Not that I disagree with allowing standalones, but I don't think the above is accurate either. What piggybacks are people running that costs $1200 plus some, and are half ass and sacrifice reliability? How exactly do they sacrifice reliability?

In my experience, the VAFC's etc are around $150-200 used, $300 new, the EMU's are around $400-500 used with harness, $600 new, I haven't seen anything like $1200 plus some for a piggyback, and they are readily available used, while standalones are not so common, so there is a cost difference, and its in favor of the piggybacks, not against. The VAFC's get maybe 80-90% of the gains on an AP1, and they have been used for a long time in honda tuning and even a few years on STR cars now, and haven't heard of any engine failures due to running them. They are a cruder way to tune though, but the EMU is more advanced and has more features and should get close to 100% of the gains of a standalone if you get it all figured out, it is just a bit trickier and more time consuming to sort out and tune. If you're taking it to a professional tuner, it should not make any difference in your cost. What are the reliability concerns with them? The biggest difference between them is probably just that the piggybacks don't have all the extra features of the standalones, but those extra features aren't necessarily needed or allowed either in STR though.

 

The actual cost detail is minor Imran. The order of magnitude is comparable. $800 vs $1200 on a class that already spends $8K or so on prep is minor IMO. You can go cheap but you of all people know how well that works.

Brian Karwan can more accurately explain to you the subtle details about the reliability. He's been on a dyno messing around with tuning with the EMU for a while now and is seeing random misfires when tuning in closed loop. I'm not going to pretend I know ECU tuning because I don't but one thing is pretty clear to me and that is the the SEB is limiting standalones for cost reasons primarily and with the current technology available, the cost differences is marginal. You can try to get away with VAFC but in real competition as the STR cars get more develops, the AP2 flashpro advantage will only grow. VAFC isn't going to cut it assuming equally good drivers in tuned AP2 vs VAFC AP1 or AP2V1. Greddy EMU is the most comparable real tuned option and the cost different is small with no clear advantage over standalone.

 

I haven't seen any NCs with Megasquirts. I don't know that they'll work, even with alternate sensors, etc.

The stock NC ECU can be tuned for all necessary parameters--spark, fuel, rev limit, etc. Mine has a non-custom Moto-East tune with a custom rev limit. It's about $500 in hardware and software, give or take a few hundred depending on where you get it and whether you get the ability to tune on your own or not (not real time though). The hardware is just used to flash the stock ECU. There's an alternative with DP Tune, which can do off-the-rack or custom tunes on stock ECUs too. Most of the STR MX5s I've seen dynoed run around 160whp and 140 wtq, whichever tune they use--and you AP1 guys think you have power problems.

IMO, you have to look beyond the S2K (which is already, as previously noted, very competitive in class, whether AP1 or AP2--just look at the most recent Blytheville tour, or even better last year's nationals--four different S2Ks in the top four, two AP1s and two AP2s, all within .051 over 135 seconds) and to the impacts it would have elsewhere in ST. Yes, if you could fit a standalone (a true standalone) inside the stock housing and maintain any OEM OBD functions, and without adding sensors, you could do it now. That applies to very few cars. For everyone else, it would involve throwing out $500-1000+ worth of existing tunes and hardware and ponying up $1500-5000+ for new stuff. That's just substituting a (moderately) expensive problem for one car with an expensive problem for everyone, and why I don't think it'll ever happen in ST, regardless of other considerations like emissions, street legality, etc.

As for the limitations mentioned by MattP, they sound good but you get into the same sort of workarounds, hacks, and expense you're talking about now, just from the other end--making the standalone work with the stock sensors, building adapters and harnesses to match OEM, etc. And having cars in a *Street* Touring class that don't have any OBD function seems crazy, regardless of whether you'd have it once you re-installed the stock ECU or not.

Plus, once you open the Pandora's box of true standalones, you have to have a handful of software engineers familiar with a dozen different ECUs in impound to see if there is anything going on beyond the allowances (ie. multiple switchable maps hiding traction control, boost control for the turbo cars in other classes, etc.). It's just not a viable solution in regards to policing.

The thing with autocross is that you pick your car, it doesn't pick you. Anyone can change cars to what they think has the ideal solution under the rules. I sold my 350Z (ran in BS then built for STR back in 2009) because it simply couldn't hang on the 255mm tires, and switched to the NC. We're seriously down on power, gearing isn't the best in either version, etc., but I still think it has its own strengths--and the results tend to support that, just as they do for the AP1.

 

I'm for allowing standalones, as I like the tuning simplicity and flexibility of them better. But it's $500-1000+ cheaper for a piggyback, certainly not more expensive as you said Steve, that was my point, for the sake of accuracy. That amount of money may be minor to some, but certainly can't speak for everyone to think that they have extra thousand(s) to toss around if its not needed to be competitive and reliable, especially if they've already invested in the current legal options and would have to start over. The cost difference is a valid concern in an ST class.

