2002 Honda Civic Coupe LX 5spd Build Thread

[Christian]

Here are photos of the coroplast lower grille block fitted on the civic.
Turns out I screwed up one of the zip tie mounting spots, so there is a ~1in gap on the edge of the grille block. To fix this, I jammed some pipe insulation in there. I will eventually fix it, but for now, my goal is to see how well the grille block works and decide on which changes can be made to improve the next version.

[Tmugz88]

I'm new here but wouldn't leaving an opening like you did negate the purpose of the grill block? No disrespect towards you I honestly am asking a question because I truthfully don't understand how this would improve aerodynamics enough to justify the work. Could you do a full block and utilize the pipe insulation as a spacer to allow some air to enter/exit ?

[Ecky]

Originally Posted by Tmugz88

I'm new here but wouldn't leaving an opening like you did negate the purpose of the grill block? No disrespect towards you I honestly am asking a question because I truthfully don't understand how this would improve aerodynamics enough to justify the work. Could you do a full block and utilize the pipe insulation as a spacer to allow some air to enter/exit ?

Even a partial block helps - you end up with a high pressure zone and most of the air goes around or over the car, rather than through the aerodynamically very dirty engine bay, then out the bottom (or wheel wells). More importantly, it helps reduce warmup times.

[Christian]

Originally Posted by Tmugz88

I'm new here but wouldn't leaving an opening like you did negate the purpose of the grill block? No disrespect towards you I honestly am asking a question because I truthfully don't understand how this would improve aerodynamics enough to justify the work. Could you do a full block and utilize the pipe insulation as a spacer to allow some air to enter/exit ?

I believe you're right, it definitely seems like it would have a poor effect on aerodynamics. I can't really speak on exactly how much of a negative impact it would make though.

However, my goal for the mod is to increase the warm-up time of the vehicle, not improve aerodynamics. The large majority of my driving is short stop & go city trips. I plan on also building an upper grille block eventually to help increase the temperature of air coming through the intake.

[EcoCivic]

Originally Posted by Christian

I believe you're right, it definitely seems like it would have a poor effect on aerodynamics. I can't really speak on exactly how much of a negative impact it would make though.

However, my goal for the mod is to increase the warm-up time of the vehicle, not improve aerodynamics. The large majority of my driving is short stop & go city trips. I plan on also building an upper grille block eventually to help increase the temperature of air coming through the intake.

If your goal is to increase intake air temperature, I'd start by removing the resonator box. This will certainly increase your IAT a bit since you will be pulling air from much closer to the engine and the intake will see more radiator heat. This will also make a lot more room in the engine compartment and save a few pounds, all good things.

I wouldn't expect huge gains from higher IATs, I have changed my intake configuration several times trying to get the coldest air possible for improved performance and I never noticed my fuel efficiency change with IAT. I do plan on eventually experimenting with using a small heat exchanger to warm the fuel going to the rail with coolant though, I'd think warmer fuel could improve cold weather efficiency by vaporizing easier but we will see.

Does anyone have any data on what the ideal IAT for fuel efficiency is in their application? Too cold would theoretically hurt efficiency by increasing pumping losses and not vaporizing fuel as well, but too hot will result in the ECU retarding ignition timing and possible knock, which isn't good either.

[Ecky]

I seem to recall someone quantifying ~130F as being where their fuel economy peaked. I saw large improvements with a warm air intake during Vermont winters, but some days the air temperature was -10F or lower, so we're talking a 140F+ increase. That's a lot of extra energy being put back into the cylinders.

Go too hot, and most ECUs will begin to retard timing to protect from detonation.