New here - to tackle an old BMW e30 guzzler - Fuel Economy, Hypermiling, EcoModding News and Forum

JoshuaM · 10-06-2009, 12:47 AM

Hi All,

Good to be here - I've always been interested in ecomodding - to the extend that I've even been involved in Solar Car racing.

Now I've bought an old banger E30 BMW 6-cylinder - and I honestly was not prepared for the fuel consumption - I didn't think a 2-liter could do this.

I'm looking at 7 km/liter - where 15 km/liter is what it should do, IMHO.

So - to work - this is the plan:

Lean out the mixture - (open loop control - no issues with Cat Converter)
Ignition Timing to current fuel grades
TC lock-up at low speed
Cylinder deactivation - running on less rather than 6 - gets a bit more complicated since I want to alternate the cylinders which are off and on, and have a range of options at hand to miss beats here and there, so to stay to WOT as close as possible.

Cheers - Joshua

wish me luck...

Christ · 10-06-2009, 02:44 AM

Good luck, welcome to EM!

extragoode · 10-07-2009, 02:47 AM

Good luck! How does one go about adjusting the speed at which the TC lock up? I didn't know that was possible.

JoshuaM · 10-07-2009, 03:08 AM

Ok - I haven't done it yet - but as I understand TC lockup is established by hydraulically actuating a clutch in the torque converter housing such there is no slip. This is done by a solenoid allowing line pressure in the transmission to the TC lock-up clutch. This solenoid can be manually activated by applying current via a switch on the dash for example. Currently - TC lockup happens at about 90 km/hr. Living in Singapore - I hardly reach that speed, highway traffic is normally at 89 km/hr..... Nothing more frustrating than having the TC lock-unlock-lock-unlock all the time. Generally my box goes to 4th - highest - gear at 60, so I should lock from 65 km/hr onwards with a switch.

Christ · 10-07-2009, 01:20 PM

You may be able to lock just out of 1st gear, as long as you're not accelerating like a mad man, and keep it locked through the other 2 gear changes, gaining some serious efficiency that would otherwise be lost to heat generated due to TC slip.

MetroMPG · 10-07-2009, 01:32 PM

You may have seen this thread: http://ecomodder.com/forum/showthrea...tch-10028.html

Welcome to the forum.

Christ · 10-07-2009, 02:18 PM

Quote:

Originally Posted by MetroMPG

You may have seen this thread: http://ecomodder.com/forum/showthrea...tch-10028.html

Welcome to the forum.

Another pea on my plate that I have yet to stab w/ the fork...

extragoode · 10-10-2009, 10:46 PM

My eyes have been opened to the FE possibilities of automatics! With a switch like that I could have a car that I could stand to drive and my wife could still drive it by just not touching the switch, since she REFUSES to learn to drive a clutch! Does all the extra locking and unlocking shorten the life of the TC dramatically?

extragoode · 10-10-2009, 10:50 PM

Not to threadjack, but lately TC has been unlocking on our '03 Jeep on long highway trips (> 100 miles, cruise set) could this solenoid you're talking about be the problem? Or maybe the electrical wiring to it?

Christ · 10-10-2009, 10:57 PM

Test the wiring first, if you have continuity through the length of the wire, get a JY solenoid and try it out. If that doesn't work, further diagnosis is required.

With the locking switch, if wired properly, and once you re-learn how to drive with it, there will actually be less lock/unlock cycles. Every time you let off your accelerator or hit the brakes, the TCC unlocks. If you have the switch wired properly, it won't unlock when you let off the accelerator to slow down a MPH or two (which you do more than you realize... trust me.), which lessens the cycles the TCC goes through.

It also allows for full-on engine braking, rather than slippage braking. If you engine brake, you'll want to try it out first in low speed situations, because if you leave the TCC lock engaged, it will hit hard and fast (which is actually better for automatics), and it may scare you.