Ecoscort - 98 Ford Escort ZX2 ecomodding thread

[hardline]

There are some variable vane turbos in the GT22 size range that are used on TDI cars. That might work great for you as well.

[pgfpro]

Originally Posted by Tygen1

In my opinion, the Turbine side of the 6.0 turbos is much to large to get a reasonable amount of spool, not to mention they weigh almost 40 lb's. There is also a GT3576VA that was on the VT365 International motors. The Turbine side on the GT3576VA is a bit smaller than the 6.0 version, but my feeling is that it is just too big. Remember it's not just airflow that drives a turbine, it's the expansion happening from the combustion. Expansion from the heat generated during combustion. When you're lean, you combustion temperatures will be lower and you will have more difficulty driving the turbine. When I was dreaming of turbos, I thought a VW TDI VNT turbo might be ideal. I don't imagine it would be hard to create a control for the VNT and they are quite small and have many aftermarket options. There is also the Dodge/Mercedes Sprinters that are a GT2056 VNT turbo if you want somthing a bit bigger...

One of the things I have found while on the road to lean-burn is that you can produce the same amount of power running 107kPa intake pressure at 22:1 A/F as you would be running 79kPa intake pressure at 14.7 A/F. You will also have a 6.4% decrease in fuel consumption and a 28% decrease in combustion temperature. Plus a 4% increase at P3 compression while maintaining the same P4 pressure. It took me a while to understand this because the exhaust pressure is the same but the internal combustion temperature has drop significantly and so has the EGT's. Then after doing my turbo compound system I have realized that the turbo is a basically a time delayed dam that stacks up not only pressure but also heat. My mid-mount low pressure turbo gets very hot pre-turbine, to the point I now have to add some heat shield in that area 6' back from the high pressure turbo.

F1 with their new power units are really breaking some new ground when it comes to lean burn and making more energy from the MGUH or "turbo generator/motor unit". They have found that they can run much leaner then stoich, increase the boost to get back to their target 100kg/hr fuel limit and double the amount of exhaust energy to feed the battery without much of a ICE power decrease.

[Xist]

Aerodynamic modifications:
Both side mirrors?
Grill block
Air dam
Belly pan
Wheel covers
Wheel Skirts

Six users posted results for deleting side mirrors, average: 2.58 x 2 = 5.08%
Grill blocks averaging 2.79%
The average air dam listed at yielded a 3.775% improvement.
Belly pan: 3.48%
Wheel covers: 3.16%
Rear skirts: 2.88%

I do not know if air dams and belly pans yield as great an improvement together as used separately, as well as wheel covers and rear skirts.

Two of the rear skirts were on trucks and both commented that they covered a much larger gap than on a passenger car.

However, multiplying those six modifications suggests a 23.1% improvement.

When you removed the seats, upholstery, air conditioning, and power steering, you stated that you removed 115 pounds from a car that you previously wrote was 2300 lbs: 5%.

Didn't you say that you already reduced the weight by two hundred pounds? That would total 12.6% less mass.

The rule of thumb given on here is that for every 2% improvement in aerodynamics or mass, you increase your fuel economy by one percent, so between those two, in theory you increased your fuel economy 18.6%, taking you from 25 to 29.6 MPG. The wiki suggests that increasing tire pressure is good for another percent.

Didn't you also cover your windshield wipers and install side skirts? One user reported 1.5% and 1% respectively for those.

I see 30.69 MPG.

Adjust the nut behind the wheel (#1 for FE)

Indeed!

I did not see all of your modifications in your garage. It currently says that you have Mazda tires. Didn't you replace those with spares? What do you have now?

[pgfpro]

Just wanted to say I'm enjoying this thread a lot!!!

Thanks Tygen1, hardline, Xist and others for jumping into the thread.

Oh and thanks BabyDiesel for starting it.

[BabyDiesel]

Pgfpro - You're welcome Thank you for the support and valuable information! Everyone who is giving input is making this thread fun for me! Thank you all!!!

