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Old 08-31-2007, 04:52 PM   #1
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Default MSPnP Faq

It would probably be a good idea to get a MSPNP FAQ going here to help get the common questions/answers together in one place as some of the same things keep coming up. To be honest, most of what's coming up is adequately covered in the manuals. Please, Please, Please read the manual for the MSPNP itself, and read the included MS1 Extra Manuals as well since that is the code running on the MSPNP, and therefore covers much of what you'll need to know to tune it.

1) Where can I find the most up-to-date MSPNP Manual?

The manuals that came with your MSPNP were up to date when the CDs were printed, but the most current information can always be found at:

2) Where can I find current base maps and tuning software?

3) Should I install the MSPNP at the same time as my new injectors, BOV, turbo, and boost controller?

Not if you can help it. Remember 'the scientific method' from grade school? The method that taught us to change one thing at a time, monitor the results, and then we knew that the one change we made was the only possible reason for the results? Same applies here. If you change a bunch of things at once and run into a problem you won't know where to start. You'll come to us with 'MSPNP problems' when you've really got a larger vacuum leak where one of your injectors seals got pinched badly during install (yes that's a true story). We end up having to help you diagnose your entire car in order to help you understand that our system truly isn't the root of the problem. Or in some cases, we can't be sure if it is or isn't because the situation is all clouded up by other mods done at the same time. One mod at a time please.

4) So in what order do you recommend I upgrade my car, I'm planning to go turbo with bigger injectors.
A}Install the MSPNP, get it running, that should be easy. Make sure everything is working properly.
B} Upgrade your injectors, scale REQ_FUEL, cranking PW, Accel Enrichments, and fine tune these in for the new injectors. Make sure everything is working properly.
C} Go Turbo! Tune your car! (that doesn't mean ask Joe Blow for his map)
This normally wouldn't all happen in a weekend, but it doesn't need to. Install the MSPNP ahead of time. Then install the injectors a week or two later. Your still saving money or gathering parts for your turbo kit during this time, now take the plunge and go turbo!

5)Do I HAVE to tune my car? Isn't it just 'plug in and drive away'?

It's Plug and Play, not necessarily just 'plug in and drive away without having to give anything a second thought'. If your car is bone stock, the base map will probably suffice, you 'might' have some very mild fine tuning but likely not. I'm betting though that most buyers of a product like this are not running bone stock cars. Some tuning will be required to get the most out of this product. When you buy a standalone EMS, you aren't buying performance, you're buying the ability to tune your car to get the best performance. It puts the control in your hands. Full control. For better or for worse. The documentation provided will help you make it for the better. The base map gets you 95% there on an n/a car even with most common mods.

6)What are the most common 'fine tuning' needs for a mildly modified n/a car?
A} Fine tuning idle VE (fuel table) for proper AFRs. For batch injection you should tune for 13.3:1 AFR at idle. If you don't have a wideband, I advise you get one when you get a chance. Not because we'd make a few bucks if you get one from us, but because guessing games with your engine aren't good. For idle I can tell you how to work around it. Elsewhere that's not the case. For idle, if you don't have a wideband, adjust the idle area of the VE table and watch your MAP (kpa) reading. You want to adjust VE to give you the lowest kpa reading possible at idle. That will get it close to 13.3:1. You should not hear any slight misfire if you have the mixture right. If you do, it's probably a bit lean.
B} Other VE tuning- Especially if you found you needed to adjust your idle VE, but regardless you should check this-- cruise AFRs are typically around 14.7:1 give or take half a point. You can go leaner if you'd like, maybe as lean as 15.5:1 or so in some cases. Turbo cars don't always like to cruise quite so lean, I generally keep them closer to stoich 14.7:1.

70-80 kpa area of the map should start richening up. This would be a part throttle accelleration, maybe 1/2 or 2/3 throttle. It should be around 13.5:1 to 13:1.

90-100kpa should be between 12.5:1 and 13:1. That would be WOT.

In a naturally aspirated application, on pump 93, I'd expect you to be just fine with the base map ignition table. Probably even on 91 though I'd suggest you run the best pump gas you can.

7)What are the main tuning needs for a forced induction car?

You really want to spend a bit of quality time on a steady state dyno to do this right. 2-3 hours should be enough in most cases. Maybe 4 if you have EBC tuned in at the same time (which is sweet BTW).

They'd want to steady state in the whole fuel table up to say 4600rpms ish, which shouldn't take more than an hour, and likely much less.

Then they scale out VE above that 4600rpm point that you quit steady state tuning at.

If you're running pump 93 they don't need to touch timing under 100kpa, just steady state it above 100kpa up to maybe 4600rpm which won't take long at all.

Then on to ramp runs for WOT tuning. Maybe starting at low boost and increasing it depending on your goals. This can go somewhat quick, but if you want to play with a manual boost controller tuning at different levels of boost, or tune EBC, it will take longer as you're playing with more variables.

AFR targets BELOW 100KPA are similar to what is described above for naturally aspirated cars. Above 100kpa each car is a bit different, but for most Miatas I generally stay around 12.5:1 up to about 5psi, then work towards 12:1 as I approach 10-12psi, and run 11.8:1 or just a tad richer up to 15psi. Shouldn't need more than 11.5:1 and that's alot of fuel...

