Haven't seen any stock LS3 dyno's have you. Mine put down 391 bone stock.

391 * 1.15 = 449 crank horsepower. The LS3 is underrated

 

Which is based on the LS3.

 

It's more than the engine.. It's the revised tranny and steering alsong with other changes that come along with a new year..

 

Iv'e owned a 06 A6 LS2 and now I own a O8 LS3 A6. The LS2 with some nice bolt on mods(headers,flow thru cats,cat back.,315 gears Mike Norris tune,and a vararam) ran in the mid 12's. Took those goodies and moved them to the 08, except the vararam(replaced with the BPP vortex CAI). LS3 ran high 11's. Significant difference due to better head design and better A6 transmission(shifting)response. Added a Stall converter and I'm running 11.44@119mph. You be the Judge!!!!. I believe the LS3 will also respond better to a cam or a supercharger than the LS2 because of the better breathing characteristics of the LS3.

 

Not so fast. You're making it seem like the LS3 is that much faster. Check the 1/4 mile list which reveals the truth. LS2 with almost the same set up ran 11.51@118 I believe.

 

You are correct....But I think 11.4@119 is still faster. I did'nt say it was a big difference JUST A DIFFERENCE in my situation. Loved my LS2..... Love my LS3 more! I also relize that there will be faster LS2's and Faster LS3 than mine. The faster LS2's will probably run the heads off the ZO6's or the LS3's. It's a good cheap modification.

 

By the way, Congratulations on that fast run.

 

For the C6DVL a whole second and @7 MPH He ran a 11.8 and 122mph..

 

In all seriousness, just get an LS2. GM failed miserably with the LS3.
































Just test drive both and buy what you think is the better value to you.

 

LS2 + $10k = Headers, supercharger, tune = 500 rwhp = unbeatable 99.99% of the time. If dats yur kup o teah !

 

12 CU IN more for the ls3.

LS1 = 346
LS2 = 366
LS3 = 378
LS7 = 427
The 30 hp difference is mostly in the Displacement and a better
Head design.

 

I have an '06 A6 w/ LP headers & cats, Vararam, 160 thermo, and CoW tune. I've only run it once, pulled a 12.64 @ 113.57 w/ a 1.989 60 ft. time. I believe my results are very typical for a bolt-on LS2. Might get slightly better results with an underdrive pulley, even better with a FAST intake.

But 11.51!!!??? 118 MPH!!!??? IMHO, those numbers are not typical at all for a bolt-on C6.

 

How much difference between the two if you add an
L92/L76 package to an LS2?

 

FAILED? FAILED? If you call getting more power without sacrificing gas mileage and emissions a failure, then yes they failed miserably. Here's hoping they fail again with the '09.

 

If your asking...How much money...About $3000.00 in parts plus labor. If your asking about HP difference...About 30 HP to crank.

 

Same with the LS3....not typical numbers for a bolt on. I believe these guys just have a nice set up and a little more driving skills.

 

I think the difference that really started it is the increased cubic inches via a larger bore.

The LS-1 had a 3.90" bore with a 3.62 stroke.

LS-2 increased that bore to 4.00" with the same stroke

LS-3 increased that bore to 4.06" also with the same stroke.

In otherwords, in simplicity, the LS-3 is a "halfway to the house" old school sbc 400 engine. What I mean by that is that they are 1/2 way to to the bore and stroke of a traditional sbc 400 engine built back in the 70's and 80's. Keeping in mind the stock bore and stroke of a traditional sbc 350 is 4.00 x 3.48, with a 4.06 bore and 3.62 stroke, they are half way to the sbc 400 stock bore and stroke of 4.125 x 3.75

And in fact the LS-3 is basically equalivent to the popular aftermarket 383 stroker motor in which most overbore the 350 block to 4.03 on the rebuild and put in the 3.75" stroker crank to obtain 383 cubic inches. The LS-3 goes 1/2 way on the stroke, but makes up for it by the 4.06" bore.... thus a 378 cubic inch mini-stroker/big-bore motor. Pretty cool if you ask me.

As far as what the overbore of 4.06 does versus the LS-2's 4.00 bore, besides the additional 10 or so additional cubic inches you receive which of course typically amounts to somewhere around 10 hp just from that, you will also typically receive another benefit...... with the bigger bore, typically this helps un-shroud the valves, thus improved airflow into the combustion chamber as well.... this can be worth another 5-10 hp......

With the extra cubic inches over the LS-2 and improved cylinder head flow, the LS-3 motor now needed to be able to get more air into the chamber, thus I believe they increased the intake valve lift from around .520 to around .550.... this more agressive cam profile would typically find you another 10 hp or thereabouts anyway.....

Long story made short, with the LS-3 they gave the motor another 60 thousands to work with in the bore, which creates a chain reaction in the motor in which you need to get more air into it now....thus they give you bigger valves, more cam, slightly improved intake & exhaust...... all of this apparently equals right around 30 hp..... and thats the difference.

I really like this motor.... with just a fairly mild camshaft upgrade, I am guessing you could literally pick-up 50-75 hp..... I think your stock cylinder heads could probably support up around 600 hp without any modifications at all....but not sure.

My only fear of buying a LS3 equipped corvette..... what is GM going to come out with in the coming year or two ? They have a lot of room for improvement if they want.... as evidenced by the Z06's 427....they could easily find a motor combination between the two.

 

Thanks. I should have clarified the question better.

What I was wondering was if someone adds the L92/L76 package to their LS2, how much difference would there be between the LS2 & LS3? Just wondering if that is an option worth considering for those that don't want to trade to an 08', if the combo adds 30 HP. Leaving warranty out of the discussion for now.

 

And that is a problem: if you wait until the next improvement, you will miss out on all the fun of the C6. I had an '04 C5, resisted the C6 as long as I could, and then picked up a late year '05 C6...and I haven't looked back since! Best thing I ever did from a vehicle standpoint.

The LS2-equipped C6 is great: I can't imagine what the LS3-equipped C6 is like! Don't wait...

 

I'm attempting to have more LS2's on the road than LS3's so I can justify selling my 08 at an inflated price.