LS3 vs L99?

[duder4thgen]

Originally Posted by epd313

I am looking for some advice. I ahve a 2SS A6 on order and keep thinking I should get the LS3 instead. Is there anyhting that says one is better than the other? Back in the day it was stick all the way. I have a stick in my 2000 SS, but have to admit, it gets old in traffic, maybe I'm just getting old, who knows. Technology today seems to point to the L99, any advise, I'm starting to get a headache and I have months yet to wait

Stock for stock its going to be a drivers race between the a6 and m6. If you are going to keep it stock, stick with what will make you happier on a daily basis. If you are going to mod it, I'm willing to bet the m6 is going to be a better place to start out at.

[camaro1]

i would say if your going to mod it go with the auto, a 3000 stall converter and delete the afm, cam and a tune and you will blow away a 6speed manual with the same cam/bolt on mods

[Parker]

Part of the AFM package is VVT and that will help with power efficiency from low to high RPMs. Just like advancing and retarding the spark does.

[Grape Ape]

Originally Posted by THE EVIL TW1N

Also, the L99 may have the same heads found on the L76, since that too has AFM. Although the castings are the same as the L92 heads, to save costs the L76 (and possibly the L99) has heavier solid valves vs. the lighter sodium filled L92/LS3 valves.

The AFM gear is in the block, not the heads.

[mike@newera]

Here are some pics of the lifters for AFM/DOD which will be used in the L99:




The LS3 will have normal hydraulic lifters, a different valley cover, and it will not have this in front of the camshaft which is for VVT:

[CamaroSpike23]

Originally Posted by camaro1

i would say if your going to mod it go with the auto, a 3000 stall converter and delete the afm, cam and a tune and you will blow away a 6speed manual with the same cam/bolt on mods

that will be debated. actually it already has been debated.

but to add to your argument, there are a nice group of AFM G8's out there running superchargers as well with no problems.

regardless of which one you go with. they will both be bad ass from the factory as well as with adding mods.

[Muscle Master]

Originally Posted by CamaroSpike23

that will be debated. actually it already has been debated.

but to add to your argument, there are a nice group of AFM G8's out there running superchargers as well with no problems.

regardless of which one you go with. they will both be bad ass from the factory as well as with adding mods.

at the cost of fuel economy, don't see the point of still having it active, the AFM

[CamaroSpike23]

Originally Posted by Muscle Master

at the cost of fuel economy, don't see the point of still having it active, the AFM

I dont know what their mpg's are after the sc install, ill have to look into it. but the other thing to keep in mind is that EPA estimates are just that.... estimates.

just like the 4th gens where people were getting 30+mpg in their cars, im sure that both the LS3 and L99 will get better than the EPA estimates

[duder4thgen]

Originally Posted by CamaroSpike23

that will be debated. actually it already has been debated.

I agree, I take back my statement about the m6 being better to mod from. Might be a little simpler to start with, but in the end, once you get to a cam swap, there isnt that much more to swap out with afm than you would with a normal ls3. Guess its all up to driver preference.

[CamaroSpike23]

Originally Posted by duder4thgen

I agree, I take back my statement about the m6 being better to mod from. Might be a little simpler to start with, but in the end, once you get to a cam swap, there isnt that much more to swap out with afm than you would with a normal ls3. Guess its all up to driver preference.

camming the L99 will be a little trickier as you have to allow some leeway with the AFM and the lifters. now if you tune it out and remove all that stuff and basically convert to an LS3, then cam swap to your hearts content

[duder4thgen]

Well, I'm not sure if anyone is making a cam right now thats compatable with AFM. I would think with the l99, if you are going to cam it, youre going to have to take out the AFM, which is a couple more parts than doing a cam swap on a ls3, but really not that much more labor.

[Supermans]

The only thing I am concerned about with the L99 are the cylinders wearing out quicker over the years on one side than the other and how that will affect things ten years down the road..

[CamaroSpike23]

Originally Posted by duder4thgen

Well, I'm not sure if anyone is making a cam right now thats compatable with AFM. I would think with the l99, if you are going to cam it, youre going to have to take out the AFM, which is a couple more parts than doing a cam swap on a ls3, but really not that much more labor.

depends on how big of a cam you are going with.

[Mr. Wyndham]

Originally Posted by Supermans

The only thing I am concerned about with the L99 are the cylinders wearing out quicker over the years on one side than the other and how that will affect things ten years down the road..

All pistons are always moving. And the fuel/valves deactivate two cylinders in each bank. No worries about wear.