doing the mapping myself and then later upgrade to an MSPNP.
Re the idle issues, once I get to bolting the S/C on I was going to switch to a dual throttle body setup anyway. Might be a good time to introduce myself to my neighbour properly (he makes parts for custom cars for a living and tends to have interesting customer cars parked outside) and check if he might be able to help out with some of the little parts that need to be fabbed up, especially if I want to bolt a bigger TB to the M45.
Anything with a programmable duty cycle table can run egr. I have done it with ms. Not sure if the pnp has hardware to do it though.
Paul_VR6 wrote:
Anything with a programmable duty cycle table can run egr. I have done it with ms. Not sure if the pnp has hardware to do it though.
If you're running a blower, you could put the boost control output in open loop and wire it to an EGR solenoid. We didn't really plan for the MSPNP to control EGR, but if you wanted to try it for some reason, that would be your best bet.
I'm not particularly attached to having working EGR in this car. Retaining it would allow me to keep the car mostly CARB legal if I didn't attach the blower to it, but other than that there isn't really any benefit to it.
We don't have smog testing where I live, but across the border in CA they do so if I ever have to move to CA for work there is a chance this car might become a track-only car if I still have it by then.
