Project 100mpg
 

So I guess its time to update this, as plans have significantly changed. New plans start on page 6. I would change the title the tread, but I cant seem to do that.





So i guess its time to start a project log for this car. Im currently over the EPA mileage, and have always been since i bought the car.

1998 Dodge Neon R/T
2.0L DOHC
5 Speed (3.94FD, .81 5th)

Modfications done as of today that might affect gas mileage;
Partial grill block
Power steering partial delete (impeller removed, pump still attached as in idler pulley to keep a/c)
Unorthodox racing underdrive pulley
Mufflerless (loud, but a noticable improvement in gas mileage)
Warm air intake based off the stock intake box
No wipers or antenna
Removed rear wing (coastdown testing showed a 1% improvement in coastdown times, which could be a slight change in conditions, however in addition to the 1% coastdown change, the things heavy)
Mopar Performance ECU (advances ignition)
Slight weight reduction (muffler, wipers/wiper motor, antenna, winshield washer resevoir, muffler, passenger seat, spare tire/jack, side mouldings, sway bars)

Modifications that shouldnt affect gas mileage;
Maddog short throw shifter (65% reduction)
Spherical rod end shift cable ends
Mishimoto aluminum radiator

Currently im running Kuhmo KH16's, in a 195/60-14 size, on stock 14x6" aluminum rims, if anyone knows the rolling resistance of this tire and size that would be great.

Immediate plans (ones to be finished this year);
A more effective grill block, including ducting for the radiator
Mirror deletes using inside mirrors
5 Speed tranny from a base model (3.55FD, .72 5th, drops cruising rpm on the freeway from 2500 to 2000)
Aluminum flywheel, kevlar 4 puck clutch and heavy duty pressure plate (saves 6.25 pounds of rotating weight over stock)

Future plans (ones that will take longer, and more money);
Lightweight rims and low RR tires
completely redesigned front bumper
boat tail
full undertray
alternator delete
lower the roof 3-4"
Side skirts/wheel skirts
more weight reduction
lower the car about an inch

Currently im getting around 42MPG average, being careful and going 55 on the freeway, where most of my driving is done. EPA combined is 29, with 37 being the freeway number. I included one pic for now, of the car with the temporary mirror deletes and grill block, more pics to come later this week when i take them.

http://i254.photobucket.com/albums/h...R61709/014.jpg

Nice work so far. I'll be blown away if this thing ever reaches 100 mpg. You got a lot of work ahead of you! Good luck. :)

thanks, im aiming for 5 days to work and back on one tank of gas by dec, which would mean just over 55 mpg. The transmission is a big deal tho, im cruising at 55mph right now, and im at 2500 rpm. The other transmission should drop me to right about 2000 rpm.

The only reason that your lack of muffler is helping is that if you give it to much gas it will deafen you, a tuned straight pipe would help, or a megaphone (it would be quieter then nothing) but the lack of muffler is making your exhaust shorter so it's going to be more efficient for a higher revving engine, you most likely want it small around and long for slower RPM's, but mostly you want it tuned for your engine and engine speed, the cost is not that much higher for larger pipe, if a larger exhaust pipe really gave you better mileage, more power and girls chasing you down the street, then wouldn't it be standard on every car? no, because the people who designed it were good at math.

check out what tires are avalible in 165/60 R14 I think that is the correct size, tires for the Insight and for the Prius.

If you want to make money while getting better mileage, sell the R/T to a ricer and buy a SOHC Expresso or base model.

I don't remember which way it goes, but you can use 2.4 cams in your engine. I can't remember if they're better for low-end or high-end, though.

Maybe, if I decide to go EVan with my Caravan, I'll have a pair available.

For cam swap information, you can check out Neons.org, turbomopar.com, turbododge.com

They all have the swap info.

ryland - i havent shortened the exhaust any, i just used a straight pipe in place of the muffler, its still as long as stock was. Again, this was when the car was stock that i did the measurements on gas mileage for the muffler, so it might have made more of a difference then then it will when the car is finished. Final plans are for a moroso spiral flow muffler, since its supposed to be the best at cutting sound down without killing flow, and an insulated exhaust tunnel to keep the flow as quick as possible

christ - i decided to use the R/T because its clean, on the inside. The expresso would probably be a little worse, as its a little heavier then the R/T, a base would be ideal, but the problem which base models around here is 90% of them are autos, which in california makes them illegal to swap to a 5 speed. I tried that route, and got my car dinged as illegal. The other 10% are usually just trashed.

