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Honda Civic Coupe / Civic Si 2006+



  • eldaino is completely right. Again, the R18 is a great economy model engine; if you wanted performance, the Si, WRX TR, EVO, MS3, GTI, etc. are great platforms to start tuning from. The base models are absolutely upgradeable, but the cost-effectiveness just isn't there. We're just helping you understand, hopefully, but in the end it's your money: throw it away however you want.

    It's like buying a fiberglass bathtub and deciding to add a set of claw feet to it... sure you can do it, it's just not a good idea. Just get the right platform to start.
  • eldainoeldaino Posts: 1,618
    thanks for the back up brotha. ;)

    this is one of the reasons i try and stay away from the 8thgen civic forums; to many nice people on that website that want to do this, and they get nuts over the parts that are available.

    Its really silly stuff too, like going through the trouble of finding si sway bars because they are thicker. Its just silly.
  • 8th gen? That place has a downright friendly Aloha spirit, compared to the more juvenile honda-tech forums.
  • eldainoeldaino Posts: 1,618
    well, yeah i guess it does.

    i can hold my own against some mugen b series whore, its just dealing with the 'i can't wait till x company is done with the turbo for the r18!' kind of stuff. :sick:
  • kenlwkenlw Posts: 190
    Taking a good base car and wanting to "fix it up" is a theme I've seen for years on other forums. Every 3rd person that logged onto the (now defunct) Camryman forum was a 16 year old kid, who being given an 93 i4 AT camry with 90k miles on it wanted to swap the v6 and a supercharger and manual.

    They seemed to think that spending 5k on a car worth maybe 3k was somehow a neat thing to do. I usually suggested they save their money for a real "fast" car someday.

    Some listened, if only when mommy-san said no.

    Others took the more than adequate v6 and after putting the charger on it, decided that 250HP wasn't enough, so dropped the pulley diameter to crank it up to near 300hp. And then wondered why their once-ultra-reliable Toyota engine was blowing smoke and drinking oil like there was no tomorrow....
  • eldainoeldaino Posts: 1,618
    i have seen it justified before though.

    taking a mid 90's civic hatchback and swapping in a performance oriented b series motor or even a new k series like in the si yields some very impressive results.

    its very common to see guys with old coupes and hatches spend about 8k on a k series swap and then have their cars doing 13's or less in the quater mile for a fraction of what other cars cost.

    but the supercharged camry is a bit much. :)
  • kenlwkenlw Posts: 190
    ..what you've done is taken a fairly reliable car, pump a bunch of dollars into it, and now you have a fastER but much less reliable car. You've also lowered the resale and spent enough $$ to buy a REAL fast car.

    It makes no more sense on an old Civic than it does on an old Camry if it is your daily driver and you need reliable transportation.

    A garage build that only comes out for real races (on real tracks) is a totally different beast.
  • punkr77punkr77 Posts: 183
    I'll vouch for the seats in the Si. Very, very comfy.

    As far as learning to drive on it, I wouldn't sweat it too much, as long as you give yourself a bit to get comfortable before shifting into boy racer mode.

    Other than a 5 minute drive in an old Porsche 944, I had never driven a manual before I bought my 95 Civic EX manual new. I stalled it a few times on the test drive. I was fairly comfortable with it in a day (though hills took a couple of weeks).

    My dad had it after me, and relearned how to drive a MT after 25 years in automatics. It still had the original clutch and tranny when he sold it 6 months ago (with 115k on the clock).

    Running a manual in traffic can be a pain for some. On the up side, the civic has a super light clutch, so it's more of a figurative pain. As long as you don't anticipate eating, talking on the phone, and shaving while you (attempt to) drive, you should be OK> Doing stop and go in my 99 Mustang Cobra for 4 hours (hurrican evacuation) was a LITERAL pain. I could barely walk when I got out of the car.
  • eldainoeldaino Posts: 1,618
    ken do you have any real knowledge about the tuning 'scene' because to say that only a garage build for real races is what works is just as bad as the kids who think they are cool with the fart can mufflers.

    ASIDE from the exquiste power to weight ratio, and stock handling traits, putting a more powerful engine into civic is easy because honda also built the more powerful engine; done properly, there are virtually no issues, and its been proven.

    And probably the main reason that souping up small honda four cylinders ever got popular is BECAUSE they are legendary for accepting powerful mods WIHOUT any affect to reliabilty. Again, something that has been proven. Do they fail sometimes? Ofcourse, but the reason many are drawn to honda is the fact that the engines are bulletproof to being with.

    As far as the camry goes, it really has NOTHING going for it, no ounce of handling or a good power to weight ratio. THAT is whats pointless.

