Mastaforga

Built a couple N/A ls7 and lsx 454's for some buddies cars and trucks.

This will be my first FI build, going in my personal stock frame prerunner...

Current Parts-
lsx tall deck block (will be 0 decked to about 9.3)
Callies Magnum XL crank 4.125" stroke
Callies Ultra I-beam rods
ARP head and Main Studs
Billet main caps
Diamond Pistons 4.125 bore 25.3cc dish 1.115 comp height

Still havent decided on heads or cam yet.

I also have 2 water/air intercoolers and dual 75mm throttle bodies to make custom cross ram intake.

I'm looking for around 900-950hp reliably with a flat torque curve to 7000rpm. What dual turbos would you recommend for fast spool at lower rpm and still have enough flow at the top end?

How much boost?

I also know nothing about different EFI controllers, I always just go stock or carbureted. Any Recommendations?

DEFYANT

First off, what's heads, cam, and Intake combo are you going with? I'd get a hold of Lil John, or Martin at Tick for a cam regardless.

If you're cammed right, and have everything else setup optimal I would say something in the 62mm range, I'm partial to Precision, but Garrett, Borg, etc. are all great companies.

Really, with that kind of shortblock, I would put twin PTE 6870's on it, and let it eat. But I'm not sure if you have certain class restrictions, or if it's just a fun truck.

venom ws7

iTrader: (13)

PTE 6870s turbos will be perfect for your setup specially if the car is auto trans.
Will easily make your power & tq goals and a lot left on the table.

I built 454ci LSX Tall Deck for a friend's C6ZO6 with PTE 6766s turbos made 1054rwhp 1085rwtq on 15-16psi straight 93 pump gas spools very hard and pulls all the way to 7100rpm we're hoping for 1400+rwhp on 26-28psi

Or you can check the Borg Warner turbos if you have some room in the engine bay great price and will make the power you're looking for.

stevieturbo

A cheap pair of BW S366's should do the job and spool well on a motor that size.

As for EFI, the Holley is popular.

Or for a new install and they claim almost no tuning required, there is Pro-M EFI

Mastaforga

It's a fun truck, no class racing, so I have no restrictions on engine. I will be putting between 200-300 miles on it at a time, almost half of that will be WOT.

My wallet isn't really deep enough to do a rebuild every few runs, so I want it to last a few thousand hours of mid to wide open throttle.

It will be mated to the GM TH400 Auto 3 Speed to handle the abuse of rock and desert driving.

Still looking for a set of 6 bolt heads to match my build and I'll figure out the cam after I get the heads and turbos figured out.

IronBlocked

get a bigass oil/trans cooler

Mastaforga

Already have coolers mounted behind cab with electric fan,
and an water/air intercooler for when I make the manifold.

Mastaforga

PTE 6870 seems a little big for twins, I don't plan on ever going above 1000hp and 6500rpm on this build. So if it runs out of breath around 7500rpm I don't mind. I just want the fastest spool I can get. I know the cam has a lot to do with how the turbo behaves, but some of the areas i want it to go are low speed rock or silt, so I need a mild cam with a long flat torque curve starting as low as possible.

Also willing to run race/pump mix but prefer to make those numbers on 91 octane.

LJMSJohn

Pair of S366's with 73mm turbines and .91 A/R housings.. Enough turbine wheel for the cubes, enough compressor to support 1200 to the tire.

Plus they are half the price of the precision units.

Mastaforga

Those seem just about perfect for my power and spooling needs, but what about cooling and longevity?

I'll be all over rocks and bumpy roads at breakneck speeds, and a lot of WOT.

Will these hold up to the abuse and heat?

IronBlocked

From my perspective borg warner is much more reliable than PT, they make a shtload more turbos too for OEM manufacturers

Mastaforga

Yeah but this isn't going to be used like a stock rig will be used, these are prerunners being driven like rock bouncers and trophy trucks.
In the sand we are WOT at redline for sometimes up to 10 minutes under heavy load. And the rocky areas have been violent enough to rattle apart motor mounts and tweak frame rails.

I just want to know it will hold up to the g's of being jumped and thrown around, and if it can survive excessive heat for prolonged intervals.

Sorry if I'm being overly cautious. I've never messed with turbos before and really nervous about spending the extra money on them.

oscs

iTrader: (19)

The BW S366 is probably one of the most durable turbo's out there. You will be hard pressed to find another turbo that can do what it can for that price and take a beating.

LJMSJohn

The only turbo that I would suggest for him over an S366 would be a 467 with a 83mm turbine wheel. the wheels are basically the same size... and you step up to a 400 chassis from the 300 which gets you a turbine shaft thats almost twice the size of the S300....

Given his statement of how the truck will be used... the S467 would probably be the best choice.

Mastaforga

Thanks for all the help, so far I'm only able to save a couple hundred per paycheck and I want to get the engine built before buying the turbos, so it will be a few months before I actually buy them...

I changed my mind about dual plennum intake, I think the intercooled holley high ram would be better than attempting a custom intake with my mediocre tig skills.

John, the S472 is the smallest BG S4xx turbo that your site shows, do you offer the S467 or will twin S472 be good enough for my power and spooling needs?

I'm also curious about wastegates and blow off valves, what would be the best size? I'll be using an electronic boost controller.

chuntington101

Could you not go for an air to air intercooler? Any air to water setup will heat soak over time. With a decent sized air to air unit you can mitigate some of this and also get much quicker recovery times. It does require the intercooler to be mounted in a location with good airflow. Also you need to think about where you radiator and oil cooler are located and try to reduce any impacts you might have on them.

Got any pics of your truck? Is you radiator / oil cooler mounted at the rear?

oscs

iTrader: (19)

I almost went with the S467 on my 7.3L but didn't want to spend the money. The S366 has been a great turbo for me and i beat the hell out of it every single day at 45+ PSI

LJMSJohn

I can get you the 67's no problem, I need to get the 67's up there... i just havent sold any of them recently and the website was put together off a sales history list... the 72's would work too.... dont think they would spool any slower.... have a little more power potential.

a pair of 40mm gates and a 60mm BOV is more than enough for this.

Mastaforga

Thank you very much for the help, I'll start penny pinching, and try to get the top end together as soon I can. I really look forward to doing business with you.

I'll leave the thread up if there's anyone looking for similar.

66Chevellelq4

Pics of truck?! Please hahah