staticlag

Yeah, AFR2 and HP2 are post flash.

I guess the evidence points to my corroded sparkplug boot & plug on the rear trailing, and the loose air horn.

acroy

I for one am really looking forward to when you get it re-dyno'ed with the new (correct) plugs and 87 octane.

Those rx-7 plugs look way too cold for the application - certianly causing power loss.

My bet is the biggest power loss was the premium gas. Higher octane, from what I understand, just raises the autignition point, and actually lowers the available amount of energy from a given volume of gas.

btw, yes this is my first post, but i've been lurking about for a couple years....

kartweb

Sort of. Spontaneous ignition occurs when there is enough heat to light off the fuel ahead of the convective wave of the flamefront. Surfaces of the metal are almost always cooler then flash point so they tend to quench the fuel a bit. That leaves Infra red emission which is far more complex then it would seem. Without getting into IR/material properties higher octane is more resistant to spontaneous ignition while maintaining pretty much the same flash point.

As far as less energy thats debatable. It really depends on the breed of fuel stock.

One inherent problem with a rotary is wasted heat. The reason the EGT is so high is due to the relatively retarded ignition - which is required to avoid detonation. As a result lots of heat is wasted, and IMO thats where the fuel mileage went on a rotary.

I'm waiting for a more controlled and objective set of results on the RB flash before I spend any money on it. Even then I may just invest in a piggyback to play with it.

staticlag

"octane" in pump gas is very debatable, power-wise, and really describes only the restance to igniton due to a low iginion point.

Consider the mechanics of the internal combustion engine. Its job is to intake an explosive mixture, explode such mixture, and harness the energy generated. Inside the engine, things get very hot. Lets say you are using ethyl ether as your fuel.

Lets examine one variable that removes air/fuel and relative saturation from the equation.

Ether has an autoignition point of around 300 degrees farenheit (not to be confused with flash point for this example which more closely involves barometric pressure) If you spray ethyl ether in your engine and it is 400 degrees farenheit, no rich A/F mixture or gentle barometric pressure is going to stop the compound from exploding.

Now the spark from your spark plug is easily over 1000 degrees farenheit in the small air space around and through the energy passes. This will ignite most anything. This is what we want, we want to avoid using compounds that will ignite themselves in the relatively tame internal environment of the engine, and only ignite in the small space that is superheated by the sparkplug.

high octane does have a higher ignion point than low octane fuel that is the basis of an octane rating.

Now, E85 ethanol fuel, that is, 85% ethanol, 15% gasoline blend has an octane rating of 105. Why dont we all use this?

Several things need to be considered.

Firstly, what is the cheapest way to make 91 octane fuel? that is, fuel that is relatively (for pump gas) resistant to exploding through heat or percussion or anything else. Is the cheapest way to use the finest and purest compounds that are not only highly resistant but also carry a great amount of long complex chain hydrocarbons (the more bonds broken among ignition the higher the energy output)?

Or is the cheapest way to make 91 octane gas, simply to stuff any old explosion resistant chemical in the gas mix and market it as "better"

The fact is that in the pump gas world, the only thing you are getting is cost effective. The compounds with the highest energy ratings in the pump gas world are unstable forms of long chain hydrocarbons. Because making stable long chains is very costly. No one wants to play $300 for a reagent 99% purity grade tank of 91 octane gas that is both highly resistant to heat ignion and contains more potential energy in the form of stable bonds.

So basically, in 87 octane, they mostly use any ol crap that comes off their distillery, that is, mostly unstable blends of compounds. BUT in this unstable blend you are mostly getting high power stuff because it is cheaper to not purify and assay.

Now in 91 octane you get the same base as 87 octane, but they shove in ANYTHING that will lower the explosive nature of the gas.

So long story short, in 91 octane vs 87 octane. you are getting 4% more inert crap in your 91 octane gas than your 87 octane gas.

Now race specific blends that cost upwards of $10 per gallon do contain more specific and powerful compounds. But the downside to most of them is that to make en entirely pure high octane, high power super fantastic damn-it-feels-good-to-be-alive-gas it takes A LOT of effort. Just checking the fisher scientific catalogue, it costs about 197 dollars a gallon for the pure precursors of gasoline.

