MegaSquirt PNP for Miatas

[tnord]

thanks again jerry, that's more great information regarding how the tuning needs to be done on specific types of dynos. i'll have to talk to my guy and see if he has that capability.

[C. Ludwig]

Those last words say it all. For the hardcore DIY crew I encourage exploring and using the MS to learn to tune too. For the race crew though... you need it right, right now. You need it dialed in to perfection on a LOAD BEARING, STEADY STATE dyno. Not a DynoJet or any other inertia dyno that's going to put unrealistic levels of load on the car causing you to tune wacky WOT advance levels, and not allow you to tune the partial throttle areas of the table at all. I'm not sure what kind of dyno avu3's car was tuned on, but I'm going to guess it was inertia only and ended up with way too much advance and very likely too little fuel, the combination of which will cause both a loss of power and detonation. A pro tuner can fudge his way through tuning WOT advance on a inertia dyno reasonably well though some guesswork is still involved, it's nothing compared to a proper steady state dyno with a good tuner. Not to mention they can tune your WHOLE table.

+1 Good advice.

[avu3]

I somewhat misspoke in my post, we spent most of our time tuning Fuel, and never really futzed with Spark.

I think the tune was off because our car is a pretty fully built ITA car. Intake track, Header, Exhaust, motor, all not stock. It started and ran, it just was lean out of the box.

Our car WAS tuned on a steady state dyno, I accept most of the blame for it not being right on track. I think another contributing factor was that the motor was already going sour, I just didn't realize it.

Thanks much for the feedback, Jerry.

Scott

[Eagle7]

...The stock ECU and some afm adjutments ...

I don't understand what adjustments you would make to the AFM.

[C. Ludwig]

I don't understand what adjustments you would make to the AFM.

It's common to tweak the ouput of the flapper door AFMs to fool the ECU into changing the mixture.

[Eagle7]

On an IT or SM car? Doesn't sound legal.

[Edit] Oh, I was thinking mechanical change. I guess resistors would be legal.

[JIgou]

The thing about the AFM adjustment is that it ventures into the whole "Can you prove it - what are the factory specs" thing that permeates the Spec Miata world.

Jerry, do you have any thoughts about the gains a well-tuned 1.6 Miata with a pretty much stock setup might see with a Megasquirt setup? I'm sure I'm not the only 1.6 SM driver toying with the move to IT.... (Yeah, I know it's hard to quantify...)

Jarrod

[FoundSoul]

I may be able to shed some light there... I actually tuned the base map for the 1.6 cars on Scott Siegel's SM car here locally, on what has since become my dyno but this was back a year and a half ago when it was at the local Subaru dealership Scott used to tune at, I later bought the dyno from them when Scott left. Long story there .

We tested his car on his stock ECU as he had been running it in SM with a fairly standard SM setup. He was running the standard issue Racing Beat intake, with the AFM, and had his timing advanced to 14* base on the stock ECU. Here are the results of the stock ECU versus the MSPNP MM9093 dialed in with the AFM still in place:


That's about 9 ft/lbs down low, and still 5.5 ft/lbs up top and 6.6whp up top, with gains across the board.

Then even though it wouldn't be legal to completely remove the AFM in SM or IT I don't believe, we tested it anyways and saw further gains:


We didn't spend alot of time on the tune when we removed the AFM so I believe we could have further improved things, gotten rid of that one dip and possibly brought out the top end a bit more, but there you have it, gains pretty much across the board.


Larger images here if you'd like:

http://megasquirtpnp.com/images/mm90...withoutafm.gif

http://megasquirtpnp.com/images/mm90...withoutafm.gif

[IPRESS]

I am going to try to get to Jerry's next month and get the "supa fly tune". We should have some info to post. on the 1.8 MSPNP, in ITA trim. I may see if we can do some tuning without the AFM too (which would work with NASA).