    Mind you, the mods in question that i was reffering to on smaller hondas are not very expensive at all. Certainly not the 30k some sports cars demand. Though you can spend that much and still obliterate them. :)
  • punkr77punkr77 Posts: 183
    I always thought dumping money into an economy car to make it something it was never designed for was kind of silly. Taking a $20k car and dumping $10k into it just never made any sense to me when you could buy a $30k car that would be faster more often than not,still keep the new car warranty reliability and drivability. Not to mention that most insurance policies will only pony up what a stock car is worth if it's ever stolen or wrecked.

    About the only thing sillier in my mind are the people who buy a $1,000 car and spend $8k on wheels and a really loud stereo.
  • eldainoeldaino Posts: 1,618
    who says the car has to be 20K? My buddies civic cost him a few grand to purchase, and his total out of pocket cost was about 10k and he has enough performance to run with a 50k car.

    Not to shabby in my opinion. It may not be everyone's 'thing' but everyone spends money, and sometimes a lot, on things that another person wouldn't. On a newer car it makes less sense, but the warranty isn't a real issue if you are the kind of guy who likes to work on your car and are only after other words a total moot point.

    I to agree with the buying of a 1k car and adding 8k wheels, but thats not what were talking about.
  • I just purchased a 2007 Civic SI Coupe. Generally, I like the car, but the are a lot of rattles. The dealer attempts to fix them ,but I am disappointed in buying a new car and having so many rattles to live with. Most of mine come from the right side of the car. Has anyone had the same problem and were you able to get this resolved. Most of the problem seems to come from the right door -- I would like to know if this is something that can be solved. Other than that, I am pretty happy with the car.
  • punkr77punkr77 Posts: 183
    The only noises I've encountered with mine are a slight rattle from the sunroof sometimes and some front suspension "popping".

    The sunroof thing only seems to happen when I've just pulled out of the garage. The alley behind my house is pretty rough and uneven, so I think it's just "settling in" after first being driven after me parking it in the garage and closing it.

    The popping only happens at very low speeds when I hit a large bump. Usually pulling out of inclined driveways or out of businesses onto a street.

    I wouldn't think a door rattle would be too hard to fix. Were it me, I'd try a different dealer. If they can't fix it. I'd get in touch with the regional service manager from Honda. Explain the problem, show him paperwork from your multiple visits, and ask for guidance. I would expect Honda would much rather make good on the problem rather than having an unhappy customer whose likely to share their problem with other potential buyers.

    If that doesn't work, the last resort could be legal action. Perhaps taking it to an indy body shop and suing to recover the money.
  • Does anybody know if you can re program the Si computer to run on mid greade or regular gas?
  • shiposhipo Posts: 9,152
    Most likely not. The Si has an 11.0:1 compression ratio and running anything less than Premium (91 AKI or higher) is a recipe for mechanical disaster. The question I have is, "Why would you want to?"

    The reality is that even if your engine could safely run lower grades of fuel, your gas mileage will drop so much that the cheaper fuel (per gallon) will end up costing you more (i.e. cost per mile).

    Best Regards,
  • Shipo, do you have real knowledge of your assertion that regular gas would destroy your SI engine ("mechanical disaster") and / or gas consumption would rise so much that it would cost more (which I guess assumes no mechanical disaster), or is this speculation?

    Most ignition time these days is done with sensor to adjust same to prevent premature detanation. Question is, is this the case with the SI, given Honda's engineering quirkiness? I wonder what the exact words in the owners manual are regarding this.
  • shiposhipo Posts: 9,152
    I'll deal with the reduction in mileage first. Fact: Any engine that is designed to be able to take advantage of Premium fuel WILL get measurably worse mileage when the timing is retarded to allow it to safely burn Regular. Period, full stop, the end.

    As for the issue of mechanical damage, no, I have no first hand experience of destroying an Si engine (or any other high compression engine that "Requires" Premium fuel for that matter), I simply will not subject my engines to that kind of abuse. That said, I've been turning wrenches for over thirty years and have seen the results of octane skimping any number of times, and it ain't pretty.

    The fact is that as compression ratio rises, the heat generated from the compression will eventually reach a point where it is too high for any amount of timing retardation to prevent detonation (and engine damage as a result). Is it 10.5:1? How about 11.0:1? Maybe 11.5:1? I don't know for sure where the threshold is (it varies by engine, OAT, humidity, altitude, and a few other variables), however, I do know one thing for sure, the engineers at Honda don't just "Recommend" Premium fuel (which is the language usually reserved for cars that CAN retard the timing far enough to burn Regular), they "Require" it. Given that Honda engineers have a very good reputation with regards to the care and feeding of the engines they design, my bet is that if they say that Premium fuel is "Required", only a fool would tempt fate and run anything less than 91 AKI in their Si.

