The Valley of Death (VOD) and Top End Progress

[Xero-Limit]

About 6 months ago I was approached to see if we can do anything with the BRZ. At first, I said no, but I'd be glad to put it on and see what the other guys are doing (moto has been MX-5 only up until 2012). So we put the car on the dyno to see what the purchased tunes did...and sure enough this is what we found. BTW, this is NOT any tuner starting with a V [thanks for the heads up though John--I owe you!!!]



So here we some good gains 4-6k, and up top with the higher rev-limit. We also worked with another tuner to send back and forth datalogs via email (as our business model) and put on nearly a dozen runs--and yet no better (actually worse than stock). So...at this point having done the MX-5 for a few years this looked easy enough. Giant torque dip, 2.0l high compression motor...wonky cam phasing and AFRs on the stock map...Sure!

However, not so easy.

After a few weeks of testing and road tuning we got to this (on a different dyno)



So we're doing better, but still up top it is a bit lacking. The nice thing is it gave plenty of time to play with the RaceROM features, custom maps, and a whole bunch of other goodies in the software. The EcuTek guys invested a ton of time and money into this. Nothing like this has ever been available for tuners using the stock ECU.

Regardless, further testing ensued. It would be as though for every two steps forwards, we went a step back. Unfortunately you won't find Subaru's in-house methods for peak cylinder pressures or their calculations for intake tract length vs. piston cup size in any textbook; but fortunately patents are actually quite useful in finding out a particular strategy. And the crux of it is that unlike the any straight DI, or straight port injection, variable intake or exhaust cam car--all of these MUST absolutely be perfect in timing to get any HP gains. Before you would tune the ignition timing, lean out the AFR, remove torque limits and there you go, 10-20 hp. Well, Subaru/Toyota, thank you very much, the job has become harder. The stock car will learn up to a very high ceiling. The stock maps are already fairly optimized. To make HP on this platform is no joke, I credit Visconti and Perrin for having real gains anywhere early on. Regardless, this is the last dyno from last weekend. We finally got the torque dip more of a "dip" rather than "pause". With custom mapping we also got the top end opened up a heck of a lot more. (note: this is the lower reading dyno again)



With all that said, dynos only tell half the story. Acceleration is about 1 second quicker 0-60, and with the latest RaceROM features you can record "longitudinal g's". This is REALLY cool, because you can actually see what the tunes are doing in real world conditions and with learning. You'll find high variability between runs based on temps on the dyno. If you have a straight road, good traction, low winds; repeatability on the street can actually be better if you're taking care since you can cool off, take advantage of the CAI, not doing ECU resets etc.... The flat foot shifting, launch control, autoblip are really cool. Another neat feature is to "calm" the rev limiter so auto-x guys aren't losing 5mph in 2nd.

So this is how you can look (anyone with ProECU can do this with RaceROM v4) and see what you're getting g wise. Look like a torque curve maybe?




The 2d view-this can be used to analyze the differences the maps are having. You can also use software like virtual dyno to get HP ratings. This is more precise for instantaneous torque, whereas the VD types are a better indicator of area under the curve since they use timing. Neither are a substitute for a dyno, but are extremely useful for tuning if done proper.


And finally, tuned we have this logged G curve on the latest tune:



Much smoother. So that's it for now, we will resume finagling with it as it warms and maybe do some E85 testing. For now I'm fairly happy to say you can definitely make HP with this car on pump gas--though any broad gains across the board I'm a bit skeptical. This I found to be very easy to do with the dyno via gearing or learning. In the dip and up top there is clearly some room.

[xjohnx]

wow, some great info here! thanks for the post and welcome to ft86 club!

your last image link is broken, so here it is:



When do you guys expect to have a product for sale? I autocross quite a bit and it definitely seems like you guys had us in mind when doing your research.

[industrial]

Wow that looks really good. Have you guys had a chance to mess with cars with various bolt ons?

[wootwoot]

I assume you will be releasing this tune for sale at some point?

[Simmons]

Originally Posted by wootwoot

I assume you will be releasing this tune for sale at some point?

Moto-east.com




Simmons

[dabocx]

Really interested in seeing what you can do what bolts do when added and then retuned especially the header.

[Xero-Limit]

Originally Posted by industrial

Wow that looks really good. Have you guys had a chance to mess with cars with various bolt ons?

