ssbandit158

iTrader: (3)

I have a choice right now to build a supercharged 376 to 427ci motor. I would like to have the 427 as my C6 Z06 came with one originally, however, if it is advantageous to go down in cubes I will do so.

My plan was to order a built ls3 short block from Texas Speed and throw my mast heads on it with about 9.7:1 compression, and add an lsa supercharger as they are pretty cost effective and can put out between 9-12 psi. My horsepower goal is 800whp so I don't think that's unreasonable.

On a side note, I know people are supercharging their Z06's with 11:1 compression with no problem, what is the optimum compression for a built 427 running 10-12psi?

Thanks all in advance.

stevieturbo

What blower ?

Surely an LSA would struggle to hit 800 ?

oscs

iTrader: (19)

Don't believe everything you read on the internet also it makes zero sense to run the risk of a high compression boosted motor when your goal is only 800whp and you have a 427ci motor.

V-seriesTech

iTrader: (5)

Big fan of compression and boost myself.

oscs

iTrader: (19)

Its ok, No body actually cares what you think around here

ssbandit158

iTrader: (3)

I understand that you want lower compression to prevent detonation, but an article I read says you want to run the highest compression you can but still keep it low enough to prevent detonation. I'm just wondering if there is a way to determine if a boosted 427 with 9.7:1 compression and 12psi is safe from detonation.

oscs

iTrader: (19)

VERY safe from detonation on 93 pump gas and a decent tune. You will easily make 800whp with that setup.

ssbandit158

iTrader: (3)

I talked to the guys at Texas speed and they said to get 800whp I would need 18-22psi with a 418 at 9.5:1 compression. I'm not saying I don't think that's right, I'm just wondering if that's a rough estimate or if anyone has achieved 800whp on 12psi.

jrpimp00

iTrader: (17)

lol, look at my sig (it was with a 4l60e not the th400)

ssbandit158

iTrader: (3)

Thanks for the reply, I'm glad to see at least one 800+hp setup with 12 psi. I'm sure there are others, although I don't know if using a turbo or supercharger makes a difference, boost should be boost right?

stevieturbo

You arent using an LSA blower which the OP suggests he wants to use though.

Not a chance in hell of the LSA doing that

oscs

iTrader: (19)

BTW im talking about using a real S/C or decent turbo not a stock LSA blower

ssbandit158

iTrader: (3)

Yeah after looking into it I will be using a better supercharger than an LSA, no point in going through an entire build to put a weak supercharger on it. I just like the roots style blowers.

rkreigh

remember another principle, it's total CFM not boost that matters. Boost is just CFM that's stacked up with no where to go.

I learned a long time ago you can go with better flowing heads, better cam, and boost goes down but power goes up and it's less stressful on the engine.

I'm a fan of high boost and low compression as you can turn down the boost but it's hard to turn down the compression +

for 800 a good cent blower will be easier and allow better intercooling than the LSA without a whole lot more $$$

good luck!