I have been messing around with the Borg Warner link you provided and it is very useful! I'm learning what everything means, so I am still on the learning curve.

I think I have been confused with all the information we have discussed. I remember use discussing engine size, and how the 2.0 is too large to run boost in lean burn unless I had AFRs of 40:1 or greater. Knowing that has made me "scared" of having any boost below 2500 rpm. The only way I can see a way around this is a larger turbo. Since this build is strictly for fuel economy, I can stand to have no boost until the mid-range. I haven't topped 2500 rpm in months!

I'll walk back through the turbo-talk we've had in the past couple weeks.

On your new theoretical car the fuel mileage would be around 108 mpg based on the very low hp needed from the car itself, but there is a major hurdle that wouldn't let this happen. Engine size. More on this later.

I understand this.

The 2.0 L engine size problem is that even at a needed 4 hp to 6 hp the 2.0L engine would have to be running in vacuum and could not utilize the turbos FE efficiency at this very light load. On my car I have to overcome AWD drive train loss and with a Cd of .29 so the hp that is needed is around 10 hp @ 55 mph.

So in your case the turbo could help with extra power when needed if you choose to run a 3 valve setup.

So no boost needed during lean burn, which is 1700-2300 rpm. I am going to run the 3.5 valve setup like you, so the turbo would help there when the rpms go up enough that I needed more flow.

It would be a normal turbo setup that would only make boost at mid and high load. So for FE the setup would be a lean burn N/A app. The results would still be awesome though!!!

This is what I have my mind set on; this set-up.

Nope 1 to 2 psi with the size engine you have won't work. You would have to extremely lean, above 40:1. Now this is based on the 4 to 6 hp needed.

See, no boost needed... boost is bad

The more I think it about it the more I like this idea. This would work awesome with a turbo for mid-load lean burn. See here I go again back to turbo world.lol

On my Talon the turbo gives me a 11% increase at 1psi in combustion efficiency over N/A. The more boost I run in lean burn the more the efficiency goes up.

So with your build you could run it in N/A at light load with a Atkinson cycle and at mid load still keep it in lean burn, but you would gain back some extra torque?

Hmmmmm. Must Ponder this.......

Alright here is the shift between our thinking. I'm still stick with N/A light load lean with boost seen in the mid range on up. You began to ponder mid-load lean... wait, you meant mid load as in the load on the engine, not the mid-rpm range correct?!? As in going from 50% load @ 2000 rpm to 65-70% load for a hill, the turbo spools up maybe 1-2 psi while still in lean burn, then I go back to N/A on the other side? If this is correct, then I am mad at myslef!!! How did I not catch this sooner??????

You wouldn't have to have the turbo wastegated at 2 psi and up to 6 psi. The proper choice in a turbo would only get you the low boost numbers, with out anything going through the gate.

With the low Cd it still looks like the you would be running in N/A even with a 1.0 L equivalent. This why i would run all four cylinders in a Atkinson cycle N/A and pull one tappet per cylinder to help with swirl. The when needed get into a mid-load and start making some boost in lean burn. This will accelerate the car up to speed and go back into light load steady state.

I see now... It all makes sense!

On my sons turbo Civic 1.5 L it had a fairly large frame turbo on it based on the engine size and we still manage to improve fuel economy. I couldn't make any low boost lean burn though do to what we are talking about engine size verses boost. What I did is setup the car for lean burn with a max around 18:1 A/F ratio and the car got great fuel mileage.

This is why I was told not to go with the 6.0 PS turbo. DANG IT!

If you drop your Cd down from what it is a sub-0.20 Cd then you will just use the turbo gain some HP when not in lean burn.

From above, it looks like I could make extra horsepower while lean burn too

So in this case i would run a much smaller turbo.

It allllll is becoming clear to me now!

In lean burn you are basically making a lean A/F hole in the fuel map. When i had my Del Sol with the 15g it worked great just enough to make around 1 psi at 22:1 A/F and i didn't have any problems pulling out of lean burn when needed.

