I'm not saying that advancing the timing is the end all be all of performance mods, but yes to a point advancing the timing increases the horse power.

My point is that switching from 87 to 93 and not doing anything to the car will not do anything at all except hurt your pocketbook.

I'll agree with that.

I've noticed than with the stock turbo setup, switching from 89 octane down to 87 octane netted noticeable power gains in MY normal rpm range (1500-4500) and 2-3 miles per gallon more at the pump. I also have the timing advanced up to around 23 degrees. Just my thoughts.

I think thats a good idea it would be nice to look in one place for the info on this

I can see it now: "EA82T Forum, for those with an EA82T looking for mods and information"

Originally posted by WJM

I can see it now: "EA82T Forum, for those with an EA82T looking for mods and information"

 

I can also see the demand and price for an EA-82T short block from CCR going way up.

 

Keith

I have read here that the 93 ignites at higher temperatures, thus preventing pinging. I think I've also seen elsewhere that the 93 doesn't release quite as much energy when it burns.

In a NA engine, would these two factors combine to reduce gas mileage and engine efficiency?

 

Thanks,

Luke

Technically.

 

But when you are trying to get more HP....take for example, a true JDM STi engine...EJ207. By putting the best Jap pump fuel in the tank, you can probalby get 320hp no problem, STOCK. Its rated at 280 from the factory. Here in the usa, the same engine, on the best pump gas we have to offer...it will run like crap, and probably net something like 260 or so. Quite a loss. That is NOT to say that more expensive gas will give you HP...but it give you the capability to extract more power from an engine.

 

WRXs in Japan run 250 stock, while here, its 227. Not that those two engines are not the same. Cams, heads, ECUs, all are different, to meet US EPA standards, and to cope with the poor fuel we have.

 

My engine, will run like crap on 93 past 4500, unless I retard the timing way back and then it just wont have any more power past that. On 100 octane, it pulls like a mo fo from 1800-3600...and drops off a little and still pull like crazy to 6k.

 

I am sure someone can explain better than me the dynamics of octane better than I. All i know, if if you take a stock N/A EA82, and run 87 vs 93, either one will give the same performance. With mods...the 93 will net more power over the 87. Likewise with 100...you'd be running 12:1 compression, race cams, some wild intake and exhaust....