I have an 2003 Acura TL. It is a non S type. I would like to raise the compression in hopes to increase my fuel economy.
I noticed that the s-type has a 10.5 compression ratio compared to the non s-type which is 9.5.
Does the s-type have a higher compression ratio because of a different head gasket, different head or a different cam that allows an increased flow or all of the above? I heard that if I replace the head gasket with a stock or OEM one and take out a few of the layers that it will increase the CR. Will I have to buy a computer that will allow the change to be realized?

Second, Does the non s type TL have high flow cats?

Thanks

 

The TLS has higher compression pistons.


Cams don't change your compression ratio. You can go with single layer head gaskets if you want to increase the compression ratio, but it's not going to change much. I think the stock gasket is a 3 layer (not sure on this), so if you went to a two or single layer head gasket, the compression probably wouldn't go any higher than 9.7:1.

 

yeah but cams DO allow you to change your dynamic compression...

 

Thanks for the reply.
I have been running 30% Ethanol and my vehicle seems to love it. Plus it is much cheaper than buying 93 octane fuel.
So if I went with a single layer head gasket I may get a slight increase in CR.
Does the TL type S use the exact same heads as the non S type?
How much piston clearance do I have if I get my head milled or am I better changing the pistons?
Is there a place that someone can recommend where I can get domed pistons and thinner head gaskets. Ethanol loves high compression.

 

do a 3.5 conversion... use 2002 RL pistons and the honda odyssey crank....

 

If I change the crank and pistons wont I then have a 3.5? I am really looking for better fuel economy.

 

get type s heads (cam and valves are diff), type s piston or rl pistons.

 

it's 10.8.1 if you have the heads milled.