1997 Mazda MX-5 Miata: Ping

No knock sensor in 1997? Wow, that IS old school. My 1982 Chevy C-10 had a knock sensor and so does my 1989 Volvo 240, and I thought they were old school.

Maybe because it wasn't a turbo (or supercharged) when new. Knock sensors have been around for a long time (my dad's 86 LeBaron GTS turbo had one) but there is no need to add one on most NA cars.

Hmm, maybe a supplemental acho/water injection kit would help for traffic. Knock sensor setup would be a better long term fix though...

My jeep used to do this with low octane fuel. It had a chevy zz4 crate motor in it.

We had a fight with a middle eastern had station owner because he was putting regular or 89 in the 93 tank

Easy way to end the life of that car...grit teeth through detonation. eek.

First Corvette, now this.... *sigh*

But the Corvette was stock.

Fortunately the Miata engine is pretty damn tough for what it is. You don't want knock and addressing it is important, but you've got to work hard to kill a Miata engine.

I think the biggest problem here is that the engine management is compromised in order to satisfy California Air Resources Board rules. CARB hates when the ECU is altered because conceivably you might change something in the cold start regime, or at part throttle which could increase emissions by 1%, or reduce the life of the catalytic converter from 15 years to 14 years. Never mind that producing 50% more power is going to produce 50% more emissions at full throttle.

You can get CARB approval for a aftermarket modification that changes the factory ECU settings, but you have to go through a serious recertification procedure which basically matches what the OEMs have to do to certify a new car. It involves spending a full day or more on a very complex (and expensive) emissions dyno which actually captures all the emissions in bags (rather than just sampling the exhaust). And if you produce even one part per million more of any measured pollutant than what the factory test car did, you fail - and your $10k investment is wasted and you've gotta go back and do it again. That's why many performance parts are only listed as 49 state legal. No one wants to spend or risk the money on CARB testing. Since most aftermarket parts will still allow the cars they're installed on to pass any end user tail pipe test, it simply isn't worth it.

If the Miata was running a full timing and fuel control setup it would undoubtedly produce more power, more efficiently, without knock and probably even return better economy. But it wouldn't be CARB legal. In case you can't tell, I think CARB is a complete joke and does far more harm than good.

Hey Church...thanks for your info on technical matters....I always learn a lot from you.

What the car needs is an intake air temp sensor. Does it have one from the factory? If it is used to correctly offset spark advance, it would probably go a long way. Well I take that back, what the car really needs is proper boost referenced spark advance...

@bodyblue- 91 octane
@church- agreed on all counts
@kevm14- IAT in the MAF, which is upstream of the IC so can't address IC soak. The magic black box that comes with the Kraftwerks kit has a MAP sensor for boost retard. I'd like an IAT between IC and throttle body and a kickass knock correction system, among other things...

Ok, so the IAT sensor is in the wrong place. GM ran the IAT with the MAF on their Gen III stuff but I think you can wire in a different sensor and place it appropriate for the common Magnacharger installations on cars such as my CTS-V. Of course the knock sensor would be nice for that tank of bad gas, but a well calibrated system using inputs such as the real intake air temp and coolant temp should be pretty consistent if nothing is mechanically wrong with the engine.

I'm impressed that the kit includes a MAP sensor for boost retard. But how is the retard accomplished?

CARB isn't really a joke, it does make sense. It's protecting the environment. Sure some things seem dumb, but that's how it goes. I had an aftermarket company use my old 350Z for CARB approval for a turbo kit (didn't happen) and it failed "cold start" which most all aftermarket turbo systems with in IC will. There is too much piping to heat up the cats fast enough to pass this test.

But any FI car...PINGing is terrible and not matter how you think it can't be hurt...certainly can.

Looks like you guys need a new oil dipstick, too.

Any chance of throwing a BIPES on that thing? They're fairly cheap and get good reviews.

http://www.crosslake.net/~dbipes/BipesACU/index.htm

No, it doesn't. CARB is a dinosaur (as is the EPA on a federal level). We've reduced emissions by 99% since the 70's. There is no more left to eliminate at any reasonable level of cost or effort, and even if we did, the actual effect would be imperceptible. Cars are so clean now that spilling a couple drops of gas at refueling substantially spikes the overall emissions profile of a car. According to the book "Air Pollution from Motor Vehicles", refueling accounts for nearly 20% of the hydrocarbon emissions profile of a gasoline vehicle. I'll bet all that oil and tar bubbling to the surface on the Santa Barbara coastline accounts for a level of hydrocarbon pollution that is a significant percentage of what cars produce.

http://www.black-tides.com/uk/pollution/natural-discharge/natural-sources-hydrocarbon.php
http://www.soscalifornia.org/facts.html

From the second link, "Hydrocarbon Seeps are the Largest Source of Air Pollution in Santa Barbara County"

The end result is that CARB regulations are costing us more and more money while delivering zero measurable benefit. And as with any rule, if you push to far and restrict too much, people simply don't obey the law (speeding, for example). Because CARB laws are so draconian, people simply ignore them or work around them. They register cars in other states, cheat the emissions test, find "a guy" who can pass their car, etc.

If California simply adopted a nice full spectrum emissions dyno test every 2-3 years (instead of the current 2 speed static load test) without worrying about what's under the hood, things would be much better. If you pass the test, who cares what's on your car? Instead, anything that doesn't have a CARB number makes you a lawbreaker, so people don't even bother trying to pass the test, they just game the system.

The whole point of what is turning into a rant, is that while reducing air pollution is an admirable goal, you have to look at the cost/benefit equation. Back in the 70's, it was easy for Los Angelenos to say, "we can't live here if the air is like this". And, at the same time, the cost to clean it up was a relatively small burden for each person living in the area. But as air quality has improved and emissions dropped, the cost for each additional reduction has skyrocketed, and the relative positive impact on health and quality of life for each reduction has plummeted.

Unfortunately, like seemingly every government agency ever created, CARB lives on. It must justify its existence in order to receive funding, so it continues to tighten the screws on the automobile, power plants, even the dust from farming operations now. But we're inside the control loop when it comes to these types of air pollution. The individual sources are so small that attempts to control them often backfire because we don't have the kind of resolution needed to make meaningful changes in the direction we want. When spilling a cup of gas creates more hydrocarbon pollution than your car does in a month, seeking to control the car any further is pointless. Just think of how much money we spend each year on air pollution measures - not just the direct cost of equipment on your car (or lawnmower, or whatever), but on the increased price of electricity, taxes, etc. Now, cut that cost in half. Emissions increase a percent or two (maybe), but what good could we do with that additional money? I argue that we're spending the funds on the wrong things. Cut the budgets for CARB and the EPA in half and the net benefit to society would be quite positive IMO.