Ls1 Upgrade Question
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Ls1 Upgrade Question So, I read here every day, sometimes 2-3 times a day. I often see people recommending upgrading from an LS1 to an LS3 for better power, because of the better heads and intake.
But isn't the wiring harness, sensors, and ECU completely different? And isn't the LS3 throttle body DBW? Wouldn't you have to change all of that as well?
Granted, the LS3 is a 9% increase in displacement. And you can't beat cubes.
Could you get pretty much the same results (more power) by changing to good aftermarket H/C/I, and keeping the rest the same? Seems like you'd save a lot of time, money, and effort, and end up in nearly the same place.
What am I missing here?
Obviously, for a max effort, max dollar build, the LS3 would be the better choice.
But isn't the wiring harness, sensors, and ECU completely different? And isn't the LS3 throttle body DBW? Wouldn't you have to change all of that as well?
Granted, the LS3 is a 9% increase in displacement. And you can't beat cubes.
Could you get pretty much the same results (more power) by changing to good aftermarket H/C/I, and keeping the rest the same? Seems like you'd save a lot of time, money, and effort, and end up in nearly the same place.
What am I missing here?
Obviously, for a max effort, max dollar build, the LS3 would be the better choice.
the ls1 computer can run whatever engine, and vice versa - so long as you have the right sensors and reluctor wheel in it.
The ls3 computer is light years more powerful, and much better at idle correction.
Edit: Also drive by wire, and requires the electronic pedal assembly.
The ls3 computer is light years more powerful, and much better at idle correction.
Edit: Also drive by wire, and requires the electronic pedal assembly.
Last edited by DietCoke; Apr 3, 2017 at 09:54 PM.
OP, great thread start. Likely to start some really good discussion.
IMO the advantage to the LS3 is the bore. All heads flow better with more bore. In the old SBC days boring 030 over was a performance mod. The LS3 is more than 4x that over bore.
Can the same results be achieved with HC LS1? Yes. And no. A person can go the route of doing the upper range of a typical LS1 build and get 450-470 rwhp. That's your top end ported LS6 heads, mid 230's cam, fast intake, long tubes, etc. if someone goes insane they can hit 500rwhp. But it takes doing everything you can.
LS3 can get into 460-470 rwhp territory with bolt ons and the only internal mod is rockers. Which I'd still call a bolt on. The heads don't generally need porting to support the HP. I sort of look at the LS3 like a "heads only" bored out LS1 build. Even if you swapped over your ported LS6 heads. They'll flow better on the LS3 than they did in the LS1. Swap over your cam also and you're a good 30hp better than you were. At least. And the added bore absorbs the cam duration, so the cam that might have been borderline PITA to DD will be tamer as well on that 376.
Guess which one is nicer to drive?
As to the harness, you can run the factory harness, but you need a box to translate the 58x reluctor to 24x. Or you swap in a crank with the right reluctor. You gotta swap to front cam sensor, but not crazy out there stuff to make it work.
So I guess bottom line FOR ME. If I've already got the LS1, I'll HC it and have fun. If I blow the bottom end, I'm swapping.
IMO the advantage to the LS3 is the bore. All heads flow better with more bore. In the old SBC days boring 030 over was a performance mod. The LS3 is more than 4x that over bore.
Can the same results be achieved with HC LS1? Yes. And no. A person can go the route of doing the upper range of a typical LS1 build and get 450-470 rwhp. That's your top end ported LS6 heads, mid 230's cam, fast intake, long tubes, etc. if someone goes insane they can hit 500rwhp. But it takes doing everything you can.
LS3 can get into 460-470 rwhp territory with bolt ons and the only internal mod is rockers. Which I'd still call a bolt on. The heads don't generally need porting to support the HP. I sort of look at the LS3 like a "heads only" bored out LS1 build. Even if you swapped over your ported LS6 heads. They'll flow better on the LS3 than they did in the LS1. Swap over your cam also and you're a good 30hp better than you were. At least. And the added bore absorbs the cam duration, so the cam that might have been borderline PITA to DD will be tamer as well on that 376.
Guess which one is nicer to drive?
As to the harness, you can run the factory harness, but you need a box to translate the 58x reluctor to 24x. Or you swap in a crank with the right reluctor. You gotta swap to front cam sensor, but not crazy out there stuff to make it work.