I was actually looking at both the stratus cams, and intake manifold, as its a super long runner with a small plenum, should move the torque down as low as possible.

as a side note, id love to go ev, but my commute and other drives wont let me at this point in battery technology. For example next month my finance and i will be driving 800 miles round trip to get married.

one of my main goals other then gas mileage is to try to keep the interior as nice as possible, no gutting for this car. My old gutted car got 45 mpg at 75mph, and it was an inch higher then stock due to the gutting. And has the windows down due to no ac. That car was a sohc neon with the same tranny i plan to put into this one, with a much larger throttle body, cold air intake and header. Car weighed 2000 pounds, compared to this ones current weight of about 2430.

When i rebuild the engine, im going to be going through a lot of things, such as fixing the restrictions in the oiling system and cooling system, such as the bedplate to block oiling port. Im also going to be using lighter rotating parts, and using swaintech coatings to both reduce friction and keep more heat in the combustion chamber. I also have an idea on reusing some of the heat from the radiator. The manifold should help, although ill have to keep the stock neon manifold for smog, cause no way will the stratus one pass visual.

Hmm, looks great so far, and you appear to have the least thirsty Neon here. I'm looking forward to some fuel log entries.

I would prioritize the tires (+ junkyard wheels if needed) and coroplast aeromods over the clutch and engine overhaul, as the bang:buck ratio is far higher.

100mpg is >300% of the EPA rating. I hope you really are too stubborn to fail, but not too stubborn to revise some of your constraints to get there.

I'd focus less on the motor and more on the EOC. Check out COZX2 over on Gassavers. He was able to get over 100mpg out of a mechanically stock ZX2. He only aero modded it and perfected the EOC. No boat tail on that car, just fender skirts and magnehilic testing to extend the coasts.

REALLY? is california really that bad? anyways, keep up the work and post alot of pics!

Yeah, Cali's that bad. I have a bunch of friends out that way, and many of them "live" in other states so they don't have to pass all the BS emissions that Cali has.

Unless it's designed for your car and CARB exempt, you ain't using it legally. Get caught violating those laws, they impound your car. (That mostly applies to racers, though.) Good luck getting it back.

Switching cams will allow you to still pass inspections, but you'll have to be good about tuning your emissions load for the dyno runs.

I didn't realize where you were when I recommended that.

P.S. Don't get caught up in the xfer gear swapping - DOHC and SOHC Neons have the same xfer gears. There are others you can use, though, just google Neon Transfer Gear Swap to get more info on it. I believe you can use the transfer gears to fine tune your rev range, like swapping a final drive, but much easier.

thanks robert, tygen, the engine rebuild isnt anytime soon, just future plans for when this one goes. The aeromods are going to be done in fiberglass for now, im starting to work on a bumper as soon as im back from my wedding. The clutch is going in because i already have it. I currently have 3 transmissions, and 4 engines. Plus one whole rolling chasis. the transmission in this car is getting sold, as its a racing gear ratio. One of the transmissions is getting put in this car, its a economy ratio. The other one is the same ratio, but its being sent off to get modified, in for the time when i can do an electric neon.

for now, theres no OEC for me, its still around 100 degrees here when driving home, and until i get my upgraded battery set up and alt removed, theres no eoc at night on the way to work either. Winter will be a different story. I am working on a kill switch tho, so my intrumentation keeps track.

and tires+wheels are coming mid next year, current tires are in too good of condition to just toss

christ, yep, thats cali for you. I figure the cams they cant see, and can be tuned with cam gears. The intake mani will have to be swapped for a neon one, and the alternator will have to be put back on, as thats also illegal.

my cars a stick, the old one was a auto, but mine has the ACR close ratio high final drive tranny in it. I have the base model 3.55FD to go in it in 2 weeks. Should drop my cruising rpms by 25%.

On tires, just curious if the 165/60-14s are really better then what i was considering, 185/70-14 bridgestone B381's, which is supposed to have a CRR of .00615. The smaller tires would be more aerodynamic, however i plan to shield the tires from the air as much as possible, similar to aerocivic. Im sure they would be lighter, but at the same time they would raise my cruising rpms by just over 200 rpms. Anyone have the CRR of the 165/60-14s? And weights, i cant seem to find the tires on tirerack.

