Megasquirt thoughts.

[Aries_Turbo]

I'm getting about 36mpgs last I checked in the neon. A small mix of city with mostly highway miles. Dead flat around here. SOHC ATX with .91 transfer gears. I'm hoping the cam swap will help with mileage a bit.

do you have the ethanol pee pee gas?

i lost mileage at some point on all my cars a few years ago when NY changed something about the mix that the state gets.

Brian

[cordes]

do you have the ethanol pee pee gas?

i lost mileage at some point on all my cars a few years ago when NY changed something about the mix that the state gets.

Brian

Yes, it's all 10% ethanol.

[black86glhs]

I've read that they don't fit very well. I think we have 175/70r14s on there now which is a bit taller than the 185/65s. 185/75 is quite a bit taller than stock.

I was more referring to shadow88's car having the 195/70's on it, however since we are on that subject, what do you guy think would be the best size for mileage and traction?
I like the 185/65R14s or 175/70R14s.

[cordes]

I was more referring to shadow88's car having the 195/70's on it, however since we are on that subject, what do you guy think would be the best size for mileage and traction?
I like the 185/65R14s or 175/70R14s.

For stock gearing the 175/70 will net you a lower cruise RPM which is pretty vital on the freeway IMO. In the snow I bet they will have the advantage too since the darn things are so light. This will be our first winter with the narrower tire on there. I don't drive the car hard, but I'm sure that the 185/65 would win out in the handling department. Anything must be better than a 70 series tire.

[black86glhs]

For stock gearing the 175/70 will net you a lower cruise RPM which is pretty vital on the freeway IMO. In the snow I bet they will have the advantage too since the darn things are so light. This will be our first winter with the narrower tire on there. I don't drive the car hard, but I'm sure that the 185/65 would win out in the handling department. Anything must be better than a 70 series tire.

I know what you mean. My 88 has the 205/70R15 base tire option. Supertankers react to steering inputs faster.

[shadow88]

I was more referring to shadow88's car having the 195/70's on it, however since we are on that subject, what do you guy think would be the best size for mileage and traction?
I like the 185/65R14s or 175/70R14s.

The tires on there now look big. They fill up the whole wheel well and there's very little clearance between the tire and the spring perch. They weren't installed for fuel economy, but rather, they were free snow tires from my ex, so I installed them. They probably help fuel economy just because they lower the hyway rpms a little. They also weigh less than srt-4 wheels with 205/40zr17's Those are heavy!

For maximum mpg's I would use something much narrower and go as tall as you can get., Like 165/80r14 sort of thing. I have no idea if that size fits, but it would help the rolling resistance.

[shadow88]

Tiny little update. This weekend, I went on a 300 km all hyway drive and IF I could stay on the hyway for a full tank (60-65 mph) I'm certain I would get 36 mpg.

It's capable of mixtures as lean at 18:1 without any issues, and a whole lot of indicated ignition advance of 60 degrees.

I'm thinking of a few other changes and wondering what they're worth if anything.
I was thinking of a warmer inlet air source and possibly pre-warming the fuel. Anybody tried either of those?

[zin]

Both work. The trick is to not over-do it. Pre-heating the fuel will give the best results, but will be the most difficult to implement without causing vapor lock, pretty much needs to be a non-return type fuel system before before the heat exchanger, which makes controlling the heat a bit difficult.

Heating the air is done pretty much just to normalize it and make it easier to maintain air fuel ratios, but isn't used much on non-carb engines as the computer can adjust, and warmer air is less dense, not that it's critical, but it will have a small negative effect on pumping efficiency.

If you want to try the warm air part, I'd just grab the heat stove and air valve from a carb'd car in the JY,if you can find one! You'll also want to grab the temp control inside the air cleaner, possibly the coolant temp vacuum switch as well.

Mike

[shadow88]

There's a factory srt-4 heat sheild around this factory srt-4 turbo. I might be able to modify it to help ingest warmer inlet air, or just run the air filter above the turbo. I think the intercooler will probably negate any heat I introduce into the inlet side of the turbo. I'm not sure if I want to be rid of the intercooler yet because this still sees 9 psi boost from time to time.

Even though this megasquirt system has an intake air temp sensor, I cannot find any tables to adjust the fuel trim based on intake temps. This one is a very basic system.

