Twin Turbo LS Boat Engine
Thread Starter
On The Tree
Joined: Feb 2016
Posts: 116
Likes: 0
Sounds stupid but don't really know. Jared quoted me the specs over the phone, went in one ear and out the other, just putting my trust in him to supply the right bits for the job as he has successfully set up a few marathon boats running turbos. People have all sorts of ideas, but I don't know much about the job so go with someone who has been there and done that. Will put up the details once I get them again. There is a bit more to this inj/turbo stuff than the dirty old blower and couple of carbs what I am use to, but will learn.
Thread Starter
On The Tree
Joined: Feb 2016
Posts: 116
Likes: 0
So I need to upgrade injectors on the 5.3 LM7 engine, are LS1 injectors the same and what I need to be looking at ? What flow rate should I be looking for, do I need to up spec the fuel rails and intake manifold or will the truck intake be fine with bigger injectors? The last thing I want to do in lean it, was thinking 160lb injectors?Thanks
TECH Regular
Joined: Sep 2014
Posts: 433
Likes: 0
Intercooled with 98 octane gas, you should easily be able to run 20psi without detonation on a good tune. Upgraded pistons, rods, and maybe crank wouldn't be a bad idea. Unless you'd rather look at the bottom end as disposable, which is my point of view. If it busts, it's pretty cost effective to replace. All I did to the bottom end was gap the rings to 0.028-0.030", new rod and main bearings (the ones in there were slightly scratched, otherwise I would have run the originals), and APR rod bolts. Springs, valve seals, ebay head studs, PAC springs, and an LS9 cam wraps up the long block. Lapped the valves.
What are the cam specs?
What ECU are you going to run?
What are the typical air and water temps on race day? Elevation?
This is the intercooler I purchased. Should be more than effective enough. Not sure about availability and price to you in NZ, but it's very reasonable here especially when comparing it to the High Ram w/integrated intercooler option.
http://www.ebay.com/itm/Liquid-Water...9S14Ce&vxp=mtr
Here's a link for some injectors in AU, not sure if that helps in NZ...
http://www.ebay.com.au/itm/GENUINE-V...-/190538103113
What are the cam specs?
What ECU are you going to run?
What are the typical air and water temps on race day? Elevation?
This is the intercooler I purchased. Should be more than effective enough. Not sure about availability and price to you in NZ, but it's very reasonable here especially when comparing it to the High Ram w/integrated intercooler option.
http://www.ebay.com/itm/Liquid-Water...9S14Ce&vxp=mtr
Here's a link for some injectors in AU, not sure if that helps in NZ...
http://www.ebay.com.au/itm/GENUINE-V...-/190538103113
Last edited by SethU; Mar 24, 2016 at 01:23 PM.
Thread Starter
On The Tree
Joined: Feb 2016
Posts: 116
Likes: 0
Thanks heaps for that info. I have gone with a Comp cam 281LR HR13, 617/.624 lift split, a 231/239-degree duration split and 113-degree LSA. Not sure about temps on race day, water should be cold as normally coming from hill country/mountains down into the lower reaches of the rivers, elevation will be low. Running a Link ECU. The borg warners that are being put together are set up for maximum efficiency at 14psi. Found an identical cooler as yours over here for $500, you sure it will be capable of doing the job? Was advised by one guy over here to use a 3 stage cooler but others have said that's overkill and @ $2000 its blowing by budget a bit. Those injectors seem good value. So are the 5.3 and LS1 injectors the same or different?
Last edited by Huffa; Mar 24, 2016 at 02:37 PM.
Thread Starter
On The Tree
Joined: Feb 2016
Posts: 116
Likes: 0
Most recreational boats run Scott and Hamilton type axial flow units, there are a few that run Berkeleys, I do in my 17ft family boat as well, but all the marathon race type boats run American Turbine, Berkeley or similar. Mine is actually a Legend unit. Not sure on my impeller cut but guessing its big as it was running a 900hp big block before I got it.