[tnord]

Jerry -

If I'm trying to research and learn how the software works on the 96-97 PNP unit on the msefi.com website, what should i be looking for?

is the MS-I or MS-II processor used? it seems like from the product description on your site that it's the MS-I, but from msefi.com it looks as though only the MS-II has ignition timing capabilities which certainly your product has.

is the version of Megatune i should be researching the MS1-Extra-Hi-Res HR10e?

i don't see any installation articles for the PNP on your site, is that because you truely do just plug the existing wiring harness from the OEM ECU into the MS?

[Marcus Miller]

Jerry -

If I'm trying to research and learn how the software works on the 96-97 PNP unit on the msefi.com website, what should i be looking for?

is the MS-I or MS-II processor used? it seems like from the product description on your site that it's the MS-I, but from msefi.com it looks as though only the MS-II has ignition timing capabilities which certainly your product has.

is the version of Megatune i should be researching the MS1-Extra-Hi-Res HR10e?

i don't see any installation articles for the PNP on your site, is that because you truely do just plug the existing wiring harness from the OEM ECU into the MS?

Speaking for the 90-93 unit, yes all you do is plug in the stock wiring harness and the vaccum line to the maf.

Would be interested to know more about your other questions though Travis.

Marcus

[Monkeywrench]

Can anyone comment on the rate of fuel burned with a PNP or other ECU set-ups? I would imagine it has a lower bsfc rating. Might make for a better enduro set-up.

[FoundSoul]

Sorry I missed your post from earlier this month Travis. I'll have to check my account here and see if it's setup for email notifications... but to answer your questions:

All three of the current MSPNP models for Miatas (90-93, 94-95, and 96-97) are running the MS-1 processor. The MM9093 and MM9495 models run the standard MS1 Extra firmware, and the MM9697 runs the HiRes MS1 Extra firmware. For those familiar with MegaSquirt these details are of course available. For those that just want it to work though, when you install the MegaSquirtPNP software package from the included CD-ROM or from the download link here (http://www.megasquirtpnp.com/mspnp_downloads.htm) the software is properly setup for your specific MSPNP model and you don't have to worry about what firmware version you are running unless you just want to know, or go out on your own and update it. (for example some of the MM9093 and MM9495 guys have ventured out and installed the HiRes firmware on these models, works fine of course)

The install is incredibly simple. Maybe an hour if you goof around. Check out the 'Quick Start Guides' for the install process in a nutshell on this page: http://www.megasquirtpnp.com/mspnp_installation.htm

That also has the full manuals linked ^^


Joe Tenney (ITA Miata #16) came by the shop today actually. We installed a unit in his car and I tuned it out for him. I pulled 3 comparo graphs before we did anything with his stock ECU in place with tweaked AFM, and have before and after comparison charts. I think Joe's pretty pleased. I'll post charts soon but figured I'd give him a chance to share if he wanted to.

[FoundSoul]

Can anyone comment on the rate of fuel burned with a PNP or other ECU set-ups? I would imagine it has a lower bsfc rating. Might make for a better enduro set-up.

With a standalone such as the MSPNP you have the capability to adjust your ignition timing and AFR at different load/rpm cells allowing fuel consumption to be fined tuned for sure. In any situation you can only go so lean to accomplish better fuel mileage, and in a race situation it's often even more important to err to the side of caution here for reliability's sake on a engine you're running harder than normal. But the fact remains with complete control of your ignition and fuel tables you have complete control. Is there a significant portion of the course where you're at 40% load(*) and 6000rpm? Don't see any reason why you can't lean it out there to get better mileage? You've got the power. And better yet, doing so won't effect the WOT areas of the tables at all. You don't have to compromise economy and power, generally these are sought in different load ranges, hence you can accomplish both.


(*) Load isn't really measured in percentages but in kPa, but it's easier to express this way here...

[wepsbee]

I have a 95 Ford Escort GT with a 91 engine. This is a Mazada BP 1.8 engine which was also in the Miata's. I am having trouble locating a stand alone ECU for this car. Does the Miata MS ECU also work for my car?

