Living Throttleless

[theunchosen]

Michelle is now truly unique in the world of gasoline powered cars(as far as I know). She has no throttle.

The Del Sol now runs lean.

Something I hadn't considered until it started happening is runaway. Since there is not throttle the same "throttle position"(resistance setting) becomes much much more aggressive every little bit it climbs up through the RPMs.

I can't report any realistic mpg(as I haven't used enough fuel). I can't report anything really. Driving without a throttle and tricking the ECU is. . .a pain to live with lol. You have to constantly play the resistance back and forth to keep the car at the right speed until you hit the magic amount of power. Any higher and the engine starts rather rapidly accelerating(increased air flow from higher rpm creates much more fuel(both more air and gas)) or starts choking(the fewer rpms means less air which is less fuel(fuel proper and air)).

I suspect my first tank is going to be a very bad mpg avg. What from the rampant acceleration that got out of hand a few times and very narrow band range of pulse and gliding finding the right resistance.

The Del Sol(Michelle) is benched for the moment. I need a much larger pressurized contained for coolant and a much faster pump. On several occasions the coolant temps, EGTs, and block temps(measured through pilfered garage equipment ^_^) have started sky rocketing. This happens consistently when the engine is intaking large volumes of air( just over 2K RPM) and running substantially lean(I've marked off 16:1 and 35:1 and its somewhere between the two). So either I get rampant acceleration or rampant heat overload. . .

I think with a reworked cooling system a more extensive oil cooler for the engine(to get Oil temps maybe 50% lower) and activating my secondary water injector full time(and installing a 3rd for backup) I can get her to run "normally" on lean and maybe ultra lean(I haven't gotten very far past 16:1 as temps start to rise too quickly for me to monitor and drive).

[Christ]

Originally Posted by theunchosen

Michelle is now truly unique in the world of gasoline powered cars(as far as I know). She has no throttle.

The Del Sol now runs lean.

Something I hadn't considered until it started happening is runaway. Since there is not throttle the same "throttle position"(resistance setting) becomes much much more aggressive every little bit it climbs up through the RPMs.

I can't report any realistic mpg(as I haven't used enough fuel). I can't report anything really. Driving without a throttle and tricking the ECU is. . .a pain to live with lol. You have to constantly play the resistance back and forth to keep the car at the right speed until you hit the magic amount of power. Any higher and the engine starts rather rapidly accelerating(increased air flow from higher rpm creates much more fuel(both more air and gas)) or starts choking(the fewer rpms means less air which is less fuel(fuel proper and air)).

I suspect my first tank is going to be a very bad mpg avg. What from the rampant acceleration that got out of hand a few times and very narrow band range of pulse and gliding finding the right resistance.

The Del Sol(Michelle) is benched for the moment. I need a much larger pressurized contained for coolant and a much faster pump. On several occasions the coolant temps, EGTs, and block temps(measured through pilfered garage equipment ^_^) have started sky rocketing. This happens consistently when the engine is intaking large volumes of air( just over 2K RPM) and running substantially lean(I've marked off 16:1 and 35:1 and its somewhere between the two). So either I get rampant acceleration or rampant heat overload. . .

I think with a reworked cooling system a more extensive oil cooler for the engine(to get Oil temps maybe 50% lower) and activating my secondary water injector full time(and installing a 3rd for backup) I can get her to run "normally" on lean and maybe ultra lean(I haven't gotten very far past 16:1 as temps start to rise too quickly for me to monitor and drive).

This is excellent work. In for updates!

[NiHaoMike]

Try water injection to reduce heat during lean burn.

[RobertSmalls]

The idea here is to drastically reduce pumping losses by eliminating the intake restriction that is the throttle plate, correct? I've thought about it myself, but I figured it would need a custom controller to replace the ECU, and the consequences of very lean operation are not trivial.

If your current arrangement is uncontrollable, what do you think about a hybrid arrangement? Leave the throttle plate in, and use it while accelerating. For cruising, open the throttle plate wide and lean out the mix to modulate power.