Even if the VAFC cars become uncompetitive (they obviously were not at Nationals) the EMU is available for not much more, so the VAFC doesn't have to cut it. As for reliability, the misfires are setup/configuration issues with the EMU/wiring, as we have seen different harnesses giving different results. This is the tricky and time consuming part of the setup, that is a con for the EMU. But you can have the same setup issues with a standalone if not wired/configured correctly. I've had no misfires or reliability issues racing on my EMU S2K for the past few months.

 

I'm a big fan of the NB and NC ever time I drive them. I believe the Miata guys and S2000 guys should work together on solutions. Thanks for taking the time to post here.

-Marc

 

I agree completely, which is why I am always reading these forums. Not everything translates across all three kinds of cars, but a lot of stuff does. And you guys have the most active/knowledgable community by far. Great stuff being done/thought up/tested here every day--like this thread.

 

Thanks Nelson. You points are valid and I appreciate your feedback. I'm not sure if you're familiar with FlashPro or not but all those functions you mentioned (switching maps fairly easily, setting traction control/launch control) can already be done today and could already be done even before piggy backs were allowed. I'm mentioning power but in reality that's not the argument I'm making. I'm just stating a simple observation that the current rule set doesn't take into account that modern ECUs with just software modification can achieve most if not all of the functions disallowing standalones were supposed to prevent. In fact, what I am arguing is that OEM reprogrammed ECUs, piggybacks and standalones are performance wise equal with one not outperforming the others. My AP1 (though not in legal STR trim) is tuned with a standalone Haltech that is fully plug and play and requires no sensor changes and I'm sure once the Greddy EMU piggy back is sorted out, a similarly modded AP1 dyno tuned will produce the same power. So all we're talking about here is cost and the car owner should have the option to choose which tuning system they want. If they want to spring more for a standalone it should be their choice but from a competition perspective it doesn't change the performance balance. Both cars will perform the same so it makes the exclusion irrelevant.

Outside of S2000s, Subarus have similarly been able to use accessport to tune their cars for years. They can even switch maps faster than S2Ks can switch maps with flashpro. That was and continues to be legal today (and accessport has always been able to modify boost levels) so those potential issues about people sneakily changing boost in their tunes exists today as it did years ago. We don't see STU complain or have issues with this. In other words, all that the standalone exclusion really prevents is those cars that cannot be simply software upgradable from having options. If you think people will come up with crazy ECUs and raise the costs because standalones are allowed, what would prevent them from creating crazy piggy backs or software upgrades now to do the same? Hypothetically, assuming you had an "iron man" like individual who had the resources and knowledge to build a special one off piggy back that did everything flashpro can today nothing is stopping them so the cost argument is again defeated. Someone could hypothetically spend $5K today to make this happen and be totally legal under the rules.

As for ODB2 functionality, I don't quite understand the concern there. If it's for legality then I can assure you allowing high flow cats is a more blatant violation of federal law. Reputable standalones still light up the check engine light and produce appropriate codes when scanned with a computer (via USB and not ODB2).

The litmus test I propose that a car can and should run with the stock ECU swapped in while in impound if there is any question about legality is a good test to make sure nothing else other than software was modified to make the car run right and that from a legal perspective my car could in fact pass a state computer based inspection of my car through the ODB2 port.

 

Imran, the ECU thing is even more straightforward than say a shock discussion where clearly the high end shocks that some can afford do offer a measurable performance advantage. In the standalone ECU case, it provides no additional advantage other than convenience so the exclusion doesn't make sense. That is the basis for what I'm bringing up with the SEB. No one is saying you shouldn't go and get a more affordable solution that fits your budget but preventing someone from using a standalone doesn't really help you out either since there are cars that can already take advantage of a proper tune even without the piggy back rule. This is why I think the argument is valid and the SEB should have no reason to not seriously consider it.

 

Final thought here, when the SEB considers things from a cost perspective it's totally understandable that they don't want to introduce a rule that would make something that costs money a "must have" so despite my annoyance with the revokation of the aero rule, I totally understand it. In this instance, we are simply asking them to give us options for allowances they already accommodate withing the rules. I suspect if someone is able to get a piggy back to perform perfectly at 50% of the cost of a standalone most would go that route but what should the competition care if someone does want to spend more money for the same performance. We see people spending $3K on custom wheels today and no one's losing any sleep over it. Why? because it doesn't make it a must have! In the same way allowing standalones don't make it a must have.

 

Well I put my neck out there by asking this question openly on sccaforums. I think it's more appropriate to discuss street touring rule changes we'd like to propose there where other cars/drivers that might be affected can have their say. It's easy to get blinded and see things only from a S2000 perspective so I figure I'd throw it out there and see what people have to say.

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