2007 Civic Coupe Modifications

[superchow]

Originally Posted by spyderbite9001

do you guys know where i can get a service manual for the civic. i've bought service manuals on all my other vehicles and do my own work on the cars. (everything from oil and brakes, to axle's, differentials...) i find they're the manuals to go with for any car. i've tried haynes and others but none compare to the ones made by the same guys who made the car.

No service manuals out yet. You can buy the service manual that the dealers use, but that costs over $100.

In Wyoming (6000+ ft.) a month ago I noticed how much weaker the engine felt. Gas mileage was still good, despite revving it more to have similar acceleration compared to sea level altitude. Not changing the throttle position going up hills will slow you down, but won't make the engine inject more fuel. I always try to imagine the 50% gas pedal position is my practical 100% position, and anything beyond that is "emergency" or "freeway merging" power. That ususally changes my driving attitude quite a bit. Not sure how well that would work with a slush box.

On a different note: Compared the gear ratios of the gear boxes and final drives. They seem quite different, and I wondered what your revs in top gear are at a comparable speed, say 60 mph?

[superchow]

Originally Posted by JamesLaugesen

Is this specifically for the honda vtecs?

I've never heard of any FI engine ever completing cutting fuel, a small amount is added to help lubricate the compression rings, determined by the "deccel" or "over-rev" areas of the fuel map(s).

I don't think fuel is used to lubricate the compression rings, but I am not sure. I remember driving a minivan (2004 Chrysler T&C) for work once and when coasting at highways speeds the instantaneous gas mileage indicator always showed "--.-". It could be that there is just a minute amount of fuel injected, but it seems less likely to me.

Any SG peeps here that can confirm or debunk?

[JamesLaugesen]

Originally Posted by superchow

I don't think fuel is used to lubricate the compression rings, but I am not sure. I remember driving a minivan (2004 Chrysler T&C) for work once and when coasting at highways speeds the instantaneous gas mileage indicator always showed "--.-". It could be that there is just a minute amount of fuel injected, but it seems less likely to me.

Any SG peeps here that can confirm or debunk?

Thanks, after some google it does look like the civic shuts the injectors off completely (and the 2007 apparently has quirk, delay engaging them again?).
I have experience mapping bikes / "high performance" engines, and we'd definitely never completely remove fuel, but with tighter emissions standards it makes sense I guess. Would be interesting to know exactly how the engines can get away with it.

[AndrewJ]

Originally Posted by superchow

Try filling up with premium instead of regular. That usually yields a 10% improvement for me. Plus, the car feels gutsier off the line.

YMMV on that one....

Premium won't get you anything.
You're paying for octane, unless your engine is high-compression it can't make use of more octane.
So you're paying for nothing.
Placebo.


Oh, and the injector cutoff on Hondas is fo-real. My MPGuino confirms it. I think it's the case in most (if not all) modern cars.

[Blue07CivicEX]

The revs on an auto at 75mph are about 2300 where the revs on a 5 spd at 65mph are 2800 so... that shows the difference in the top gear. Also I would like to apologize for the lack of updating on this thread, I have been out of town for a couple weeks but I have cut out some coroplast chunks I'm going to cut down for the front wheel covers (17 and 1/2" discs to fasten over the rims) and I also got my hands on some ABS plastic that will make EXCELLENT skirts for the back. I bought a milwaukee cordless drill and hardware to mount the skirts now I just need the time to fit and mold them to shape. hopefully I can accomplish something this weekend.

[spyderbite9001]

Originally Posted by superchow

No service manuals out yet. You can buy the service manual that the dealers use, but that costs over $100.

In Wyoming (6000+ ft.) a month ago I noticed how much weaker the engine felt. Gas mileage was still good, despite revving it more to have similar acceleration compared to sea level altitude. Not changing the throttle position going up hills will slow you down, but won't make the engine inject more fuel. I always try to imagine the 50% gas pedal position is my practical 100% position, and anything beyond that is "emergency" or "freeway merging" power. That ususally changes my driving attitude quite a bit. Not sure how well that would work with a slush box.

On a different note: Compared the gear ratios of the gear boxes and final drives. They seem quite different, and I wondered what your revs in top gear are at a comparable speed, say 60 mph?

Hey guys, yeah, i plan on purchasing the service manual that the dealers use, heck, we just had my dads yukon xl worked on yesterday, its $108/hr for just the mechanic, if i save myself one stop to the dealer for work the book has payed for itself. (could you post the link to where to buy one)

in other news, my rpms at 60mph (assuming 5th gear, and level road) is roughly 1900 to 2000, its difficult to say exactly, i dont watch the tach for too long. at 65mph (same assumptions) roughly 2200. at 75mph (same assumptions) roughly 2500 rpm. of course these vary depending on grade and who i'm following (i love semi's) i plan on filling up the tank today to see how i'm doing with all the trix you guys have told me.

[Keen]

yikes, the auto trans is much higher geared than the manual. On my 5spd 70mph is 3000 rpm. makes me want an Si tranny minus the problems they have with 2nd + 3rd gear.

[spyderbite9001]

is the gearing bad? what r the problems with the si tranny?

[Keen]

higher gearing isn't bad it's good. I always thought that my 5spd reved too high at 80mph. Anyway gen 8 civic si's have been know to have problems with their tranny. Check out the 8th gen forums.

[superchow]

60 mph = about 2550 rpm
69 mph = 3000 rpm
80 mph = 3500 rpm

If the automatic revs almost 1000 rpm lower in top gear, then that could generate some amazing mpg numbers.

However, in the 5 speed I love to accelerate "vigorously" in first and second and then pop it into fifth at 35 mph. First off the line AND awesome cruising mpg.

Maybe you'll have to trick the computer to shift earlier by accelerating moderately and then lifting off to allow the highest gear/overdrive to engage and then slowly reapply some throttle. Also letting up on the throttle on uphills artificially kept the transmission in overdrive. That technique worked very well with an old car of mine (3.3L V6 Oldsmobile Cutlass Ciera). That usually yielded about 33-35 mpg highway.