eg6noise

Hi, my B16A3 may go for a rebuild in the future, and I was thinking about some basic upgrades to go along with it. I'm planning to have a higher compression, like 10.8:1 which is doable without aftermarket pistons and is reversible. The problem is, 95 octane gas here is considerably more expensive than the standard 87 octane, and is not available everywhere. With that compression, it would be mandatory to run a very conservative tune to avoid detonation, at the cost of power. This problem would be solved with something like the Moates 2-timer on a chipped P30 ECU, which would allow me to run dual maps and change them when I want the best performance when running 95 octane. Does anyone have any experience with it? I know horsepower is very relative to tuner, setup and dyno, but I think more experienced people could give me an idea of what to expect with my specific setup, so I can consider if it's worth it:

- 10.8:1 Compression (milled head for .2 and thinner headgasket for .4)
- Valve job, port and polished head
- Port-matched stock intake manifold and throttle body (62mm)
- Simota "Big Tube" Short Ram Intake with an IceBox style velocity stack
- 1320 Performance or PLM Toda Style Header (or decent quality equivalent)
- 2.5" Exhaust, Stainless Steel, Mandrel Bent with dual resonators and a high quality Twin-Loop style muffler replica
- Chipped P30 ECU tuned on Crome or equivalent

turbociv910

stock cams? not much

eg6noise

Yes, stock cams, at least for a while. I was hoping for at least ~15whp over the roughly 136whp baseline (160hp with 15% drivetrain loss).

Chance EG

Sounds reasonable for the bolt-ons you listed and the raised compression.

Take this with a grain of salt as I've never worked with flex-fuel or any other dual map configurations, but I don't think you'd be able to accomplish that with Crome (at least not efficiently). I think you'd need some type of a sensor along with an S300 chip. I know AEM V2's also allow for flex fuel setups but most don't use those ECU's with D/B/H/K series engines.

Also I'd be somewhat sceptical of what type of sensor you'd be using as well for the different octane levels in the gasoline. I think most GM or other flex fuel sensors try to measure the ethanol content, which wouldn't really apply in what you're doing... You'd need a way for the ECU to be able to distinguish between 87 and 95 octane, and I don't really know how you'd do that.

Once again, out of my ball field so maybe I shouldn't be talking at all, but I think you have some pretty confusing hurdles here to overcome.

eg6noise

So ~15whp is possible, good. The way I would overcome this is simple, but again, I'm not sure if it would work. The Moates 2-timer uses a 27SF512 chip that can hold two programs (maps), which can be manually switched by a button. The idea is that I would have a tune to be used with 87 octane and another with 95. The switching would be done based on what fuel I have on the tank. Let's say I would only switch to 95 when the tank is empty if I was using 87 before. I don't think it's possible to run that compression with 87 octane and a decent tune without detonation, unless I'm wrong.

Chance EG

I understand what you're trying to accomplish with the Moates chip, I just don't think manually switching between the maps depending on the fuel content you think you have will be an efficient or effective solution. There will always be at least some blend of those octanes in the tank, and there are too many variables for the 95 octane map to ever really be safe, or at 100%.

It can be done as you're describing I'm sure, but I don't think it's a good or necessarily safe solution.

eg6noise

Yes, I understand your concern, and you're right, there will always be a blend of those octanes, be it in the tank or the fuel lines. The best I can do is to be sure the tank gets on reserve before changing octanes, and running the more conservative map for some miles. There's one thing that I'm curious though: Around here the FA5 Si is very popular, and the K20Z3 engine runs on 11:1 compression. Honda states that the car can be used on 87 octane, but it will only reach it's full power on premium gas (lower 0-60 times and what not). Does the ECU only changes ignition timing, with the help of a knock sensor, or it adjusts on the fly for something else that the P30 (or any ECU of this generation) cannot? I'm sure the map is conservative to be able to work between 87 and 95, thus very different from a 95 only tuning which would give me the best performance for my modifications.

