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MSPNP3 Swap Advice Needed - NA6 with BP1 Engine Race Car
Looking for SuperMiata Racing / MegaSquirt "communal wisdom" as I convert from our stock ECU'd NA6 to MSPNP3 for our endurance race car.
'99 BP engine swapped into '90 Miata NA6 chassis last Winter and successfully ran 4 WRL endurance races this season. Car was reliable & fast... hope to run SuperMiata S2 also as the series expands west to CO.
MSPNP3 ECU and Skunk2 Throttle Body ordered from 949 for "Build Season 2017".
I'm a fairly skilled mechanic / fabricator with 5 years experience building "lower tiered" race cars and do most of my own work including engine builds, but I am a Total Newbie to aftermarket ECU's and Megasquirt.
Car - starting point: '90 chassis with stock harnesses, '99 engine with BP4W head incl VICS, plus normal "SuperMiata bolt ons" - RB header/exhaust, coolant reroute, oil cooler, etc. Stock ECU with larger RX-7 AFM now but will will delete AFM and install IAT sensor. Stock 1.6 throttle body with adapter to 1.8 manifold now, will install '99-'00 Skunk2 TB.
a) Should I install a '99 TPS on the Skunk2 TB? Any benefit for racing? MS documentation says it's "optional" and MS can run off MAP sensor only...
b) Engine currently has CAS on exhaust rear side. Should I run MSPNP3 off the CAS or install a '99 Crank Trigger and wire it up to the MS? (no Crank Trigger on engine currently and has NA6 engine harness)
c) Have AEM AFR gage and wideband O2 sensor. How does the output from the AEM wire into the MS?
d) Running stock flow matched '99 fuel injectors and adjustable 5XRacing adjustable fuel pressure regulator. What fuel pressure should be set with MS and these injectors?
e) Have a standalone Knock Sensor Idiot Light Display in car now using a '99 stock knock sensor. Any benefit to wiring the knock sensor into the MS?
f) Current alternator is a '94-97 unit with built in voltage regulator for the old ECU. Any benefit to installing a '99 alternator and connecting to the MS?
g) Did not have IACV installed on the 1.6 TB, just capped off all holes / fitting. Any reason to install IACV on the Skunk2 TB? I'm fine with the 5 minute warm up / rough idle period (...because RaceCar)
h) VICS solenoid is currently controlled with a stand-alone MSD rpm controller. Better to have MS control directly?
Thanks in advance for sharing your knowledge and advice.
a) Should I install a '99 TPS on the Skunk2 TB? Any benefit for racing? MS documentation says it's "optional" and MS can run off MAP sensor only...
TPS sensor allows easier implementation of acceleration enrichment (extra fuel on tip-in).
b) Engine currently has CAS on exhaust rear side. Should I run MSPNP3 off the CAS or install a '99 Crank Trigger and wire it up to the MS? (no Crank Trigger on engine currently and has NA6 engine harness)
c) Have AEM AFR gage and wideband O2 sensor. How does the output from the AEM wire into the MS?
Depends on which MS you get but -- you can either splice the wideband output signal to the old stock o2 sensor wire or wire it in directly through the options port to the O2 input ADC (thats how I do it with a DIYPNP).
d) Running stock flow matched '99 fuel injectors and adjustable 5XRacing adjustable fuel pressure regulator. What fuel pressure should be set with MS and these injectors?
I think if you set the FPR to a set value (stock is 60psi, I think?) and set your 'req fuel' up to the resulting injector flow rate you'll be fine (flow rate of injectors dependent on pressure, right?).
e) Have a standalone Knock Sensor Idiot Light Display in car now using a '99 stock knock sensor. Any benefit to wiring the knock sensor into the MS?
Can retard timing with knock detection -- safer than just a light.
f) Current alternator is a '94-97 unit with built in voltage regulator for the old ECU. Any benefit to installing a '99 alternator and connecting to the MS?
Alternators on a stock 99 have the voltage regulator in the ECU -- if using the 99 alternator you will need to set up a field control circuit. (I'm basing this off my experience running a 99)
g) Did not have IACV installed on the 1.6 TB, just capped off all holes / fitting. Any reason to install IACV on the Skunk2 TB? I'm fine with the 5 minute warm up / rough idle period (...because RaceCar)
You can control the idle with MS very well -- i'd suggest hooking it up and using it. (Cold starts/hot starts/AC, etc)
h) VICS solenoid is currently controlled with a stand-alone MSD rpm controller. Better to have MS control directly?
MS will be able to control it. (My DIYPNP is set up to flip it on at 5000rpm -- can set it in software.)
