Compression Ratio's effect on HP
 

I have a 2000 ITR. I am looking to stay pretty mild with the car.

I was wondering if there was an estimate on how increasing compression ratio effects horsepower. I know it should increase, but is there a general rule of thumb? ie. if I raise my compression ratio by .5 it will yield x horsepower gains or a % increase.

Does anyone out there know? The reason why I ask is because I am due for a new head gasket and I was thinking about a thinner gasket with flat valves as long as the head was off; but I don't want to waste the time or money on aftermarket parts if I wasn't able to pick up any extra power.

Any help or advice would be huge.

Thanks

Re: Compression Ratio's effect on HP
 

im not sure what you mean by " I am due for a new head gasket"

is it leaking or overheating?

Re: Compression Ratio's effect on HP
 

I'm not 100% if you know about this or not but someone came out with this website called google it took me less time to search find and see what would happen if i switched higher compression what my horsepower difference would be

Re: Compression Ratio's effect on HP
 

The car is consuming coolant somewhere. I fill up the reservoir and in 3-4 weeks its try. I don't notice any leaks, So I assume its burning off slightly

Re: Compression Ratio's effect on HP
 

Of course I searched that new fangled future man invention called google before posting this. All I cam up with was v8 references

Re: Compression Ratio's effect on HP
 

~4% per point.

Re: Compression Ratio's effect on HP
 

So you figure that a raise in compression would result in a different result in a V8? Engine basics such as this are pretty much universal.

There is no real hard number for power increase per compression increase. Some say 3% or 4% more power per point of increase. However that is based on static compression. During operation with your cam and head setup your engine may never even notice that .5 increase unless you make adjustments to cam timing/having it tuned.

In short......there is no real solid percentage of power increase for any given CR increase. If someone tells you 4%/point of compression, it's more of a approximate guess as to what you might see.

Re: Compression Ratio's effect on HP
 

i dont think there is a direct relationship between TQ and comp ratio. a higher comp ratio will make a more efficient engine and yield the possibility for more power. and under your circumstances i would say you would def see more power. but there is also a limit. if you raise your comp ratio too high and your cams are not large enough, you will see a loss of power. from what i have learned, stock itr/ctr cams like about 11.5:1 but no higher than 12:1.

Re: Compression Ratio's effect on HP
 

Which would be good because if I were to do the 2 layer head gasket with the flat valves that would put my static compression at about 11.7/8:1. I know I would have to get the car tuned and adjust the cam timing to see a difference in effective compression. I wasn't looking for an exact answer, thats why I just asked for a general rule of thumb. I knew I could put my engine specs into a calculator and do the math, then compare to the numbers with the new CR, but I didn't want to go through that hassle. I just wanted a quick answer to determine whether or not a thinner gasket and flat valves made sense to me.

Thanks for the responses.

Re: Compression Ratio's effect on HP
 

You're going to admit that you want to be spoon fed! You really shouldn't tell the people that you you know how to do it but you are to lazy to do so....... :beer:

Hard for people to take you seriously after that!

Re: Compression Ratio's effect on HP
 

if you have an OEM radiator, that might be the cause of your cooling issues. they tend to crack and its hard to spot.

So when you say your due, its probably for a radiator, not a HG.

make sure to clay the P2V clearnace when adjusting your cams

Re: Compression Ratio's effect on HP
 

Thats a good idea, I didn't think of that because I didn't see any leaks. Do you know where they usually crack or where I should look to check for cracks or hidden leaks?

Re: Compression Ratio's effect on HP
 

I'm about efficiency, if someone could give me a general answer to save my time, I prefer that. My time is too valuable to waste. Its not laziness, its intelligence.

Re: Compression Ratio's effect on HP
 

You should be intelligent enough to figure this one out!

So what you are saying is that for the people who take the time to do the research, their time is worthless compared to yours. The way I see it, it probably took you longer to get an answer here than it would have to do the research yourself. To me that is not a display of intelligence or efficiency.

Re: Compression Ratio's effect on HP
 

Heavy valves and high rpms are not a great ideal either.

Re: Compression Ratio's effect on HP
 

check the top plastic area.

then dont be cheap and get an ebay rad. If you want a replacement, theres the aftermarket or just goto the parts store and get an oem replacement.

Re: Compression Ratio's effect on HP
 

could be around 10 WHP per point of compression

Re: Compression Ratio's effect on HP
 

lol like i said it took me less time to find then answer then to type the post it doesn't sound like he's to intelligent but maybe i'm to stupid to realize his brilliance i'm just a lonely honda technician the retard that has to fix his repairs

Re: Compression Ratio's effect on HP
 

^^
That made me lawl

Re: Compression Ratio's effect on HP
 

You must not be in management, you must be a doer. Managers have people get things done for them.

Re: Compression Ratio's effect on HP
 

Well a sign of your stupidity is not using too/to correctly. Just sit back and fix cars. Don't try to think.

Re: Compression Ratio's effect on HP
 

That's the way to do it bud. Insult the people you are trying to have spoon feed you. Remember this, someone had to think about this info because you are too efficient to do so for yourself.

Good luck fixing your car. Hopefully you treat your mechanic with more respect than you have done here. It's quite obvious that you do not possess the intelligence to fix it yourself.

Re: Compression Ratio's effect on HP
 

i don't have to think to fix cars....well apparently neither do you cuz your pos ass just pays someone else to do it cuz your to pathetic to turn wrenches yourself

Re: Compression Ratio's effect on HP
 

why does every single thread have to turn into an argument. just whip em out and measure up so this can be over...

Re: Compression Ratio's effect on HP
 

Leak down test and pressurizing the coolant system to see if there is a leak somewhere. Thanks for the help and good feedback.