Is there any way you could have an electronic nanny to add fuel, or at least sound an alarm, as EGTs skyrocket?

I'll be watching this thread, and I'd love to see any data you gather.

[theunchosen]

Don't hold your breath, ^_^

I've got a few water fountain solar pumps, I'm going to rip the panels and wire them directly into the battery to replace the power draw from the pumps(still lose the mechanical losses associated with the alt but still). The pump does a little over 1.2 GPM which my current one only does about .2-.3 GPM. So the fluid will be moving through the block much faster. I've got a spare water resevoir(that can hold the nominal pressure) and I'm going to put it in the now vacant area where the AC fins/compressor/fan was. Its got straight shot air exposure coming in from the front grill so it should cool a little while it sits there(its a 1.5 gallon tank opposed to the puny sub quart size resevoir I've got standard).

I'm also going to have to find the current leak in the cooling lines. It seems to have mostly stopped. . .but I definitely don't want to hook up with expensive cooling fluids just to have them pour out on my driveway(more expensive than water(anti-freeze has less cooling capacity than water)). It's mostly an alcohol water mixture that takes advantage of the interstitial placement of alcohol molecules between water molecules(more mass absorbs more heat).

A brief materials list to get this underway(I don't have much time for the project let alone to upload pictures and do you guys justice for the times you've informed me ^_^)

Current:
3 new pumps(Engine Oil cooler, Radiator(extraneous but prudent after some terrifying shifts and forgetting to drop resistance ^_^), pump for water injectors)
1 Large water resevoir(water injection to keep cylinder. valves, sparks cool)
2 Mister/Injectors(1 full time, 1 backup)
3 radiators (Engine, Trans, BM coolant radiator)
2 1000 ohm variable resistors(1 for MAP, 1 to get the O2 to read stoich all the time(You could do this with a regular static resistor. . .but I didn't want to fool with it. . .lazy ^_^))
Lots of switches(water pump, cooler pumps, MAP On/variable resistor on, Emergency Limp Switch(ELS). . .)

Planned:
1 more pump into coolant systems to rapidly move fluids
1 more multi gallon in loop resevoir for coolant
3 more injectors(One per cylinder one backup before the manifold break)


More than anything its terryfing lol. Its not natural habit to constantly monitor the temp gauges instead of the mph/tach and it requires [b]alot[/b[] more attention to make sure the "throttle" stays where its supposed to be. I imagine its alot more like a turboshaft engine would be. When I shut off the resistance the air is still getting sucked in through WOT. . .WONT(Wide Open No Throttle) and the cylinders are still very hot. Even under the idle and limp functions in the ECU its injecting enough fuel to keep it at high RPM if the clutch is engaged(1K+ and it starts to climb. . .as do the temperatures -_-). On the otherside of the coin when I drop the resistance the acceleration comes rather aggressively and quickly.

The most often problem I discovered in just a 3 mile loop is that I killed the engine frequently by accidently cutting the resistance and the engine hit an AFR that was too lean to run and died. Also the problem is obnoxious because at different RPMs the amount of fuel needed to just shut the engine to idle is variable so my idle mark doesn't always do it. . .

Its honestly like learning to drive stick for the first time ever. . .instead of having some new pedal called a clutch you've got a new nob called a "throttle."

[theunchosen]

Mike, yeah I am working on that. I have it in place but its apparently not enough. From Tuner forums I picked up that 1 of my nozzles would be more than enough but apparently boost is nowhere near as hostile to engines as lean and ultra lean conditions.