These numbers are with bolt-ons but generally the ECU can compensate just fine for the little stuff. The fuel trims are still within only a couple of percent. Stuff like headers or anything before the throttle body is a different story though. Same goes with changing MAF size.

Originally Posted by wootwoot

I assume you will be releasing this tune for sale at some point?

Yup. as above it's been out, but not advertised as I wanted to make sure we have something solid. All of the above runs are 4th gear, 5th gear we were up to 192 whp uncorrected on the "lower" dyno, but for the sake of not boiling the oil on back to back runs, we kept it in 4th and not published that one since it has no comparison on the same dyno.

Originally Posted by dabocx

Really interested in seeing what you can do what bolts do when added and then retuned especially the header.

Me too! The header testing will start pretty soon. Going to add some more tech stuff below for those interested.

Originally Posted by xjohnx

wow, some great info here! thanks for the post and welcome to ft86 club!

I autocross quite a bit and it definitely seems like you guys had us in mind when doing your research.

You bet--last year we had several nationals folks running our tune in STR on the MX-5, and we've done the "smooth" rev limit on some of those as well so that you're not dropping MPH top of 2nd

[Lonewolf]

Welcome!

[Xero-Limit]

Perusing through the 150+ datalogs we see another reason dyno's don't show everything. See the screencap below, can anyone guess which one has the CAI and which one doesn't?

(No, we don't make one for the BRZ so not a sales thing!)



Will it show gains on the dyno? Nope. Will it give you a bit more in the midrange on the street? Heck yes. Hats off to Perrin for the intake above. No tuning changes necessary so it is the same exact size, and we can see up top the airflow is peaking at 160 g/s vs 154 stock. (not pictured). Not a huge deal, but if you increase the rev limit it is important. Of note, it is not as simple as rigging some aluminum together....

[Xero-Limit]

Now that we have our own BRZ here to play with, we spent the break-in period testing variations on the stock setup, 3rd gear for higher sample rate. That and tweaking the racerom features for friendlier driving.

Here's a virtual dyno comparison on a flat road going in the same direction...disregard the ultimate numbers, but the differences should speak for themselves. Note the one stock-ish [red] "freak" run could not be repeated; while the tuned runs were back to back consistent. This map has 2-3-4 increasing in aggressiveness, hence the increasing plots. Orange is more akin to what was seen in subsequent logs with mostly stock mapping. Can't see it here but the graph starts at 3400 RPM, ends at 7400.

Making headway but there's more room to go. Compared to the car with bolt-ons, that one is making at least 8-12 hp more everywhere with a cat-back, CAI, and overpipe.

[wgnzlz]

It's nice to see you on here Mike.

[funbeatsfast]

Wow. This looks like a winner!

Edit: That looks sarcastic. It's not. This tune looks like what I would have done, had I the skill to do it. But , you know, I don't. So thanks.

[OrbitalEllipses]

Interesting.

[Xero-Limit]

Originally Posted by funbeatsfast

Wow. This looks like a winner!

Edit: That looks sarcastic. It's not. This tune looks like what I would have done, had I the skill to do it. But , you know, I don't. So thanks.

LOL didn't notice! The amount of work it takes to get a single hp (let alone 10) out of the dip I didn't even thing sarcasm was possible

Have been working on getting it consistent and repeatable over the last several days. Had a chance to put on a few hundred more miles (this car is a daily driver after all) and the learning on this ECU continues to improve. Unlike piggybacks though, we can alter it. The latest maps are all done using custom RaceROM features so that Map 1 is nearly stock, which means it makes for an easy comparison to the stock tune without having to to re-flash. Map 1 is still a few HP over stock in the dip, but this way we can empirically test variations of cam phasing and injection ratios.

Here's another one from today, can you guess which is the stock run vs most aggressive?



That's the car with bolt-ons. The stock tuned car is a few HP down but otherwise the same. Still have room to go but this tune variation leaves ALL learning intact for reliability purposes without compromise. This way 91 octane folks have nothing to worry about and no cats will be harmed in the long run.

The rev limit is finally tamed with a buttery smooth 7600 here (or whatever you want) without the 300+ rpm dropoff. Hopefully will have time tomorrow to shoot some video to demonstrate.