Hello everyone, this is my first post. I have a 07 Z51 coupe that I am prepared to mod. I am beginning to get cold feet. Specifically, I am wondering if the LS3 motor is that much better than the LS2. From what I gather so far, stock versus stock, the LS3 should win 10 out of 10 times with the drivers being fairly equal. Now my question is this, what about heavily modded? Take an LS2 versus LS3 with headers, CAI and supercharger or h/c cars. I'm guessing the LS2 will make approximately 500rwhp while the LS3 will make about 540rwhp. With this being the case, is it now a drivers race because the horsepower has surpassed what the car is capable of? Basically, is there no real performance difference between the 2 when heavily modded. Whereas stock the LS3 would win everytime with equal drivers, would that now no longer be the case?

 

This is just my .02 but if both cars are at over 500rwhp its a drivers race. Just to put the power to the ground would be the challenge for both drivers. When the power is that high i don`t think 40rwhp will matter much

 

There will always be someone faster. Meaning, mod your LS2 and be faster than some LS3's and slower than other LS3's. Do you run your car at the track anyway? If you don't run it, race it, then does it matter?

 

If you just want a little more grunt for some street fun, then stick with what you have, but on a true CAI, long tube headers, a Fast Intake/ported TB, hi flow cats, a good tune, and some gears and let her rip. There will be more than enough power there for that.

And you will save money if what you are suggesting is dump the 07 for an 08. You will take a bath on resale - and what you would pay extra for the 08 will more than cover these bolt on mods.

 

Welcome to the forum, for all practical purposes it really doesn't matter, don't lose 5-10k to gain a few extra hp. Like he said there will ALWAYS be someone faster than you. With a s/c, headers, and cam you will make more power than you could ever control so what difference does it make if it says LS2 or 3? Your car has all the potiential that you can handle so enjoy blowing your $$$

 

Here Here!

 

I have an 07 Z51 that I dropped off at DTE for heads/cam/headers with 450 miles. I ended up with 460 rwhp/ 432 rwtq with a very small cam.

 

Welcome to the forum.

No, they're both great motors but the LS3 does make more power in stock trim and (like the LS2) has responded VERY well (maybe even better) to modding.




Yes I agree that it certainly should but as of right now it hasn't even won 3 out of 10 times...yet.

 

The LS3 has the L92 heads. If you put the L92 heads on a LS2 and put the same cam in (I think the Z06 MAF is also a point of freeing up power, then still mod for mod the bigger bore will net 15 more HP. I dont know what the original poster used as his 540rwhp reference but the max I have seen for the LS3 was nowhere near 540rwhp. In fact, a huge cam on the LS7 barely hits that. Ported L92's didnt net much either by one tuner. 508 has been hit with a 238 cam in an LS2 and about the same for a LS3.

In the long list of mods, getting a lingenfelter shortblock for 6200 nets you a 427. In the world of modding you can make any car as fast as another. Just because GM puts some cast piston garbage in a car doesnt mean youre stuck with it.

In the end its 15hp and not the massive 40 he gave the bore credit for. The L92's do the same for the LS2 as they do for the LS3.

If you talk about FI, then the tune will vary more than the difference in the bore size. The fastest car I was ever in was a 5.7 liter S/C car and the C5 chasis is a better drag race platform to begin with. Mod for mod it runs quicker 1/4 times. The record for a H/C only C5 is 10.54. No LS2 or LS3 has even come close. Things dont always improve as a car gets developed. At least not what people talk about here typically.

The LS3 is abetter motor and always will be. It is cheaper to buy the LS3/L92 stroker than to whine about the difference or if you should trade in your car for the newer model. If youre going to mod, just swap the motor. At least you get a forged unit and bore size choices up to 4.2 inches. You can have a 400 all bore.

 

Yes the LS3 is an overall better motor but not so much better that you need to swap motors to gain 40hp. Yes they have made a few nice improvements to the LS3 but the LS2 is still just about bullet proof IMHO, they maybe cast pistons but I have several friends here in Houston making 700rwhp with stock bottom ends and have been doing it for over 2 years now.

My opinion is if you just want to go out and blow of the doors off of 99% of all the cars on the road get a D-1 with a 4.25" pulley, headers, and a meth kit. You will make 600+rwhp which is more than your street tires could ever handle.

 

Actually, so far I've only run it twice at the drag. As a novice, I ran a best of 13.2. Previously, I had an f-body with headers and nittos and ran a best of 12.7. So even though I do run it, technically it probably doesn't matter anyway becuase I'll probably never be able to get the best out of it. But I love to bench race also! Basically, I'm just thinking out loud that with a supercharger and headers the LS2 and LS3should be an even match. Does it matter ABSOLUTELY (My neighbor is about to buy an LS3.

 

Are you talking a supercharged/header LS2 vs stock LS3? A supercharged stock LS2 vs stock LS3 should easily be the winner. Again, you can't beat them all so mod and enjoy what you have.

 

All things being equal there is no substitute for cubic inches, period! Put the same mods on both, the cubes win out.

 

true, and not true. i have seen 350 vs 454 and 350 win same mods same car, same tires but the big block was nose heavy and couldnt transfer could spin the whole 1/4

 

Okay, the LS3 is bigger by what.... .2 liters? The LS6 still matches are cars, mod for mod with it's .3 less liters. Not always the case I would think.

 

I didnt say you had to swap motors to gain 40hp and i have no idea what gave you the idea that I was preaching it. In fact I reduced the differences to being 15 after swapping heads and, intake, and MAF. I was talking about a max effort LS2 vs max effort LS3. The bottom line is 15rwhp from the bigger bore. A max effort LS2 wont have the stock cam, stock heads or any other inferior part. I have the LS3 heads, L76 manifold (ported) and the bigger MAF. There are many who still dont see the LS3 heads as the be all head of choice. Without getting into that non-sense, my point is that in buying all the best parts currently available, the LS3 is not anywhere near 40hp over the LS2. In fact I havent seen an LS3 exceed the best H/C LS2.

My point in bringing up an after market 427 was to illustrate the silly issue of a guy wanting to sell any C6 to get an LS3/2008. Just install the 427 and then the arguments of the LS3's bore being better wont matter.

I'm over 600rwhp. With street tires 470rwhp N/A isnt usable. While N/A numbers always outdo a FI set-up with the same peak number, I agree that FI ends the differences one would see. A boosted LS3 and a boosted LS2 will have nearly the same output and it will come down to tires.

I guess what I am trying to tell people is that if you took your bone stock LS2 that dyno's 355rwhp and add LS3 heads and the required intake manifold, It will dyno 380-385 with a tune. SLP showed this already. Comparing that to a stock LS3 will illustrate what I was trying to state.

 

It doesnt matter because it still wont be a Z06. hehe Just thought I would beat some of the Z06 owners.....

 

If I could live without a removable roof I would get a new viper GTS. They are rare enough to qualify as exotic.

 

....just as a C6 Z06 is FAST ENOUGH to qualify as one as well IMO.

 

You say the stock LS3 will win every time against the stock LS2...I don't know. Granted the LS2 has a 3 year head start but so far the LS3 has not proved that it is faster than the LS2 in 1/4 mile times for the showroom stock category (the last time I looked one LS3 finally made it onto the top ten list at #10). I expect the LS3 will prove to be slightly faster than the LS2 but even after this amount of time....it hasn't happened. It's that close.

IMO there is no need to buy a different motor or a newer C6 to get an LS3 engine. You can get great performance modifying your LS2 motor. No matter what you do to any engine, there will likely always be someone faster.

Modify your LS2 and enjoy it for what it is.