PFS PMC Installation and Tuning

Last updated: April 4, 2002

Installation

Date: Sat, 24 May 1997 00:39:54 -0400
From: Rich (rmvpa@interpoint.net)

I found the following installation instructions for a PFS PMC computer on the net. Anyone who has installed one of these care to comment on how easy or hard it was to install, and how long it took?

This is what comes in the box from PFS:

Additional things you will need:

Things I would recommend:

Go ahead and buy a DB-9 (mouse) extention cord now. This will attach to the open port on the PFS computer (This port is used for the keypad and data logging). Remember that the computer will be buried under your carpet, and if you later decide to get the keypad or data logging, you don't want to have to go digging for it.

Doing the deed:

- - Disconnect the battery (just unbolt the negative cable)
- - Unbolt & remove the passenger seat (5 bolts)
- - Pull out the door sill (just pulls off)
- - Remove the kick panel (2 pop clips)

This exposes the factory ECU.

- - Unbolt the factory ECU, and remove the four harness connectors
- - Plug the PFS harness between the factory ECU and factory harness
- - Bolt the factory ECU back in
- - Plug the other end of the PFS harness into the PFS computer

Your electrical connections are now complete.

- - Roll back the carpet, and decide where you want to place the PFS
computer unit. (behind the passenger seat)
- - Cut and remove a section of carpet backing where you want to place
your PFS computer.
- - Position the computer, and route the harness along the chassis rail
near the door.
- - Decide where you want the 3-way switch, and run its wires also.
- - Decide where you want the end of the data logging/keypad cable to be
and run it.
- - Go ahead and re-connect the battery and start the car.  You want to
make sure that
  everything works before you put the interior back in.
- - If everything works OK, re-install the carpet, seat, kick panel & door
sill.

Now go out and test drive the car

This will determine the programming adjustments you will need to make, and if you will need to replace the restrictors in the lines going to the wastegate actuator and the turbo precontrol actuator.

Important things to note are the O2 sensor voltage at wide open throttle, and the maximum boost pressure you hit.

__________________

Date: Fri, 6 Mar 1998 13:18:00 -0600
From: "Westbrook, Chuck"

>1. Where to house the computer unit? Is there enough room
>behind the passenger kickboards, or is it better under the
>passenger seat.

I placed my unit under the passenger seat instead of in front of it. This prevents any one from standing on it. I've seen my wife stand on that spot in front of the seat where PFS says to place it. Only one problem with under the seat, I had to raise the back of the seat in order for the seat bottom to not rub the carpet.

>2. Where is the best place to install the Lo/Med/Hi switch
>so that is isn't too obtrusive or easy to knock against.

I cut out a 2.5" square section of the back upper left part of the glove compartment box to reach the switch which is mounted to a bolt on some ?? electrical unit behind the glove box. I had to make an aluminum bracket to mount the switch, and also had to extend the switch wires by about 1 foot. At this location the switch is hidden and does not interfere with the box or what ever is in it. Just open the box and reach in to the left rear to turn the knob.

>4. Are there any areas/pitfalls to note or to look for e.g.-
>besides for setting Boost too high. I was recommended to program
>the settings as follows:

    >Lo  10/10 Boost
    >Med 10/12 Boost
    >Hi  12/14 Boost

Just make sure your initial fuel settings are rich and that for every PSI of boost over 10PSI, retard the timing by 1 degree. The MAX BOOST in menu 9/900 is not boost but the fuel map selected. Place this 2 to 3 PSI higher so that the system will still add fuel when and if boost spiking occurs above your selected boost in menu 6/600. Start off with the lower levels first in order to get a feel for how the unit runs and reacts. The unit must read "WOT" on the keypad for the vent learn to work. Adjust the TPS if it doesn't read WOT.

Tuning

Dale Black has kindly offered to let me host a copy of the PMC data sheets he created. There are three sheets, one each for Low, Medium, and High. --Steve

From: Dale Black (dale.black@pncbank.com)
President
West Penn RX-7 Club
Date: November 27, 2000

Here is the latest Excel spreadsheet containing programming variables for the three PFS PMC settings.

For reference (should probably put this on the website) relative mods are intake, downpipe, mid pipe, cat-back, no emissions components, larger stock-mount IC, Efini turbo Y-pipe and top pipe.

