Cascade Crew

[scott in wa.]

I was wondering,

1. I thought that the stock 305 distributor was the same as the 350.
is this correct?
I have changed the knock sensor and esc module.
Also

Iam running a stock 87 gta 350 prom in the new motor, since I have done a few up dates like head work, Lt4 hot cam, 24lb injectors, headers,

2. Will there be any potential damage if I run the above bin? as long as I can get the lean condition adjusted?

3. Can I desensitize the knock sensor, just a little?
what parameter is this called?

And,
4. There is a single fire setting and a double fire setting for the injectors, If I lower these will it decrease my lean condition?

thanks
scott

[Twilightoptics]

Sorry haven't had a chance to pull the bins off my old laptop. Should have time tonight when I get off work.

1.) They are the same. A 350 bin is best to start with. FWIW My stealthram and 262 cam wouldn't hardly get down the driveway with the factory bin.

2.) Damage? Hard to say. Adjust the condition in the chip. What do your BLMs look like? When is your lean condition?

3.)Yes you can. You can A: Unscrew it from the engine block just a hair, or B there are a few tables called Knock retard. I'm not sure in your definition file... the $6e (ARAP '89) bin/def files are best to use. Lots of adjustability. But you really don't want to desensatize the knock sensor, it's there to save your engine. If you put it into the block too far (there is a spec for this) then you might need to adjust. Find out WHY the engine is knocking. Gas? Compression? Overheating? Timing?

There is an ESC attack rate and an ESC recovery rate. Attack rate is how many degrees it takes out (attacks the timing) per milisecond, recovery is the opposite, how quick the timing comes back in.

4.) You put your injector size, which if you have 24#ers, in GM terms that's about 25.5# per/hour. Place 25.5 in BOTH single and double fire setting. If you lower that number, you would get more fuel yes, BUT, if will give you more fuel on every aspect: Idle, cruise, acceleration enrichment(off the line), power enrichment(wot).

That's why you need to tune each area you need.

Is this an auto or a stick?

[scott in wa.]

I am running rich, I can smell it, that is before I lost the one header gasket.
I will be replacing it and trying some data logging after that.

Didn't know about the spec on the knock sensor. I just got the GM service manual yesterday, they were pricey, but probably worth there weight in gold.

That's what I thought about the single fire and double fire. Its a constant.


1. I did some live data viewing when in closed loop, just sitting in the drive way, and the O2 Numbers seemed high, but I haven't done it while driving yet.

2. The reason I ask about the distributor is, when I time it at 6 deg.
I unplug the brown wire, I notice that when I rev it a little (snap the throttle) the timing jumps about 4 degrees, then as the rpm goes down its back at 6 deg.
I thought it wasn't supposed to do that when the tan wire was unplugged.

3. What are the BLM's ?



Whenever you have time on those bins, I have a hard time getting my lap top out also, seem to be very busy this time of year.



Thks
scott

[Twilightoptics]

The BLMS are your fuel correction notes. If it reads 128 in your data log.... 124-132 are ideal. Lower than 128 is rich. Over 128 is lean.

Don't look at your o2 readings unless you are in open loop, or at WOT. Otherwise it has to swing back and forth and you CANNOT tell an approximation of your air fuel ration. You can look at the o2 on tip in(acceleration) to see if it's lean or rich.

With that cam you'll need more timing. Try one of my bins, I'm copying them now. You may have to combine parts of some.


You unplug the brown wire with black stripe BEFORE starting the car. Set timing. I believe it will advace a little, the one in my Jimmy does. But it's some sort of mechanical advance. That or you are unplugging the wrong wire.