Should I hold off on the cam change and get the engine fired up as is (hoping to test fire it this winter), and do the cam down the road?

I went through this myself several times. I bought my LS1 from a guy here in Texas, used, but rebuilt with about 5K miles. The motor has a big cam in it along with ported heads, FAST intake, bigger injectors, and a tune to match it.

The cam has a lot of duration and I'd rather get the power curve down a little lower for the street. When I would mention a cam swap to friends/family they would all tell me - just getting it running and driving first. See how you like it, and go back later if you still want to swap it.
Hope this helps, I can't answer your tune question directly. My opinion when I researched this was, it would not hurt to drive it without the matching tune if you keep your foot out of it. I would think you could drive it to a tuner.

 

as soon as you open that motor up the warranty is void, period. that said some people are out of warranty before they finish the build. I say go for it and do the cam. do some detective work and see if you can find a good tuner in your area. I would also add an extra O2 sensor bung in your exhaust so a tuner has a place to put a wideband sensor for the tuning. much more accurate to have it near the stock sensor than at the end of the tail pipe like a lot of tuners do.

the big issue with the can swap and the ecm is that when you get it running if the tune is far enough off it may run like crap until you get a tune.

 

Depends on what you are doing with the car. Like Jake alluded too, a big cam moves the torque curve in the wrong direction for a street motor.
Having more grunt down low (1500-2500 RPM) is better off a light then a cam that doesn't start to "work" until it hits 4000 RPM. How often do you cruise around town at 4000 RPM?
You also need to post the current cam specs. Look at where the torque peaks are compared to the test cams.
It really boils down to how and where you are driving the car. A torquey stump puller build will be much more fun to drive around then one that has to be up on the pipe to get moving... After the initial "newness" anyway.
Mark

 

The two things to watch for are the tune (changes are almost certainly required) and pushrod length (you must check it and get new pushrods if necessary). That said, Tooley should be able to give you guidance on the pushrod length.

The duration @.050" of the cam you're considering is roughly halfway between the LS3/480 cam (GM "hot cam") and the LS3/525 cam ("ASA" cam). So by that logic, it should split the difference between the 2 engine's power levels - in other words about 510 hp, a 15 hp increase (about 3%). Maybe slightly more, considering that the aftermarket cam can sacrifice longevity which GM won't do given the warranty and design goals. Should be worth maybe .05 second in the quarter mile. Is that enough increase to warrant the trouble and expense? Why not go with the ASA cam or something similar in duration, and get the other 15 hp? Keep in mind if you do that, the tune becomes even more critical.

I think you are correct in thinking that a manifold change would be even less benefit than a cam change. The only reason to do it at this power level would be for bling.

 

:tu

Man if it was me.......
wow I am really torn. I would say run the original set up first without modifying it to make sure it's right...... but then who wants to tear their car back down?

 

Install motor and drive it. If you want more power cams swaps are easy, well easier on an LS. Just have to remove rad etc to do it. No that big a deal well unless you have A/C then it little harder with the condenser in the way.

The 480 version makes plenty of power run IT and see. Any more and you'll want more stall. And drivablity issue some don't like with the larger cams.

Also exhaust size plays into it and the fuel grade you run effect it too. You will want long tube headers and dual 3'' pipe with an X pipe. And you will want to run 92 or 93 gas to make rated power so that is required.

If you do it I would see if there is a good GMPP dealer in your area some will do the swap for you and warranty it then mine will.

There are several good tuners in the Tampa area too. VINCI is in orlando they have some good cams and beleve they tune and install as well. Call them http://www.vincihiperformance.com/

But reality the 480 LS3 should make 430-440 at wheels on good tune with setup I mentioned maybe more maybe less depends on dyno. Thats alot of power alone. I seen the ASA cam version make 475-500 at wheels but typically via manual cars. So may gain 40-50hp over cam you have now. Is it noticeable depends personally. lol


As far as intake there are alot of intakes for LS3's search. Most major manufactures have 3-4 styles alone.

 

Thanks for all of the replies. I will keep what I have for now, and if I crave more power down the road, I might stab another cam in it. BTW, that BTR 224 cam made 547 hp @ 6,300 and 510 ft. lb. of torque @ 5,100 on an otherwise stock LS3. This cam actually beat the stock cam EVERYWHERE in the RPM range. Pretty amazing what these LS engines can make with just a bolt-on or two.

 

I hope you realize that is on a engine dyno and no accessories and a electric water pump right. Not to mention an ad basically so not sure how "loose" their dyno is.

That cam is closer to 450 maybe 475hp real world in a car with correct setup. People get caught up in numbers and spend tons of money and never even see the ouput they supposedly make on a mag dyno. Not bash the cams listed.

But GM rates the LS3 at 430hp dressed with a SAE settings which is setup real world corrected. Most dyno shops and magazine use standard setting what numbers they get that day so it its cold etc it will make more power one reason they made the power with the stock LS3.

