pon55

iTrader: (19)

Factoryas in Honda USA tech!

thiscrackerntam

Thats a funny story jrfish and I feel your pain too. If I were you, I wouldve wanted to punch him in the mouth for being for such a retard. I'm suprised they let him wear that uniform. I do wonder however, maybe he was just playing dumb because he didnt wanna take the job for some reason?

gearbox

iTrader: (95)

Ya they do that. I have to be very careful what I tell them about my car or else...we're sorry your car has too many mods so we can't change your oil anymore.

Jrfish007

iTrader: (3)

Okay, I know what you are talking about. What happens is the engine runs rich, which means there is not enough air to burn all the fuel, so the fuel gets dumped out the engine. Then fresh air is added just after the exhaust leaves the block. At this point the exhaust is hot enough to burn the unburned fuel with the extra fresh air thus heating up the gas that's about to hit the cat, hence making the cat get warmer faster. It's a pretty good idea VW had, but it never caught on until the mid 90's, and '96 (or '95 for some cars) is when the OBDII systems came out, so the air injection method was replaced by the current one (two cats).

Jrfish007

iTrader: (3)

Yeah maybe they just didn't want to do it... But it was just a stock USDM B16A out of '99 Si, I thought it would be really simple. What makes me not believe that though is that the guy actually though it was a D15, if he would have just said, we don't work on modified cars here, I would have left mad, but I would have still had some confidence in them. I don't know what he was thinking

Jrfish007

iTrader: (3)

Getting back to your question Gearbox,

1. Check your pcv valve, it kind of a long shot, but it's easy to check and only cost $3-4 to replace.
2. Take your intake off so that you can get a good look at the throttle body and make sure nothing is in there. Some time dirt will collect along the sides near the butterfly and cause a low air flow.
3. Reset your ECU
4. Adjust the throttle screw and reset you ECU. Sometimes the ECU will try to compensate. This reminds me, do you still have the VTEC controller on there, maybe that's your problem? It’s possible that thing is calibrated for manuals and thus has a low idle. Not sure if it can control idle, remember that just because you can't adjust it, doesn't mean it doesn't affect it.

These are all things I've had problems with in the past with various cars, that's why I listed them

gearbox

iTrader: (95)

Thanks I'll check pcv valve. All the rest I've tried. TB is clean, ecu reset, vtec controler was installed before head with no problems.

mclean987

iTrader: (1)

ive been using 93 for years on all ym cars and havent had a problem but i only drive hondas, ive heard of people burning up injectors with higher octanes but only on domestics, the d17 is almost high compression at 9.9 and it feels much better with 93 instead of 89 or 87, we also have a egr valve so any unburned fuel is returned

Hendo_Honda

Mine has a notation right inside the gas cap area saying the car was made to run on Premium. The salesman also stressed over and over not to use hi-oct.

In older cars (like pre-emissions) higher octane was needed to prevent "engine knock" and "runover" (when you turn off the key, the motor sputters on for a few minutes). Today's cars don't need it. Just like they don't need lead anymore (I have to buy lead additive for my 69 Camaro and use hi-test, or she'll buck like a bronco).

S2000man01

iTrader: (1)

run whatever your car's recommended octane is. that's the best advice I can give. if you use premium on a car that only requires at least 87, you're wasting money at the least. your car won't perform any better unless you're in extreme high temperature areas and are knocking.

this is a VERY old thread, so I'm not going to go into the technical reasons.

mclean987

iTrader: (1)

they recommended 89 to me at dealer and i told them i only use premium and they said even better i always use premium in my 95 civic it has 12.5 compression so i have to, i have 60,000 miles now on 7thgen and havent had a problem never used anything but 93 octance

S2000man01

iTrader: (1)

.....

Jrfish007

iTrader: (3)

So you guys using this high octane stuff... what kind of gas mileage are you getting? Have you actually put your cars on a dyno to see if it is making more power, or are you just relying on your butt dyno? Any of you taken your heads off to investigate carbon build up? Or check your cats lately?

