Rarity- Accord V6 6MT Hypermile/Build Thread
 

This Thread is really long, so here is a table of contents.

42 MPG!

Rear diffuser, wheel boattails, upper grille block, and frondertray.

Tuft test video, scangauge relocation, mid undertrays, lower radiator panel, and rear diffuser extension.

New grille block, new best trip back home, and EOC questions


42.3 MPG!

Rear wheel spats and more undertray panels

43.6 MPG and minor tire spat modification

New best tank, 35.9 MPG!

Engine mod plans

New best tank, 38.1 MPG!

45.1 MPG!

47.1 MPG! Another new record!

Block heater

Exhaust channel deflector and new record tank 38.9 MPG

It was a dark and stormy night...And I got a 40+ mpg tank!

A few months ago I sold my 4 cylinder accord because I found my dream accord, a white V6 6MT sedan with ivory interior. So far the V6 has really impressed me with its mileage, although it was a step down in gas mileage, it wasn't as big as I thought it would be. The V6 has about 84 more horsepower than the I4, 256 more pounds, and an extra gear, the thing I was really looking for. Despite the low city rating of 18 MPG, this thing could probably beat the I4 mileage-wise in a short trip of less than 3 miles from a cold start. I blame the pre-cats. :D

Since I have a new commute from when I had the 4 cylinder, I can't directly compare mileage, but I have had enough highway trips to compare those. So far I have been getting around 36 mpg, until I adjusted the valves and cleaned out the intake manifold and runners. After the service, the car felt more responsive and about 10 hp more powerful. Then on my next commute i got 40.3 MPG! :D Best trip in the V6 as of yet! Clean out your intake!

I have not done much modification to the car yet because I’m busy with college and I need more coroplast and ideas, but I have done some stuff. When I first got the car I noticed that it had DRLs, those had to go. I pulled a few fuses before finding the right one, a little 10 amp fuse. No noticed mileage improvement, and a DRL light popped up on the dash, which I can ignore.

The next mod was a grill block, thanks to inspiration from Istas I decided to try to make both upper and lower blocks. The upper block was a failure because I accidentally cut it too short and tried to expose the Honda badge. I have a whole other sheet of brand spankin’ new coroplast, but I didn’t want to cut into it in case I wanted to do a belly pan. The lower block however was a success and I think it looks decent. I thought about putting the hole in the middle, but I wanted to have cooling air going to the A/C evaporator to retain full A/C performance should I need it. The block is attached with six strips of Velcro on each surface: 2 long strips, top and bottom, and little strips on each side of them. The grill block did not raise the operating temperature and I did not notice any mileage improvement either.

After that I remembered the stupid little glovebox light that turns on whenever the headlights are on, so in the interest of reducing electrical load, I took it out.

Planned mods: Wheel covers, Rear wheel skirts, Engine and rear undertray, Hybrid diffuser if i can find one for cheap, airdam, and upper grill block.

http://ecomodder.com/forum/attachmen...7&d=1443558564

http://ecomodder.com/forum/attachmen...8&d=1443558564

http://ecomodder.com/forum/attachmen...9&d=1443558564

http://ecomodder.com/forum/attachmen...0&d=1443558564

http://ecomodder.com/forum/attachmen...1&d=1443558564

Great find and awesome fuel economy from a V6!

Subbed.

Thanks! And thanks! It took me months of searching to find the specific color and interior i wanted. There are enough 6-6 sedans out there, but hardly any of them are white. I think i just so happened to choose the rarest color of the rarest optioned accord. Its a little rough, but i hope to get it into much better condition than when it was purchased. Im going to rip out and clean the carpets probably next weekend, brace for the weight reduction jokes.

I blame Honda for making a great car and putting good ratios in a manny tranny. 6th gear is about 2100-2200 rpm at 65 mph. I'm pretty mild with my hypermiling as my commute gives me traffic to deal with. I'll stick to 65, coast downhill, DWL and some more basic hypermiling techniques. No EOC or going 55 mph. I accelerate at 80 LOD and shift at 2700 RPM, ill be in 6th gear by 40 (1200 rpm) and will hold down to 35 if acceleration is not required. 44/42 PSI in tires.