[FoundSoul]

I have a 95 Ford Escort GT with a 91 engine. This is a Mazada BP 1.8 engine which was also in the Miata's. I am having trouble locating a stand alone ECU for this car. Does the Miata MS ECU also work for my car?

At this point no-- you're right the motors are the same, but the ignition systems are different which is the EMS's key interface to the motor. We're actually looking at making a minor update down the road a bit to make it support this model as well though. It's on the to-do list and won't be hard to accomplish. We had a working prototype of this running in the GRM $2008 Challenge this year. Different car, but same ignition system and motor you're running.

[FoundSoul]

Alright, Joe must be busy, but he had given me the go-ahead to share everything anyways, I just wanted to give him a head start .



Here's the best of three pulls on the stock ECU as the car arrived. Tweaked MAF, advanced distributor. WAY LEAN as observed during the pulls.



Here's the final pull after we installed the MSPNP MM9093 and tuned it out. I let the dyno auto-scale to show you the exact peaks, I'll post a direct comparison of before/after next with manual/matched scaling to make everything prettier. Right off the bat here though you can see peak numbers improved. 2.7wtq, and 5.3whp. And because it was so dramatic, you'll probably also notice the torque line stayed left and above the HP line after, where it hugged it before and even dipped under. There is a dramatic changed there, but it's hard to really read as part of that has to do with scaling, so let's scale it evenly and take another look:



Here's the direct comparison. Down low that's a 16ft/lb increase (nearly 20% there), that slowly tapers off as he heads toward 4800rpm. Up top there's a 4-10whp increase all the way to redline. You can see where I laid the line on the graph at 6800-6900 there's a 10.2whp/7.8wtq increase. Still making more power there than the stock ECU was at it's peak at 6300rpm.

[rockytenney]

Remove stock ecu and bracket, plug in your new DIYAutoTune Megasquirt PNP MM9093 , bolt it down, run Map line to intake, pull ST SGN 10 amp fuse, start car, goose it a couple of times, hit the kill switch, eat sandwich while looking at the car, congratulate yourself on how clever you are generally, and specifically in this case, how you exceeded your own cleverness expectations. All this for the price of a set of go to the race tires. Of course, an interface in the form of a laptop (cable included) and a dyno (not included) would be required to further optimize for your engine.
The dyno sheets as posted by Jerry indicate that the device as configured by DIYAutoTune does improve torque and hp across the range significantly. The air/fuel ratio is controlled by the unit and the AFM could be tossed for more gain. Someone may notice this missing in SCCA impound.
Jerry and the folks at DIYAutoTune have an impressive product line and development facility, and are definitely focused on customer service.

Joe Tenney
90 Miata ITA.

[tnord]

Joe -

I have little doubt that getting the car to run on the MS PNP is easy as can be. Do you do any of the tuning yourself? The dyno I will take the car to is not familiar with Megatune, and I want to be able to tune the car myself at the track, so it's something I really need to learn.

i think those are pretty good gains considering you had an already tuned AFM. was that an AFM you had tuned at the dyno before? was it an ART? i won't be running a 1.6, but i know someone who is and is considering a MS PNP. i'll be in a 96.

[rockytenney]

Travis,
I was the watcher and not the doer. I am confident that if I had read the manual I could have muddled through. Populating tables is a repetitive function that is easily handled and you would be working from an existing baseline specific to your 1800 as opposed to a cold start. The displays are great and the menus are more intuitive than your basic cell phone. I am sure the folks there will be able to deal with the various install and tuning problems the user gets himself into. The manual and install procs are on the web site. You will need a wideband sensor to tinker at the track.
Mac Spikes has an 1800 and is going to see Jerry on his way to the ARRC. He would probably let you know how he made out with his "supa fly tune".
The AFM was tuned by John Williams with that engine on a dyno. I am pretty certain that he got all he could get using an AFM.

Joe Tenney