I'll try to lump these all together so as not to clog the forums with my noobery. Spoilers, wheels, noob mods.

For FF cars like the civic, what purpose does a spoiler serve? I know the spoiler is meant to increase downforce, but what benefit is there to increasing the downforce on non-drive wheels? More downforce on the rear tires could also increase understeer, which is already a problem with an FF vehicle. If anything, it seems like it will just increase the overall weight and drag of the vehicle. If people want them for appearance, that's fine, but I really can't see any performance gains.

In regards to larger wheels (let's see how much physics I can remember), wouldn't a larger radius of wheels require more torque to drive, and thereby decrease your acceleration? With a larger circumfrance you can achieve higher speeds for the same wheel RPMs, but getting to that speed will require more work from the engine. Is the lesser mass of performance tires enough to counter this issue?

I drive on the highway a lot; my civic ('05 lx 2d 5spd) is my primary vehicle. I won't be looking to race in events in this vehicle for any time soon, so hardcore weight reduction isn't up my alley. I am interested in increasing fuel mileage (be it greed or environmentalism, I can't stand spending money on gas), boosting power for better acceleration on the highway (merging and overtaking), and every once in a while wiping that smug look off of a ricer's face (to that purpose, I'd like to maintain the stock look of the car as much as possible). I see some simple options are to install a cold air intake and new exhaust system; even the quality stuff is not as expensive as I initially thought it would be (I was expecting in the kilobucks range). What mods should I be particulary careful of, in case they might totally **** things up if not done properly?

Since the '05 lx doesn't come with 4 disk brakes, I should probably get those ASAP.

I have a degree in computer science; I'm a fairly decent programmer. Is there much I'll be able to do with the ECU? I think it might be pretty cool to build some kind of custom system display out of an old PDA or GBA or something.

You guys probably get these questions all the time. Sorry in advance. I know what it's like, I get the same damned questions about game design all the freaking time.

 

The spoiler is only used for appearance (on a daily driver). You get more performance without a spoiler due to the reduced weight.

As far as wheels go, you are not supposed to increase the diameter of your tires, only the diameter of your wheels. (example: if you have stock 14 inch wheels, you could move up to 16 or 17 inch wheels, and use a low profile tire to keep your outside diameter the same so that your speedo is not affected) The larger wheels and low profile tires usually weigh less than the stock, which also helps.

A CAI, header, high-flow cat, and a cat-back exhaust would be a nice starting point for you.

And YES, if you're gonna go faster, you should also upgrade your brakes. Keep this in mind: Anyone can go fast, but do you have the power to stop?

[sm=welcomesign.gif] to HCF. [sm=groupwave.gif][sm=groupwave.gif][sm=groupwave.gif]

 

okay, makes sense on the wheels.
Okay, I'll take a look around. In keeping with the unassuming ricer smacker, any particularly quiet ones that you can think of?

 

Greddy Evo2. and technically, a spoiler can help if its a properly designed one (most arent) and you need more traction in the rear. so unless you have a lot of suspension work done, and your rear tires get squirrely when you push it, a spoiler is just for looks. but any downforce helps with cornering, especially if you can balance it right.

 

That's why I wrote with a "daily driver" on my above post.

 

A spoiler will help a FF but not much and not any at most speeds we all travel at.

Bigger tires will lower your accelerration and if they are big enough you will notice the signifigant loss. But one thing is when you go bigger with the wheel you go smaller with the tire and tires wiegh too so it is somewhat of a trade off. Alot of aftermarket wheels, even though bigger, will wiegh considerably less then your stockies so upsizing your wheel 1 size or maybe 2 may actuall result in a performance gain.

As for more power and better fuel economy, I may suggest the ins and outs you arleady stated and maybe some type of user adjustable fuel programmer, ie...Apexi SAFC. Then you could lean it out a little, gain some power and MPG.

Id really only suggest the rear discs if you are getting serious into handling, the brand new drums will hold the rear fine and just use that money on some nice upgraded front brakes instead. I think the cost/bennefit ratio would be better if used for some type of big brake kit then trading to discs in the rear.

Not sure if you could crack the code on the ECU, people have been trying for years and years and only found succes a year or two ago with it. Maybe even look into a Hondata.

 

Thanks everyone. I think I'm going to try and find a cheap CAI (<$100) and get that installed. I've never done any auto work before, so I'm trying to be really careful and learn as much as I can. From what I've learned so far, a CAI is a pretty simple upgrade.

A big problem is that I don't know how knowledgeless I am right now (other than "yeah, I'm dumb"). I've been reading some articles on wikipedia, I've bought a book on honda tuning (it's upstairs right now, can't remember the title), and I'm definitely going to verify anything I try here. So any links to articles and any book suggestions would be much appreciated. Think of me as virgin clay, ready for the molding.

Just one other issue: how interchangeable are parts? Like I said, I have an '05 civic, but I haven't seen parts that specifically state they are for anything later than an '03 civic anywhere. Will I have to make sure that I buy a CAI that specifically states it's good for my model year, or are their others that will work? I guess '04 was the new model year, right?