Lesson learned thanks to Steve Wong....

[175K911]

Don't ever assume anything when it comes to these cars.

I've been trying to fine tune my software to get max potential out of the engine/header/muffler configuration for track use. I'd been baffled by several things after the first set of dyno pulls I'd done. Both the 20 year old Autothority software and Steve Wong's software showed extremely lean, over 14 for the AFR. So pulled the AFM apart and reset the contacts, adjusted the fuel pressure higher (yes the car has an adjustable Bosch fuel pressure regulator which I've never seen before), installed a new set of plugs and checked all vacuum lines.

Reran the car on the dyno again, much better with AFR's in the mid 13's. But still leaner than I'd expected. But OK, and by turning the ECU one turn I was able to get the mixture into the low 13's.

But I kept looking. Last night for the heck of it I thought why not look at the brown California wire? No reason to since the car was sold new at a Virginia dealership and seems to have lived it's life on the east coast. But sure enough the brown wire is connected! No wonder it's lean. Quick call to Steve W again and he asked if I'd checked the stickers on the engine lid. So I pulled the original lid out of the blanket it's stored in down in the basement, and sure enough it's a California car!!

So how did a CA car get sold new at a VA dealer? Who knows. Maybe diverted at port? But just shows that we can never assume we know what we have. And thanks to Steve for sticking with me on this.

Now it's back to the dyno for round 3. Hope to better the 201.5whp my tired old 193,000 mile engine produced in CA mode. I'm hoping for 210whp (240 at the flywheel) this time around.

[911st]

I wish you the best.

On my 85 I got the SW custom chip option and Steve fine tuned my chip using the dyno numbers.

I got 215-217 w a cat bypass. My friend had a bypass, chip and Bursh sport muffler and he got 219rwhp.

Of course dyno results do not compare well. However, the operator said his dyno compared to others in the area reads low if that means anything.

[mag232]

Hi 911ST,

i see that you're in sacramento, and the thread talked about a track car, but as I'm close to buying an SW chip and some exhaust bits, i thought I'd ask you the question.

Do you smog that car that is showing 215hp with a cat bypass? I'll put the pre-exhaust on and a dansk sport muffler on.

I don't need krazy power, and I definitely want to keep this thing legal here in the PRC. (I'm in palo alto)

thanks in advance
mag232

[911st]

I am coming up on having to do that.

I will probably put the cat back on, plug back in the O2 and might put the stock chip in thought I hear most pass w the SW chip.

The best.

[vreference]

Does steve recomend doing a baseline run? I suppose I'll be getting a chip from him in the near future.

[175K911]

Originally Posted by vreference

Does steve recomend doing a baseline run? I suppose I'll be getting a chip from him in the near future.

Steve has an amazingly large database of almost every conceivable combination in these cars. He started with software that he felt best matched my 3.2 with European Racing 1-5/8 headers and an M&K 911R muffler. I did my dyno pulls with that and a 25 year old piece of Autothority software that had been dyno developed with my previous '86 on their dyno back when I lived in Virginia and Al Collins was still doing the software work. In both rounds of dyno runs 2 weeks apart, I compared the SW and Autothority rather than versus OE since the car wasn't running a stock exhaust.

The dyno pulls (on a Dyno Dynamics 4 wheel dyno which is generally more conservative in it's numbers than some of the other types of dynos out there) were done to tweak out the last couple of hp and maximize the area under the torque curve. Round 3 of the dyno pulls will be next week so I'll be curious to see if unplugging the brown CA wire will yield much more hp.

[911st]

Check with Steve at www.911chips.com

For the most part it is a plug and play. However, because of the age some cars may vary from original spec and a custom chip migh be better.

I am not an expert but I would recomend dynoing you car after installing the chip to make sure your AFR's are solid. Expecially if planning on traking the car.

Still, it is good to put you car on a d

[dimeified]

It's amazing how much trouble one imaginary line drawn across what used to be a land dominated by dinosaurs can cause.