HATS (heat attenuation throttle system)

[pgfpro]

Originally Posted by Howard

I hate to be rude, but frankly this goes entirely 100% against my 30 years of experience with internal combustion gas engines........ To put it bluntly, I honestly I find it absurd that one could claim to be running boost (below the throttle) and put out less than 100% of the horsepower available at that RPM. It is completely illogical, and irrational. Pressure in the manifold is proportional to power output at a given RPM range. I'm not trying to be insulting, but I simply cannot accept what you are claiming.

Howard

I'm not trying to be rude also but have you ever own a petrol turbo car?


Howard's Quote
"I frankly consider turbos a liability where economy is concerned. You have to throttle back your induction during cruise, so it is doing nothing at all for you. One rarely uses WOT, and that is the only time a turbo offers any benefit at all. Turbocharged engines also have a lower compression ratio to allow for the extra air being pushed into the cylinder at WOT without having per-ignition issues. This in itself results lower efficiency. This is observable in both gas and diesel engines. The higher the compression ratio (diesel) the greater the efficiency. Also the smaller the injector orifice, which results in smaller droplet size. I also do not like the additional system. Personally I do not have turbos on any of my diesels, and I refuse to own a turbo gas engine."

[GasSavers_Howard]

Yes!

[GasSavers_Scott]

I love your theory about using heat to throttle an engine. It also brings to mind people who were great experimenters with Hot Air Engines. Smokey Yunich, had his turbo Pontiac Fiero that got 51 mpg, by using a exhaust heat exchanger, to get the incoming air charge up two stages from 225, to 488, then turbo charging it into the engine.

GM's HCCI engine, which uses super heated air and gas vaporized fuel to achieve a turbo feed throttle effect. They claim they have a 100 mpg engine.

Now this is in theory, but there are plenty of You Tube video's about Paul Pantone, GEET engineering. He uses a carb passing through a exhaust heat exchanger, then feeds part of the exhaust through a water tank, that uses steam, exhaust, and fuel to run an engine. There is a video on You Tube called, "Water Fuel." where if you go to the GEET web site, it will teach you how to convert a lawnmower engine over to run on steamed water.

All three of these developements use heat to take fuel vapor and turn it into a gas, its worth checking out.

I also agree that auto manufacturers are obsessed with WOT horse power numbers. 99% of driving is not spent at red line. I keep moving from apartment to apartment, if I had a garage, I woulod love to take an old VW and modify the brains out of it for ultra high mpg. Congratulation on excellent research.

[DRW]

Originally Posted by Howard

I hate to be rude, but frankly this goes entirely 100% against my 30 years of experience with internal combustion gas engines........ To put it bluntly, I honestly I find it absurd that one could claim to be running boost (below the throttle) and put out less than 100% of the horsepower available at that RPM. It is completely illogical, and irrational. Pressure in the manifold is proportional to power output at a given RPM range. I'm not trying to be insulting, but I simply cannot accept what you are claiming.

Howard

Perhaps a more suitable tactic would be to ask 'How is this possible?'
After all, he didn't say he was running max boost, he said he's getting 1/2psi during light load freeway driving.

I've seen a similar effect on my car which has a turbocharger, 7.9:1 compression and lean burn capability. If I accelerate gently on a slight uphill I can stay in lean burn mode with the AF ratio around 18.0:1 and see the boost gauge reach 1 to 2 psi before it drops out of lean burn mode. The car is not making max power at that point because the AF ratio is much too lean. BTW the max boost I run on my car is 24psi with much richer AF ratio.

I'd like to add heat to the intake charge somehow, or maybe a fuel heater to help the fuel vaporize but it will be tricky since I have conflicting goals of keeping high HP along with high FE. How do I heat the air or fuel during cruise while being able to feed the engine cool air and fuel at full throttle? I wonder if a small air to water intercooler could warm the intake air enough if it was fed with hot engine coolant, but not be able to pass much heat during max airflow and keep intake temp low enough for good power? If anything the air/water intercooler might allow a larger grill block since the radiator wouldn't have to shed as much heat.

[GasSavers_Erik]

DRW- how about a hot air intake with a cable operated bypass door that progressively blocked the hot air and allowed more cold air in.

The cable could be tied to the throttle cable so more throttle= cooler air.

[DRW]

Originally Posted by Erik

DRW- how about a hot air intake with a cable operated bypass door that progressively blocked the hot air and allowed more cold air in.

The cable could be tied to the throttle cable so more throttle= cooler air.

That's a good idea, but the problem with using it on my car is that I have an intercooler mounted in front of the radiator which keeps intake air close to ambient temp. I'd need something between the intercooler and the throttle.

[GasSavers_Erik]

Originally Posted by DRW

That's a good idea, but the problem with using it on my car is that I have an intercooler mounted in front of the radiator which keeps intake air close to ambient temp. I'd need something between the intercooler and the throttle.

Hmm- yeah- you'd need a second air filter box for the hot air intake side to do something like this.

[pgfpro]

Originally Posted by DRW

Perhaps a more suitable tactic would be to ask 'How is this possible?'
After all, he didn't say he was running max boost, he said he's getting 1/2psi during light load freeway driving.

I've seen a similar effect on my car which has a turbocharger, 7.9:1 compression and lean burn capability. If I accelerate gently on a slight uphill I can stay in lean burn mode with the AF ratio around 18.0:1 and see the boost gauge reach 1 to 2 psi before it drops out of lean burn mode. The car is not making max power at that point because the AF ratio is much too lean. BTW the max boost I run on my car is 24psi with much richer AF ratio.

