mpe488

I've been putting 89 in my car lately due to lack of money and lack of job. My tank is down to a half and I'm going to a dyno tomorrow, I'm going to fill up the other half with 93 octane. The mix should be about 91 octane, I guess. Should I dyno it like that, or run my tank down alittle bit more and add 93, or should I just put in as much 93 as I can and add some octane booster?

black01_WS6

iTrader: (13)

you should dyno tune with the type of gas you use all the time. if you raise you octane by better gas, when you put 89 back in it will not run right. If you always use 89 then put in 89 and tune for it.

camarokid94

iTrader: (2)

Just a question but if your borke why are you dynoin? but other than that i agree if you ru around with 89 you might get some knock retart that will cost some power and the dyno will tell you what you really have on the street not the max your motor will make.

68ss_00ss_87_95

iTrader: (1)

although the compression isnt way high i always ran with the highest pump gas with my stock ls1....octane booster isnt as effective as advertised....on the pump if its calculated octane is the (R+M)/2 method octane booster will be theoretically half of what it advertises...since it raises 1 rating by say 10 points....i have also read about dropping air inlet temp by around 25* and you can lower the octane by 1 point...maybe its not as drastic as 25* but either way your running a performance motor you should use premium....knock sucks...

trever1t

iTrader: (14)

I look at gas like this... the difference between regular gas and premium is about 20 cents a gallon. If my tank (26 galllons) was completely dry, the difference from one to the other is only $5.20.
Silly isn't it?

mpe488

well its not silly if the car runs pretty much the same with 89 as it does with 93 (I have never experienced knock, but if the car has cut back on timing I haven't noticed much of a decline in performance either), and I'm short on funds until I can manage to land a job somewhere. Also, it's not a dynoTUNE, I'm just getting some numbers. The reason I'm doing it now is that theres a dynoday and it's a jet, not a mustang.

black01_WS6

iTrader: (13)

sorry didn't see that you weren't getting a tune. then throw in some 93, it will help out a little.

Drewstein

That's because your car's knock sensor is doing it's job. Your butt dyno won't notice the 15-20rwhp loss at wot. When timing is pulled, the car doesn't fall on it's face or anything drastic because it's so gradual. The only way to tell is on a dyno or running a buddy on one fuel and then the other. You'll save more money watching what you eat than by being cheap on octane.

Just feed her the good stuff.