Daniel60

Somebody tell me why my engine pings on 87 and 89 octane but not on 93? I do have the famous CAI/Brenspeed tune. I have to run the 87 tune with 93 octane so it will not ping. Does this mean it really is a 93 octane because of the timing that is on my tune it can't handle a lower octane?

wmtheflash

You need to contact Brenspeed and have him modify your tune. If it's an 87 octane tune, then it should not ping with 87 octane in the tank.

Daniel60

I already did and he said he would take some timing out and I'm just happy now since it isn't pinging. I'm afraid if we go changing **** around again that it will ping all over again.

wmtheflash

Well, you do have a point there. If he doesn't back down on the timing enough, then it could start pinging again when you fill up with 87 octane.

Hmmm...is there a shop near you that does dyno tuning? I know it would cost more money, but you could have a shop give you a custom tune.

Or you could contact SCT directly. They have a great forum. I find that SCT has great customer service and would probably help you correct your tune.

Daniel60

It does run like a ****ing gorilla through the jungle that's why I haven't cried any tears. Thanks for your advise. I am looking for a local dyno shop to work with my tune on giving my tune ever more, forgive me for saying a canned tune. But I haven't look to hard yet and I don't trust just anybody.

GTlust

Where are you getting your gas and what state do you live in? I've been running the 91 tune since Friday using 93 octane gas with no pinging. I put 93 in prior to getting the tuner, but was shorted my 93 tune, so i loaded the highest one which was 91. I'll try the 87 with 87 gas next time I fill up to see if it pings. I'm assuming pinging is something obvious you can here at idle? Anyway I buy exxon gas.

Daniel60

I live in Summerville, South Carolina. Next to Charleston, South Carolina. Yes I used to buy cheap gas however now I only buy Sunoco or Hess.

AirborneCZ

i wonder where guys who buy those Makkinen edition EVOs and so on that uses 100 octane fuel buys that fuel in the US? Or those imports are designed for lower octanes specially for the US market??

imyy4u

no offense, but most of you guys don't know the first thing about octane. the higher the octane, the better the fuel, the more power, period. the higher the octane, the more resistance to detonation, and the more you can advance the timing meaning more power. so, in EVERY scenario, keeping the tune the same but putting in higher octane can do NOTHING but increase horsepower.

i tested it recently on my last car, my supercharged rsx-s, with hondata k-pro. on the SAME tune, 87 octane caused knocking, but 93 resulted in the engine running smooth. at least 20whp increase on the dyno (don't remember the exact numbers). if i upped the gas to 100 octane (keeping the tune the same), a few more whp. if i then TUNED for the increased octane, another 20whp, easy.

yes, tuning for the higher octane results in MUCH higher hp numbers, BUT in our mustang gt the computer advances the timing as much as it can (from 87 to 93 octane) based upon the gas we put in the car. when i first put in 89 octane from 87, no difference, but after a tank or two, there was a noticeable gain in rwhp as the computer adjusted. this car was designed to be smart, so that if an idiot put in 85 octane, no serious damage would result as the engine would pull timing. at the same time, it was designed to adjust for higher octane, to increase hp and performance.

i'd guesstimate the following:

93 octane + 93 octane tune = 25whp more than stock
93 octane + stock tune = 5-10whp more than stock (after running a full tank or two for the computer to adjust)
91 octane + 91 octane tune = 15whp more than stock
91 octane + stock tune = 5whp more than stock (after running a full tank or two)
89 octane + 89 octane tune = 5-10whp more than stock
89 octane + stock tune = 3whp more than stock
87 octane + 87 octane tune = 3-5whp more than stock
87 octane + stock tune = stock hp

rmays06

Holy shnikes...this is an over abundance of info and baby I love it thanks alot.