PMC Data Sheets

Data Set 1 - Low

Idle   Fuel Adjustment (+ 2% Steps)         Idle   Timing Adjustments (+1o Steps)    
-10             0        
                       
    Part Throttle             Part Throttle    
RPM 2200 4000 6000 7800     RPM 2200 4000 6000 7800
Light Load 2 2 2 0     Light Load 0 0 0 0
Med. Load 2 2 2 0     Med. Load 0 0 0 0
High Load 0 0 0 0     High Load 0 0 0 0
                       
    Wide-Open Throttle (WOT)             Wide-Open Throttle (WOT)    
RPM 2200 4000 6000 7800     RPM 2200 4000 6000 7800
High Load 2 2 2 2     High Load 0 0 0  
                       
    Boost             Boost    
RPM 2200 4000 6000 7800     RPM 2200 4000 6000 7800
1 psi Boost 0 0 0 0     1 psi Boost 0 0 0 0
Max. Boost 6 4 8 8     Max. Boost 0 0 0 0
                       
    Nitrous Oxide             Nitrous Oxide    
RPM 2200 4000 6000 7800     RPM 2200 4000 6000 7800
N2O On 0 0 0 0     N2O On 0 0 0 0
                       
Boost Features     Rev Limiter       N2O Features     Acc. Switches  
      Feature             No. 1 No. 2
ON Max. Boost   ON Max. RPM     ON Max. Boost   ON ON
OFF 11 psig   OFF 9000 rpm     OFF psig   OFF OFF



Data Set 2 - Medium

Idle   Fuel Adjustment (+ 2% Steps)         Idle   Timing Adjustments (+1o Steps)    
-10             0        
                       
    Part Throttle             Part Throttle    
RPM 2200 4000 6000 7800     RPM 2200 4000 6000 7800
Light Load 4 4 4 0     Light Load 0 0 0 0
Med. Load 4 4 4 0     Med. Load 0 0 0 0
High Load 0 0 0 0     High Load 0 0 0 0
                       
    Wide-Open Throttle (WOT)             Wide-Open Throttle (WOT)    
RPM 2200 4000 6000 7800     RPM 2200 4000 6000 7800
High Load 2 2 2 2     High Load 0 0 0 0
                       
    Boost             Boost    
RPM 2200 4000 6000 7800     RPM 2200 4000 6000 7800
1 psi Boost 0 0 0 0     1 psi Boost 0 0 0 0
Max. Boost 10 8 12 10     Max. Boost 0 0 0 -1
                       
    Nitrous Oxide             Nitrous Oxide    
RPM 2200 4000 6000 7800     RPM 2200 4000 6000 7800
N2O On 0 0 0 0     N2O On 0 0 0 0
                       
Boost Features     Rev Limiter       N2O Features     Acc. Switches  
      Feature             No. 1 No. 2
ON Max. Boost   ON Max. RPM     ON Max. Boost   ON ON
OFF 13 psi   OFF 9000 rpm     OFF psig   OFF OFF



Data Set 3 - High

Idle   Fuel Adjustment (+ 2% Steps)         Idle   Timing Adjustments (+1o Steps)    
-10             0        
                       
    Part Throttle             Part Throttle    
RPM 2200 4000 6000 7800     RPM 2200 4000 6000 7800
Light Load 6 6 6 0     Light Load 0 0 0 0
Med. Load 6 6 6 0     Med. Load 0 0 0 0
High Load 0 0 0 0     High Load 0 0 0 0
                       
    Wide-Open Throttle (WOT)             Wide-Open Throttle (WOT)    
RPM 2200 4000 6000 7800     RPM 2200 4000 6000 7800
High Load 2 2 2 2     High Load 0 0 0 0
                       
    Boost             Boost    
RPM 2200 4000 6000 7800     RPM 2200 4000 6000 7800
1 psi Boost 0 0 0 0     1 psi Boost 0 0 0 0
Max. Boost 12 10 14 12     Max. Boost 0 0 -1 -2
                       
    Nitrous Oxide             Nitrous Oxide    
RPM 2200 4000 6000 7800     RPM 2200 4000 6000 7800
N2O On 0 0 0 0     N2O On 0 0 0 0
                       
Boost Features     Rev Limiter       N2O Features     Acc. Switches  
      Feature             No. 1 No. 2
ON Max. Boost   ON Max. RPM     ON Max. Boost   ON ON
OFF 15 psi   OFF 9000 rpm     OFF psig   OFF OFF

__________________

Date: Thu, 14 Sep 2000 21:50:32 -0400
From: Wael El-Dasher (wael.el-dasher@efini.net)

> I was recently told to leave the WOT maps alone, set at 0, and only alter the
> boost@max map to compensate...Can I get some input as to why this is?