Be careful about cam gears, they're illegal too, AFAIK. They can't see them under the cover, but don't be too blatant about your tuning, either.

I can't believe it's illegal to not have the alternator... that's just stupid. Maybe in that case, you could just use a kill switch for the alternator, instead of actually deleting it? You don't get as much of a gain, but at the same time, you gain the ability to turn 'er back on at will.

im pretty lucky and have a decent smog guy, even if he saw the cam gears, i would be ok as long as it passed the sniffer test.

as far as the alternator, thats considered a "driveline" modification according to CARB.

i talked with them about it, only giving my first name. In order to be legal, i would have to apply for a CARB EO. Which means, i would have to first make sure i could do it while keeping the engine light from turning on, then explain how i was able to do it without the engine light turning on. Then they would have to test the idea on a car for emissions. Of course, since im not planning to sell the product, im at the very bottom of the list and will be gotten to whenever they get around to it. Heres where it gets funny tho.

The director of communications for CARB, told me this. That theres 2 kinds of pollution, "smog pollution", which is carcinegens, and "global warming pollution". He also went on to say that while global warming pollution and gas mileage usually go hand in hand (improving one improves the other), that smog pollution doesnt, and often improving gas mileage increases "smog" pollution. He then went on to say that in no way can i increase the amount of "smog" pollution the vehical puts out. As far as the "global warming" pollution, they dont care so much about that.

Like my dad said, there basically saying that if i make 1 more person sick out of the already overpopulated 6 billion people, they'll fail me. But if i make a 1 in 60 million chance the end of the planet as we know it more likely, they dont care. On the california smog test, your allowed a huge amount of co2 compared to anything else on the test, 100 times as much. And i still dont see reducing my gas usuage by 50% or more increasing any kind of pollution, period. My dad has a masters in physics, and he basically said their full of it.

Well it isn't all that simple. It is possible to increase NOX (smog component) emissions and improve MPG by leaning out the mixture. But there are MPG improving techniques that reduce all emissions too. I would think a cam that did more of an atkinson cycle would improve emissions and efficiency.

But NOX does peak on the lean side of stoic, and cars designed to lean burn have special catalytic converters (and probably still aren't sold in CA).
http://www.scooterfocus.com/emissions2.jpg

lean burn is still sold here, i know my dads civic hybrid is noticeable when it goes into lean burn, but i believe your right, that different cats are used.

as far as the neon, i wont be doing lean burn in it. closest thing to really messing with the engine is possibly the cams from a 2.4L stratus/van, and the intake manifold, both of which should significantly lower my torque peaks rpm. Everything else to help mileage will be reducing drag, weight, and parasitic losses.

dcb - is that graph specific to a certain type of engine, or universally applied to 4 stroke engines?

From that graph, it looks like one could get lowered emissions by going to about 17:1, which lowers CO and HC, but keeps NOx the same or close to it.

It's your standard issue mixture graph, can't swing a dead cat without hitting one :)
http://franzh.home.texas.net/images/afr.gif

What do Hydrocarbons do when you go past 23:1 A/F?

When you get into the engine, I would like to see modification to improve efficiency, and reduce parasitic loses. Oil drain back tricks could be considered, perhaps even tubes to return oil to the pans without dumping it on the crankshaft. Knife edging of the crank would help too.
I would love to see the benefits of a max ported head. I am not advocating a hog out, but a complete stream line and bowl blend, especially on the divider in the intake runner, that separates the valves. I would think that a modification of the oil pan, to drop it down (extended oil pickup of course) to let the oil pool out of reach of crank would also yield benefits.
As I recall INDY has a replacement intake manifold, that let the engines breathe. I don't know of the CARB, but it would not be too hard to get smogged, and switch it over for the other 364 days of the year.

the indy intake manifold is horrible for the neon, unless your boosted or are making rediculous power na. On a basically stock motor, you lose power almost everywhere with it, runners are just too big.

I have a guy thats going to port a head for me, nothing big, almost nothing to the intake side, smooth out the exhaust, while keeping velocity as high as possible. Guy has a flow bench in his garage. Combustion chambers and exhaust ports will then be ceramic coated, to waste less heat into the head itself, and use more for power.

