KeukaZ71

i always run 87 for gas. is it worth it to get a 93 oct tune from nelson? i really want to still run 87 since the gas prices are huge. will i lose alot of potential gains if i run 87?

F8L Z71

Depends on how hot it gets where you live would be my opinion. In colder climes you can get away with less octane. Kinda like us Cali guys durring the winter. But as soon as those 115deg days come rolling around I'll be dropping my timing.

In areas where gas prices are astronomical then staying with an 87 octane tune isn't a bad idea. I doubt you'll see more than 20hp with a 93 octane tune. Well, unless you are running forced induction.

one03sierra

iTrader: (1)

hey buddy he is having a gp on ls1truck. and you can get a dual octane tune from him.

KeukaZ71

that is one reason why i was asking. i am thinking about a nelson tune. so how does the dual oct work? you can use both 87 and 93? 89 oct is common here too instead of 91. i really want to use 87. but wouldn't mine running the higher maybe a few times a year. like if i go to the track

JayStew

iTrader: (3)

I think the PCM can tell what octane you're running and make the timing adjustments for it.

mudz5.3

Hey keuka, I am debating the same thing. The thing with the dual tuning is if the comp senses any knock, it goes to the lower timing table. I know there is a 89/91 tune or a 91/93 and I am pretty sure there is a 87/89 tune as well. There is a few hp diff between these tues, obviously the most would be the 93 tune. If you like to run cheap gas then get the 89/91 tune and just upgrade to the 89 since its in between. Then when you feel like it go to the 91. The thing is, if you get the 89/91 tune and it doesn't pick up any knock with using 89 tune it will use the 91 tune. I think I have decided on the 93 tune as this thread on truck racing sucks wants me to go faster. So every advantage I can get I want to go for, - fi. Hope this helps.

KeukaZ71

thanks. ya, what is up with guys bashing trucks that want to race? i read those threads too. makes me want to go faster too so i can whoop on one. but i don't see that happening with my '99 heavy sled

TnTrk53

I have a Nelson tune,and it runs fine on 87*,I even sprayed it on 87* looking for knock retard. It was a cool night though.

onyx

cmon keuka... lets get these ext. cabs flyin!

KeukaZ71

i'm with ya. at least you don't have a couple hundred pound transfer case weighing you down. you probably would gain .2-.3 tenths on me. plus i have the shitty '99 5.3