For those who have made the LS3 swap into their C5 Z06...was it worth it? Thinking about replacing my LS6 with a 525 HP GM LS3 Crate Engine. Crazy? Really don't want to supercharge and liked this option. What clutch would you recommend? Also, I know various sensors are in different locations and there are aftermarket extensions but I can't remember the company right now. Little help please. Thanks.

 

why not supercharge?
I spent less than $10k on my supercharger and cam -- that included labor, and I'm at 531 hp at the wheels, vs the 525 at the flywheel. With that ls6, you'll be even higher on the power curve. You'll get a lot more bang for your buck, won't have to mess around with wiring harnesses, mounting brackets, etc. Super is also very streetable, and is a pussycat until you stomp on it.

Sorry, don't mean to hijack your thread, if you're deadset against a super, ignore this.

 

JMG2, you beat me to it. Why are you so against a supercharger? A&A superchargers are well priced, high quality, and extremely reliable. It will be much easier to install. It will give you more power, and will be just as easy to drive as an LS3. JMG2 and I both have A&A supercharges, so we know what we're talking about. If there's a particular reason you don't like superchargers, that's fine. It is your car. However, since you asked for opinions, this was my $0.02. Good luck.

 

I prefer NA engines also. Boost can be hard on components, and the whine is annoying. Not for everyone.

Lingenfelter makes the conversion box for the crank and cam signals to convert to the LS3 electronics. You should be able to use all the same mounts and hardware since the LS platform is very similar. You may need an LS3 specific flywheel, but clutch should also be the same.

 

conservatively, by the way, at 525 hp at the crank, you're likely looking at around 450ish hp at the wheels, vs. 530+ at the wheels with a SC.

And if you're really dead set against the SC, why not just do head/cam etc. on your ls6?
the ls6 at the wheels is right around 345 hp, give or take. It's really not that hard to get it to the 450ish the ls3 will be at the wheels. a HELL of a lot easier than dropping in an LS3.

by the way, where'd you get 525hp on the ls3? I thought the ls3 was 430 hp?
ls3 gm crate motor

Anyway, I'll stop. not what you asked, and I'm likely not being very helpful.

 

If you like NA sure its worth it.
Yes theres cheap crates out there offering more for less...nothing like all brand new, block and all
'Brand new everything, steel cam core and good lifters rather than a chinese iron cam, heads, lifters from god knows who for starters. There is a crapton of junk out there with fancy names, marketing etc. Reboxed garbage

Maybe in the long run the hp for $ is better with S/C but the whislte/clanging noise alone drives me up the wall;heating problems, less working room etc.
A roots style blower different story

4xx to the wheels is plenty for the street. Not everyone needs 5-700

I

 

Love my LS3 in my 03 Z!!! My first question is what are your intentions for the vehicle? My car is 90% track and I have the 495 HP GM crate engine that has an intoxicating lope at idle. I also have an LS7 clutch and plenty of racing related suspension and brake upgrades. Casper's Electronics is listed in my paperwork for harnesses and adapters. My buddy has the 525 and it too is a nice road racing vehicle.


My car was set-up by Vengeance Racing for the previous owner so I can't tell you the level of difficulty doing the swap but there's enough info out there to do it with minimal frustration. If your LS6 is tired and ready for retirement I say GO FOR IT!

 

It's not too bad of a deal to swap the engine out especially since if it's in good shape you can get 4k to 5k for an LS6 engine if it's in good shape.

 

True on the whislte -- either you like it or you don't, I think it sounds insane. Clanging noise? yet to hear it. Heating problems? runs ice cold all day long in 90 humid weather in NY. In fact the *advantage* of a centrifugal SC over a roots style is that it *doesn't* have heat soak issues if installed properly.
Less working room? you loose some room in the front, but surprisingly little. Roots style blower? looked into it, unfortunately, as far as I can tell, no one is making kits for the ls1, so fab work involved (not a big deal from my perspective) and you'll likely have to get a new hood.

Here's the really big question.. WHY swap in an LS3??? motor swap is not trivial, I've done half a dozen of them at least, and doing one right now (already ordered a ZZ632, just waiting for delivery). If his ls6 is working, this just doesn't make sense. His ls6 is 405HP at the crank. Stock LS3 is 430 at the crank (OP said a gm ls3 @ 525 hp, I don't see that listed on the gm crate motor page).
swapping in a motor -- for only 25 extra horse power is insane.

You can easily get an LS6 to outperform an LS3 with new heads, a cam, headers, etc. If his motor is running-- if the block isn't cracked or something horribly wrong with it, an ls3 swap doesn't seem worth it to me.

Now, if the motor is crapped (not just tired, like, something devastaing like a crack in the block), then a swap is in order. But why an LS3? Go for something more potent!!

 

NA LS3 over a SC LS6 all day. Reliability is key.

 

what's unreliable about a SC? Lots of old wives tales being spread over SC's. I'm as big a fan of NA motors as the next guy (I''m doing a zz632 swap in the next few weeks.. months.. whenever the motor comes in), but ther'es nothing inherently reliable about a properly installed SC.

And forget about a super charger, whats wrong with new heads/cam/etc on the LS6?
ls3 just isn't that much more powerful than an ls6, not worth the hassle of a swap when an LS6 can be built far more powerful for far less than the cost of the swap, and far less hassle.

 

Pretty sure OP has been eyeing the Summit catalogue. 525 horsepower full of good, wholesome, family entertainment. If ordered today It'll ship Feb 22. So they say.

 

If a fella doesn't want to use boost I'd suggest rebuilding the LS6 w/TEA ported heads and all new valvetrain. A higher pressure oil pump and a new harmonic balancer. You'd have the same 500-ish at the crank and a whole lot of the stock parts would still work.
A good engine re-builder and a good tuner could get you close to even with a LS3 swap.

