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Differences between LS9 and LSA

34829 Views 12 Replies 9 Participants Last post by  gonfishin
I tried a search on this and failed so sorry if this is covered ground and I just missed it. Does anyone have a comprehensive list of the differences between the LS9 in the ZR1 and LSA in the CTS-V?

I know it has a smaller displacement supercharger (1.5L vs 2.3L I think) and I also don't think the LSA has forged pistons, but what else is different? Does the LSA use the same 3-layer head gaskets? Does it have the piston squirters of the LS9? Is the ECU the same?

I'm up early this morning and was just wondering aloud...
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Also, I'm curious to hear about how the power delivery compares between the two motors. I know Short-Throw has extensive seat time in both. I've heard that the ZR1 was very docile below ~4K RPM and comes on very strong beyond that point.
LS9 has a bigger supercharger (2.3 L vs 1.9 L) and is hand built in Michigan. The LSA is built in Mexico. The LS9 compression ration is 9.1:1 and the LSA compression ratio is 9.0:1. That's all I could find today.
Different blower, different rotating assembly, BIGGER cam, lighter valves. MOST if not all the gain though is in the better blower, the camshaft and the more aggressive tune, is the difference in horsepower between the two.. Most others where mearly to make the zr1 last longer at the higher hp levels.
There are a LOT of differences, so much so, it's easy to wonder if the motors are even related. One of the biggest differences was that the LSA uses cast pistons, while the LS9 uses forged pistons.

I can't recall where I read the comprehensive list, but I'm thinking I found it as LS1tech.
Compiled from GM Media Online (differences in bold):

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Thanks GMX. Good summary and I also found that article while digging through old posts.
So I have a question, since many members have obtained and surpassed the 638 hp bench mark of the ZR1 with the LSA motor through countless set ups and modifications, would it be possible to remove the 1.9L supercharger and install the larger 2.3L on the LSA motor reasonably easy to produce a substantial hp gain without a whole lot of other mods. Of course a tune and long tube headers would probably be a must to accomplish this transformation for (air in/ air out). But other then all the Forged and titanium internals the LS9 motor has for longivity and abvious prestige is it do-able?
Compiled from GM Media Online (differences in bold):

Is that correct that the LSA has the Piston Oil Spray Coolers?

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Yes the lsa has piston oil spray.
Jess, Ben & I were talking compression Saturday and how the LS9 and the LSA had the same compression etc. etc.

The conversation then turned to me needing a different drag pak to handle my torque. :bonkers:

So I went from compression to depression. :)
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