Robert, That was originally my intent. . .but I went a little overboard. I tried using the throttle and the resistance at first. . .the problem is working the two controls simultaneously. When I would go to depress the throttle(actual, or without quotes) I would have to turn turn off the MAP sensor(I bypassed it with a wire and a resistor to simulate what data it would be gathering) and turn up the resistance at the exact same rate as I pushed the throttle, Also I had to engage the injector(it was injecting too much fluid to leave running while the throttle was in place). Very much too many things for one person to do. I'll definitely be looking for ways to piggy back some of these things onto other systems(like piggy backing the pump flow rate to the tach so it drops the right amount of fluid to keep up)

The system has an ELS that rotates a ball valve(much wider than the rest of the intake tract so no restriction). flip that switch valve turns to an equivalent of 1/4 throttle position(enough to maintain 1.8-2K RPM on level ground in all gears) so I could shut the system down if the engine overheated(and so I wouldn't have to tow it back). Its just on a spring switch keys a solenoid releases spring, intake mostly closed.

Also alarmingly. . .it goes through water about as fast as gas. The tank is mounted in the trunk so it can stay reasonably cool, easy access and convenient place to route the piping, its also slightly higher in the rear than the front so the top half of the tank is higher than the engine so I get some free potential energy(or energy I burned lifting it there.) I'll need something the size of a 5-8 gallon tank for extended trips unless I know for a fact I can stop and get more water frequently. I've tested this at fast food places around town that are near my driving route. So far all of them have been willing to give me a 5 gallon bucket full of water(I had to return the bucket -_-). Most of them didn't ask but one of them(arby's) the manager asked. I informed him and then showed him the tank(not in use ^_^ but he didn't know it was the secondary Del Sol).

Like I said though. . .Its going to be probably a good week or two before I get another chance to even test drive it, let alone start pulling apart systems to actually make it work properly. I'm entirely open to speculation or suspicions on what to do next.

I also yanked the Cat as its now only in use during Limp mode, it helped alot as far as available power down low(no backpressure whatsoever(yes there is nominal pressure. . .but its nominal lol)). The engine has alot more juice down low now like most diesels, because its not fighting all that restriction(up front and out back).

[Christ]

So if you're running this lean... what about NOx production? Are you monitoring it or doing anything to treat it?

[theunchosen]

At the moment no I'm not. At this point in the game. . .its much less of a concern for health reasons than. . .my daily sugar intake ^_^. I've only had it on the road for 3 miles, and running total time of less than 30 minutes so I'm not terrifically worried about my foot print atm.

Theoretically with the WONT I should be able to get a greater ability to ignite fuel. The difference in this and anything in any other gasser is. . .it instead of limiting the fuel that goes in(to far less than normal, HF, VX, Insight) I'm holding fuel about where it normally is. . . and just adding alot more air.

In the short road test and the sitting tests with it out of gear(dangerous no air flow and I am not going to repeat) I was able to simulate a MAP read out at 1/2 of WOT(or close to 30:1) before I had to back it down for heating issues. If I can keep it near 30:1 I'm outside of Tier II Bin 5, or rather under it, or in it. . .whatever. This is theoretical right now, but the NOX curve peaks at 20:1ish somewhere in there and then begins an exponential drop. If I can stay above 23-24 I'm doing better than older diesels.

Also I think I can wash out some of the NOX particles with the steam bath/cooling. At least theoretically. Its how its done in Coal power plants. I may be well under "acceptable" NOx output for the mileage with just the water injection, but if I am not when I get Michelle back on the road permanently I'll be keeping her as high in the spectrum as I can(most of the charts I've dug up indicate anything above 28-29 puts you under .0odd grams per mile and thats good enough for home grown lean burn for me).

[Frank Lee]

Incidentally, years ago I read about BMW's experiments with no conventional throttle. They manipulated the intake valves to provide the throttling.

[theunchosen]

Originally Posted by Frank Lee

Incidentally, years ago I read about BMW's experiments with no conventional throttle. They manipulated the intake valves to provide the throttling.

Frank I'll take it as a compliment you think I am that clever ^_^.

No such luck here. surprisingly and fortunately for me the engine doesn't suck as much air as it does under stoich conditions. I can still read the MAP from the diagnostics onboard and it shows much less air being flowed through the intake than normal. Less power all around means less dedicated power to intake. Otherwise. . .I'm pretty sure I would have detonated the engine 20 seconds after I started it. . .(remotely)