As far as oiling, theres a couple of spots where oil ports dont match properly, that will be fixed, as well as oil shedding coatings on everything in the lower end and the bottom of the inside of the head, where oil pools up. Theres some small restrictions in the cooling system by the water pump from casting flaws that will be fixed as well. The crank will be knife edged, and lighter, and all bearings will be coated to reduce friction. Main journals, rod journals, and cam lobes/journals will all be micropolished.

for the manifold, im looking at the stratus manifold, as it puts the torque peak in a lower rpm, which might help mileage. Of course, my idea is to dyno test, to make sure its doing what it should do, or the smoothed stock mani will go back on.

lots more pics up tomorrow.

went from 42mpg average with
stock+
cai (with half dirty air filter), 3mm larger throttle body, removed wipers, removed antenae, 2660 pound weight with driver, no muffler, underdrive pulley, gutted power steering pump being used as an idler pulley for the ac

got 43mpg average with the addition of
hot air intake (with dirty k&n, was broke last week so no new air filter), grill block (pics tomorrow), removed the passenger mirror for one day out of the 3 days on the tank, and a unhooked up ground (was rushed to finish the hot air intake as it got dark), in addition to driving a 6th of that tank in the rain, plus the rear stock spoiler delete

for this next week, im going to do the upper grill block, airdam, change the oil from 5W30 to 0W30 (time for an oil change anyways), delete the drivers mirror (using an inside mirror), along with a new pcv valve, mopar oil restricter in the breather that attaches to the intake so liquid oil doesnt gunk up the intake mani, and clean out the port for the EGR in the intake mani (it looks at least half way clogged), plus a new air filter

on a side note, just realized its been exactly a year since i picked this car up, and its gotten 34000 miles added to it from that date. Im going to try to aim for 32000 next year, i think i can do it.

work adds up to 27000 a year
this years extra was from stuff around town, and concerts out of town, picking up an engine in socal, and picking up some parts from a junkyard in norcal.

if you still have the stock throttle body, you could put that back on for more precise throttling.

i wish i did, but i sold it

ill be picking one up from the jy in a couple weeks, this week ive got my plate full, and next week will the the transmission swap, 10% lower rpms in 1st through 4th, and 25% lower rpms in 5th

well this sucks, wanted to have more updates but my attempt to do more work imploded on me.

got the new valve cover gasket, oil restrictor and pcv valve in this saturday. drove it around for 30 miles afterwards.

this morning i got the new air filter in, drivers mirror removed, mudflaps removed, and checked the tire pressure, and on my way leaving for work, the car died. Instantly, no cough or sputter, just stopped dead in its tracks. Its not seized, and turns over fine, the timing belt is ok as well.

theres no spark. Tried another computer, crank position sensor, cam position sensor, and coil. I dont think its the asd relay, because as far as i know, if the relays bad, the fuel pump wont prime and it does. I havent found any bad wires yet either. My dads coming up with his multimeter and were gonna go through everything, as this is my only car.

sucks, i wanted to get the upper grill block, egr clean out, and oil done today. And after checking my tires, i was super excited about getting over 45 mph on this tank, since my tires were right at 30psi, and i was going to put them at max, which is 44.

cars dead, less than 30psi per cylinder. Dont know what happened, the timing belt is in one piece, and i dont see any sheared teeth. Cams are also still in time to each other. Looks like the engines coming out.

Crank could have skipped and left the cams timed to each other, but not timed correctly with the crank.

I doubt a blown head gasket would show <30PSI per cylinder, so that's probably not it. Unless you broke all four pistons, or broke/bent at least 4 out of 16 valves, it's gotta be valve timing.

no spark makes me wonder if you need to double check that gauge (or gauge operator ;) )

Might just be a camshaft sensor or something too.

yep, its timing. timing belt is only 54000 miles old, however, i guess the dealer didnt replace the idler pulley, cause the bearings disintegrated. in the time it took the hydraulic tensioner to retighten the belt, the crank jumped ahead 90 degrees. Dont know if the valves are bent yet. Also dont know if being 90 degrees off would prevent spark, since i still have that problem as well.

oh well vacations coming up, and im not giving up on it.

90* off could definitely kill spark, as the ECU would see that the CKP and CPS aren't lined up and prevent the spark from occurring to prevent further engine damage.