8)How do I wire a wideband up to the MSPNP?

By following a combination of the wideband's documentation, and the MSPNP's documentation

The wideband's documentation is going to tell you how to properly install the wideband in the car. It could care less about the EMS with one exception. You need to SHARE GROUNDS between the 'system ground' of the wideband, and the EMS. In this case we're using the stock ECU grounds through the harness, which terminate at the engine.

On the 90-93 cars this is at the rear of the head, right by the CAS, hanging off the hook/hanger on a bracket. There is a pair of wires here, and another just below this. These four wires are the ECU grounds. Ground your wideband here as well. Take care not to disturb the ECU grounds though-- it may be best just to get a new nut and at it to the top of the existing exposed stud to ground the wideband.

On the 94-95 cars the ECU ground are on a small bracket just under and to the right of the throttle body. It's easiest to see if you remove the throttle body inlet tubing. Pics are in the manual. Again, don't disturb the factory grounds or you'll be sorry! They need to be at least as good as they were before you got there.

Last edited by Ben; 08-31-2007 at 05:29 PM.
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Old 08-31-2007, 05:19 PM   #2
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Default part II

9)Do I really need to dyno tune my car? It's expensive! Is an inertia dyno good enough?

Everyone here has seen people spend $500 on an exhaust system to pickup maybe 6whp. Or $200 on an intake for 2-3whp.

You've got the tool-- it needs the proper tune. Without it, it's just a tool sitting in the toolbox not being used to it's potential.

I can't speak to the skills of a particular tuner that I've not met, your experiences with tuners will vary. But what I can speak for is a good tune, a proper tune covering the tables in full, which only a steady state dyno can accomplish (no matter what an inertia dyno owner tells you about 'bumping the brake' -bullcrap-). And that proper tune.... it's worth the money.

$900 is on the high side in our area-- some would pay it gladly to a reputable tuner with a good dyno though. $600, that's more than some, but not that bad really. Think about this. That steady state dyno cost that shop owner AT LEAST DOUBLE what that inertia dyno cost they other guy, maybe triple, and in theory at least he bought it so he could do the job right for you. They're also a bit more complex to run... it's not just 'push the green button to go, and the red button to stop', you have to have a operator with at least half a brain.

That's why you see so many crappy inertia dyno's-- they're cheap and most people don't know any better. They measure how fast you can spin a heavy drum, but they can't put your car under an accurate load and hold it there while the tuner dials each and every cell into perfection. The best they can do is try to 'roll through' those cells, but the cars not under normal load when they do that. It won't be 'right' when you get it on the road. If you've already got a rock solid base map and all you care about is WOT tuning, then inertia dynos can do that to some degree, still not as well as a good steady state dyno though. As a SS dyno can control the load in a ramp run too, want a 5 second pull from 1000-7000rpm? NP. Want the same rpm range but in 15 seconds to simulate a big hillclimb really loading up the engine? NP. Ask an inertia dyno owner to do that. They can't. They can only spin their little drum. Well, ok, big drum.
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Old 09-28-2007, 12:47 PM   #3
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Default cooling fan activation temp adjustment

Under 'More Settings' > 'Outputs'

You'll see the lower output, #2, is set to activate on CLT, and the default temp is 215. Note that it actually activates 40 degrees under whatever this is set to, notice the note on that screen (F+40). So this is really activating the fan at 175 degreesF. You could raise it a bit if you wanted, I believe stock doesn't activate until 197*F, but I wanted to have it default a bit lower.

Last edited by Ben; 09-28-2007 at 01:07 PM.
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Old 09-28-2007, 01:38 PM   #4
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Default 90-93 Idle Transition Stall Remedy/Linear TPS Conversion

When I decelerate to a stop while cruising, my car will sometimes stall instead of stabilize at idle speed. The problem is worse with my A/C on.

Add a linear TPS

1.6 manual tranny miatas don't have real linear throttle position sensors. They simply have a open/closed switch, which isn't very effective.

The simple wiring modifications needed on the MS are covered in the MSPNP owner's manual. You will remove 2 stabilizer resistors off the DAUGHTER BOARD (not the main board) and add 2 jumper wires. Please consult the manual and if you are not comfortable have DIY Autotune perform the procedure for you. Their labor rate is extremely reasonable.

You will need to source a linear TPS from the aftermarket or from another application. The easiest swap is probably a BMW TPS Bosch part # 0-280-120-402 from an auto E30 or E36, or Bosch #0-280-120-406 from an E32. Both of these should bolt on your miata TB w/o modification. You will need to adapt the wiring harness to accomodate. The BMW pinout is
Pin 1-black wire-5volt in
Pin 2-shielded wire-ground
Pin 3-yellow wire-signal out
Pin 4-ground
Pin 5-WOT switch
Pin 6-Closed switch
6 1
5 T 2
4 3

Another option is to use an aftermarket sensor. I went this route with a Wells TPS and wired it to use a miata TPS connector

Once installed and wired up, there is a brief calibration procedure and some software settings need to be changed to accomodate. This procedure is pretty well covered in the MSPNP 94-95 manual. Good base to work from:

Adding the linear TPS not only offers increased ability to stabilize idle, but other tuning and safety options as well such as closed loop boost control.

Last edited by Ben; 09-28-2007 at 02:25 PM.
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