Masterl1nk

Hi!
I've used to build my own homemade 2-timer, using a 27sf512 eeprom, a socket and a piece of drilled board for a nitrous D16 engine. Works pretty good, so you are good to go that way. Just take care about not swapping to the hi-octane map when you are running the 87 oct fuel lol

This is a dyno graph from a B16a2 engine, with ITR cams, Skunk2 alpha series exhaust manifold and an AEM cold air intake. stock bone, stock head and 100.000+ miles on it. Upper red line is an estimative crank horsepower, the lower red line is wheel horsepower, blue one is torque and yellow AFR.

Masterl1nk

Take care about the K-series knock sensor is actually pretty modern, so it changes the ignition maps on the fly when detecting high knock levels.

eg6noise

Thanks for the dyno sheet, pretty good numbers! About that, you're running stock compression (10.2:1), ~13:1 A/F at high rpms and what octane gas?
So, you used the chip on a socket, soldered it to the perforated board and switched the ground between the correct pins with a simple circuit and a switch? I may try that. I'll take care about the switching when flooring the thing!

I knew there had to be something more advanced than our standard knock sensors. I guess with a conservative tuning with the ignition timing already set lower, the engine would have a margin to compensate if detonation occurs.

JRCivic1

I am not sure where you are from, but in the US, all Civic Si's have markings on the instrument panel, inside the fuel filler door, as well as in the service manual stating clearly "Premium Unleaded Fuel Only". It is NOT recommended to run 87 octane fuel in ANY 10:1+ compression Honda engine. Now, as stated by Masterl1nk, the knock sensing circuit in the 7G and newer DOHC Civic's is FAR more advanced than that found in a '92-00 Civic or Integra ECU, and is designed to retard the ignition timing under all operating conditions to protect the engine in the event the operator of the vehicle introduces an improper/substandard fuel.

This means that what you are asking really is can you make two tunes... one for 91 octane fuel and one for 95 octane... and switch back and forth between the two when you make the switch in fuel choice ??? The answer is yes... but then the next question is WHY ??? The HP difference between these two fuels when tuned for maximum performance will likely be within dyno error with the engine combination that you have described. I say keep it simple and make a really good tune on 93 octane and always run that. The only reason to run the engine on 87 octane is because you are being cheap... and you cannot save enough money over the long term with this method to cover the cost of engine failure due to detonation/pre-ignition from the lack of octane. Trust me... I have seen too many people try.

eg6noise

I'm not from the US. The FA5 Civics produced and sold here are slightly detuned and rated at 192hp/195PS instead of 198hp/200PS like on other countries, so there is evidence of a different map to be compliant with the standard 87 octane fuel sold here. Honda recommends premium, but says it's fine to run with 87, otherwise they wouldn't sell as well here. I'm not trying to make a tune for 91 and 95 octane, rather giving a solution to the present issue. 93 octane is not available, it's either 87, 91 or 95 and the difference between the premium ratings is negligible (2%). As I said, the price difference between ratings is 40% or more, and it's not available everywhere. Different realities. With all due respect, it's a bit of a stretch calling someone "cheap" while not knowing anything about them. I'm aware that you are trying to give me advice, and I will consider it. I even know that the stock B16 is not supposed to run on 87 ideally, but that's the way it is here for almost everyone running them.

Masterl1nk

Thanks!
Actually it's a bit richer than the AFR plot, due the sensor was located almost at the end of the exhaust, on a probe tip. It's actually more like 12.7-12.9:1 all way long. We're using the best available fuel wich is 91 octane (USA).

Yes, you're right about the circuit, take a look at this one:


The first "normal" map should be offseted by 0x8000. then the "race" or secondary map shouldn't be offseted at all. So on normal operation the 4k7 pull up resistor keeps a high state level on vdd, reading the 0x8000-0xFFFF memory sector from a 512k memory (twice as the honda's stock eeprom size). If you push vdd to gnd, then you'll be using the 0x0000-0x7999 memory sector, where you burned your race map.

CandyRedRC46

Looks like there were a few posts deleted, weird....