I'm installing my tsp stage 2.5 5.3L heads 59cc when I go home for spring break. My question is when I go to get the dyno tune done will it be safe for the motor to run on 87 octane, or will this start to trigger detonation?

I really don't want to pay for 24 gallons of 93 octane

I believe the 59cc is around 10:1 correct me if I'm wrong PLEASE!!

 

If its tuned for it, it will be fine. You'll just make less power.

 

In all actuality it's less the $5 difference per tank full from 87-93 octane fwiw.

 

My LS1 would not run on 87, even with a tune. Its was pinging nasty, 10.3 ratio.

 

too run 87 octane with 10 to 1 and up. you have to drop your part throttle and mid throttle timing by 10* or more. MAKES FOR A in traffic or just cruising. NOT WORTH IT.

 

If your looking to save money, modding the truck isnt the best idea. lol Just run the good stuff, you dont want junk pump in your engine anyway.

 

I don't know how you can say that. The L33 is 9.95:1, the LS1 is 10.25:1, and the LQ9 is 10.08:1, and they all run on 87 octane just fine. I've owned all of them, I'm telling you this first hand, not just saying something I've guessed at or read somewhere.

Add to that, I'm currently running a L33 in my truck, supercharged (10 psi), on 90 octane. And it's a beast.

To the OP, obviously you could get more aggressive with the tune if you ran better gas. But that's the case with ANY setup. 10:1 compression ratio is not extreme, just get the tune right and you'll be okay.

 

Weight of the vehicle also plays into this question....cheap gas in a f-body no problem, cheap gas in a LS1 truck is a different story. My tuner tried to get my Avalanche to run on 87 but in the end it just not worth it to be cheap and hurt the engine.
Last year I changed an engine in a 06 Sierra L33, detonation from cheap gas eventually killed the engine, will see if I can find pictures of the carnage....there was more of the #8 piston in the intake manifold (pieces) that was attached to the rod.

 

^^^ Agreed 100%!!! I do all the tuning on LS stuff around these parts so I've dealt with this many times. It works fine, not recommended, but works fine.

 

when and not "if",he decides to TOW with his "truck". His pistons will (piece by piece) be sent out the tailpipe. That is a guarantee. Big difference between 9.9 to 1 and 10.5 to 1. I have seen detonation scars on LQ4 pistons. (9.4 to 1)

Being a "tuner" and 87 octane are not words I would use in the same sentence. LIABILITY, if your worth anything at it. Splitfire plugs will NET a better power increase than a 87 octane tune..