LSA supercharger: Put it on a stroker LS3 or a stroker LS2

[srh3trinity]

I have poked around a little on LS1tech trying to find the best combo, but haven't found a straight answer. I have two blocks. One is an LS3 block that was taken out .005 that I was going to do a 418 stroker build on. I have all of the parts and was going to use this setup naturally aspirated in my current build. Then I stumbled on a local guy getting rid of an LSA supercharger so I picked it up. Since then, I have picked up another LS2 block and LS3 heads. The only reason I ask which motor to put the supercharger is because I have heard that the 418 will be a little too much motor for the LSA supercharger. I am sure it would still make nice power, but I would be at the limits of the blower. There aren't many CTS-v's or ZL1's that have been stroked.

As far as application goes, my current build is a second gen Firebird and my aim is to build a great all around car with some auto cross mixed in. The next car I build will probably be a less cosmetically finished track rat kind of car. I am thinking a naturally aspirated stroker will live better in a track rat and the LSA motor will live better in a mostly street car.

[1989GTA]

What compression ratio does the 418 stroker have? Also what horsepower level are you looking for?

[srh3trinity]

No specific HP levels, and I am not wanting to build a 1000 HP car either. Either build should make some nice horsepower. I would imagine the bigger cubic inch stroker would be around 500 HP and I would think 600-650HP would be pretty obtainable in a smaller stroker with the supercharger. If I do the supercharger on the 418, I will likely go with a dished pistons. The ones I have now are essentially flat with valve reliefs. I would have to look at the CR. I have a stock LS3 crank and was tempted to do some stock pistons and rods out of an LY6 and supercharge the 6.0L in a mostly stock style budget build with an LS9 cam and upgraded trunions and valve springs. Then I started looking at prices and decided that I might as well buy good internals while I was building it. I know the stock LS3 crank snouts have had some issues on blown builds.

[cwylie]

I dont think the 1.9L blower will move enough air for a motor that sized. Most of the built engine CTS-v guys are running stock displacement.

[srh3trinity]

I dont think the 1.9L blower will move enough air for a motor that sized. Most of the built engine CTS-v guys are running stock displacement.

I was thinking the same thing. I may try to find a stock stroke forged crank and buy some blower pistons and build up the 6.0L. Maybe even go to a 402 ci or so, but not much bigger. If only the ZR1 had that isolater problem that the CTS-v/ZL1's had. Then the 2.3L blowers would be more available.

[Trevor @ Texas Speed]

I completely agree that the 1.9L LSA supercharger will quickly be maxed out with a larger cubic inch engine. The stroker will be nice for the added low-end power when driving, but it's not going to do much for you with respect to peak power. The little blower is going to be maxed out either way. I'd recommend building it as a stock-stroke application and raising the boost on the blower. The LS3 block will be better for resale if you're looking to sell it at some point down the road, but the LS2 has thicker sleeves. So, it would be better for a supercharged application IMO. With that said, the LSA blower can't produce enough boost to cause an issue either way, so I'd just go with whichever block you prefer for the build.

Let us know if we can help! We have lots to choose from for rotating assemblies, pulleys for the LSA, etc.

Thanks!

Trevor
Texas Speed & Performance