Looking for SuperMiata Racing / MegaSquirt "communal wisdom" as I convert from our stock ECU'd NA6 to MSPNP3 for our endurance race car.
I will assume you mean an MSPNP Pro by that, and answer accordingly.
a) Should I install a '99 TPS on the Skunk2 TB? Any benefit for racing? MS documentation says it's "optional" and MS can run off MAP sensor only...
For an endurance racing car, I would get a real TPS as it opens up a lot of tuning options you don't get with the on/off switch that the 1.6 cars used.
b) Engine currently has CAS on exhaust rear side. Should I run MSPNP3 off the CAS or install a '99 Crank Trigger and wire it up to the MS? (no Crank Trigger on engine currently and has NA6 engine harness)
The crank trigger will improve accuracy; I'd use it.
c) Have AEM AFR gage and wideband O2 sensor. How does the output from the AEM wire into the MS?
Run the AEM analog output to the MSPNP Pro's Analog In 2 or to the factory O2 sensor wiring.
d) Running stock flow matched '99 fuel injectors and adjustable 5XRacing adjustable fuel pressure regulator. What fuel pressure should be set with MS and these injectors?
Use the stock fuel pressure level unless you need more flow.
e) Have a standalone Knock Sensor Idiot Light Display in car now using a '99 stock knock sensor. Any benefit to wiring the knock sensor into the MS?
Wiring the sensor to the MS will let it pull timing if knock is detected.
f) Current alternator is a '94-97 unit with built in voltage regulator for the old ECU. Any benefit to installing a '99 alternator and connecting to the MS?
The MS3 can reduce alternator voltage at full throttle for less alternator drag.
h) VICS solenoid is currently controlled with a stand-alone MSD rpm controller. Better to have MS control directly?
I would. That way you can adjust everything from TunerStudio instead of having multiple points of tuning.
This is nearly the same setup we have on our WRL/Lucky Dog car, although we went with a VVT motor, but the same MSPNP pro. We debuted the car when WRL joined with Lucky Dog at the Ridge 2 years ago, ended up getting 1st in class out of 3 in B group. We've also finished in the top 5 including a few podiums since then. NA with a BP swap is a great chassis.
Here's my answers with my own experience in this setup.
a) Should I install a '99 TPS on the Skunk2 TB? Any benefit for racing? MS documentation says it's "optional" and MS can run off MAP sensor only...
Yes. As others have said, you can use accel enrichments properly, instead of reacting to MAP changes, MS can predict changes due to the TPS signal. There are many other features that use TPS, everything from switching the fan off at WOT, to launch control settings.
b) Engine currently has CAS on exhaust rear side. Should I run MSPNP3 off the CAS or install a '99 Crank Trigger and wire it up to the MS? (no Crank Trigger on engine currently and has NA6 engine harness)
You'll have to wire both the CKP (CranK Position) and CMP (CaM Position) sensors to get rid of the CAS. It's a simple extension of the CAS wiring, which you already had to do to get the CAS mounted on the exhaust side anyways.
c) Have AEM AFR gage and wideband O2 sensor. How does the output from the AEM wire into the MS?
As the others have said, just wire the AEM's analog out to the NA6 narrowband wire, should be all you need to do.
d) Running stock flow matched '99 fuel injectors and adjustable 5XRacing adjustable fuel pressure regulator. What fuel pressure should be set with MS and these injectors?
Get rid of the 5xRacing "adjustable" FPR, more complication and 100% useless. MS tells the injectors how long to stay open (pulsewidth). Need more fuel? More pulsewidth, not more pressure. Once you install a stock FPR, set your required fuel and dead time, then never change anything, since all your fuel calculations are off those initial figures.
e) Have a standalone Knock Sensor Idiot Light Display in car now using a '99 stock knock sensor. Any benefit to wiring the knock sensor into the MS?
Does your light ever turn on? I've never had good luck with the NB knock sensor. Knock input on the MS is 0-5v, myself and a local tuner have tuned dozens of Miatas and never gotten more than .1v from the knock sensor. This is an incredibly narrow range that renders it fairly useless. I installed a GM sensor that responds more. On most naturally aspirated engines I don't use the knock sensor. Use dyno tuning common sense (that's another story) and you won't have an issue with knock.
f) Current alternator is a '94-97 unit with built in voltage regulator for the old ECU. Any benefit to installing a '99 alternator and connecting to the MS?