When I'm ready to add power I'm going to upgrade the whole valvetrain, high pressure oil pump, and a centrifugal SC

 

exactly.

 

I did a GM LS3/525 crate motor in my C5 Z06. I do 90% autocross and a few track days with the car. Super chargers seem to have their own set of issues on the track. I'm not saying they won't work, but NA seems to be the way to go for what I do. It came from GM with a full warranty too. Physically it is a bolt in swap that I had done in a couple days. There are some electronic connections that have to be adapted, but everything is available online. I'm very happy with my swap and it has been rock solid for at least six years. If I had to do it over again, I would do the same. BTW, the car dyno'd at just over 450 RWHP.

 

An LS6 w/stroker kit might even feel as strong on the street and way cheaper while having the original motor with better quality parts and zero miles.
This old blog rated it at 551 hp so with newer gen cams and heads 570 would be vey plausible and affordable. Could equal a SC car and be a real sleeper with some nitrous
https://www.motortrend.com/how-to/17...rked-over-ls1/

 

IMHO I would go with a motor swap or build the motor. NA power is my personally preference.

 

Just curious, what issues? I've done a few track days with both my c5 and my trackhawk (which has it's own, many substantial issues), and autocross in the c5, the only issue I had was getting used to the power. As for SC's, maybe you're thinking of roots style super chargers? If so, I totally agree-- they have a lot of issues on the track -- heat soak being the main one. Centrifugal Sc's (and likewise, turbos) have no such issues -- they'll run all day without losing power, roots style starts losing substantial power after a few laps. . On power, I spent about $8k on a cam/SC install, had it done in a week, and putting down am 531HP at the wheels.

Anyway, I think I'm turning this into a debate over NA vs. SC, which maybe should keep to another thread. If the OP is set on a ls3, and if he's going for that 525 hp one, he could do far worse.

 

I’ve wanted to swap to LS3 crate and also put A and A supercharger on my LS1.

Still want to buy LS3 new and put in my 1965 C10 pickup, but will probably not.

Did watch some videos of street and road races where C5 Z06 outran a C6 LS6 with M6, then other times the C6 was in the lead.

Apparently the LS6 Z06 may be quicker under 100 plus mph, and C6 LS3 starts to pull away at higher speeds.

The 525 hp LS3 has ASA cam, the 495 ho, previously rated at 480 hp has the GM hot cam.

Have read both hit cam and ASA cam versions of engine can be tough to get tuned good, engine stalling when let off gas etc, could have been bad tuner.

You can buy long block LS3 for $4999.99 from Karl kustoms or other dealers, they sell long block versions with hot cam, and ASA cam for extra like the complete crate engines.

The cams are the only thing changed, so you could buy the base engine and put in a custom cam that might work better for your car.

Once I read where a guy put the stock crate LS3 in a old Chevelle or something and he said the stock 430 hp was more than enough, maybe his car had traction issues, if I buy LS3 for my truck I would go with the stock cam since it might be too much for a old truck, can always do cam swap later if wanted.

 

It's natural for people to often defend the mods they've chosen, because they feel they've debated the decisions and made the correct choice. Your comments though are filled with inherent bias, solely because of what you've chosen to build, which is totally fine. The issue is, that doesn't make it the right choice for everyone; it's the right choice for some people.

Personally, I debated an LS7 I had on the engine stand, vs an AA kit some years back and I agree with much of what you said, as I chose the AA (very regrettably later). I tuned the AA to 579whp on a bone stock LS6 and drove the car like I wanted it to die...literally off the limiter every time I drove it. It was quick, it was fun, it sounded great, I got pulled over a bunch, etc.....and I hated it so I took it off 3yrs later. Why I hated it is something many folks would disagree with, and that's because what they want out of a car, is very likely not what I want.

I've had Lambos, Ferrari's, Porsches an NSX, multiple Corvettes and I've even built 4cyl imports that were turbocharged/tuned (fabbed and tuned on by me, on my chassis dyno) that would walk my supercharged Z06 in an embarrassing way. Point is...I've had a lot of experience in a lot of different types of cars, speeds of cars, power/weight ratios, etc. In my opinion, the supercharger killed the identity of the Z06 and it's intended purpose.

In brief, I felt like the power exceeded the chassis, when I like the chassis to exceed the power. I also felt an immediate imbalance due to the weight on the nose, it increased inherent push and it added mass to the car exactly where I didn't want it. Lastly, it took away all the linear power delivery and rev range/noise that makes the car fun to drive. Much of what I'm saying here may sound laughable and foreign to some, but Jim Mero and I spoke at length about these very issues at the Bash in 2014. He VERY much preferred the C6Z06 to the C6ZR1 and said it was no comparison for him. He understand that, and he is a particular type of driver/enthusiast.

For me, putting on the AA was a choice I made over the LS7, because at the time, I was opening a restaurant and I just wanted to get it done. The LS7 (with aftermarket heads) needed opened up, and I just didn't want to do the swap at that immediate time, I wanted to enjoy the car for summer. Looking back....one of the worst decisions I ever made, absolutely. 3yrs later, I removed it all, went back to the LS6 with bolt ons, and inversely invested heavily in brakes, suspension, square setup and small details that make the chassis beyond the power, by a margin. At this stage, I am building a motor for it, shaving every pound of mass, without impacting the car negatively. Think GT3RS vs Porsche Turbo...there's a reason people buy the GT3RS.

Not all people are about peak hp numbers and a certain recipe of power and delivery. NA motors, in a car setup properly will always be the legacy of motorsport and purists will always prefer it.