It made boost when you pushed the go pedal down, opening the throttle plate, allowing more air in, which meant more expansion and this equaled the turbo making the 1 psi of boost while in lean burn. I get it now!!! The big turbo would not be able to do this, as you found out with the 5.9 Cummins turbo. A smaller turbo will make boost ONLY when I need it while in lean cruise conditions.

I am the smiley on top of this turtle -> I'm getting to the place of understanding, but veerrryyyy slowly LOL!!!

[BabyDiesel]

Originally Posted by pgfpro

One of the things I have found while on the road to lean-burn is that you can produce the same amount of power running 107kPa intake pressure at 22:1 A/F as you would be running 79kPa intake pressure at 14.7 A/F. You will also have a 6.4% decrease in fuel consumption and a 28% decrease in combustion temperature. Plus a 4% increase at P3 compression while maintaining the same P4 pressure. It took me a while to understand this because the exhaust pressure is the same but the internal combustion temperature has drop significantly and so has the EGT's. Then after doing my turbo compound system I have realized that the turbo is a basically a time delayed dam that stacks up not only pressure but also heat. My mid-mount low pressure turbo gets very hot pre-turbine, to the point I now have to add some heat shield in that area 6' back from the high pressure turbo.

F1 with their new power units are really breaking some new ground when it comes to lean burn and making more energy from the MGUH or "turbo generator/motor unit". They have found that they can run much leaner then stoich, increase the boost to get back to their target 100kg/hr fuel limit and double the amount of exhaust energy to feed the battery without much of a ICE power decrease.

This is too cool now that I understand the concept!!! Can you translate the kPa into a lingo I can understand? Psi maybe?

[BabyDiesel]

Originally Posted by hardline

There are some variable vane turbos in the GT22 size range that are used on TDI cars. That might work great for you as well.

I will check those out sir

[BabyDiesel]

Originally Posted by Xist

Aerodynamic modifications:
Both side mirrors?
Grill block
Air dam
Belly pan
Wheel covers
Wheel Skirts

Six users posted results for deleting side mirrors, average: 2.58 x 2 = 5.08%
Grill blocks averaging 2.79%
The average air dam listed at yielded a 3.775% improvement.
Belly pan: 3.48%
Wheel covers: 3.16%
Rear skirts: 2.88%

I do not know if air dams and belly pans yield as great an improvement together as used separately, as well as wheel covers and rear skirts.

Two of the rear skirts were on trucks and both commented that they covered a much larger gap than on a passenger car.

However, multiplying those six modifications suggests a 23.1% improvement.

When you removed the seats, upholstery, air conditioning, and power steering, you stated that you removed 115 pounds from a car that you previously wrote was 2300 lbs: 5%.

Didn't you say that you already reduced the weight by two hundred pounds? That would total 12.6% less mass.

The rule of thumb given on here is that for every 2% improvement in aerodynamics or mass, you increase your fuel economy by one percent, so between those two, in theory you increased your fuel economy 18.6%, taking you from 25 to 29.6 MPG. The wiki suggests that increasing tire pressure is good for another percent.

Didn't you also cover your windshield wipers and install side skirts? One user reported 1.5% and 1% respectively for those.

I see 30.69 MPG.



Indeed!

I did not see all of your modifications in your garage. It currently says that you have Mazda tires. Didn't you replace those with spares? What do you have now?

Xist - I will have a detailed answer for you later this afternoon/evening covering all of your questions. My paycheck is calling my name atm, and we both need each other

[hardline]

Havent topped 2500 RPM in months? I should take you for a drive in my ZX2. 8200 RPM redline, yessir.

[pgfpro]

Originally Posted by BabyDiesel

This is too cool now that I understand the concept!!! Can you translate the kPa into a lingo I can understand? Psi maybe?

100 kilopascal = 14.503773773 psi

This way you don't use two measurements (inch/hg verses psi) just one