By the way, the EGR valve has nothing to do with unburned gas, it doesn't selectively take unburned gas out of your exhaust and put it back, that just doesn't make sense. All it does is equalize pressures, separating the unburned gas would require distillation, and I KNOW no body has a car that does that since those columns are often a few hundred feet tall.

SevenCyrus

iTrader: (1)

Directly from Hondas Maintence website.

S2000man01

iTrader: (1)

rep for you two.

usafstud

iTrader: (2)

here u go

Your inquiry has been forwarded to us here at Chevron Fuels Technical Service.

Heat Content

Chevron does not and is not required to test its gasolines for heat content.

The Auto/Oil Air Quality Improvement Research Program calculated that conventional (non-oxygenated gasoline whose composition and boiling profile were equal to the U. S. averages for these properties would have a net heat content of 114,900 Btu/gal. Oxygenating this gasoline with 10 volume percent ethanol or 15 volume percent MTBE would lower its heat content about 3% to 111,400 Btu/gal.

Traditionally, premium grade gasoline has had a slightly higher heating value than regular. The difference-less than 1%. The differences likely to be less or non-existent between grades of reformulated gasoline.

There can be differences in heating value among batches of gasoline from the same refinery or among brands of gasoline from different refiners because of compositional differences. The differences are small and there is no practical way for the consumer to identify the gasoline with a higher heating value.


Burn Rate

There is no credence to the idea of different rates of burn for the different octane fuels.

There is no correlation between octane (fuel grade) and the concept of slower or faster or hotter or cooler running of engines. Chevron supreme gasoline will not burn hotter than the other grades.

Gasolines with oxygenates (ethanol or methyl tertiary butyl ether - MTBE) may burn hotter than those without oxygenates, but the octane has nothing to do with it.

There are a number of text books on internal combustion engines. Two well known authors are J. B. Haywood (MIT) and E. F. Obert (Northwestern University). They both discuss flame speed.

Flame speed in a spark-ignition engine is more controlled by the engine design and operating conditions than by fuel hydrocarbon composition. The design of the combustion chamber and inlet ports and how they affect turbulence is most important. A turbulent motion of the fuel-air mixture increases the speed of flame propagation by rapidly intermingling the burned and unburned portions of the flame front. Increasing engine speed increases turbulence and flame speed. Fuel-air ratio also is very important with the fastest flame speed occurring at slightly rich of the stoichiometric (chemically correct) air-fuel ratio.

Fuel composition also can affect flame speed. The gaseous fuels, methane and propane, have higher flame speeds than gasoline. Methanol has a higher flame speed than the gaseous fuels. In gasoline, isooctane (a paraffin) is about 20% slower than benzene (an aromatic). Benzene has a similar flame speed to 1-hexene (an olefin). Flame speed does depend on composition. However, it is just not directly related to octane level, but, rather, on the compositional makeup of a particular fuel. Thus, there is no direct correlation between octane rating and flame speed. Octane rating is only a measure of resistance to knock, or delay before autoignition.

From the above fuel discussion it is concluded that although the composition will vary between regular and premium gasoline the difference in flame speed is very small and no correlated with octane level. Further, the fuel composition effect is small compared to the engine design and operating factors.


Additives

Most gasolines contain negligible amounts of gum when they are manufactured, and most contain ("stabilizers') to retard gum formation. It is stabilizers that make it possible to store Chevron gasolines for a year when the conditions are good.

Detergent type additives:

Our Supreme gasoline contains the same ratio of Techron as our regular and mid- grades.

All our grades of gasolines have the same amount of Techron to maximize performance and minimize emissions in the great majority of vehicles, Chevron Supreme is designed for use in those cars that perform better with a higher octane gasoline.