So I guess bottom line FOR ME. If I've already got the LS1, I'll HC it and have fun. If I blow the bottom end, I'm swapping.
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Also, could you put a 24x reluctor wheel in an LS3 block? Or is it just simpler to use a new sensor and reprogram the ECU?
Moving the cam sensor to the front is a piece of cake.
Last edited by .boB; Apr 4, 2017 at 12:10 PM.
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And turbos in a light weight car can be difficult to handle. That sudden surge on corner exit can make for exciting moments.
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On The Tree
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From: Leeuwarden
More power isn't always better. The father of a friend of mine drove the 1/4 mile in 6.9 seconds and wanted to go even faster, as always. So he tuned his engine and guess what? The chassis couldn't handle the extra power so he became slower. In the end, he couldn't get the car to go faster..
Next to this, what's your goal? Do you want more grunt, would you like more high-end power, do you want both or..?
Next to this, what's your goal? Do you want more grunt, would you like more high-end power, do you want both or..?
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As a racer, I'm always looking for more power. It's up to me and my right foot to then manage that power correctly. I can't use that extra power coming out of all corners. But I can use it coming out of some of them.
What I can really use is some extra rpm's. When I get time, I need to work on upgrading the valve train.
What I can really use is some extra rpm's. When I get time, I need to work on upgrading the valve train.
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Oh, I won't have time to actually do anything until the end of the season. I'm elbow deep in another project right now.
The current engine is running so good now, I'm kinda afraid to mess with a good thing. The car is almost as fast around the track as a Porsche GT3, and slightly faster than a stock Corvette ZO6.
But eventually, I'll look at some good aftermarket heads, shaft type rockers, and beehive valve springs. Durability is the key, so decent cam duration, but not a whole lot of lift from fairly gentle ramps. What I need is a broad flat torque band.
Instead of rebuilding the LS1 short block, it might be easier and cheaper to just install a good used LS3 short block and go back to racing. The current short block is used, and has about 50K miles on it. It runs like a champ, and I just love driving it.
The current engine is running so good now, I'm kinda afraid to mess with a good thing. The car is almost as fast around the track as a Porsche GT3, and slightly faster than a stock Corvette ZO6.
But eventually, I'll look at some good aftermarket heads, shaft type rockers, and beehive valve springs. Durability is the key, so decent cam duration, but not a whole lot of lift from fairly gentle ramps. What I need is a broad flat torque band.
Instead of rebuilding the LS1 short block, it might be easier and cheaper to just install a good used LS3 short block and go back to racing. The current short block is used, and has about 50K miles on it. It runs like a champ, and I just love driving it.
Last edited by .boB; Apr 11, 2017 at 04:41 PM.
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From: Leeuwarden
Being in your position I would go for the LS3 for several reasons. The most important one is the amount of money I was going to spend on the LS1. You don't know which parts you want, but assuming you want soms good stuff the pricing could look like this:
cam $350,-
heads $2500,-
intake $800,-
Pushrods $100,-
Valvesprings $250,-
Retainers $150,-
Rockers $1250,-
Total $5400,-
You can spend less, but It'll cost you.. I think. Next to this, selling the LS1 will free up some extra money. With this, switching to the LS3 won't be such a big step financially.
So what will be the benefits of switching to the LS3? First of all, bay to bay breathing, better baffles, block structure, more cubes, lighter waterpump et cetera. But next to this, you'll also get:
I would only change the cam and valvesprings, but keep the stock rockers, pushrods et cetera. The stock rockers have a great geometrical design and are very light above your valvesprings. Next to this, when your valve meets a piston the pushrods are the parts that bend if you use stockers.
cam $350,-
heads $2500,-
intake $800,-
Pushrods $100,-
Valvesprings $250,-
Retainers $150,-
Rockers $1250,-
Total $5400,-
You can spend less, but It'll cost you.. I think. Next to this, selling the LS1 will free up some extra money. With this, switching to the LS3 won't be such a big step financially.
So what will be the benefits of switching to the LS3? First of all, bay to bay breathing, better baffles, block structure, more cubes, lighter waterpump et cetera. But next to this, you'll also get:
I would only change the cam and valvesprings, but keep the stock rockers, pushrods et cetera. The stock rockers have a great geometrical design and are very light above your valvesprings. Next to this, when your valve meets a piston the pushrods are the parts that bend if you use stockers.