Weber 32/36 thread

[95Compact]

FWIW, I made up a 'long trip' fuel map for the Megasquirt in my '95 BMW 318ti (now you know where my nickname came from). I set the cruise realm AFR target to 15.2 and had no trouble whatsoever with heat, backfiring, detonation, etc. Changing from 14.7 to 15.2 AFR targets, along with some other changes such as deceleration fuel cutoff, effectively netted me about an 10% improvement in MPG on the highway - went from about 400 to 440 miles per tank.

Narrow-Band O2 sensor response curve:

http://upload.wikimedia.org/wikipedia/commons/7/71/02-sensor-vs-Voltage.jpg

I run an Innovate LC-1 Wide-Band on the BMW, but for the narrow-band sensor, it looks to me that you'd want to shoot for about 0.1-0.2V range for a (barely) lean burn.

Also, if you use a volt meter (or even an O2 gauge), make sure that the voltage displayed is the same in the car as it is at the sensor itself... There is a lot of wire between the O2 sensor and the dash, and cheap voltmeters are notoriously inacurrate at very low voltages like these. To bring the O2 voltage into the car, you probably want to use a shielded cable (TV coax is probably fine) with the shield grounded at both ends.

Cheers

[TominMO]

I have an '89 with an '89 B6, a Weber 32/36, and the original intake manifold. (Hoping for the Matt Dickmeyer model to become available) I was getting 34 MPG and thought it should do better. My main idle jet was a 50, but I had to turn the mixture screw out more than 2,5 turns so I went to a 55. Secondary is a 50. Mixture screw was then at 1.75 turns and she ran better. MPG stayed the same. My primary and secondary mains were both 135's so I changed the primary to 130, and the secondary to 145. After a tank of gas I now get 39.1 MPG. My question is, should I be happy with that or try a 125 primary? Don't want it going too lean and nuking my engine. Timing is at 14 btdc. The car runs perfect. I know there is no way to do it properly without at least a wide band, but I don't have one. Open to suggestions.

A carbed B6 getting 39.1 MPG sounds good. My EFI B6 gets 41.9, steady cruising test @ 60 MPH. But now it gets 45.0 with the front spoiler.

[blueoval]

what's a front spoiler?

[TominMO]

what's a front spoiler?

I use the terms airdam and front spoiler interchangably. It's a lower extension of the front bumper, which keeps much of the air from going under the car. Under-vehicle air is very turbulent and is a significant drag on vehicles, at hwy speeds. My airdam is 5", and made of aluminum mesh gutter-guard and duct tape, held on by stainless fasteners and L-brackets. Total cost about $20.

[Movin]

Lost thread, sorry! with the original o2 .1 to .2 would be as lean as you would want to go with no changes from stock. When the motor is accelerating you would want to see it moving in the .8 .9 neighborhood. At idle .5 is not bad but make sure to check it before the sensor cools and becomes unstable.

Using long leads I have not really noticed a problem reading voltage with the cheap meters. They should not be used for ohm testing and amp testing is usually a quick cheap meter demise with a nice aroma.
The leads themselves need to be checked with every use as they are not made of quality materials.

Its like using cheap jumpers in a shop so that the good ones don't wear out so fast.

[zoe60]

I went ahead and got an Innovate LC-1. It idles at 11.9-12.2, when cruising on the road it stays between 15 an 16. When I get on it it drops back down around 12. Runs great. I guess 39.1 is the best it will do driving conservatively and mostly highway. My overall average is more like 36. I ordered a Matt Dickmeyer Max MPG cam, but I am still waiting for it to arrive. Should be interesting, and I'll keep everyone posted. Thanks Movin, you always have good info.

[greywolf200]

That sounds good, guess I'll get me one of those. I wonder if anyone has gotten and run their Dickmeyer can yet? I've been waiting a couple of months.

[zoe60]

That sounds good, guess I'll get me one of those. I wonder if anyone has gotten and run their Dickmeyer can yet? I've been waiting a couple of months.

Yeah, me too. Can't wait. I'd like to get one of his intake manifolds if they become available too. I'll bet it would make a huge difference on a carbed car. I think my crappy intake is the only original part of my engine.

[ted88]

I use the terms airdam and front spoiler interchangably. It's a lower extension of the front bumper, which keeps much of the air from going under the car. Under-vehicle air is very turbulent and is a significant drag on vehicles, at hwy speeds. My airdam is 5", and made of aluminum mesh gutter-guard and duct tape, held on by stainless fasteners and L-brackets. Total cost about $20.

TominMO do you have any pics of your airdam?

[1chrisapple]

like to see pics to please