If you are able to access the INTERNET please visit Chevron's website at www.chevron.com. Within that site there is a listing of available Chevron publications that deal with the subject of fuels, additives, oxygenates, etc. The publication entitled, "Motor Gasolines Technical Review" should be

of special interest to you. Just click on the titles to open the publications. The site is at:

http://www.chevron.com/prodserv/fuels/

Other sites to visit that talk about Techron would be:

http://www.chevron.com/prodserv/fue...advantage.shtml


http://www.chevron.com/prodserv/fue...ech%5Fcon.shtml


http://www.chevron.com/prodserv/fue...ech%5Fgas.shtml

http://www.chevron.com/prodserv/fue...s/history.shtml

http://www.chevron.com/prodserv/fue...gas/index.shtml

mclean987

iTrader: (1)

i would agree with the manual if were talking about a stock civic but with mods the higher octane feels much better to me ive tried all octanes and the higher always feels better unless its a stock car, i dont see any disadvantages to doing it except carbon buildup but you get that anyway and you can just use lubecontrol, my friend put 103 octane is his type r and dynoed it again and he got like 8hp more just from the higher octane.

aznboysrfr

iTrader: (10)

I'm not for or against higher octane usage, but here is something interesting to look at ...

Compression Ratios / Recommended Octane:

D17a1 - 9.5:1 (iirc) / 87
D17a2 - 9.9:1 / 87
K20a3 - 9.5:1 / 87
K20a2 - 11.0:1 / 91+ (premium)
K20a - 11.5:1 / 93+

now take a look at this...

B16a2 - 10.2:1 / 91+

I wonder why a .3 compression increase should warrant a jump from 87 to 91+ (premium) octane fuel from the D17a2 to the B16.

orion_squall

well, can someone explain why the acura EL uses primium and yet has the same engine as EX?

Honda would not suggest it if it burns the injectors!

S2000man01

iTrader: (1)

your car will not benefit from higher octane gas. and any "difference" you feel is completely a placebo effect. sorry, but even with your mods (unless your FI) it won't make a lick of difference.

and a dyno showing an 8hp is meaningless. how did he dyno the car, then swap in race gas, and then dyno again? was it even back to back? and did he do at least 3 pulls to get a baseline?

there's the problem with dyno'ing. your standard dyno often has a 3-5hp error factor. this means that you can run 3 times and get as much as a 5hp variance.

I could run my car on a dyno 3 times, and take the worst run, say 200hp peak. then, while my car is on the dyno, i install a spoiler and run my car 3 more times. now i take the highest run of 204hp. hey what do ya know, my spoiler just added 4 horsepower!

your friend's dyno was meaningless. and even then it's a type R that already requires premium.

S2000man01

iTrader: (1)

it's likely because the timing on the B16 is more advanced than the D17a2. at least off the top of my head from what I remember.

Jrfish007

iTrader: (3)

That's half of it, the other half is because of the higher RPM's the engine can produce. At higher RPMs the fuel injectors and not spray as nice of a pattern, so the fuel tends to form droplets, so you get lean and rich regions in the air/fuel, hence a higher tendency to knock.

There is more than just the compression ratio when figuring out what octane is appropriate for an engine

Jrfish007

iTrader: (3)

Huh? what is the Acura EL, as far as I know no Acura uses a civic EX engine, infact the civics are the only SOHC engine Honda makes to my limited knowledge.

stepchild

I used to ALLWAYS use 87 or sometimes 89 in my car and the stock performance was extremely inconsistent. Then about a year ago I started using 93 octain Shell and my car runs great.

zen_master

iTrader: (6)

i start using 89.........about two tanks ago......

i know this probably stupid....but i have this theory.....maybe if i use 89.....i got less possibility of gettin mis-fire on the engine.......due to 89's harder-to-explode characteristic compared to 87...LOL

SevenCyrus

iTrader: (1)

Yea, and they also have done experiments with people where they give them pills filled with sugar or water(placebos)...and they claim that they feel much better. Same thing with surgeries, people would go under surgery, come out and say there leg feels amazing and what not...but the doctor never really did anything to them, it was just an experiment.

This is getting old

S2000man01

iTrader: (1)

<cough>placebo<cough>.

even IF your car made a slight improvement from high octane, NO HUMAN IN THE WORLD could feel it. we simply don't have the sensory perception for that.

people who say they feel a difference with higher octane have NO IDEA what they are talking about.

S2000man01

iTrader: (1)

EXACTLY.

Jrfish007

iTrader: (3)

Thanks!!! But I must spread some rep around before giving to S2000man01 agian

S2000man01

iTrader: (1)

damn rep gremlins.