I was actually inspired by your thread to start my own thread. I love the consistent mileage reports and frequent modding you do. I'm certainly planning on mileage updates, but mods may not be so frequent.

I neglected to mention that on my I4 accord I made an engine undertray and mid trays for each side. The mid trays have been sacrificed for my grill block, but I'm hoping i can slap the engine tray on this one and get some pics soon.

Congrats on the new car. Its always great to finally find the one you've been looking for. Nice mileage too.

I wouldn't mind a 6-6 sedan. The J30 and 35 have to be the smoothest V6 engines ever.

I've decided that i'll save mileage-posting for when i have both halves of the commute, so here they are:

37.9 and 38.1.

Part 1: Traffic reduced the mileage, but not by much. 37.9 is still really good for a V6. # of times VTEC kicked in yo: 1-2 (i forgot)

Part 2: I left in rush hour so traffic was worse than part 1. It even had a standstill moment. As i was pulling away from a stoplight, some business-looking dude in an old fading odyssey was impatient, he was right up on my tail when i shifted from 1-2. I saw him put his hand on his face like 'I really don't need to be stuck behind some slow accord since i'm late for work', so I VTEC'd it; # of times VTEC kicked in yo: 1

http://ecomodder.com/forum/attachmen...5&d=1443706176

http://ecomodder.com/forum/attachmen...6&d=1443706176

Glad to see another V6-6. I love my 05 coupe. ive never broke into the 40s before but mid 30s when it was stock on trips down south. Now it full bolt on slammed with fat tires ready for autocross haha. great find tho im debating on getting a 4dr 6-6 as a daily.

Aww shucks :o:D That means a lot to me! It is always good to know that your work is inspiring!

You're doing a great job so far! I would cut back the freeway speed to 60 though, unless you happen to get better mpgs @ 65 rather than 60. For me, that is a 2-4 mpg gain on my instant readout depending on conditions.

Also, ditch the carpet. Your Accord could stand to lose a few pounds :p

Aww shucks :o:D That means a lot to me! It is always good to know that your work is inspiring!

You're doing a great job so far! I would cut back the freeway speed to 60 though, unless you happen to get better mpgs @ 65 rather than 60. For me, that is a 2-4 mpg gain on my instant readout depending on conditions.

Also, ditch the carpet. Your Accord could stand to lose a few pounds :p

Welcome aboard. That's great mileage for any v6. That's currently what my HX is getting.

Yep, being appreciated is awesome. I try to go 60 when I can, but traffic doesn't permit it much. I would remove tons of things to reduce weight in my car, but my dad hates when i leave any car parts around, and we like to have fully functioning interiors. Also, if i'm going to reduce weight I would love to take weight from the front of the car instead of the rear to keep the weight balance under control. I'm planning a power steering delete and may go through with it once i see a picture of an accord hybrid's accessory belt setup.

42 mpg!
 

I think reporting VTECs seems gimmicky so i'm going to stop.

Commute 1: More traffic, traffic was faster and more random than usual and prevented me from using DWL for almost the entire expressway.

Over the weekend i 'cleaned' the EGR valve and battery terminals, which required me to perform the idle learn procedure and burn 0.13 gallons of gas. I subtracted the .13 gallons from the fillup so it would be more accurate as to my DRIVING average.
Fillup right before commute 2: 364.8 Miles, 10.539 Gallons. 34.6 MPG :D

Commute 2: Much less traffic than usual, was slower than usual, and it often permitted me to go 60 mph and use DWL and coasting in neutral extensively. :D So i got a new record for the best trip in the V6! 42 MPG! Thats 56% over the HIGHWAY EPA! I never got above 2,800 RPM for this trip.

I'm going to go post this on Driveaccord.net. Let's see how many freak out. :cool:

Im just curious, because I hear so many say this, but why wont traffic permit you to go slower? The main stretch of my commute is a 65 zone of I-5. I generally go around 62ish on it, and I pass all sorts of people doing 55 or less. I am almost always in the far right lane, and have never had a single problem. In my experience, just drive how fast you want to go, everyone else will just flow around you. I am really starting to like it, because it allows me to just keep going straight ahead and never have to worry about passing anyone, I can just putt along and mind my own thoughts. It takes a lot of the stress out of driving.

