Question about doing a carb'd LS3
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Racer
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Question about doing a carb'd LS3
If you have an LS3 bare black and wanted to build it up to 700-800hpish, in the end would it be more effective (in terms of cost, reliability, and power) to use a carb or go EFI?
The past car I've built was carb (ford 351w stroker motor) and I love carb because it's simple to setup, understand, and diagnose(and to be honest I don't understand EFI all that well ...... I'm not even a backyard mechanic, so cut me some slack!!)
So I'm wondering, with an LS3, will a carb be cheaper in the end? (no controllers or computers to buy) and can an LS3 make similar power (+ or - 20-30hp or so) with a carb vs efi?
The past car I've built was carb (ford 351w stroker motor) and I love carb because it's simple to setup, understand, and diagnose(and to be honest I don't understand EFI all that well ...... I'm not even a backyard mechanic, so cut me some slack!!)
So I'm wondering, with an LS3, will a carb be cheaper in the end? (no controllers or computers to buy) and can an LS3 make similar power (+ or - 20-30hp or so) with a carb vs efi?
Race Director
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From: Fort Worth, Texas
curious what you're gonna put it in? What are your plans with the ignition system? It might be cheaper to run the efi setup, unless you already got a carb. Saw a mag article show the carb intake make more power up top.
Safety Car
Joined: Nov 2007
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From: Bethesda MD
If you are building for NA power at high rpms (e.g. 7500 rpm shift), the carb will make more power as most EFI intake manifold runners are not optimized for high rpms.
I have not looked into whether the intake manifolds run with carbs on other LS series engines will fit an LS3.
BTW, there are plenty of 700+ RWHP FI systems running EFI that are very streetable thanks to EFI and good tuning. You may want to consider that path.
I have not looked into whether the intake manifolds run with carbs on other LS series engines will fit an LS3.
BTW, there are plenty of 700+ RWHP FI systems running EFI that are very streetable thanks to EFI and good tuning. You may want to consider that path.
Race Director
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From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
No mention of ignition requirements, but look here.
http://www.gmperformanceparts.com/Pa...l.jsp?engine=2
http://www.gmperformanceparts.com/Pa...l.jsp?engine=2
Thread Starter
Racer
Joined: Aug 2009
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) )
In terms of power, I'm not overly concerned about top-end power, just good all-around power (if there were a 10-20hp difference between card/efi I wouldn't care, but I'm wondering on an LS if we're talking a much larger difference, like 80)
For ignition, sky's the limit. I'd ideally like to wire it like I did my 351w stroker in my cobra (i.e., a key-on ignition with a push-start button, using an I2 1+1 million controller and an MSD ignition controller). The I2 is basically like a mini-ECU that controls all the electronics in your car (fuel pump, ignition, headlights, etc.....)
My main reason going for carb is simplicity - I understand it and can work with it. EFI has far too many wires, fuel injectors, etc.. etc... ..... sure, I could learn it, but when problems start I wouldn't have a clue where to begin. Plus I'd have to learn all new 'safety' techniques - for example, with fuel injection if I wanted to pump the tank I have to relieve fuel pressure first. With carb, I just open the fuel line on my external pump and out she flows, haha.
Last edited by infinity4life; Oct 6, 2009 at 01:44 PM.
Thread Starter
Racer
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I know that's the theory (and at these hp levels, who really cares about MPG, hehe), but I have no idea if the same concepts apply with a modern engine like an LS. (this may be a stupid question/comment, I don't know, but I really know nothing about engine building)
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Safety Car
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From: Madison Wisconsin
St. Jude Donor '08
I know that's the theory (and at these hp levels, who really cares about MPG, hehe), but I have no idea if the same concepts apply with a modern engine like an LS. (this may be a stupid question/comment, I don't know, but I really know nothing about engine building)
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Racer
Joined: Aug 2009
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Btw, speaking of ignition, how exactly does that work with an LS engine? I see there's something called an ignition controller, but it comes with stuff like MAF, 02 sensors, etc..., so it's obviously not meant for a carb.
Can one use an old school setup with it - spark plugs go to a MSD distributor, which is connected to a MSD controller/MSD coil, and then wired into switched 12v?
Race Director
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From: Fort Worth, Texas
Good to cover all grounds
Btw, speaking of ignition, how exactly does that work with an LS engine? I see there's something called an ignition controller, but it comes with stuff like MAF, 02 sensors, etc..., so it's obviously not meant for a carb.
Can one use an old school setup with it - spark plugs go to a MSD distributor, which is connected to a MSD controller/MSD coil, and then wired into switched 12v?
Btw, speaking of ignition, how exactly does that work with an LS engine? I see there's something called an ignition controller, but it comes with stuff like MAF, 02 sensors, etc..., so it's obviously not meant for a carb.
Can one use an old school setup with it - spark plugs go to a MSD distributor, which is connected to a MSD controller/MSD coil, and then wired into switched 12v?
Safety Car
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From: TEXOMA
St. Jude Donor '08-'09
if the ls3 is going to be stock, then id go with the Stock EFI all the way. its when you put on heads/cam and F/I is when it starts to be a PITA! the pcm is only like 200 bucks and just get the harness
Race Director
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From: Fort Worth, Texas
he's wanting to make some serious power, so stock is out of the question
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Racer
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If you have an LS3 bare black and wanted to build it up to 700-800hpish
Shooting for a bit more than stock