If you want to check for bent/broken valves, get a fitting that screws into the spark plug hole, and blow each cylinder full of air up to 100 PSI. If the cylinder pressurizes (even if it doesn't hold the pressure very long) they're most likely OK.

A better test is to fill the cylinder with a light oil like 5w30 when it's only a few degrees from TDC and the valves are supposed to be closed (line the cams up so the valves are closed on the cylinder you're testing). Manually turn the crank against the pressure of the oil and check the intake and exhaust ports for oil seepage.

If you find any seepage, make sure the valves are closed and repeat the test if necessary. If the valves were closed and you get seepage, you have damaged valves.

The latter test will help you determine whether to just put a new timing kit on, or remove/rebuild the engine.

In either event, replace the WHOLE timing kit. While you're in there, if you've got the money, check out some adjustable cam gears.

If you need to replace the head, don't worry, just bolt on a head from a Caravan or PT Cruiser - they're the same casting, you just use the sensor and cams from your engine. If you wanted to use the 2.4's cams, you have to use the 2.4 sensor, IIRC, and something has to be changed, but I can't recall what it is.

If you flip the 2.0's cam gears over, they say "2.4 Liter Side" or something to that effect on them. They're the same parts. Isn't that nice of Chrysler? LOL.

I've done that, but with air. I don't think there's a need to make a big mess with oil. I used my radiator hose "stethoscope" to listen at the intake then at the exhaust for the sound of moving air while the cyl was pressurized.

I usually do it with air, and listen at the TB/Carb and remove the O2 sensor if it's equipped, or unbolt the down pipe from the header and listen there, with a piece of fuel line.

I suggest oil at times, though, because it's sometimes easier to just dump some oil in there than to go find a fitting that will match up with your spark plug holes, then pump air into the cylinders, etc..

BTW - When I put the engine in my wife's Saturn, it wouldn't start - the compression was less than 60 PSI across all four cylinders. I put about 10 squirts of 0w30 in each cylinder, compression tested it, and it came up with ~240 on all 4 cylinders... put the plugs back in, and it started right up, like it had never sat in the junk yard for almost a year uncovered with rain, condensation, snow, etc... all getting into the oil and cylinders.

That engine is interference based, so I am betting valves are bent. :(
Wife's Neon, the water pump failed, and ate timing belt.
We pulled a JY head, and pulled valves out.
Head was big bucks, valves were 2.00 each, so we escaped for 32 bucks.

If you come up with a TDI motor, I'll give you the 2.4 in my Caravan. It has less than 100,000 miles on it, but has a slight rod tap when it's cold.

I'm not joking, either. Of course, you'll have to come get it and drop off the TDI... lol.

I'd actually consider a swap for any 3 or 4 cylinder automotive diesel engine, whether it's legal for emissions or not. (We don't have emissions testing here, so if you don't get caught, it's not a problem.)

haha, nice, i wish cali was that good with swaps

im headed out now to pull the vc and look for loose rockers, then im sure i have a fitting somewhere

when it goes back together, the entire timing assembly will be new, just might have to wait till after my wedding in 4 weeks, spend all my and her money getting that and our vacation set up. So i might be riding my dads dual sport to work for a few weeks.

then again, if the cars down that long, i have a whole week of vacation to do things like cleaning out the egr

Start a fuel log for the Dual Sport - I'd love to see mileage figures on it for a commute.

I almost bought a Honda TwinStar 185 a couple weeks ago, but it wasn't older than '73 and the guy can't find a title for it, so I'd have to spend a good bit of money and time on getting one. I passed, even though it was preserved in mint condition, even the OEM paint was untouched.

i believe it gets around 45-50mph, KLR650. Gotta be pretty heavy on the throttle to cruise on the freeway on that thing.

Well, the car started, im going to replace the rest of the timing components, then test the compression, if its good were back on.

good thing too, as i have 1200 miles of driving on my vacation.

Unfortunately, that means my next tank will have a huge jump in mpg, and i wont be able to pinpoint which items helped the most. Oh well, im at 43mpg now, we'll see what 44psi vs 32 in the tires, a little more grillblock, drivers mirror delete, cleaning up the half blocked egr, and the 25% reduction in cruising rpms and 6.25 pound lighter clutch/flywheel do for it