Quote:
Originally Posted by Mjrn.
let me see if I can find it...yeah I heard about the frozen thing too.
here we go:
Honda Civic Si AccessTUNER Tuning Guides, Worksheets, and Tuning FAQs. - COBB Forums
Cobb: "Removing the coolant lines to the throttle body is proving to be a "significant" modification as far as the ECU is concerned. Removing these coolant lines will likely allow for poorer fuel economy as another side effect. As will setting your fans to turn on at colder coolant temperatures. Combustion chambers are more effective at warmer temperatures and having coolant warm up your throttle body helps increase the intake air temperatures to a more efficient temperature for internal combustion. We are just stating this so you have an understanding that much of what Honda did was done correctly for a performance street vehicle. We are simply trying to do our best to explain what could be going on with your vehicle after a recent mechanical change." |
Ah ok i see what Cobb is talking about now, He's talking about when the car receives cold air which is much more dense than warm air your cars computer has to adjust for that change therefore allowing more fuel to enter your engine as it tries to maintain an A/F ratio that is optimum levels for your car e.g. not too rich not too lean. That's one way that this mod is creating power, more air or more dense air tells your computer to inject more fuel creating a bigger combustion thus creating more power. In somewhat cold temperatures this 'can' lead to a decrease of fuel economy due to more fuel being injected into the engine but i highly doubt it would drastically make a difference in fuel economy if even at all. Cars have to be designed to account for differences of temperatures because cars are sold all over the world where temperatures differ even just in North America places up near Canada can get very well below 0 with the windchill I've lived in places where it was -80 with windchill and i've also lived in places where temperatures got over 100 degrees quite regularly. With such a drastic change in weather conditions if cars were not able to adjust for this then cars would not be able to be sold in certain parts of North America or their computers would have to be tuned very differently and if we were to ever move our cars from a place where it was warm to a place where it was cold we would have to get our computers readjusted every time.
However he is right about our engines needing to be at an optimum temperature for combustion to happen but, our engines already do this on their own. Engine will get hot no matter how cold the intake air coming in is. An engine is designed for this to happen that's why even when we run Nitrous Oxide (which is VERY cold) through our engines it can still account for that cold and get to an optimum temperature for combustion.
I also do agree that much of what Honda did for our cars as a performance vehicle was correct stock. We have a pretty decently made car as far as performance is concerned. However because the Honda civic is a mass produced consumer product they have to satisfy as many of their customers as possible, along with making sure it's Legal for street use in America. Therefore Honda cannot cater to only one type of consumer and one region of America because that would be bad business. To maximize profits there must be aspects of the car that appeal to the Sport compact Racing consumer, as well as the average joe daily driver consumer. They have to run throttle body coolant through the throttle body because if they did not people in Cold climate areas (Chicago, Minnesota, Detroit, New York, almost all of Canada) would not be able to drive this car safely (throttle bodies might get frozen at WOT that could be very dangerous) therefore eliminating a large portion of it's business. So you can rest at ease that in a place like San Diego where temperatures are nice year round you won't have to worry about this happening.
If it still worries you I've thought of a way to make it so that u can turn it on and off through a 4 way pipe coupling and 2 extra coolant hoses. Basically you take the bottom hose and top hose and do the same thing that i did except you use a 4 way coupling with a turn valve that goes from straight through (1 end to the other, same as just a 1/4"-1/4") to all 4 ways open. That way you can bypass the tb coolant in the summer and then have it go through the TB in the winter just by turning the valve. If you want since u live in San Diego i can do it for you.
I guess using 91 octane gas instead of 87 would help with ease worries you might have about losing fuel economy.
I'm not sure what the reasoning behind warmer temperatures making your internal combustion better is, because every air induction mod that we do for cars aims at lowering the temperature of incoming air into the engine. That's why CAI's work and Intercoolers/Aftercoolers work and we have IMG's and TB Spacers and Gaskets those are serving the same purpose. They are aimed at trying to make the incoming air into the engine colder. The intake manifold gaskets and Tb spacer + gaskets are actually a good combo in conjunction with this TB coolant Bypass because then the entire intake pathway until it hits the engine will drop in temperature which makes for more power.
However thank you for the information it's always good to have all the facts before anyone decides this is what they want, because it's all up to the individual if they want this mod or not.
Here is a site that did the TB coolant bypass on a Integra LS motor and the guy dyno'd and found 10 ft/lbs of torque after car was at operating temps
Free Mods for your Honda Prelude, Gain Horsepower for Free, 97-01 Prelude, cheap horsepower
There's a little blurb about weird idles at the bottom but I didn't notice anything different about my idle. Just make sure there are no leaks and nothing is left just open cap everything off.
Actually maybe when Galaxy comes to my place to do this mod we'll take pics or record video of me doing it on his car and post it up in here. Stay tuned ^^