My point is more toward other member, don't get caught up in the numbers especially, in the online mag numbers.

 

Most engine dyno guys use the old "standard temperature and pressure" for their weather corrections (the one in engineering and physics texts). I believe it's 60°F and 29.92" Hg for the barometric pressure. The SAE correction for weather is something like 85°F and 29.50" Hg barometer. There's about a 5% difference right there. That's 25 hp on an engine in the 500 hp range.

So you need to pay attention to that part. Make sure any comparisons use the same correction factors.

That's why a bone stock LS3/480 which GM now rates at 495 hp will often do 510-515 hp on a hot rod shop's engine dyno. Now compare that to the 547 hp number. It's the real difference. And it doesn't surprise me that it would beat the stock cam throughout the rpm range because it doesn't have the "soft ramps" of the GM cam. But it will come at the expense of valve train life - maybe not a concern though on a hot rod that isn't going to get 100000 miles anytime soon.

Edit: just looked up the SAE temperature and pressure. It's 77°F and 29.23" Hg. Lower temperature and pressure than I said above. Net result is similar, about 5%. Also note that STP is for dry air. Not sure on SAE. But there's no such thing as dry air, except in Arizona in the winter.

 

Most engine dyno guys use the old "standard temperature and pressure" for their weather corrections (the one in engineering and physics texts). I believe it's 60°F and 29.92" Hg for the barometric pressure. The SAE correction for weather is something like 85°F and 29.50" Hg barometer. There's about a 5% difference right there. That's 25 hp on an engine in the 500 hp range.

So you need to pay attention to that part. Make sure any comparisons use the same correction factors.

That's why a bone stock LS3/480 which GM now rates at 495 hp will often do 510-515 hp on a hot rod shop's engine dyno. Now compare that to the 547 hp number. It's the real difference. And it doesn't surprise me that it would beat the stock cam throughout the rpm range because it doesn't have the "soft ramps" of the GM cam. But it will come at the expense of valve train life - maybe not a concern though on a hot rod that isn't going to get 100000 miles anytime soon.

Edit: just looked up the SAE temperature and pressure. It's 77°F and 29.23" Hg. Lower temperature and pressure than I said above. Net result is similar, about 5%. Also note that STP is for dry air. Not sure on SAE. But there's no such thing as dry air, except in Arizona in the winter.

From what I heard, the 495hp number is without the FEAD. it makes 480 hp with the FEAD. If this info is wrong, then I'd like to see the proof that its wrong.

 

Can't answer that. Next question, what's the configuration when they rate the 525 hp version? And has that one always been whatever it is? In other words, is there real world 30 HP difference between the two? Or more?

And is there 50 hp or 65 hp real world difference between the LS3/430 and the LS3/480?

Just shows the need to be careful with your expectations.

 

My expectations? Regarding what? What are my expectations, Rick? You have the same engine, are you expecting that it makes 495 hp or 480 hp at the flywheel?

 

It really doesn’t matter, its a base line, all are engine dyno numbers. Stick it in a car and you lose 30-40% easy less with a manual. And again don’t get caught hp in numbers. Pick the drivability you want and power. People option on drivability vary too.


I do know a stock ls3 with simple tune and exahust work will make 400-405hp at wheels via the manual seen it on couple different shops dyno’s it was pretty consistent actually. But numbers can be easily changed in the dyno software to make it better unfortunately some shops and online articles do it.

And imo you lose drivability with larger cams some people dont like but want big numbers. 400hp is alot in a light trifive enough for most.

 

 

My personal expectations are that the engine will perform fine as delivered. If I'm disappointed, I'll do something then. I doubt I'll race it, either at the track or on the street.

If I had wanted more than that, I would have either purchased the 525 hp version or I would have gone another route entirely.

Personally I thought the price for the 525 hp version was high relative to the 495 hp. But pricewise, changing cams after purchasing the 495 hp engine would not be very different if at all. Buying a 430 hp version and modifying it would probably make more sense.

 

... and I'm a little annoyed that there isn't an aftermarket intake manifold that is better than the ugly and boring stock intake.

I'm with the other folks in saying get yours going to confirm everything is good before cracking it open.

There are different intake options, some look better than others, just depends what you want out of it. For all around use, the general stock form (FAST LSXR for example) is a good piece. Price of sheet metal intakes have come way down.

Charlie

 

I have to agree with Bo here. Vinci does all my la cams. Even my own personal everyday truck has one. 2001 Silverado 5.3 slightly reworked high lift trucker with duel springs and yellow terra rocker. 12 psi whipple 3200 Fti triple disc and it works great. I wanted to make good power while still pulling a camper and my race car. If you are really interested in swapping I would give Roger a call. Tell him what your looking for and I’m sure he will know what’s right for you. He uses different love profiles that are easier on the valve train from what he was telling me. If it was me I would probably stick the motor and drive it first. I think that motor will make more power then the car can use on the stree as it is. As a gear head though I fully understand.