Boost effects on low compression engines vs high compression engines

[Blown3000]

What are the benefits of boost on a low compression engine VS high compression engine? Is there really a need to lower your compression ratio if you are going to use sometype of forced induction? If so why?

[RealMcCoy]

Yes, you will severely limit the amount of boost you can run by using too high compression ratio... The cylinder pressure gets pretty extreme.

[Blown3000]

Yes, you will severely limit the amount of boost you can run by using too high compression ratio... The cylinder pressure gets pretty extreme.

Can you be more specific.

[IPD]

wait....aren't you the dude with the supercharged 3/s?

[Zaroth]

Can you be more specific.

Too much pressure, engine go boom.

[whitedragon]

How to add a turbo to a non turbo car.

Some light reading that should break it down simple enough.

[IPD]

i swear this is the same guy who loudly protested when he was told that superchargers aren't that great of an option for these cars. i don't know if he'd take the advice of people who run turbochargers.

[Blown3000]

wait....aren't you the dude with the supercharged 3/s?

Yes and still running fine.

[Blown3000]

How to add a turbo to a non turbo car.

Some light reading that should break it down simple enough.

Have done so now I want to hear from the forum.

[futurevr4man]

blown3000, you need to look at the effects of gasoline at a high pressure. as you increase the pressure, the gasoline will ignite sooner. when you increase the pressure high enough, gasoline will ignite with no spark, thats called pre-detonation (or knock). so when you have a high compression engine, then throw boost on top of that, you can cause the gasoline to ignite before the piston is at the top of the stroke. as you can imagine, that is extremely hard on your engine internals, and more specifically, your bearings. this is how you flatten out your main bearings (rod bearings are affected more by oil starvation).

and just so you are aware, what i just explained is how a diesel works. they dont have spark plugs. they also run like 16:1 compression ratio so they can get a whole lot of cylinder pressure built up. also, diesel burns at a lower temp than gasoline FWIW which is why gasoline wont run in a diesel... ignition wouldnt occur as it should. diesel: ~210C, gasoline: ~230C