Well first I don't like getting in people's way. Then at the first part of my commute the expressway is only two lanes and people are too dumb to notice that i'm going slow in time and they will get stuck behind me while traffic passes on the left. In the later parts of my commute there is about a 2 mile stretch where even 65 is too slow and everyone is going 70-80 and it would be very dangerous to not adhere to the flow. Back when i had my first flat tire :mad:, i put my 4-way flashers on and went 55. People still were too stupid to notice and went right up on my ass before changing lanes or more often they would hit the brakes then change lanes. As one of my philosophies of fuel efficient driving is to save gas overall, whenever i cause other people to burn more gas I feel that i'm not helping. So i try to stay out of people's way.

Hmm, maybe it's just different here, I've never had any of that happen.

I think the winter gas has arrived. :mad: For both commutes I drove like I did when I got 42 mpg, and around the same amount of traffic. My mileage for each half of the trip is similar, but my commute to school seems to give better mileage.

Commute 1: Drove like I did for 42 mpg, low traffic. Dunno what happened, but it was in the other direction.

Commute 2: This was at night, so I had my lights on, and there was one long stoplight where i kept my engine and lights on because there was a cop near me. So I figure give 1.5 mpg if those didn't happen.

This weekend i'm going to clean out the interior and probably attach the engine undertray. If I have enough cardboard or coroplast I will make some front wheel arch gap fillers. Also, since I have previously forgotten the PCV valve, I will clean it this weekend.

I drew up some concepts today. Some of the mods on the pictures are not listed on my list of projected mods on the first post. Some pictures also do not represent my car, but are essentially the same body design.
Attachment 18858Attachment 18859Attachment 18860Attachment 18861Attachment 18862Attachment 18863

caltrops! you would think Jesus made 'em because they make miracles happen!

This weekend I cleaned out the carpets and found out even more about the previous owner's family. I found more toys, boy and girl toys, as well as two different types of antidepressants, some gum, and an unidentified pill. Too bad I didn't find a timing belt receipt.:rolleyes: Unfortunately due to time restraints, I wasn't able to clean the PCV valve or try out my engine undertray. :(

As I pulled off the rear seat cushion, I discovered this mess underneath. Attachment 18873
Just look at that! EWWW! I had to dig through that by hand!(with gloves)

Close up Attachment 18878

As I was working hard on cleaning the inside of the car, the weather got jealous and started to clean the outside of the car. :p

Attachment 18874

I joked about America becoming Britain that day, it rained on and off at least 3 different times.


Unidentified pill.

Attachment 18879

Carpets out of the car.

Attachment 18880
Attachment 18881

Cleaning the seatbelts. Check out that color difference!
Attachment 18882

Metal surfaces cleaned up as best as I could. Check out that stripped interior. Weight reduction, bro. #sub3000lbs <---(Not really, rarity is still a 3k+ fatty :o)
Attachment 18875
Attachment 18876

Carpets going back in.
Attachment 18877

Another view of the carpets in the car. Attachment 18883 CLEAN! :D

This week's commutes: 38.2 and 38.6

38.2 Going, drove faster than usual.

38.6 Coming, spent more time at 55, floored it to 80 to try and catch up to and take a picture of what looked like a volvo S80 with 5 inch diameter exhaust tubing. Sounded pretty mean.

I have two theories on my mileage drop: 1. Winter gas. 2. I FORGOT TO PUT ON MY FRIKKN GRILLE BLOCK! Oh and also I disconnected the battery before this commute, so the computadora has to re learn the engine. And I have to find time to burn more gas and do the idle re-learn...again...


Rarity found a friend in the parking lot, or 2. Attachment 18886

Which one is mine? Bonus internets for a correct guess.

the one in the middle.

