Even though gas prices have been steadily declining the past few weeks, I am still a cheap *** and have been buying 87 octane. I have been running 87 octane for the past two months now and I have had absolutely no issues. This piggyback was the one designed to use 91 and higher. So for all of those wondering what would happen if you put lower octane in your car with the piggy, you will be fine.

 

How often do you fill your tank? I mean the most you are saving is like $2.00 per fill-up, right? I can't imagine it being worth the risk/performance of a product engineered to run on 91 octane.

You must not be that cheap, ****, you bought a $450 part!!!

 

With all the driving i do, i fill up about 3 times in a two week period. Been doing 87 octane for 3 or so months now. It will not hurt your engine.

 

The misconception is that the piggy changes timing (advances) to allow for the 91 octane. The piggy back does not do this and only the a/f ratios are altered. 87 can be used with no problem if only a/f ratios are being tuned. The only arguement that I've ever heard is if RRM so agressively leaned out the a/f that the 91 octane is needed. If it was this lean to begin with, there would be many problems with the mod for our engines, regardless of octane used. Not to mention what would happen on a bad tank of gas if 91 was truly needed...

 

We say what we say as a margin of safety. One could argure that stock ECU will sense lower octane and potential detonation and pull enough timing. Looks like Black has been testing that theory. That is even better for us and the piggy.

Thanks Black.

ROAD/RACE

 

I'll say this... you can't alter the MAS signal without altering timing. The two are dependant of eachother. The same map for timing bases itself off the frequency seen from the MAS signal.

All dsm guys have dealt with this over the years and it's still true today. Lowering the MAS signal to lean out the fuel will result in a more advanced timing curve usually. The timing starts getting pulled as the MAS signal increases. Running bigger injectors often kills the timing curve so we pull the timing back out of it in order to keep things happy.

Shouldn't post if you don't fully know

Is cool thought that you can run 87 in the NA piggy... ROCK do you think i can get away with 87 in my Ralliart turbo'd car? Just kidding.

Of course though RRM can't be responsible for anything that happens since your running the non-recommended octane right?

 

I don't know if they give different people different answers but I asked about running the RRM piggyback with my nitrous setup and they said it would allmost surely detonate my engine. I'm thinking that the stock ecu was pulling timing for the 87 octane.

 

YEa try 87 in your turbo, just don't call me!

ROAD/RACE

 

Is this a joke... why lean out your ride for NOS? You gotta be educationally challenged!

 

BLK, did you notice any diference on your car performance now that you are using 87 oct. versus the premium one? I always use 93 on my car and feel the diference in the power and acceleration ,and also notice more miles x tank of gas. Anyway great to know that the pb. can work on 87oct.

 

Getting premium gas will not give your car any more power, its all in your head. The reason you are getting more miles with 93 is beyond me, but it has nothing to do wit your gas. The power was the same throughout my gas changes. The first month I had it I put 93. The next two months i used 89 and recognized nothing different. I went even further down to 87 and just like my story said, I recognized nothing different than when I was with 93.

 

Thanks for the reply BLK I dont know but my head is feeling a diference in power between premium and regular gas (93and 87). Escuse me I'm newbie and I'm finding a lot of knowledge on this forum . My question is why if there is no gain between both types of gasoline then should be one type only . Im ready to learn again my friend!

 

Yes, it's true that timing is advanced automatically, but nearly to the extent that it's advanced for taking advantage of 91 octane to its fullest potential. We're talking only slight advancement in timing, but nothing where using 87 octane will be a dangerous situation.

We're talking about a 10-15 whp gain for timing advance to use 91 octane and proper a/f. Not the 5 whp from changing a/f ratios alone. There is a difference in the amounts of timing change we're talking about.

 

only the voodoo gods and RRM know huh?

 

heh heh, that could be the case.