hi,
right now im running 93 performance tune and have half tank of premium in the truck.
do you see a problem in me loading the 87 performance tune just to see if it runs ok ?
im about to make a long trip again and want to use the 87 performance for cost savings, but dont want to wait and put lots of reg 87 in it and find out its not good then have the 87 in it and have to go back to the 93 tune ???

the 93 tune was dyno'ed, but i believe the 87 tune was not even tested.

 

ok, got no reply so , i loaded the 87 performance tune.
wow nothing compared to the 93 performance tune so i went back to the 93 doubt i will ever load that again lol
the 87 seemed to run a bit rough, but as i said it was never data logged .
my 93 tune was dynoed for data logging , and gone through with a fine tooth comb
anyways thanks (Mike T) if i ever can come up with a lap top i will data log the 87 performance tune and get back to ya for a beter adjustment.
Im very happy with that 93 performance tune.

i will recomend that anyone needing tunes go with troyer!!!

 

Hi Fallingup,

Sorry it took a little while for me to get to your post!!

TO answer your question just for future reference - what happens is you lose power, but it does not actually hurt anything to run higher octane on a lower octane tune.

For example, let's say yo have an 87 octane tune loaded up and you have 91 octane in the tank - or 93 octane. Well, what happens is that you just don't'; make as much power, as the engine is not actually tuned for that higher octane - so the peak cylinder pressure does not occur when it should. What normally happens in a case like that is that on the bottom end, it makes god power, but then the power peaks early, like about 4000 rpm or so, and then from there on up it does not make any *additional* power even though you may take it all the way to say, 5200 rpm just for example - again, it's due to the fact that the engine is not actually *tuned* for that much octane - so you are using too much octane for the tune. That will NOT hurt the engine, it just means you don't' make as good power and the fuel mileage usually is not as good, either.

Now if you did the opposite, and ran 87 octane on a 91 or 93 octane tune, then you would usually get pinging, or what is called spark knock - and that *is* bad for the engine if it is prolonged & sustained, so that is a very bad thing to do to an engine - meaning running too LITTLE octane for the tune.

But what you did, running too MUCH octane for the tune, will not actually hurt the motor - it's just a waste of money, and you will not make as much power as if you simply ran 87 octane on the 87 octane tune.

By the way - when we dyno a vehicle, we typically dyno it on it's higher performance tune, simply because most people come here (or get datalogged at their local dyno) with premium gas in the tank - then we make the corrections, if any are actually needed, to dial in the A/F ratios. It's called calibrating the mass airflow sensor's transfer function.

Now once that is done on ONE tune, then that same calibration is put into your other tunes, as that same calibration for that sensor will not change whether you are running you 87 octane tune or your 93 octane tune, etc.

I hope that sheds some more light on this for you, & glad you are enjoying our Troyer Performance tuning!!