Nope, its actually the one on the left :p

I got new Yokohama YK580s put on the back. The new tires on the back caused an unstable and loose feeling front, funny thing is that I didn't realize it until about 50 miles in. It happened at 60 mph, thought it was worn suspension at first, since I didn't feel it the first time i drove on the highway with those tires. So that cheated me out of driving my car for a week :(, instead I was stuck with my dad's auto G35X, I got 29.8 at the highest.

When the tire crap happened, I had let my dad drive the car home so he could see if he could feel it, so he drove with the a/c on and at 75 mph, he got 26.9. That brought down the tank average from almost 36 to 34, then more short trips brought it down further. I filled it up with 407 miles and 12.224 gallons. Thats 33.3 mpg. Lower than two of my previous tanks. I'm going to save my mileage reports for when I have the other part of the commute, but it doesn't look good. Winter gas is around for sure, and I drove faster than usual because traffic was denser, and I wasn't used to my car. Scanguage was also off a few percent, due to the larger diameter wheels I assume. (new tires on the front now)

I recently tried out some air to fuel ratio x gauges with my scangauge, of course none of them worked :mad:, and I ran my battery down, so I had to drive and charge it. The result was about 16 mpg. bleh.

Good news time! I finally found the part number for the accord hybrid's rear diffuser and it is $41 at majestic honda. More than i'm willing to pay for its anticipated gas savings. Another thing I discovered about the accord hybrid is that it has an aluminum hood! Ever since feeling an s2000's super light hood, I have wanted an aluminum hood. Now I can have one! Also, I remembered that I can set waze to avoid highways, so I can cut off more than 5 miles off my commute, drive slower, and possibly get better gas mileage. I will have to see if the increased number of stoplights is detrimental to my mileage.

Parts wanted from accord hybrid: Decklid spoiler, hood, and rear diffuser

Unfortunately for me, there are no nearby accord hybrids in my color being parted out. And I learned from my previous accord to not spend lots of money on parts expecting to get that money back in either resale value or gas mileage improvements.

I will be spending this weekend replacing shocks and maybe rechecking the valve clearances, its gotten noisy.

You're getting that high without engine off? :O I must be doing something horribly wrong, I can only average a little over 40 while killing the engine whenever coasting, and I have a more efficient engine that I tuned.

love waze except when it sends me to the feeder road, hit 3 lights, instead of staying on the freeway and taking the correct exit.
aluminum, love that also. there are fantasies of me in the VW stamping room, feeding sheets of aluminum instead of steel.

I do not EOC yet. I want a kill switch, PS delete, and 4.13 EM scanguage update before I do EOC.

I'm getting confused about which trip is which, but i think i got it. I need to post these earlier before i forget.

Commute 1: Forgot what happened, 36.5 mpg.

Commute 2: Tried out a different route. 71% OVER EPA! What's that? Its city epa? Awww. It turned out to be 30 mpg, i calculated an EPA estimated 17.5 mpg from the 27 mph average i had. This was with tons of stoplights, and a dying battery, so no engine off at lights. I don't like that route, back to my old one I guess. Take these trips with a grain of salt, it could be up to 4% off from new tires and winter gas.

Got a new battery after 30 mpg trip because car barely started even when warm. New battery was $126 :eek: I actually neglected to check water levels before going to store, so I hope it was really dead. It lasted only 3 years and 10 months, not very good. I'm used to batteries lasting about 8 years.

Guy who replaced battery for me(free/paid with jacked up prices) hooked up something to retain ecu memory :), but it had already reset when it got too low during a start :(. After the new battery, it went back to its usual super fast and awesome sounding starter noise.

Replaced front shocks and took off clutch slave cylinder to clean out debris, car is 100% more enjoyable to drive now!

I'm Back Baby!
 

Thread revival! Yay! Its been a while since I last updated this thread, so I figured I should update it. Lots of progress has been made, and lots of pictures have been taken. Unfortunately I have not seen big mileage improvements yet, probably because it has been steadily getting colder outside. Last time I drove the car it was 40 degrees F outside.

