How much Boost?

**Zoo York** · 12-01-2008, 05:22 PM

Hi. I'm looking to do a twin turbo setup on a motor I just bought.I need to know a few things before I start spending money I dont need to spend. How much boost can the 5.7 hold? I'm throwing away all of the 5.7's internals for all forged.The block isn't at the machine shop yet I'm still waiting on pistons and weather or not to use billet main caps.I've read that the stocks are powdered metal, but then again are the stock mains good? Also what's the weakest link in the motor? Thanks for any input.. Gerry

**Hemi31** · 12-01-2008, 05:29 PM

The weakest link was the pistons.......if your forging the pistons,rods and crank well you should be good for alot......we have not seen a block failure yet.There are some hefty 5.7's out there but nothing to insane......most of the big boost is on the 6.1's and there are a few 900-1000 crank hp cars out there.BTW......get ready to spend 5k on a transmission.

**Zoo York** · 12-01-2008, 05:51 PM

Thanks for the info. The tranny I have covered, I'm using a FB turbo 400 with a adapter plate I got from PATC

**Hemi31** · 12-01-2008, 05:58 PM

Nice!

**dudeiwin86** · 12-01-2008, 06:14 PM

using a new rear end/drive shaft with the tranny?
the half shafts will go if you put anything sticky on those wheels with that kinda hp

**dynosteve** · 12-01-2008, 06:23 PM

Originally Posted by Zoo York

Hi. I'm looking to do a twin turbo setup on a motor I just bought.I need to know a few things before I start spending money I dont need to spend. How much boost can the 5.7 hold? I'm throwing away all of the 5.7's internals for all forged.The block isn't at the machine shop yet I'm still waiting on pistons and weather or not to use billet main caps.I've read that the stocks are powdered metal, but then again are the stock mains good? Also what's the weakest link in the motor? Thanks for any input.. Gerry

Hey mate

was accutally make a twin turbo system as well as a single unit, if we can help you out just give me a call and we'll make sure you have a huge smile on your face when we're done mate

Thanks Steve

**Zoo York** · 12-01-2008, 07:55 PM

Thanks for the help guys.I should of posted up that the motor isn't going into a dodge. It's going into my 2005 subaru STI. Please don't beat be down

Had a Twin turbo LS2 motor that made 1100 to the wheels and ended up selling the motor harness and turbos for a nice chunk of change. Now I just want to do something different..

**dudeiwin86** · 12-01-2008, 08:41 PM

so a rwd subi? ill be damned.
if putting a mopar block in a foreign car aint sin for a dodge dude....
is putting a rwd into an awd sin for a subi? thats like... part of being a subi.. its all about the awd yea?

i guess before stating the above... will you be keeping it awd?

it may not be a dodge body, but its a mopar heart, and ought to be a cool project no less, please keep us updated!

**Hemi31** · 12-01-2008, 09:06 PM

Originally Posted by Zoo York

Thanks for the help guys.I should of posted up that the motor isn't going into a dodge. It's going into my 2005 subaru STI. Please don't beat be down

Had a Twin turbo LS2 motor that made 1100 to the wheels and ended up selling the motor harness and turbos for a nice chunk of change. Now I just want to do something different..

Whoa.....no sh*t?WOW!Pics of this one please!

**Fargo59** · 12-01-2008, 09:08 PM

whoa, a hemi STI? going to be a TON of front weight to deal with

**Zoo York** · 12-02-2008, 12:54 AM

I could of made a adapter plate to mate the 5.7 up to the STI 6 speed but the engine would sit to far forward, it's alot longer and ALOT heavier then the boxer motor. I have custom springs made for the coilovers when I had the ls2 in it.Here's a few pics when I first fit the LS motor in. I have finished ones on my other comp, i'll post them up later.