The WOT maps can be used but there is no need for them in our application.

They are used for normally aspirated applications where they can't use the boost menu. The boost maps are what you use for wide open throttle maps. Confused? Good :)

I will step back and explain a few basics of the system, the system is additive (or subrative) so changes in Boost are effected by Part throttle maps (and WOT if you choose to use that menu). When you at wide open throttle then you are on boost in this car. If you add fuel to the WOT maps and add fuel to the Boost maps then you have little control. So what if you can use both and perhaps think you can get better control using the WOT maps you say to yourself...

Well its not that simple. I'll use an example to illustrate. Let's say you put in +4 at 4000rpm in the boost map for Max boost. And you are in setting 2 (ie 12/13psi) that means at 13psi you have +4% fuel at 4000rpm, and at 7psi or so you have +2%...the system interpolates. If you enter these numbers in the WOT maps the system can not interpolate based on boost level. You only add fuel as boost increases.

_______________

Date: Fri, 23 May 1997 09:04:22 PDT
From: "Ryan McDonald" (ryanmcd@hotmail.com)

Well I thought that I could help some people out as far as tuning there car up with the PFS PURPLE computer. Here is a quick rundown of some things to start out with while setting this thing up.

From what I have seen as far as the EPROMS that Peter is putting in these computer after Doug makes them and sends that to him is that Peter is making the computer run very rich. I have seen cars like mine have to be set to like - -4% or more on the fuel when boost is say 12 to 13 pounds. I do not know about LL PT OR WOT maps I would say that they may be okay. here are some thing to do when you start up

Go into the 9 menu and if you want say 10 pounds of boost I would set the MAX BOOST to 12 the max boost is NOT the boost that the car is making it is the fuel curve. Say you set the car for 10 pounds and it spikes to 11 or 12 when it is cold the fuel map will still work upto 12lbs of boost. I would always set the MAX BOOST 2 pounds higher to makeup for the boost spikes. Okay next...

Still in menu 9 set the vent learn to ON and reset all of the vent values if you want 10 pounds and the vent on 10 is say 72 change it to 60 so that it resets it lower. Save this and then start to drive. Remember that the computer is LEARNING the car make sure it is warm and make sure that all of the values in menu 6 under press are set to 10. When tuning these cars I have found that it is best to go WOT from 2000RPM to 7500 rpm I would recommend 2nd or 3rd gear. The reason I take the car so high in the rpm range is because if you do not it will fall on its face if you do runs from 2000 to 5000 and when you hit 6000 rps the boost will drop off and not learn the upper RPM ranges and if you stomp it say 6000 to 7500 5-6 times when you go from 2000 to 7000 it will spike at 6000 and you will have to remap the vent learn to fix this problem. Do it right the 1st time little traffic and on a interstate road. after you get 10 10.5 pounds about 6-8 runs turn the vent learn OFF. if you leave it on it will keep getting higher and higher 10 pounds will become 12-13. I spoke to doug on this and took him for a ride in my car with the boost set to 10 and I hit 14.5 pounds. He is working on a fix. also a rule of thumb is after 10 pounds go -1 timing per pound of boost.

Also do not go into menu 5 I think it is no2 n2o whever I did this and it set my idle fuel to -15 and messed with everything in the computer. Also working on a fix.

Known problems:

Boost spikes. If you go say in 3rd gear and hit say 6000 rpm and both turbos are on let off of the gas and at 4000 stomp it boost will continue to climb if you try this BE CAREFUll and keep a eye on the boost gage it is worse if you are running 12-13 pounds of boost.

Running rich. The computer from peter is almost always set RICH I would recommend a setting of .84.82 on the o2 voltage. I like to start out rich say .86.88 then get it down to 82 84 I would rather spend $10 on plugs then $3000+ on a engine.