Lets start in chronological order, so first up is the underside. If you paid attention to my previous posts you would have seen me desiring some sweet hybrid diffuser action. Well, I got one! Attachment 19521 Looks sweet! Installed it in an hour or so, wasn't as simple to install as I thought it would be. Turns out the normal accord doesn't have the holes drilled for it already, so I had to take care of that. Drilling into metal in a car is always scary, but this lead into the spare tire well and was super thin, so I was okay with that. The metal was so thin that I couldn't tap threads into it, so a nut was used instead.

Before: Attachment 19522
After:Attachment 19524 Attachment 19523

After being tightened down, the entrance angle to the diffuser changed, I don't like that. Might do something about it at some point, like some spacers, but not really high on the list. The underbody before the diffuser isn't horrible, but I imagine it isn't allowing for much diffusion :p.
Attachment 19525

Any results from the diffuser have been lost in data noise, haven't noticed better coasting. I'm guessing it needs some underbody trays before it can do its job. A nice side benefit to the diffuser that I didn't notice when I first spotted a hybrid is that it actually mates up with the rear bumper really well, I imagine it severely reduces the parachute effect in the bumper. :)

The next mod I worked on were some nice wheel boat tails. I brought up what little information I could find about them, used the template, and created these: Attachment 19526Attachment 19527 To minimize road debris risk, I used hot glue and coroplast only, until later on that is. Here is how they looked behind the front wheels, the first place I put them. Attachment 19532
I think that they actually enhance the appearance of the car, anyone else feel that way? I got to test their speedbump impact index on the first test drive, luckily it didn't register :p. I took them off a day later because they were falling off. Minimal velcro and a poorly placed ziptie on each tail meant they didn't stay on well. Also, in the front they blocked the jack point, so it would have been a PITA to deal with anyways. Too bad, they looked cool up there. :D

So I put them behind the rear wheels this time, and used a sturdier mounting system this time: L brackets! Yay! Attachment 19530

Attachment 19529Attachment 19528Attachment 19531

Results? You know the drill, I don't do testing (yet...?) so I can't narrow down little things. Which means absolutely no improvement noticed. However, I do have an insight (no, the other insight) into why. Thanks to forza 6 I saw the back of an Indycar and their form of wheel boat tails. Take a look: Attachment 19533

See how the tail is open to the wheel well? Guess what my tails aren't? Yep. They are closed in the front. I think it should be open after seeing an indycar, anyone else agree? These things have stumped me for long enough.

After I saw how effective the L brackets were at holding on the boat tails, I decided to finally make some rear tire spats. Unfortunately the L brackets were too long, so the spats had to be mounted away from the floor of the car. I didn't even try these out because I thought they wouldn't help. :( Attachment 19535

Another easy mod up next :) This one actually went on the car. Upper grill block woohoo! Attachment 19536

I made it out of clear tape so it is really hard to see, just how I like it. The right side is completely blocked, but the left side is only half blocked. You can see where the tape ends right at the transition from radiator fins to the silver edge of the radiator.

This was the first mod in a while where I actually saw some results! Rarity definitely warms up faster. The unintended side effect is that the operating temperature is higher now. The fan will kick on in slower traffic, and I had to take some tape off the first time I drove with it. Good news is that it raised intake temperatures. It was 40 degrees F outside, but 100 in the intake in slow traffic. My usual driving style keeps IAT about 40 degrees above ambient when moving. I cannot report any mileage improvements though. :(

I was in the mood to mod today, look what I did!Attachment 19537

Undertray, Yay! Pun not intended but welcomed :p. What a pain to mount though. I kept trying to push the clips through the bumper, undertray and oem undertray. Said screw you to the clips, hello zip tie technician.

Here is what the underside used to look like: Attachment 19539Attachment 19540

Here is the tray: Attachment 19538Attachment 19541

I am satisfied that it will stay attached, and am sure it is an improvement over nothing. Excited to see SOMETHING, ANYTHING, the next time I drive it. :rolleyes:

nice set of mods there! looks good to me. hope you see some improvement. will be hard to tell which one works and doesn't. hope one doesn't cancel the other one then you'll never know.

There is a newish thread on mounting the scangauge.
might want to review it.
IMHO, the gauge is WAY too low. Takes your eyes too far down to read it. :thumbup:
especially if you are pushing any of the functions while driving.

