Chip octane difference?

[honkey]

i've searched and i didn't see what i was looking for. i'm interested in getting a mark d chip since it comes reccomended by everyone, and i see that there is a 91 and a 93 octane chip. is there a hp difference in the 2?

thanks for reading.

[Atreus]

no. just some areas dont offer both octanes, i think. in colo, i never see "93" 91 is all we get...

more octane does not automatically = moar powuh

[honkey]

thanks. i had a feeling it was regional thing but you can never be too sure.

[Sagaris]

Yep, I live in Wisconsin right now and there is 93 available (Ethanol be damned!). I am planning on moving out west within the next few years (higher elevation states get 91 as mentioned above) So I went with the 91 octane chip.

[honkey]

did you feel the difference with the chip?

[10/10ths]

I will keep this thread in mind, I am planning on adding the WAR chip to replace the GenII one in the car now (Miller MAF). Other than headers/exhaust the motor is stock.

I am also curious about the octane level difference in performance between 91 and say 94, which I have available to me at a few stations. I'm guessing it's not much at all but I plan on running my car on a dyno in the next couple of weeks. I would like to try a few combinations of chip tunes with the WAR, from stock/87 octane to the one size fits all 91 octane tune that it is at now, to a custom 94 octane tune.

I know the MAF itself might skew the results, but I want an idea of just how much can be gained with "chipping" a car. My guess is somewhere between 5-10rwhp from stock to tuned.

[Patrick_Bateman]

You can increase horsepower with different octanes by adjusting the compression ratio of the engine. A chip like Mark D's does exactly that. If you have 93 octane in your area you should go for it because the chip will give you more horsepower over 91. I'm not sure what the delta is but it's definitely something. I have the 93 octane chip and it made a big difference over stock.

[decay]

the only thing that affects (static) compression ratio is piston dish/dome and head volume.

what a chip changes is ignition advance and fuel enrichment.