I was just wondering how much of a power difference is there between a boosted lt1 and an ls1. Assuming all factors are equivalent and a safe amount of boost is run.

I was thinking about it and thought to myself, maybe when i get out of college, my lt1 will be in need of a rebuild. I can build a forged 383 for it and add some boost (I realize that a forged 383 would beat a boosted stock ls1 since it could take more.) Basically I thought of that and just keeping the ls1 a reliable street car.

Just throw in some opinions/words of advice. Basically what I am wondering is, are lt-1s at any disavantage boost wise?

 

If you could get the cylinder heads on an LT1 to flow as well as ported LS1 heads, then there really should not be much of a difference in power output. It does seem much easier to produce 700 rwhp out of an LS1 based engine when compared to an LT1. Bob

 

Exactly, heads/intake make the difference.

 

I would think with the heads and intake the Lt1 should be better because of higher resistance to detonation

 

The way I look at it is the Heads, Intake, and the cam are the main things that enable what power a car will make of course others attributes like compression and cubes play a part . Ls1's out of the box are nice b/c of their head flow, fairly good intakes, and a bigger cam opposed to a Lt1 cars.
You can take an LT1 and LS1 and set them up as identical as possible with cam size, head flow, intake, ci, compression and slap on a D1SC and spin it to 60000 blower RPMs and they would make roughly the same amount of power.

Lt1's have Iron blocks and are reverse Cooled so a higher Compression or static compression can be achieved before detonation which is nice. A buddy's car did 700RWHPnd 640RWTQ with a crappy air to water intercooler, and a stock air filter setup on a 383, gasket matched Trickflows ( flowed like 255 on the intake at .600) a 236/248 114 LSA cam, spinning to 6500 through a 6-speed and a 12-bolt on a D1SC and I believe they were spinning the blower to 61000 RPM out of 62000.

LS1's are nice b/c they are pretty powerful out of the box, the 15 degree heads can flow 330+ (Have to go Gen 1 heads on an LT1 to get that), has a 55mm cam so a more radical cam can be done, aluminum block (can uprgade to a nice 408 Iron block).

So what I am saying a Motor is Motor no matter if it is a LS1 or a TPI. Anything can be done and if they have similiar setups they should make similiar numbers in my opinion.

I have a stupid friend who when I show some LS1's making sick numbers 650RWHP+ on D1SC cars and he says b/c its an LS1. The thing is they are running a LS6 intake, with some heads that flow around 290 and around a 22X/23X cam nothing fancy (which is very much like my LT4 383 D1SC setup).

 

I say look at HPE's LT1 it has laid down 1,240 wheel so its all in the combo and choices that u and ur Engine builder make. You just can't be cheap if u want to make big power!