For fuel, It's already a non return fuel system, So I was thinking of a fuel line that wrapped around the upper rad hose a few times before getting to the rail? I know there's an inherent safety issue with this type of system.

[zin]

There's a factory srt-4 heat sheild around this factory srt-4 turbo. I might be able to modify it to help ingest warmer inlet air, or just run the air filter above the turbo. I think the intercooler will probably negate any heat I introduce into the inlet side of the turbo. I'm not sure if I want to be rid of the intercooler yet because this still sees 9 psi boost from time to time.

Even though this megasquirt system has an intake air temp sensor, I cannot find any tables to adjust the fuel trim based on intake temps. This one is a very basic system.

For fuel, It's already a non return fuel system, So I was thinking of a fuel line that wrapped around the upper rad hose a few times before getting to the rail? I know there's an inherent safety issue with this type of system.

For the hot air, you'll want to limit that, the best way I can think of is to use the themo-switch off of an carb'd air cleaner (the vacuum switch on the inside on the "clean" side of the air filter. It should break the vacuum to the air door feeding the hot air into the intake stream... Actually, thinking about it, the intercooler (if it's a good one) would pretty much take that heat right out, so you may want to look at using coolant in some kind of a heat exchanger (water to air intercooler in "heat mode") comes to mind, or something similar, plumbed in after the intercooler. Nice thing about this set-up is that since it uses vacuum to add heat, as soon as you go 0"vacuum, it will automatically cut off and let the intercooler do its thing normally.

Wrapping a hard line around the radiator hose would be a pretty safe way to go, some of the one's I've seen/familiar with actually ran the line on the exhaust manifold! The radiator hose will help ensure temps can't get much over 200*F, though that temp might be a bit much in the end... Also be sure to use flexible hoses to and from the hard line, don't want things waving around, that'll lead to metal fatigue and a possible car-b-que...

Might shoot a PM to MPGMike for an optimum fuel pre-heat temp, too much temp might encourage varnish build up on the injector tips, a bit of Sea Foam in the tank will cure that if it becomes an issue... Check out this tread for some "everything including the kitchen sink" MPG tricks: http://www.turbo-mopar.com/forums/sh...-Prize-Daytona

Mike

[shadow88]

Great link!! How did I miss that when it was current? I'm thinking fuel heater first. Possibly different injectors with different spray pattern.

I kinda remember the facotry injectors have 4 orrifi and the ones in ther now (stage 1 srt-4??) have just one. I wonder which is better?

[zin]

So long as they atomize well, and the pattern doesn't hit anything but the back of the valve (for the most part) you'll be fine. But verify the pattern, some are designed for multiple valves and split the stream to each valve. And the number of holes doesn't always indicate what's the pattern.

Mike.

PS that is a very interesting thread isn't it?

[shadow88]

Ok, so I have a few new things to report. This is turning into more of a MPG thread, but that's kinda how the car is pointing me.

I swapped to stock fuel injectors and a stock rail about 3 weeks ago and adjusted the fuel trim accordingly. To try to keep things even, I filled up the fuel tank until it spilled out, as I did on the last trip. I drove at an indicated 100 to 105 kph and when I approached a hill, I held the throttle at no less than 5 inches of vacuum.

In short, I was trying to drive conservatively and in a style that is repeatable, including fuel level. I drove to see my friend, almost entirely hyway driving, and I travelled 296kms from door to door. I took a picture of the intrument cluster for an accurate fuel level and trip odometer reading.

2 weeks ago, I made and installed a fuel heater. It's made of 5/16" fuel tubing wrapped 7 times around the upper rad hose, then to the stock rail. I filled up the gas tank until it spilled out again, drove to Kingston and attempted to the best of my abilities to reproduce the driving style of the trip I took a couple weeks before. The only difference is the fuel heater installation.

I drove until the fuel gauge read what it did on my last trip as compared by my passenger using the saved files on my camera as reference. When the fuel gauge read the same, I had travelled 45 kms further on the same amount of fuel!!! Possibly adding as much as 80-90 kms to the range of the vehicle with no other changes.

