VTEC single cam DOUBLE CARBY??

[jdmEG5]

correct and i feel putting 98 on a d15b4 makes it smoother

would that make the engine better? LOL i heard it does, thats wad dedy said from top one

[trism]

advantages of 98 over 91 include

-more resistant to pinging/detonation.
-has additives the help clean carbies/injectors/valves
-will give you better fuel economy

[jdmEG5]

so it does make a difference? I cant really tell, usually caby engines sounds ruff, lol, all i can tell is, its more efficient than a normal unleaded. When i used 98 octane on my EG5, i cud tell the difference by performance, sound, and fuel efficiensy. But when i use unleaded on my EG, it makes this ratlling noise inside the engine block.. donno if thats normall..

[Sp00ny]

advantages of 98 over 91 include

-more resistant to pinging/detonation.
-has additives the help clean carbies/injectors/valves
-will give you better fuel economy

First point is that alot of the higher octane fuel's have lower combustion energy due to the artificial additives to clean the engines internals and burn "cleaner"... although there is no direct relation between RON and Total Energy... it is a general rule of thumb...

Although these advantages are true, I truely don't see how a carburettor engine could compensate for a higher octane fuel... It doesn't have knock sensor's or a crank angle sensor to determine pre-ignition... Unless you advanced the ignition timing manually. Keeping in mind though my carburettor experience is restricted to small Two/Four Stroke engines and not car engines... They may have sensors I don't know about.

Also even though a higher octane fuel WILL provide these benefits in an EFI car, the benefits will be VERY limited... Stock ECU's are made to be very conservative and won't change the ignition timing/fuel mixture much outside of its original scope... To prevent leaning out / rich mixtures... Thus why ultimately to achieve noticable gains from modifications/change of RON we get cars Dyno/Road Tuned......

[~Sp33~]

donno if thats normall..

Sounds completely unrelated to what petrol your using. Sounds more like something that you happened to notice after filling up with a certain petrol grade.

[jdmEG5]

i mean like, it sounds very... "dirty" like.. it makes this kind of sounds when ur chewing a kfc of something.. i unno :S this happens all the time when i use normal unleaded on my EG.. no good maybe valves or wadever's in there is stuffn up lol..

well, i used V power for.. 3 years now, and at one stage where i needed fuel, i was in the middle of no wer, fuel tank was empty .. as in empty, and i filled up half tank with unleaded.. and engine sounded it was gonna fall apart :S.. this always happens on the EG wen i uses normal unleaded. Wen i use V racing/power, everything's fine :S

any ideas what can be the problem?

[~Sp33~]

I've never been able to hear the difference in fuel grade. Unless you put diesel in it.

[Sp00ny]

i mean like, it sounds very... "dirty" like.. it makes this kind of sounds when ur chewing a kfc of something.. i unno :S this happens all the time when i use normal unleaded on my EG.. no good maybe valves or wadever's in there is stuffn up lol..

well, i used V power for.. 3 years now, and at one stage where i needed fuel, i was in the middle of no wer, fuel tank was empty .. as in empty, and i filled up half tank with unleaded.. and engine sounded it was gonna fall apart :S.. this always happens on the EG wen i uses normal unleaded. Wen i use V racing/power, everything's fine :S

any ideas what can be the problem?

Could be pinging/pre-ignition? Have you/previous owners manually advanced your ignition timing?

[jdmEG5]

erm no, i havent done anything to the engine :S besides CAI.. and nah i havent mod any igniton - internal mods, previous owner probably did it

[~Sp33~]

It's not an internal mod, it's just a matter of moving your distributor. Push it toward the firewall to advance, and pull it toward you to retard.

[Sp00ny]

It's not an internal mod, it's just a matter of moving your distributor. Push it toward the firewall to advance, and pull it toward you to retard.

^^ As above.

If there is no marking on the distributor (normally is if it's been changed) then it might be wise to take it to a mechanic or purchase a timing light to see what it is currently set at. I would say there is advanced timing thus why you would see a gain by running a higher octane fuel and pinging/noise when using a low octane fuel.

[jdmEG5]

i'll check it out with my mechanic.. But this isnt serious, its just a thing i would like to know.. thanks anyways..