Asian Candy

So I did my first mods a week ago. P2r throttle body spacer with thermo gasket and tb coolant bypass. Fairly easy for never doing any mods before. Can't say I've noticed any performance gains, and sense throttle response is actually a little worse... Maybe it's in my head. But my fuel economy is about 2 mpg less than usual. Driving habits, conditions, or routes haven't changed. I'm 99.9% positive I installed the tb spacer correctly and dont hear any whistling or hear or feel an air from tb either. Anyone else experience lower fuel economy?

dyrtyred

Its from the tb coolant bypass. Same thing happened to me when I did that mod.

Asian Candy

Guess its not that good of a mod afterall. You notice improvement when you changed it back?

thunderbt3

Sounds about right. Just thinking out loud...air flows through throttle body into the intake. Intake senses air temperature and ECU adjusts fuel accordingly. Disconnect the coolant lines from the throttle body and now cooler air flow into the intake. Intake sense cooler air which causes the ecu to add more fuel. Cooler air is denser (more oxygen molecules per unit volume) than warm air which requires more fuel to properly burn it. If the ECU did not add fuel, you would end up burning too lean.

Honda says they use the coolant lines in the throttle body to prevent the throttle from sticking in cold climates. Maybe its an added benefit (for Honda) that the air is warmed before going into the intake so they can trick the engine into using less fuel and bumping up fuel economy numbers.

Italiano

Useless mod.no offense..get a CAI and u will be happy...

Asian Candy

I have an icebox intake I'm going install soon. But if it's true that the ecu senses more air and adds more fuel, wouldn't the same thing happen with a CAI? It seems that anyone who adds a CAI gets better gas mileage.

ceb

Really? Where did you read that?

There is no mod that will pay for itself over the life of the car in gas savings and a CAI certainly won't save gas.

ed_423

lol depends on the way you drive. a lot of people lose a few mpg because they get so excited about how much power they think they gained from the sound of the intake and floor it and hit vtec everytime. i tried to keep my feelings neutral and drive normally, my mpg DID increase, but i don't think it was due to the intake. i just happen to drive more highway at that time compared to before.

Tannis

You get the icebox installed yet? I swear, that plus the downpipe were the best mods yet. Now the PCD is available I may have to go for it. Only problem is my oem secondary cat is long gone and I honestly don't see $165 for a test pipe being reasonable. Anywho, off the soap box I go. Good luck with the install!

Oh, btw, I actually saw mileage gains for a good while. Then winter kicked in and i said f#ck it and kept driving like an asshole so I'm still only getting 24-26mpg on average city/highway combined. (25/75 respectively)

Andrew Civic

the reason for CAI's getting better mpg as i was taught is that the engine is yes adding more fuel. so in high revs and VTEC you get lots of air lots of fuel and lots of power and less economy. but in regular to low revs, "normal" driving shall we say, the engine is using less air and fuel(VTEC off) but it still able to more easily pull in the small amount of air it needs because its measuring o2 NOT volume so it needs less volume of air than stock. beacuse the engine is not working as hard to pull air into itself it needs less power to go the same speed. similar to if you strip some weight. same power. just applied differently if any of that makes sense

Asian Candy

Im not all that familiar with all the mods, so what is PCD?
It will be about another week before I get to install the icebox. Did you have to take the front bumper off? I'm a little nervous about that as I have a tendency to easily break things. But looking down thru the engine bay, it looks like there is enough room to pull the resonator and rest of stock assembly up thru the engine bay, piece by piece, if i take the battery out. Maybe it's just wishful thinking
I've been getting about 24mpg, but I do all city driving. Went down to 22 when I installed tb spacer and coolant bypass. I undid the coolant bypass and it went back to 24.

ceb

Huh? How does it measure O2 and not volume? What does the measuring and why is it different with a CAI?

It is uninformed postings like these that keep the aftermarket junk industry in business.

Please don't post unless you actually understand the technology behind your post.