Benefits of High compression

[Bad92GT]

I understand the whole theory, design, and way it works, So thats all just fine and what not. What i'd like to figure out is how much of a gain can you see from this.. lets say you bumped a standard stroke, standard bore 302 to 10.5:1.. pump gas.. (premium 92).. will the differences actually show up on your dyno chart? A couple cars dyno sheets were high compression and there numbers didn't impress me, basically because your giving up your ability to run boost for it, yet you get minimal gains (so i've seen). I'd like to just figure out if it is in fact worth the money/time to go high compression? Can someone explain this to me.. thanks folks

 

[poneypower89]

Boost is *somewhat* another way to raise the peak compression of an engine. Generally, you can create a higher maintainable compression rating with boost than you can in high compression N/A form... which is why boosted cars USUALLY put down higher numbers than high compression cars...

Compression WILL raise HP numbers... but you gotta incorperate the flow too. I'm not sure what examples you are talking about that didn't impress you. Im sure I could find 15 good examples of what compression can do.

To name one.

Me and my bro built a mild 302 from an 86 block.

- Stock e-7 heads (from a truck) with exhaust bump ground out
- 289 high dome high compression pistons
- e-303 cam
- edelbrock intake and street avengar carb

every else... STOCK

We estimated the compression to be somewhere around 12:1

It laid down 317 HP at our dyno in Bloomington.

What was so special about this combo? Nothing really. The only real different between this combo and a stocker would be the compression rating. Hell, you hardly see 302's with the trickflow topend kit pushing these numbers..

In my neck of the woods... compression is known as the poor mans racing trick. It doesn't really cost anything and its effective.

 

[bubba-dough]

In my neck of the woods... compression is known as the poor mans racing trick. It doesn't really cost anything and its effective.

True. I went with the high compression because I wanted all I could get out of said money. It cost the same, basically, to do "combo A" low compression or high compression. My plant was closing so money was tight. I knew a charger was out of the question however spray was not. So I end up with 11:1 347 with spray.


Maybe someone like Rick will chime in with some hard data for you.

 

[legalize420]

It laid down 317 HP at our dyno in Bloomington.

just wondering, is that at the wheels? did it have a/c and power steering?