matrixiskool

iTrader: (12)

I have a new 6.0 iron block untouched, callies crank, callies rods, and wiseco -3cc pistons. I was going to do a 408 with Ls3 heads that I have, but now I want to do a turbo build because I don't feel like doing this all over again when I want more power. Now my problem is that my compression will be way too high with these pistons and ls3 chambers for boost. Ill have all arp hardware with whatever way I decide to go. So my question is what pistons should I go with for a 4.03 bore/4" stroke with these ls3 heads. I have trouble figuring out compression ratio and I would also rather not get rid of these heads if I don't have to (yes I know I have them for sale, if someone wants them ill still sell them). They are untouched so stock chamber size. Im looking into the 700rwhp range with a 6 speed.

Fbodyjunkie06

iTrader: (10)

Edit: NVM I see you are wanting to get new pistons.

i don't know how to calculate it there are calculators online to plug all your specs into. I'd shoot for around 9.1:1.

Only problem I see is that TC78 being WAY to small for a 408. You need at least a PT88 or a little bigger, a PT78GTS would sneak by, but not past 15-16 psi.

matrixiskool

iTrader: (12)

Would it be alright if I stepped up to like a 1.15 ar or 1.32 housing I forgot to mention that. Found these pistons too, probably what Ill need to keep my ls3 heads. Diamond pistons 11576. Also what the hell does -28 cc mean? Does it mean -28 cc of compression or -28 cc from a flat top piston?

MUSTANGBRKR02

iTrader: (91)

No the TC78 is to small for that engine.

matrixiskool

iTrader: (12)

Are you saying no to the upgraded exhaust housing? Not sure if you saw my reply or not. Thanks guys.

turbo iroc

iTrader: (1)

TC 78 is too small for that size engine. -28 CC is a dished piston. I have a 402ci lq9 with l92 heads 72 CC chamber and my compression is right around 9.3 with a 21cc dish. I'm also running a pt88 Turbo with a 1.08 a/r housing.

Fbodyjunkie06

iTrader: (10)

It's the turbine size itself not the housing. In fact a bigger turbine in a tighter housing usually almost always performs better.

cleonard

i too am building the same motor and considering this turbo. unsure of why it is to small as i am not looking for huge horsepower. i have the callies 4.00 crank with rods and i went with diamond -28 ibf pistons and my compression is around 8.5

matrixiskool

iTrader: (12)

Looks like ill go with a pt88 or turbonetics t88. DAMN these are expensive compared to tc78.

cleonard

tc is rated to 1100 hp not sure why it cant hang.

matrixiskool

iTrader: (12)

That's what I thought. What are the disadvantages of using it with a larger exhaust housing. Im only going for 700 wheel.

IKnowtheFuture

iTrader: (5)

use the tc78 with a big housing.

stock48

iTrader: (17)

If you have room a S475, or Garrett GT76 would prob get the job done. There is also the S480, and GT80.

gimmeluvin

iTrader: (10)

408 with a tc is going to destroy your engine. Backpressure will be through the roof causing your exhaust temp to be at dangerous levels. A pt88 would work great with a 408, if your looking for quick spool. If you can fit a T6 S480 that would work best.

matrixiskool

iTrader: (12)

S480 is too much much ill look into a t88. What about pistons, are the diamonds I was referencing OK? maybe get them coated.

Fbodyjunkie06

iTrader: (10)

It's not about wanting to only make a certain amount of power and matching that with a smaller turbo to get more spool. Your EGT's will be through the roof, you will blow header gaskets, or seals on the turbo if and when you decide to push it.

yes it will work, but you will mark my words be changing it down the road.

A better option would be a turbo from Work turbo's with a 83mm comp side and a 87mm turbine or 93mm turbine side with a 1.10 housing.

gimmeluvin

iTrader: (10)

i would think diamond pistons would be fine, Problably no need to coat them either.. 700rwhp on a 408 isnt exactly pushing it.

cjmatt

iTrader: (4)

If youre stuck on the TC78, just run a stock dimension 6.0. youll get better gas mileage

Sarg

iTrader: (6)

Or the $899 S480 from Forced Inductions with the big turbine wheel and T6 housing would probably be ok. They are about the most reasonably priced bigish turbo I could find. In the end I decided to just go twins.

matrixiskool

iTrader: (12)

Id definately get that but im hesitant because its so cheap compared to others...