TECH Regular
Joined: Sep 2014
Posts: 433
Likes: 0
Thanks heaps for that info. I have gone with a Comp cam 281LR HR13, 617/.624 lift split, a 231/239-degree duration split and 113-degree LSA. Not sure about temps on race day, water should be cold as normally coming from hill country/mountains down into the lower reaches of the rivers, elevation will be low. The borg warners that are being put together are set up for maximum efficiency at 14psi. Found an identical cooler as yours over here for $500, you sure it will be capable of doing the job? Was advised by one guy over here to use a 3 stage cooler but others have said that's overkill and @ $2000 its blowing by budget a bit. Those injectors seem good value. So are the 5.3 and LS1 injectors the same or different?
Yes, that intercooler will do the job... Trying to get a better picture showing the intercooler for you, but this 5.3 ran 17psi on 92 octane and 20psi on 100LL (100 octane aviation fuel) with an intercooler about 1/4 to 1/3 of the size of the one we're talking about, in considerably warmer lake water. It's a blow through carburetor deal (have you considered that as an option?)
Not sure on my impeller cut but guessing its big as it was running a 900hp big block before I got it.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo Thread Starter
On The Tree
Joined: Feb 2016
Posts: 116
Likes: 0
I don't know what rpm it turned, the ex owner has passed away. Sounds good re cooler, some pics of where to mount it would be great. Havent really considered blow thru carb as I am told the ability to get a better tune with the computer is a huge benefit.
TECH Regular
Joined: Sep 2014
Posts: 433
Likes: 0
Wherever it fits. In front of the engine, behind the engine, partially up under the rear deck...
One consideration to take into account is the water in/outlet's are centered on the end tank, so if the intercooler is mounted flat/horizontally it will trap air and only fill +/- half way with water unless you either relocate the outlet high on the tank or install a small bleed (to overboard) high on the tank to allow the air to escape and completely fill the intercooler with water.
Mounted on angle between 45º and straight up and down, I wouldn't worry about it.
Carb/EFI-
Guys are running blow through deals with a lot of success and it's worth strong consideration for your application IMO.
I'm personally running a MicroSquirt ECU on my deal. Just something I've wanted to do for a long time. But, I'd consider a blow through carb in a heartbeat. They are as tunable as anything but a new emissions controlled vehicle would need.
Have you chosen an ECU?
TECH Regular
Joined: Sep 2014
Posts: 433
Likes: 0
TECH Regular
Joined: Sep 2014
Posts: 433
Likes: 0
I assume you're asking about an intercooler circulation pump typically found on automotive applications. If so, there's no need for one in a jet boat application. Intercoolers are typically fed raw water (lake, river...) from a pressurized port on the jet drive it self. It's not uncommon to have them fed without a pump at all too, from a water pickup on the bottom of the boat that forces water through when the boat is moving.
Thread Starter
On The Tree
Joined: Feb 2016
Posts: 116
Likes: 0
So got the Borg Warner S300 63mm .88AR anti surge turbos and 50mm Turbosmart waste gates. Now trying to decide on intake/injectors and throttle body. Am I correct in saying its harder to fit aftermarket high flow fuel rails and injectors to the 5.3 truck intake? If I change to another manifold will keeping with a cable TB be difficult? My 5.3 TB would be unlikely to fit another manifold wouldn't it? So a standard LS1 manifold flows poorly, does that matter in a boosted application? I realise LS6 manifold would be the way to go but hard to get here. I can get an LS2 manifold easy enough, or do I pay the money for a Holly high ram? Still to scared to buy injectors in case I get the wrong ones for my set up. These any good? Whats the go with been a short injector?
http://www.ebay.com/itm/262373339601...xe=exe,ext=ext
http://www.ebay.com/itm/262373339601...xe=exe,ext=ext
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
LS1 intake can make power too...but yes the LS6 will be better
I cant see any point in a high ram, unless you're regularly in the 6000rpm and upwards range, as below that it probably wont be much or any better than the LS1 intake.
And there shouldnt be any problem using a cable TB on any of the intakes it will bolt to.
I cant see any point in a high ram, unless you're regularly in the 6000rpm and upwards range, as below that it probably wont be much or any better than the LS1 intake.
And there shouldnt be any problem using a cable TB on any of the intakes it will bolt to.