Compression HP gain chart

[Kenny]

I thought I would put up a chart for general compression gains. These gain are listed in %, and these are general guidelines. Notice the diminishing returns as compression ratio goes up. You can build a big power engine without high compression, but you will normally see more power up until combustion chamber shape or fuel quality becomes a problem

[Colorado700R]

what about TQ?

[Troy]

Damn, I need to get up to 16:1, that 15:1 isn't cutting it at all.

[Kenny]

See what I'm sayin'?

[SprinterX]

Damn, I need to get up to 16:1, that 15:1 isn't cutting it at all.

[Krandall]

15:1 is for girlz troy

[preddy08]

15:1 is for girlz troy

Girls and THIS GUY 

[Troy]

I don't know why that made me think of that joke preddy, what has two thumbs and loves blowjobs?  THIS GUY!!!

[preddy08]

I don't know why that made me think of that joke preddy, what has two thumbs and loves blowjobs?  THIS GUY!!!

You can't see it but I typed that with two thumbs up, pointing to myself. 

[nikita]

what about making this sticky?

it will good if u could add the gas octane number in the chart, sir

[Kenny]

About all that can be said about octane ratings are general guidelines each builder finds through experience on specific builds at his particular altitude. We normally find that a 12:1 Raptor motor will do just fine with a WEB 290 (4) on pump gas. Change that cam out for the RJ and you may find you'll need to do a mild mix in high temps with a hot motor......... A spark plug heat range change, a piston a piston with tighter squish, combustion chamber shape and seasonal fuel blending etc..... The Raptor motor will normally run at about 175° if you are riding at a fairly fast pace with plenty of airflow through the radiator, if you do a lot of slow technical riding the fan won't cut on till about 220°. That can make a huge difference. We have had motors that wanted to use race/pump blend at sea level with 11.5:1 at the same time we have specially built pump gas engines to over 13.7:1 on pump gas at sea level. It is just to broad to define. Even the age of your gas can change this.......

[Tim Barker]

About all that can be said about octane ratings are general guidelines each builder finds through experience on specific builds at his particular altitude. We normally find that a 12:1 Raptor motor will do just fine with a WEB 290 (4) on pump gas. Change that cam out for the RJ and you may find you'll need to do a mild mix in high temps with a hot motor......... A spark plug heat range change, a piston a piston with tighter squish, combustion chamber shape and seasonal fuel blending etc..... The Raptor motor will normally run at about 175° if you are riding at a fairly fast pace with plenty of airflow through the radiator, if you do a lot of slow technical riding the fan won't cut on till about 220°. That can make a huge difference. We have had motors that wanted to use race/pump blend at sea level with 11.5:1 at the same time we have specially built pump gas engines to over 13.7:1 on pump gas at sea level. It is just to broad to define. Even the age of your gas can change this.......

ANSWER YOUR PHONE

[VelociRaptor]

Yeah! Answer your phone lol.

[preddy08]

YES ANSWER YOU PHONE!!    I need a TB bored form a YFZR