WOT switch 3.2?

[911st]

I just rotated my WOT switch clockwise so it will trigger as soon as possible. Confirmed it triggers continuity at the top two leads.

Any reason why can I not rework the mounting so it triggers at 50% throttle instead of about 75%?

Is there a range where it stops?

I have a custom SW chip and use the car for mostly for DE's and driving to DE's.

Thx

[burgermeister]

Why would you want to switch to WOT fuel & spark mapping at 50% throttle? Outside of wasting fuel and running a hotter cat (if you still have one), I don't see what you'd gain.

[stlrj]

For that matter, then why not go WOT off of idle and rocket to your next filling station. Who cares about no load cruise. These Bosch folks must have fools for engineers.

Now that's performance!

[avt007]

I had a 78 240Z with Bosch injection, and the WOT switch was infinitely adjustable. I tried all (sarcastic) suggestions above, and they worked like a dream on that car. Having said that, I don't find the switch has as much effect on my 3.2.

[911st]

Thank you for the helpful suggestions.

Sounds like some here are against doing anything that improves performance like euro style pre muffler, sport mufflers, and SW chips.

These are all pointed at the same goal as mine. Porsche had to make a few compromises to accommodate EPA and other issues but my goals are performance as I stated.

I do get great gas millage and trigerin the acceleration maps at say 50% is not going to effect things much.

I suspect at cruse the throttle is at only about 15%.

[Won]

I'm assuming you've been reading the thread about EFI tuning. Study the fuel and ignition maps carefully and see if you really want the WOT map at say 2500RPM or something. Just by looking at it there's a large ignition advance at low load conditions in mid-RPM range and if you replace that with the WOT map, you won't be improving anything with retarded timing. I don't think you want that.

[Pazuzu]

Another quick option is to disable the switch ( run a jumper). Same as WOT all the time. Drive it a bit, and find out exactly what issues it causes, then adopt the switch to get rid of those things that annoyed you the most.

[911st]

Good points all.

I have been at WOT on the dyno from 2000rpm w no issue. The WOT map should be optimized for all acceleration. Not for cruse tough.

All I am talking about is moving triggering of WOT from something like 90% of full throttle to say 6o%.

Probably not as big an issue w the SW chip as I think he has optimized it for part throttle TQ already.

[burgermeister]

If you trigger the WOT map at 60% throttle, you'd be running quite rich. The engine would be getting fuel as if you were at WOT, but because the throttle is partially closed, you'd be getting less air than at WOT. Same fuel, less air = rich mixture. And the spark timing would be off also.

If you insist, try it out and let us know what happens!

[vreference]

More fuel (than required) is less power. I can't imagine this would do anything but hurt performance.

[911st]

I am not and expert but my understanding is there is a cruse map and a WOT map. The WOT map is optimized for power. This should mean there is just the right amount of fuel deliver there on acceleration, not to much.

I suspect that on a quality performance chip like the SW chip, the maps start looking much the same under acceleration.

With our systems acceleration is sensed in two ways. One is the triggering of the WOT chip. The other is it calculates acceleration by the rate of change in the output from the AFR. Thus, the WOT map is often triggered this way before the switch is triggered.

Thx.

[vreference]

Fairly certain that with the WOT switch activated, the ECU uses a fuel map to determine the volume of air entering the engine for a given rpm. If the volumetric efficiency of the engine deviates from this map the computer does not compensate. Performance parts can do this, headers & mufflers, cams, intakes; the engine is actually moving more air than the computer is mapped to fuel for and you end up leaner than expected. If you were to engage the WOT switch with an obstructed intake, e.g. a throttle body only open 50% or 75%, the opposite happens. The computer is still supplying fuel as though the engine were operating at WOT even though less air is entering the engine. An early WOT switch only effects part throttle, as the throttle is opened more you get closer to the mapped volumetric data.

I had read for years that lean meant more power for natural aspiration; I don't think Steve subscribes to this so maybe you are on the right track anyway.