Sinister_Z28

Ok so i have been playing with the idea of going FI for a while now and just wanted some advice. As of now my 408 has 11.2:1 compression ratio on pump gas which i know is to high for forced induction. My question is could i run some boost if i switched to e85? I have been all over the place looking for info on this and just cant seem to find any solid info. Oh and i have e85 readily availible to me where i live.

Sinister_Z28

Anybody?

SR-71 SS

iTrader: (2)

The e85 will allow for some boost but your still going to be limited by your compression

The Alchemist

iTrader: (19)

You should be able to run E85 with that much compression, but it's not static compression that's the key, it's dynamic compression. A 10.0:1 motor with a stock cam makes a lot more dynamic compression that say a 225/235 cam due to the overlap.

SKULL

iTrader: (7)

you can put boost to a motor with that much compression. dont let anyone tell you other wise. just comes down to a well thought out setup and great tune

Sinister_Z28

Any ideas on how much boost i can run. The motor is a fully forged with arp everything in a iron block. Top end is LSA heads, stock ls3 roker arms, arp head studs, LS3 intake, and my cam is a 236 intake and 242 exhaust 114 LSA +3.

Sinister_Z28

Anybody?

I8UR4RD

iTrader: (16)

Run as much boost as you can. Just get a great tune. As far as how much boost you can run, that depends on the overall setup. my blower might make 16lbs on my car and make 19 on yours. All depends on airflow/restriction altitude etc...

5w20

iTrader: (21)

The more powerful an engine is N/A, the easier it is to make power when boosted. Good fuel and a good tune go a long way. If you think and search outside of the LSx world, there are many boosted 11.5:1+ compression setups.

Sinister_Z28

I got the idea from a buddy who is into imports. I noticed they were boosting cars with really high compression so i thought why cant i do that. Now at what point would e85 start detonating and all the problems associated with fuel? And when i ask about how much boost i can run i mean how much can i make before i start breaking things.

SKULL

iTrader: (7)

run it till it breaks, then take a half lbs of boost out. put as much boost till youre happy with what it makes

Cam72aro

iTrader: (28)

Higher boost will need meth and race gas. A good tune with conservative timing is key.

The Alchemist

iTrader: (19)

Considering the LS3's are at almost 11.0:1 compression, and there are plenty of people running boosted setups, I think you're fine. That's a decent size cam, and with e85, I think you're not going to have issues. Start out with a conservative amount of boost, make sure the tune is good, don't try to push a crazy amount of timing, stay in the low teens with it, and you'll be fine.

SKULL

iTrader: (7)

and if you dont wanna run e85 cause you changed your mind or something. just run meth and you should have a great car

Sinister_Z28

Isnt it dangerous to run lower octain gas and rely on meth to keep ur engine alive? So if i was to convert to e85 how much boost would u start out with? What would be a safer and more powerful route run e85 or pump gas and meth?

SKULL

iTrader: (7)

meth is some what of a oct booster and cools the iat the same thing e85 does. if you tune the car so that when the iat see 135+ degree you can set it to pull out so much timing and as the temps increase. pull more timing and youll save the motor for if you do run out of meth. but i believe in meth and running pump gas. its ALOT cheapier then e85 i think. buy a meth kit and done. buy 5 gallons of m1 meth every once in a while. e85 needs alot more fuel to make the same power an gets horrible gas milage. just my opinion

also im saying 93 oct and meth. i would never do 87 and meth or something like that

Sinister_Z28

Ok well im still looking for 93 octane cause i live in socal and its hard to find but 91 is everywhere. Would 91 octane and meth work? Or should i just go 100 octane?

I8UR4RD

iTrader: (16)

about 21-23 lbs is where testing has shown them to start pushing water im told.

5w20

iTrader: (21)

E85 > pump/meth in terms of power and safety. One cools the charge while the other cools inside the chamber. Not saying that pump/meth is garbage, but it isn't as potent. Pump/meth will still net you good results.

Boost is a relative number and there's no equation to tell you what the magic number of lbs boost to run. Impeller speed is what matters when it comes to prochargers. I don't even recall you mentioning what head unit you planned to run.

Sinister_Z28

I was thinking about running a D1SC but i dont know exactly which procharger i want to run because i dont know how much boost i can safely make. I was thinking i might be able to run 8-12lbs but i dont know. Thats why im here asking questions im just trying to learn and figure it out before i start buying stuff.