I know. I found this hard to believe as well. It's possible I was driving a little differently, but I still did some back road, very hilly driving and a little showing off what a boosted neon feels like All in all, I'm calling the fuel heater a success. It will restart hot with no vapour lock issues either. The difference in temperature according to my infared thermometer is as much as 50degrees F from fuel entering the cooler to leaving it at the rail.

So a quick summary.....

A/F ratios in the 18's is doable with very little load (12 inches at cruise)
Ignition advance can be as high as an indicated 60 degrees advance without a stumble.
Hot or warm fuel seems to atomize better and promote complete combustion.
And lastly, 40.3 MPG can be achieved in a 1998 neon with the right mods, a steady pedal and ideal hyway conditions and speeds.

Pics of the a/f display. It reads --- if it's leaner than 18:1 and pics of the fuel heater. YES, before anyone gets on my case, I'll re-do the clamps with the right ones!!!!

[shadow88]

http://www.youtube.com/watch?v=1rhJk...ature=youtu.be

Now averaging 34.8 mpg mixed city / hyway. If I could get some all hyway drives in, I'm pretty sure I could get 41+mpg at 70 mph.

[cordes]

http://www.youtube.com/watch?v=1rhJk...ature=youtu.be

Now averaging 34.8 mpg mixed city / hyway. If I could get some all hyway drives in, I'm pretty sure I could get 41+mpg at 70 mph.

I'm sure. We average as consistent 37mpgs in the neon when it's running right. probably 25% city type driving. It's an auto with the .91 transfer gears.

[shadow88]

When I'm leaving traffic lights I have a difficult time keeping it out of the boost area. It's just so much fun!! I'm also probably 40% city

[cordes]

When I'm leaving traffic lights I have a difficult time keeping it out of the boost area. It's just so much fun!!

---------- Post added at 08:24 PM ---------- Previous post was at 08:23 PM ----------

When I'm leaving traffic lights I have a difficult time keeping it out of the boost area. It's just so much fun!! I'm also probably 40% city

Great point. We definitely don't have that problem.

[shadow88]

I lack the discipline you must have to get your numbers. Care to share any driving tips?

[cordes]

I lack the discipline you must have to get your numbers. Care to share any driving tips?

Drive a super slow car lol. Don't forget that we have NO hills around here too. We cruise at 2500RPM (a little over 65mph) on the freeway and around 2250 on the highways. We never let the car kick down into a lower gear if we can help it. We never pass anyone in a hurry.

I was really surprised when I changed that O2 sensor that the mileage shot up like it did. We got several tanks of 37mpg averages before the sensors started acting up.

[mpgmike]

For the hot air, you'll want to limit that, the best way I can think of is to use the themo-switch off of an carb'd air cleaner (the vacuum switch on the inside on the "clean" side of the air filter. It should break the vacuum to the air door feeding the hot air into the intake stream... Actually, thinking about it, the intercooler (if it's a good one) would pretty much take that heat right out, so you may want to look at using coolant in some kind of a heat exchanger (water to air intercooler in "heat mode") comes to mind, or something similar, plumbed in after the intercooler. Nice thing about this set-up is that since it uses vacuum to add heat, as soon as you go 0"vacuum, it will automatically cut off and let the intercooler do its thing normally.

I used a D-Valve so the engine could draw hot air from behind the radiator until the engine went into boost, then it would get the cool air needed to make power.

Wrapping a hard line around the radiator hose would be a pretty safe way to go, some of the one's I've seen/familiar with actually ran the line on the exhaust manifold! The radiator hose will help ensure temps can't get much over 200*F, though that temp might be a bit much in the end... Also be sure to use flexible hoses to and from the hard line, don't want things waving around, that'll lead to metal fatigue and a possible car-b-que...

Might shoot a PM to MPGMike for an optimum fuel pre-heat temp, too much temp might encourage varnish build up on the injector tips, a bit of Sea Foam in the tank will cure that if it becomes an issue... Check out this tread for some "everything including the kitchen sink" MPG tricks: http://www.turbo-mopar.com/forums/sh...-Prize-Daytona

Mike

I've done the "wrap the fuel line around a radiator hose" trick before. It helps some, but not much. If you have a manual tranny car, and have a radiator with the AT cooler, run the fuel line through there. Maximum temp to heat the fuel is coolant temp. Beyond that expect component failures.

Mike