CTS-V.....which engine to look for?
 

Well Im considering looking into one of the older cts-v's (04-07) but I would like to get some details about which engine would be the best to look for (ls6 or ls2).


So far from what I understand the ls6 would probly be the one to go with if I was gonna stay stock or even stay N/A but thats not what I would want to do.

My main question is which of the two has a stronger bottom end in it in stock form? The .3 liter difference doesn't matter to me. Ill would probly end up leaving the engine stock and just slap on a turbo or supercharger along with exhaust and a tune. (keeping it simple since this would be a daily driver)

Also I thought that the ls2 was more similar to the ls6 and ls1 than to the ls3 and ls7 buy it is grouped with the ls3 and ls7 so if someone wouldnt mind shedding some light on that for me I would appreciate it.

If someone has a link to another thread that answers these questions that would also be great.

THANKS

I would go with a LS2 block personally. Not that there is anything wrong with a 5.7 LS6. However with a LS2 you are getting a 4"bore not 3.90". That little difference will allow much more versitility as far as lower engine combinations, it will allow not only bigger heads, but bigger valves without shrouding, it will also allow you to go to a L92/LS3 style square port head. (if you choose so)

Who knows where you will be in the future. If you ever wanted to build it for whatever reason or put some different heads on you will kick yourself in the ass for not having a 4" bore.

Boosted LS6 is a great motor too but for the money I would take the cubes.

I would go with the LS2 personally, has a broader torque curve then the LS6. Both make about the same power in the end and neither is necessarily stronger than the other.

Ok that is kinda of the way I was starting to lean anyway. Evidently 600 whp would still be pretty reliable with the ls2 which will probly keep me pretty happy since it would be a daily.

What is the difference in the ls2 that allows it to use the square port heads like the ls3? It has the cathedral port style heads stock doesn't it? Sorry I'm not real familiar with every detail of each of the ls engines.

600 at the wheels would have to have a perfect tune for it to last. Not saying it can't be done reliably as several people have, but that's kinda pushing it for the stock block and driving it like it's meant. If you take it easy 99% of the time sure that will be reliable. If you like to have fun or go to the track a lot, that's not going to last long.

L92 style heads require a minimum of 4.00" bore when the max of the LS6 block is 3.905. Although they do make small bore L92/LS3 heads that would work on the smaller bore but obviously won't have the same benefits as a regular square port head on a 4.00"+ bore.

i would go with the ls2 as well is it was me

Ok thanks for the info guys.

I was looking into the sts twin turbo kit and I like most things about it. 480 whp wth 5 psi. Adding in headers and exhaust modds would take it over 500 at the wheels i would think. what would it take to up the boost up to 8 psi or so...maybe even 10 to increase power to closer to the 600ish mark.

would the injectors that comes with the complete kit be enough or would it be better to just buy the base kit and then buy injectors seperatly and have a custom tune done?

Remember these are high compression engines without forged internals. Adding boost to them becomes tricky at a certain point.

Yah that partly the reason Im looking into all this now to help make my decisions as to what Ill end up doing. What is the compression for a ls2? 10.5-10.7ish?

Get some 317 heads to lower the compression ratio and maybe some thicker gaskets. I think that will put you at 9:1 or a little less. Anyhow it will be alot more on the safe side

I'd go for the LS2 car for both the larger bore, and also the newer PCM. The LS2 CTS-V has an E67 PCM in it. The Gen 3 PCM running the LS6 in the 04/05 cars is good, but the E67 in the 06/07 cars is far superior.

Ls2

Theres no replacement for displacement plus its all on gen IV architecture and electronics

600?

Better stroke it and forge it with 6-10 psi.

Im not a fan of the STD kits, I'd look into a roots type blower for your kind of heavy car. More TQ lower in the RPM range. But that's just my .2 I'm not trying to get an a turbo/supercharger debate just my thoughts on a nice and fast luxury SEDAN. Lol

i'd buy the base kit and get 83lb injectors & a real tune.in fuk that lower compression stuff,my 06 gto aps car was putting down just under 600hp all day for 60,000 miles.lower compression & boost = GEN1 get with the ages