Got hotshot headers, octane question

[apzak]

I was reading somewhere that catalytic converters work better with lower octane fuel which was why in the 70s cars had low horsepower. Because I have a hotshot header, it replaces my catalytic converter, so now I don't have one. Should I start using premium to make my engine more efficient, and will it make a difference? Or am I just wasting money?

[sixxdeuce]

yeah, I would recommend using premium, even if you had a cat. The car was tuned to run right on premium. I think theres even a sticker on the inside of the gas filler door that says to use premium. if its better for your car then its not a waste of money

[Zebrahead]

if its better for your car then its not a waste of money

God damned right.

Nick.

[Zebrahead]

Btw, You see any difference with the header?

Nick.

[driftin240]

gas is so mother ****ing expensive now i have to use half my paycheck on gas each week the way i drive...i get around 20 mpg usually which isnt too bad

[I am Technoman]

I have a HS header an my 240 loves sunoco 107 race fuel I think it has led in it. So dont use it if you have a cat...

[Mayhem_J30]

gas is so mother ****ing expensive now i have to use half my paycheck on gas each week the way i drive...i get around 20 mpg usually which isnt too bad

20 mpg in a little 240..isn't that real low? That's what I get in my obese J30. BTW, you going to Bowling Green tomorrow?

Apzak, I wouldn't pay any attention to what you might of heard especially when it applies to vehicles made in the 70's. Those were carburator motors compared to your FI motor. Two completely different ideas. What gets the catalytic converters working well nowadays (if you still have one) is the warm up cycle your car goes through. It runs rich until the 175(aprox) degree Fah coolant temp is reached. The extra fuel warms up the cats to where the chemical reactions of the converter become efficient. This is why when you're at the emission testing center they encourage your car to be running at least 15 minutes.

[apzak]

I'll try $5 dollars worth of permium and see if I notice a difference. Realy? Theres a sticker that says we should use premium? Wow I didn't know that, we don't have self service stations in nj so I never filled my car myself.. sounds kinda sad but it's illegal if I do. I thought the whole reason we got the ka24de in america is because high octane wasn't as available as it is today which is why we never got the sr, and the ka was used to take the low octane. That is why all these factory turbos are starting to pop up all of a sudden. Turbo gti came after 99, maybe if we got a 99 240sx it would have a turbo.

EDIT:

oh yea and I read on a different forum that high octane is a waste of money, and in some cases is bad for the car if it isn't ment to run on it because it's harder to burn leaving build up in the engine, or something.. i cant remember or find it because I have been members to so many boards.

I'm ganna double check that sticker thing, and if i got a sticker or it says something in the manual i guess i gatta wait for "super tuesdays" or wensdays whenever they take .05 off super.. 1.55 is a good price for regular around here, altough i saw a station that sells regular for 1.45!!! CHEAP!!

[Mayhem_J30]

using fuel with more octane than recommended (or tuned) for your vehicle would be a waste. Sounds to me like you need to take a lot of what you've heard (or at least thought you heard) and toss it and start over. Higher octane makes fuel combust at a higher compression. Because of this your timing may have to be retarded or advanced to componsate for the incorrect fuel...in the end losing power, gas mileage, knock sensor life and engine life.

[apzak]

yup just read the manual, says 93 recommended, and if i dont want to use 93 i should use 87, and the least i could use is 85 anything lower will cause engine knocking. also, it didnt recomend the stuff you put in to clean the engine up. I was thinking of puting something in my fuel to clean up my fuel system, but the nissan manual says fuel additives can harm the fuel system.