just had a quick ? about the ls motor
- Thread starter umair
- Start date
You said it yourself. Lower compression.
Higher compression is better for making power, but harder to run on pump gas. That plus the fact that the LS head doesn't exactly flow well compared to vtec heads.
higher compression engines will make more power boosted there just harder to tune
Billy.
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not necessarily. it is easier to tune a boosted motor with a lower compression ratio, but it will not make the same power as a high compression motor of equal displacement and equal boost. the lower compression adds to stability in the power band from variables like ambient air density, temperature, humidity.
ls long blocks are non vtec and have a lower compression ratio than b18c and b16a, therefore they are more ideal for boosting, but can be upgraded by swapping out the head to a vtec head.
True, but do you know why? When you run a certain psi on your turbo, that increases the cfm in your motor. Basically, the most psi you run, the more compression builds up in your engine, therefore producing power. Higher compression is, well, higher compressoin to start, where as lower compression starts at a lower compression; easily understandable right? It's like saying, if I have 5 pennies, and I add 10 pennies, then my friend has 6 pennies to start, and adds the same amount, who has more pennies? Why a B16 will make more hp on a same turbo setup is simply that, it starts out with more, "pennies", or higher compression.
Then theres the fact that vtec heads flow better and such, but that's a different aspect of this.
MMMMMM, can't wait till I get mine going. That 193hp 170tq under your avatar, are those to the wheels? What's your setup?
Lower compression is easier to run on the street, it most certainly does not make more power. Quite the opposite.
the ls motors have the same weak cast pistons the other b series motors have. unfortunately they dont carry torque as well into the upper rpms due to the head flowing like crap compared to the vtec heads, this is why the LS motors are tuned at lower HP levels. an LS with 260whp makes 200-215ftlbs, and a b16 with 200-215 ftlbs makes 300whp. both have the same stress on the motor.
if you pushed an LS motor to 300whp it would be pushing 240-250 ftlbs, that is a bit more stressfull on those bottom ends.
if you pushed an LS motor to 300whp it would be pushing 240-250 ftlbs, that is a bit more stressfull on those bottom ends.
Also, Ls motors have a lower red line (6800) and have a longer stroke = more torque but, smaller torque band. Vtec motors have quite (depending on which) a high redline, but a short stroke = less torque and less displacement.