I'd like to add heat to the intake charge somehow, or maybe a fuel heater to help the fuel vaporize but it will be tricky since I have conflicting goals of keeping high HP along with high FE. How do I heat the air or fuel during cruise while being able to feed the engine cool air and fuel at full throttle? I wonder if a small air to water intercooler could warm the intake air enough if it was fed with hot engine coolant, but not be able to pass much heat during max airflow and keep intake temp low enough for good power? If anything the air/water intercooler might allow a larger grill block since the radiator wouldn't have to shed as much heat.

Thanks for the input!!!

My stock 91 AWD Talon Auto at 70mph will be at 0 to 1psi. on the stock map.

Some data from my turbo-charged Honda.

Engine 98 CI. Four Cylinder.
RPM 2500
65 MPH
HP needed to maintain 65 MPH is around 17HP

Example #1 (stock at light freeway load)
ABS/KPA 63
IAT 100*F
A/F 14.7
Air lbs/min 2.30 = 17 HP
Fuel lbs/min 0.0392 per injector
MPG 41

Example #2 (stock at WOT)
ABS/KPA 100 (WOT)
IAT 100*F
A/F 14.7
Air lbs/min 6.65 = 33 HP (Over the 17 HP so car accelerates).
Fuel lbs/min 0.0621 per injector
MPG 26

Example #3 (turbo-charge at .5psi)
ABS/KPA 103 (WOT)
IAT 100*F
A/F 14.7
Air lbs/min 3.77 = 34 HP (Over the 17 HP so car accelerates).
Fuel lbs/min 0.0642 per injector
MPG 25

Example #4 (turbo charge .5psi w/heated air)
ABS/KPA 103 (20-30% throttle)
IAT 300*F
A/F 14.7
Air lbs/min 2.78 = 28 HP (Over the 17 HP so car accelerates).
Fuel lbs/min 0.0473 per injector
MPG 34.5

Example #5 (turbo charge .5psi w/heated air and lean burn)
ABS/KPA 103 (25-40% throttle)
IAT 300*F
A/F 28.0
Air lbs/min 2.78 (17 HP)
Fuel lbs/min 0.0248 per injector
MPG 66.0


Howard,

I think were in agreement that when you increase intake air temperature you will have to open the throttle up more then before based on the engine needing x amount of air density? In doing so you will reduce intake pumping losses. So this makes the engine more efficient or creates a better BSFC number. This is what I did with the Honda last year.

What I think you don't agree with is a turbo engine can run at vacuum or a small amount of boost and make less then WOT HP? I have seen this happen on several lean burn engines from a 351 CI Ford to a 1.5L Honda.

This is what I have found. As soon as you start taking away fuel and leaning the engine out you will notice that you will have to increase the throttle position. When I first experienced this, I thought the engine was hunting for more fuel. So I decreased values in the fuel cells towards vacuum. This didn't help and the engine still wanted the throttle to be open more. So the question is whats happening?

IMHO, when you start running over 20:1 A/F your drastically slowing down the flame speed. So now you have to increase ignition timing. But there's a point of diminishing returns. To much ignition advance and you will sacrifice maximum cylinder pressure at the correct crank angle. So it becomes a sensitive area of tuning with a very narrow margin for the lowest BSFC numbers. Once you get it dialed in you will have even less pumping losses due to an even greater opened throttle position.

The Honda likes around 0 to .5 psi. This gives me the best BSFC with heated air at freeway speed. Anymore then this I end up having to run way to much ignition advance. I did experiment with some N2O to increase the flame speed.
But that's a whole other story

One other point to keep in mind is that I am running a "Home Built Lean Burn Prechamber". This is something I have been developing for the last 15 years.
It helps a ton in making a nice flame kernel to promote a faster flame speed with out any miss-fire.

The turbo also helps with directional air velocity at lower rpm due to "pressure gradient force" from the turbo compressor outlet to the intake valves. The highest pressure is at the compressor outlet. Also if anyone is looking into this type of build I strongly suggest to keep the heat chamber as close to the compressor outlet as you can.

What all this comes down to is these four things to create a better BSFC number at freeway speed.

#1Heat to reduce pumping losses.
#2Heat to create better fuel atomization.
#3Turbo Charge Lean Burn near vacuum or slightly above to reduce pumping losses.
#4Turbo Charge Lean Burn near vacuum or slightly above to create better fuel atomization.

[koji_kabuto]

i know its a bit ot but this also pertains to bsfc.

#3Turbo Charge Lean Burn near vacuum or slightly above to reduce pumping losses.

wouldnt it be ideal to run perhaps 80-90kpa instead of 105kpa? my reason is your cutting the slack on the intake stroke meaning less resistance but your also increasing the pressure on the compression cycle. i mean its not balanced.

[pgfpro]

Originally Posted by koji_kabuto

i know its a bit ot but this also pertains to bsfc.

#3Turbo Charge Lean Burn near vacuum or slightly above to reduce pumping losses.

wouldnt it be ideal to run perhaps 80-90kpa instead of 105kpa? my reason is your cutting the slack on the intake stroke meaning less resistance but your also increasing the pressure on the compression cycle. i mean its not balanced.

Good Input!!!

I think it has to do with different engines and their compression ratio.

On my 1.6L SOHC Z6 Honda its a lower compression engine (Vitara YCP pistons). So it needs a little more boost then say a higher compression engine.

The same goes on my Talon engine with its lower stock compression ratio.

It would be interesting to take a VTEC-E and add a turbo to the mix and see if you could improve on its efficiency?