And you may ask, why do I want pure? Well, you want pure because most of these high power compounds are tainted with heavy metals and other nasty ions that bind unfavorably to the wideband sensors that our RX8s use to determine running Air/fuel mixture.

I could go on, but whats the point....

So now you all know the REAL story of 87 vs 91

RotorManiac

may I ask how long does this battery last, without firing the engine? I think its pretty small, and it'll be dead in a few days if you don't move the car... I might be wrong, but aren't these batteries used in race cars only?
I had mine relocated too at the same spot, also a custom washer tank was made, smaller and lighter than the stock one...

Spin9k

It's actually a few weeks in normal temp weather, definitely shorter than the 640cca 800ca battery Mazda puts in the car. Still, that's not much of a penalty for a front end 20lb weight savings. And yes, they're used in HPDEs & racing for weight savings.

Nemesis8

iTrader: (3)

When I was younger, in my CZ days, I was shooting for around 13 AFR to be very conservative for a NA ratio. This is still rich IMO, and this is the race flash? I wonder what the street flash looks like?

Jeromie

hey guys i just got my race flash and i wondering. did i do something wrong?....

i dont really feel anything. i can just rev it to 10k but it dont feel like it wants to go that high. i thought i heard it takes time to learn the new setup. true?

i have custom intake, gutted cat, 3" all the way single exhaust.....

staticlag

Pull your battery cable and let your car sit overnight. See if that helps.

Jeromie

but the ecu was out 4 3 days..... ill rty it still

staticlag

But then again Racing beat really isn't known for all out performance mods on the 8.

Nemesis8

iTrader: (3)

Yea, that makes sense - conservative aren't they.

staticlag

yeah, give it a shot,

also, is your security light abnormally flashing?

a few things that helped my flash feel (marginally) better: using 87 octane gas, and putting a hundred or so hard miles on it.

Also, ive found that it loves 6K+ the more I drive at that and higher the faster it progressively feels.

Spin9k

Why is your light flashing (too)? Mine goes out after about a minute.

How about CEL light, does that flash?

staticlag

Yup, security light is being stupid,

Yes, I got a emissions CEL about 100 miles after installing the flash.

if your CEL is flashing it is probably signalling misfires. Go to autozone or advance autoparts to get it read.

staticlag

Again my "first impressions" on the flash.

https://www.rx8club.com/showpost.php...5&postcount=64

Too bad that it put down fewer HP than when using the Recall flash.

Jeromie

staticlag

"Pull your battery cable and let your car sit overnight. See if that helps."




ok so i tried it... i does feel a lil better. i also used 87 octane. i put in the rb ram air duct. i dunno wat set this off cuz i changed so many things at once but now, whenever i slow down with the clutch in... the car dies out.......
thinkin this might have something to do with my intake since its just a filter and it doesnt have that screen. i just ordered the rb intake to eliminate that as the problem. the reason im posting tho is cuz i think i read that someone had the same problem after the flash.

r0tor

iTrader: (1)

agreed...

r0tor

iTrader: (1)

tighten up on the battery terminal

8rotor8

iTrader: (2)

I have the car die out on me when I pressed on the clutch too. My problem was haing no screens, with the revi my idle got a lot smoother.

Jeromie

yea i should get my revi like tommorow.....

Astral

Which gas is better for this flash?

On one hand, since it leans things out, it seems that 91/93 would be a little safer, but on the other hand, it doesn't lean things out *that* much and 89 may burn a little cleaner. *shrugs*

staticlag

driven it in 93 degree stop and go traffic. No knocks or detonation with 87.

Jeromie

im usein 87 and no problems. it actually feels a lil better....

Jeromie

hey guys just lettin u know that the race flash is not the cause for my car diein out. i just installed the rev intake WITHOUT the screens and the problem is completely gone. also with time the car started to feel faster and faster! i wasnt happy at first but now i WOULD recommend this product.....