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Tune Up Tech

Thanks to many people, I lost all  this for more than a year but someone, (Ron Porter) pulled it out of their personal archives.

New 10/23/01


-----Original Message-----
From: owner-v8sho@purdue.edu [mailto:owner-v8sho@purdue.edu]On Behalf Of
Michael T. Ivy
Sent: Friday, April 07, 2000 11:36 AM
To: v8sho
Subject: Secondaries DON'T close


Guys and Gal(s)
I just mispent a portion of my morning finding out something I think we all knew. The secondaries do not close at shifts. Here's how I did it. After my class this morning I went to the local wally-world and bought some 3M t-taps and butt connectors. Next off to Radio Shack to buy a 12V green LED with pigtails. Follow along if you are interested...

Removed Appearance cover
Removed four IMRC lid retaining screws
Removed five metal phillips-head screws and one plastic allen-head screw
that hold solid state controller card
Lifted up IMRC motor (Simle low RPM Johnson Controls Motor)
Placed T-tap on positive and negative leads to motor (since there are
multiple inputs on the controller I figured as long as the motor had power
the secondaries were open or opening)
Ran cable from interior with LED to t-taps
Resecured all harware (the lid was not able to be placed correctly but is
intregal in holding the motor in place so it was held down with HD zip-ties)
Drove it like I stole it.

What I found. At roughly 3250rpm the LED would turn on meaning that the motor had power. The LED stayed on through the shifts...all of them. I made several runs to verify that it did indeed stay on. In fact the LED stayed on until I let off the throttle and the rpms dropped below 3250. Knowing that LED's are not that discriminatory towards the voltage that they operate I figured I would see if there were any fluctuations in the voltage. So, I hooked up my Fluke in with the LED and had a passenger (my brother-in-law) watch the output...11.99v the whole time.

My conclusions. The secondaries open and stay open until we let off.

My questions. Why the sudden drop off in power near shifts? What limits the RPM? Is there really any more room?

Oh and by the way the secondaries open in neutral and park!

Mike


****************************
Michael T. Ivy


-----Original Message-----
From: owner-v8sho@purdue.edu [mailto:owner-v8sho@purdue.edu]On Behalf Of SHO Jim
Sent: Tuesday, April 04, 2000 3:21 PM
To: V8 SHO; Dave Kegel
Subject: PCM Info


1996-99 SHO Questions


1. Are the secondaries programmed to switch state @ 6800 RPM?

· Yes - This action provides better control of engine speed when limiting maximum RPM. Switching the secondaries (IMRC position) reduces engine power, thereby reducing the need for cylinder cutoff to control engine speed.

2. Is the timing on the SHO conservative for midwest driving conditions & premium fuel?

· No - The SHO has been calibrated for optimum performance on Premium fuel. The knock sensor reduces spark advance automatically for high temperatures or poor quality fuel. Other spark compensation has been built into the calibration for extreme conditions.

3. Is there a timing retard while shifting?

· Yes - The retarded timing reduces engine power during shifts, which enables quicker shifts with reduced wear on transmission components.


4. Are there performance gains to be had with the right table settings or software changes?

· No - Optimum power was developed on dynomometer tests & validated on prototype vehicles. The knock sensor allows optimum spark under normal conditions, and retards spark as knock initiates.

5. Do you know anyone who does quality after-market chips for the EEC-V processor?

· No - Customers have reported that some after-market chips cause excessive "spark knock". This could lead
to engine damage under some conditions.

6. Are some EEC-V SHO ('96-'99) programs more aggressive than others?

· No.


Thomas F. Mausolf
Calibration Engineer
Taurus/Sable Vehicles



-----Original Message-----
From: owner-v8sho@purdue.edu [mailto:owner-v8sho@purdue.edu]On Behalf Of SHO Jim
Sent: Tuesday, May 30, 2000 11:02 PM
To: V8 SHO
Subject: More PCM info from Ford


I passed a few more questions through to the guys at Ford responsible for V-8 SHO calibrations. Got back more answers. No big surprises - use premium in Texas, less exhaust restriction will increase hp on a SHO, keep your air & coolant cool for good 1/4 mile numbers, and you could blow the tranny if you get too much hp. Not listed here is a response that power is NOT reduced in lower gears as has been suspected.

----
How high octane can the spark advance take advantage of under normal driving conditions? 94? Higher? Only 89-91? How would you know if the timing has been bumped back due to low octane gas? Would there be a ping code in the PCM?

*Under many conditions, maximum power would be improved with 94 octane fuel. These include high ambient temperatures and dry weather. Also, extended idling tends to raise inlet air temperature, causing spark to be retarded. Rapid throttle openings also increase the knock tendency.

*There is no direct method for customers to view spark retard. Spark advance can be viewed through equipment hooked up to the SCP port. However, the amount of spark retard is not one of the parameters that can be displayed. This information is generally limited to engineering consoles.

*There is no "ping code" in the PCM. Spark retard through the Knock Sensor is part of the normal engine operation. The knock sensor retards spark in proportion to engine "knock" as it occurs. The knock sensor will be retarding spark based on knock that is not perceptible to most customers. Other pre-programmed spark retard is built into the PCM based upon high ambient or engine coolant temperatures.

----
Why do accelerometer readings indicate that the engine produces more HP in cold startup (open loop) mode? What would be the effect of using these settings for normal operation or brief ¼ mile runs?

*The SHO engine produces more power during cold startup for the following reasons:


**Cooler air produces a denser cylinder charge (more fuel/air mixture).


**Cooler air can tolerate the optimum spark advance.

**The SHO engine operates in Open Loop mode during cold operation for a short period, and during all maximum power modes. Fuel is enriched during maximum power operation to protect the engine and catalyst, and optimize potential power. Spark advance has been optimized for cold & hot operation.


**The best way to improve stabilized engine power is to keep the air into the engine as cool as possible. One way would be to avoid extended idling prior to a ¼ mile run.

----
The SHO has the same PCM as the '96-'00 Cobras which were reprogrammed by Ford to produce more power
(along with exhaust upgrades). Did the same team program the V-8 ('96-'99) SHO's? Could similar improvements be made?

*The SHO and Cobra engine were calibrated by different groups. Extensive exhaust development work was undertaken in conjunction with the engine manufacturer to produce as much power as possible. Limitations such as vehicle package constraints, exhaust noise limits, and emission control systems control the maximum engine power. Certainly, a more free flowing exhaust will produce more power. We are not aware of a Ford after-market exhaust in
this category.

*It should be noted that if engine power were increased significantly over the design power, transmission shifting could become a concern.


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