    Best Regards,
  • I recently bought a 08 si coupe and love it. The one thing that I noticed is that there Are some squeaks coming from the passenger dash and wondering if I should even bother taking it back to the dealer? Any thought or similar noises out there?
  • i have the same problem...where is this intake air temperature??
  • drmbbdrmbb Posts: 80
    You don't have to reprogram anything. The knock sensor in the engine will retard ignition to accommodate the lower octane fuel automatically.

    However, as shipo has posted, you cannot change the engines compression ratio (unless you plan on rebuilding it yourself), so you would be running your engine with continually retarded ignition. That is going to give you worse gas mileage and will increase your exhaust emissions (if you care about the air you breathe).

    So, I too do not see the point. If you really want to run regular gas, you'd have been far better off buying a regular EX sedan instead of an Si.
  • tayl0rdtayl0rd Posts: 1,926
    As was already said, you'll have horrible gas mileage. I have first hand experience with that one. Not in an Si, but another car where premium was only "recommended." I would get a solid 50 miles LESS per tank of gas, and the car ran and felt very anemic. With an 11:1 compression ratio, I'm sure your owners manual states that you should only run regular gas in an emergency situation with just a few gallons of it in the tank and to fill up with premium as soon as possible.

    Sure you can run regular in it, but I wouldn't dare trying to run that engine up to 8K RPM with it!! That would be begging for busted pistons and/or bent rods. And there's no way it'd pass an emissions test.
  • ok i have a big problem this honda civic and i dont want to junk it . this is what happened normal drivening for a few miles like 5000 after i got it and the #4 pistons blent on me so i got a head from a junk yard the car was running`good the parts car . so i went home got a new head gasket checked to make sure the head wasn't bent and the block they checked out so i put the head on just like to service manully expained in detail changed the old and antifreez also new plug and wires . ok so to make it somewhat shorter it run but only 1&4 r working so it doesn't run right anyone got any ideas to help me out on this one ?????? :sick: :lemon: :confuse:
  • ramzaramza Posts: 1
    ok this may or may not help you but if you message me and give me some more info on the car and what is doing when you start it i may be able to help you some. it could be a timing problem or sparkplugs weren't put in correctly. most likely its your distrubuter is off or cyl 2 and 3 spark plugs are not plugged in correctly. hopefully this may help you i would check all of your connections and COMPLEATLY switch the plugs to see if its just faulty cables. also check the head you pulled and make sure there is no damage to the intake valves that may cause a major problem even if its a chip the size of a large grain of sand.well message me back and ill try to help you my email is i am not a pro but im good with cars. if i cant help you ill get u info from one of my friends.
  • Hey all,
    I was wondering what typical MPG you Si folks are seeing? I am coming from a Subaru Forester XT, and I'm probably in the low to mid-20's MPG. I know both cars take premium fuel, but if the Si gets better gas mileage I would consider switching over. My commute (95%) is mostly highway.
    Any advice/help would be appreciated.
  • cz75cz75 Posts: 210
    I average 26-27 mpg, which is mostly suburban and rural secondary roads.
  • motonationmotonation Posts: 34
    There's a whole thread on Civic mileage - check it out:

    There's also info at about it.

    Most people seem to average in the mid to high twenties overall, but many people have reported hwy mileage in the 33-34 range. I'm thinking of purchasing one myself, and have a friend with an 07 Si sedan that gets that on the highway, so it can be done; maybe even a bit more if you have everything working in your favor.
  • Very good info. thanks a bunch.
  • unkownuserunkownuser Posts: 23
    For those who have indicated that fuel efficiency will be crushed by using regular, I would like to know by how much, if any. I hear strong definite assertions, but little (actually, no) empirical results, and so must ask.
  • cz75cz75 Posts: 210
    Unknown. However, it is because the ECU retards spark timing to prevent detonation and keep the motor together on more volatile lower octane fuels.

    One thing about using premium, is that most places the differential, no matter what fuel prices rise to, is always going to be $2.60 more for a 13 gallon tank.
  • shiposhipo Posts: 9,152
    I've seen several scientific studies that showed as high as a 15% reduction in fuel economy, however, most reductions show up in the 5% to 8% range. With regard to the Civic Si, Honda doesn't just Recommend Premium, they Require it. The fact is, the Si has a high 11.0:1 compression ratio, a ratio that is so high that detonation is almost guaranteed to occur at all but the lowest power settings if Premium fuel isn’t used.

    Long story short, the bigger issue with the Si engine isn’t fuel economy, it is engine protection. If someone holes a piston, Honda’s most likely going to charge the owner a pretty penny for the repairs.

    Best Regards,
This discussion has been closed.