Mileage is going up! I think the undertray is doing its job, and so is the sun, its finally warming up. First trip after the undertray was 39 mpg, today's trip was 40.6 mpg!
Attachment 19579

I got stopped at a few more stoplights than usual but was still able to pull off 40 mpg, thats awesome!

I'll try pulling the wires out more and putting some velcro on top of the steering column next week. As is, I don't need to move my head to see it, just my eyes. It can be improved though.

Nice work on the underbelly! Lets hope that the zip ties hold up to the abuse of daily driving.

I've had at least 3 different mounting version of undertrays on my WRX Sti..and all have fallen apart, lol.

http://i101.photobucket.com/albums/m...20mounting.jpg

My latest v4.0 mounting has held up well for the past 9 months of my daily 100mile commute in Los Angeles Traffic.

Tuft tested the accord yesterday, filmed with camera car and passenger after camera car footage was a letdown. Will edit out personal information when I get back home, and will post link here after.

Tested areas: Hood, windshield, front bumper before wheel, all along side of car, mirrow and areas after, rear glass, rear of car, and THE MUFFLER TIP.

The hood was actually awesome, flow stayed nice and straight without much turbulence (laminar?).
I put tufts right behind the wipers and further up the windshield. Tufts at wipers did not move, tufts further up were turbulent.
Front bumper looked good, air after wheel was turbulent. It didn't seem like air was coming up from underneath the car, so that is good.
The mirror caused some nasty turbulence, and it looked like it got worse when I folded it in. Drivers side folds in less than passenger side (untested airflow)
Air towards the rear quarter panel seemed to be going UP towards the roof. The rear glass was turbulent on the sides, and it separated in the middle ;(. I'll have to look over the footage to see if it reconnected nicely on the trunk. There is a less than optimally shaped antennae hump right before the rear glass in the middle, maybe it is causing the separation. Rear bumper did not get good footage so I don't know what was going on there, but there did seem to be attached flow on my wheel boattails. Yay!

...

I am approaching the limit of parent-tolerated modding. My dad was pretty suspicious with my idea of a tuft test because it would likely mean more mods in the future. I have considered the idea of a mirror delete, Checked Georgia law and it seems legal to remove both exterior mirrors. I may go through with it eventually, but would need some interior mirrors to replace them. Rear wheel skirts and kammback are most likely outside of parental acceptance. I want to try out clear tape wheel covers though, and see if they help.

Tuft test video is up!
 

[youtube]TSvW7Nh6-2k[/youtube]

Sorry for the crappy focus, apparently iphone cameras can't focus on the fly. Watch to the end for some naughty fuel consumption. :cool:

Scangauge relocated to instrument cluster. Attachment 19637

I know how you feel. My fiance wouldn't let me go crazy with aero mods on my Sti, however, she agreed that if i made the mods look "presentable," then she'd allow it.

However, to make mods look presentable takes a lot of time, effort, and money, which reduces your return on investment. At which point, ecomodding becomes more of a hobby instead of a way to save money.

So it's up to you, i guess.

Mid undertray complete!
 

Decided to get off my lazy butt and rig up a mid tray today. I took out my brand new sheet of coroplast, and out popped one of my old mid trays for my previous accord! I thought I had used it already! Slapped that on with some screws and velcro. Made the other side and attached it as well. I overlapped the mid tray with the front tray so the airflow is more smooth there, and air does not go in between them. Sealed off a gap at the wheel wells that would have ducted air in between the floor and the mid pan. Here it is!
Attachment 19686Attachment 19687Attachment 19688


I also cut out a piece of posterboard(thick paper) to stuff in between the front bumper and radiator. It should prevent air from going underneath the radiator.
Attachment 19690Attachment 19691

Took it for a drive after the mid trays were put on and noticed two things: 1. It didn't catch on fire. :D 2. IT COASTED BETTER! WOOHOO!

I wanted to make a rear pan as well, but couldn't lift the back to a workable height so I gave up for now. Instead I extended my rear diffuser. Attachment 19689 It will help to compare it to the picture of when I got it back on page 3(?) so you can see where I added material.