View Full Version : The Hall sensor (cam position sensor) is same part number across the board for all 2.8 12V engines


VAP
06-04-2003, 06:33 AM
So that means timing is being handled exclusively by the ECU's. So no short-cut there. However there is still a work-around that will net us a little more advance timing. Every electronic sensor in this car is triggered by some form of mechanical sensing device. Since I nor anyone else seem to be able to modify the ECU by virtue of re-programming or a chip I think the next best thing is to approach the mechanical aspect and physically move or relocate the timing sensors by "x" number of degrees and "lie" to the ECU to attain a greater degree of timing advance. As long as it's tested thoroughly and done with care and conservatism we should be able to maintain 100% of the safeguards built into the engine via knock sensors.

Of course I'm presuming there is some measure of available timing advance left unused on the table by the ECU. A well-tuned car should still pass emissions if applicable easily and without even approaching threshhold limits.

The goal: What I have to come up with is a compromise (aint it always the way!?!) ie; a degree of advance thats suitable in all areas of the country without knocking/pinging and doesn't throw codes even if 'regular' gas were put in accidentally and passes all known emissions standards including Colorado and California... the two toughest in the country.

For those that really don't know the benefits of spark advance or timing benefits let me say it's one of the, if not THE, most important aspects of wringing as much pwer as possible from an internal combustion engine. It enhances stock or modified engines in much the same way and 15-25HP gains are not only possible but maybe even probable given the displacement of our cars and my suspicion of it's current programmed timing tables. And it's an across-the-board benefit... the engine idles smoother, rolls from a stop easier, climbs in RPM's faster and opens up significantly better at high RPM's. If done right you'll feel it on initial start-up after the conversion at idle.

Still a LOT of homework to do on this as there's nothing beyond the conceptualization stage in place right now. But I'm going to pursue it slowly, carefully and with both eyes wide open. One cool thing about it is it really doesnt require anything other than what's already in-place and on the car right now. Only a slight movement of the crank timing sensor or pickup and a coressonding, albeit smaller, rotation of the cam timing sensor. Worst thing that will come from all this is I will have to run several full tanks of unleaded regular gas in my car to set it up. In order to make it an "all things to all people mod" I have to test it in the worst possible scenario. One benefit of living at 6,000 ft elevation is if it works for me up here with regular gas without pinging it'll DAMN SURE work for you guys nearer sea level with "any" octane rating.

As the Little Engine That Could once said... "I think I can, I think I can."

scott12v@pghaudi
06-04-2003, 06:56 AM
I personally would like to see a "stage 2" version that does away with the emissions concerns and gas quality issues (in other words, something for those that don't need to pass emissions and who always use the proper octange gas).

Scott

VAP
06-04-2003, 07:12 AM

moribundman
06-04-2003, 08:35 AM

MM120
06-04-2003, 08:36 AM

VAP
06-04-2003, 08:38 AM
back in the late 70's.

MM120
06-04-2003, 08:43 AM
Are you in mensa?

moribundman
06-04-2003, 08:47 AM

Audiboy
06-04-2003, 08:48 AM
I should just plug and chug hehe

Speaking of timing, as I mentioned my other cars are modified. Some stories:

On my first car that I bought in 1987 (whew no more driving mom's rabbit), a Mazda 323, I modified the AFM (air flow meter) spring and added 12 degrees of timing. I also modified the distributor vacuum advance/retard motors because it tend to retard things on the Freeway. I worked as a smog technician from '87 to 91 so I was just tweaking my car after work with the aid of my sniffer - hey I had to be clean burning ;P
One night from school, as I was strolling with a chick, a fixed up 323 came on a traffic light booming and all - drowned my 16 speakers - yeah I did that ;P He wanted to race. My friend said go for it. 1st gear, 2nd gear - he started honking and signaling me to pull over from about 6 cars behind. When he caught up, he was like - "what the heck do you have in that motor?!" I told him my custom dual pipe exhaust and some intake mods only. He couldn't believe it. Shortly after, I beat a Ford Escort GT and then blew up my tranny hehe. Replaced it with a 5 speed. My car has beat and kept up with 16V GTI's and my cousin's CRX who would take me after 50mph only. Torque baby! 0-60 in faster than stock 10 seconds that's for sure :) I timed it a few times around 8.5 to 9. My 323's still alive with 150k miles on the motor and 146k miles on the tranny with redline oil ever since ;P Oh yeah, I think only 14 speakers work now
<img src="http://pictureposter.audiworld.com/9/aboy_f3.jpg">


On my '92 SUV, 4500 lbs, 150hp 180 lb-ft of torque (stock) - tuned at one point for Premium Fuel, but backed down to '89 - yeah I embarrass cars with it till this day. Stopwatch, it goes 0-60 in 9 secs give or take a few ticks. I don't think it was designed that way. Oh and it blows away 190hp Jeep Cherokees on the way up to Tahoe. That one has 6 degrees advance in it's current tune. Went as high as 10 before.

The timing in the A4 is pathetic watching from VAG tool.

However, here's one puzzle I haven't figured out yet. Our 12V has no separate air temp sensor. So the only way the ECU must figure out the air temp must be from obtaining from the MAF readings and the EGR sensor. Air temp plays a vital role in timing.
- And that's how we tuned my friend's 1.8T APR stage 3 A4 to hit 280 hp at the wheel with a slipping clutch, a number I haven't seen rivaled by other 1.8T dyno charts

MM120
06-04-2003, 08:48 AM
a scramjet fitment for Audi's? ;0) When I was in the Air Force, one of my teammates had his old badge from "Dreamland."

moribundman
06-04-2003, 09:02 AM
And the camo dudes keep you on your toes.

MM120
06-04-2003, 09:18 AM