Due to the PO butchering the NA harness, we're actually running 01-05 harness/ecu/engine, and therefore alternator. We've had ~4-5 alternators fail, luckily they're easy to replace. Is that due to our kill switch wiring? Gutted harness? ECU? Who knows. Next one that goes we're switching to an NA unit. So personally, I'd stick with your current alternator, but MANY other people have had trouble free experiences with the ECU controlled units.
g) Did not have IACV installed on the 1.6 TB, just capped off all holes / fitting. Any reason to install IACV on the Skunk2 TB? I'm fine with the 5 minute warm up / rough idle period (...because RaceCar)
Don't be that guy. Because RaceCar is just an excuse to be lazy. Hook up the idle valve, tune everything like it was your street car. Drivability is just as important on track as it is on the street.
h) VICS solenoid is currently controlled with a stand-alone MSD rpm controller. Better to have MS control directly?
Good god yes. Tune everything from your lap top, you'll thank me later. Later on, if you choose to swap in a VVT head (which will be as simple as adding power and a single wire from the solenoid to the MS), I've actually found extra power by having two switch over points for VICS.
And although you didn't mention anything about it, I'd take your upper intake half off and have it port matched to the bigger throttle body. Not sure if it makes any difference, but every little bit helps. Then search about all the different locations and modifications necessary to make the Junk2 throttle body survive an enduro race.
Finally, here's a little motivation for you. Blue line is an NA8 (less compression, worse head) with stock NA6 AFM/ECU. Red line is my own 99 engine, MS, and a stock NA8 intake (just no MAF/AFM). Both have Ebay headers. You can see they're not that far off each other in the lower RPMs, but above 4500 (where you spend all your time), the AFM really chokes off power. to the point where the MS has a nearly 30hp advantage over the AFM car.
Ok, I'll try to not be "that guy" and put the Idle Control back in,.. you made me laugh, thanks Curly.
Your Dyno results certainly are motivating in what can be gained with the MS Add and AFM Delete. I'll red LocTite the bejeezus out of the Skunk2 TB tonight and the MS3 from 949 should arrive in a few days.
Off to the salvage yard to pull a NB Front Suspension, Rack & Cradle to upgrade the front geometry and also swapping in the larger '94-'97 fuel tank. Let the Winter Build Season commence!
Hope we meet at the track someday... Thanks again, very helpful advice.
stooge,
At the last HPR event, we were parked next to each other. Good to see you found this board.
If you need a hand, let me know. Even though mine is a MS2.
GraemeD: Thanks for reaching out. Pulling engine tonight to bump compression as this was originally a 9.0:1 supercharger build. When I get the engine back in and start down the MS3 tasks I'll be in touch. Thanks & see you soon at HPR.
Savington: Read the thread and it answered most every question I had. Thank you for sharing your knowledge and facilitating the thread.
Glad Emilio pointed me to this community...
Just what it sounds like. Simply don't assume VICS wants to be on or off at any point. Do a pull with it on, do another with it off. Compare and you may see that it wants more than one switching point. Every engine and configuration is different so nothing you read on a forum will be half as useful as actually spending 20 minutes on a dyno getting dialed in. IOW, don't use someone else's switching points.
After an unforeseen engine rebuild the past month due to leakdown test results (85 mm bore, high compression, valve deshroud, NA5 intake cam, Boundary oil pump, ATI Damper)...
I'm back to the MSPNP Pro install in the '90 Chassis with a '99 BP4W engine.
First WRL race at High Plains in 3 weeks! All Sensors wired in per Curly's recommendation above.
Looking for guidance on a few issues:
Which base map should I load? I'm thinking it follows the engine, not the chassis... so '99-'00?
Where do I wire in the VICS Solenoid control to the MSPNP Pro?
I would probably start with a basemap that matches the wiring harness of the car, then change settings from there. But I have not spent a lot of time playing with PRO's and adding wires and such.
Base map should be as close as possible to the sensor package being used. Engine and chassis year are mostly irrelevant. IOW, using an NB1 cam and crank trigger, then load a 99-00 base map. Using an NA6 AFM and CAS, load a 90-93 base map, etc.
Deleting the AFM/MAF, choose that option (Speed density vs AFM voltage table or MAF Alpha-N).
No idea on the VICS. It's just a simple 1D switching circuit. I think you can pick from a several auxiliary I/O channels. RPM vs 5V/0V
The only reason I might be hesitant about loading a newer basemap, is going through and verifying all the inputs/outputs match correctly. Not sure how the pro handles it between the years between hardware and software.
12-29-2016, 05:04 PM
MSPNP3 Swap Advice Needed - NA6 with BP1 Engine Race Car
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