turbocdubs

I've got a LY6, its been bored over and has a cam in it yada yada yada. So I've sold the weekend warrior but kept the motor thinking about adding a supercharger to it and possibly putting it in a DD and be able to drive anywhere and what i mean mostly by that is--can i safely run it on 87 octane with boost.

the reason i need it to run on 87 is for anyone else but me driving it say, mother, grandma, gf, etc. i dont want to worry with someone else driving it,

and ive been to some places in the country with no 93. I'm just trying to make a reasonably powerful dd truck motor that can go anywhere stop at any gas station without worry of it killing itself.

Yes i'm well aware of how much more power 93 or e85 makes id really love that but the availability isnt always there, but 87 is, plus i wont ever have a wild call of "hey i just put gas in the truck and its knocking and ticking now"

so is it possible to make decent reliable power on 87 or am i just dreaming- again not trying to set records just trying to make good power (ie 550-600rwhp)

tobyerob

iTrader: (1)

You could but it's not the power that you have to worry about its detonation. Especially with throwing boost at it I wouldn't risk blowing the engine. If nothing else put a sticky note on the dash that says 91 or 93 whatever is avalible.

Bob@BruteSpeed

iTrader: (16)

I don't see you making 550 to 600 rwhp on 87 octane, as you would have to run a very low amount of boost. Methanol injection would certainly help, but I still don't see you achieving your goal. Bob

Forcefed86

iTrader: (4)

Ain't gonna happen unless you drop your compression down to 8:1...ish.

93camaro_zzz

iTrader: (13)

Instead of putting all of your efforts into trying to build a boosted motor for 87 octane, why dont you spend your effort on educating the people that would ever drive your car, to put the correct fuel in it?

Just a thought.

turbocdubs

See its not so much the worry of error of putting the 87 in, its the lack of availability I'm more worried about. There's so many places Ive been thru like little 1 light towns and they either have 87 or 89 and if you do happen to stumble upon 93 the pump is either out or hasn't been touched in 6 months.

turbocdubs

where do you see it being safely maxed out at with boost on 87

Forcefed86

iTrader: (4)

You're already at 9.6 to 1 or so. The ECU dumbs down the tune to run 87 as it is...na. You really should run 91 or higher in all the LS engines for best performance. The only way to properly run low octane is to drop the compression way down which will make for crap MPG. Get the CC's hogged out to drop compression and/or run a custom thick cometic head gasket. They make them as thick as .120.

A decent set of heads,cam, headers, and intake will get you darn close, and be a much better option IMO. Little nitrous could also be run very easily. DD and 600rwhp don't usually go together well. You're talking over 720 at the crank through a 4l80e. That much power will also chew up transmissions and rearends if not built properly.

Bob@BruteSpeed

iTrader: (16)

I've never tried it but you would probably be around 5 psi max. I just don't see you getting to 550 to 600 rwhp on 87 octane, even it you lowered the compression ratio. Bob

Forcefed86

iTrader: (4)

FWIW, I made roughly 600whp on a 7.8:1 383 gen1 SBC. I ran 87 octane in it regularly. (was my daily for 2 years) Trapped 120ish in a full weight gbody with a 200 shot. Though I did run premium 93 when I raced it. I could easily see a 8:1 LS doing the same with boost. I'm actually building an alum 5.3 block with 4.8 crank and 5.3 rods right now. Looks like it will be right around 7.6:1 with the piston .17 in the hole. I believe I'll clear 600whp easily on pump gas.

ls3fox

Put a meth kit in it and run straight m1 and itll be fine