Things in the works. I am going to remove the air pump but when you do it goes rich. I am going to leave my car with doug EFI for a couple weeks to see if he can get this resolved.

Also the boost spike he is makeing some software that will lock the turbos say the 1st turbo get 12 pounds it will only let the 2nd turbo make 12 pounds as well. He thinks that this will fix the boost spike problems.

Also make SURE the car is warm the O2 does take a little while to warm up it is rich untill it warms also watch the o2 in 4th and 5th to make sure it does not go below .80 if it does at 2-4% more fuel. I found that it goes lean in the upper RPMs I add 2% more fuel at 6000 and 7800rpms.

If you have any questions let me know. I hope this will help some people and and save some money for people.

Happy tuning

_______________

Date: Thu, 14 Aug 1997 22:54:50 +0000
From: "Dave Girvan" (fd3s@sprynet.com)

GREG WROTE:
> Just need to make sure everyone is on the same page.  Anyone with a
> PMC and the O2 sensor hooked into the ECU should get the following
> results:
> 
> The goal for maximum performance (with those '7's equipped with a
> PMC) is ~.80v O2 on boost whether a car has cats or not.  The difference
> would be the global variables and input settings will be higher for fuel
> with no cats.  The end result, ~.80v O2, is still the same.

Greg, how much of a power difference are we talking about, if you are tuned to .86v O2, under full boost, with the PMC? (versus .80v) I was told .84v on the O2 was about as lean as you want to go. I'm running .86v on the O2 now at 10 psi max boost. This feels slower than the stock ECU with 7 psi on the wastegate spring. (Profec off) I'm running only 10 psi, because I still have the stock IC and it's been 100 degrees here lately. (ASP Racing IC on backorder) ;-) FWIW, I had the 3k hesistation bad with the stock ECU, it's gone, with the PMC. Here's the setup...

3" Mindtrain Ceramic coated downpipe
3" Custom ceramic coated mid-pipe
GReddy cat-back
Pettit 3-wire O2 kit
RS Akimoto intake
sans air-pump
GReddy Profec
PFS PMC Gold computer with keypad

Also, how much fuel are you guys adding under the max boost settings in menu 600? I realize each setup will be different, I'm just curious and want some general numbers. I'm adding up to +14% at the higher RPM ranges...

________________

Date: Thu, 13 May 1999 10:19:57 GMT
From: skan@ticnet.com

I use one map for all my boost. I optimize my fuel map for the high boost setting (14.5psi) and it seems to work fine from 7-12psi. Here's my fuel map below:

rpm     2200    4000    6000    7800
fuel    +14     +24     +28     +32
timing  0       -2      -3      -4

Max boost setting is at 10psi (it does something for the fuel map if you switch it to a different psi level)

Please note that I maxed out my duty cycle at 6krpm. The only reason why 7800rpm is set at +32 is that I believed the PMC only reads the primaries duty cycle and not secondaries. Therefore, I think the secondaries wasn't maxed out when it says it did.

BTW, I'm using the good old Gold box. (had it for 5 yrs) Please don't use my fuel map since my car is totally different than everybody else. I figured that it may be fun to add mine in there for the kick. My car also gets 21-22mpg on highway by leaning out LL and ML from the PMC.

________________

Date: Sat, 08 Apr 2000 01:23:41 -0400
From: Wael El-Dasher (wael.el-dasher@efini.net)

> 1. What does "vent" learn actually mean?

It means it will maintain your boost setting and compensate within a range (about 10% +/-) for varrying conditions, such as ambient temp. altitude...etc.

> 2. what are the +'s and -"s of haveing the "vent" learn on or off?

You always want it on.

> 3. How do i change boost settings

use the switch.

dataset 1: 10psi primary/11psi secondary
dataset 2: 12psi primary/13psi secondary
dataset 3: 14psi primary/15psi secondary

> 4. Why am i getting very low 02 readings ("0", sometimes "15-65") during idle,
> i thought our cars run rich during idle??

Because there is no boost. You want it to be in the .74 range when no boost is present, and .88 under boost.

I am assuming you bought the system from PFS, if you bought it from EFI then you have to set it up, ie select twin turbo, put in fuel maps, set boost for each...etc.

_______________

Date: Sat, 08 Apr 2000 08:23:26 -0500
From: Gordon Monsen (gmonsen@fast.net)

Just to expand a bit on wa-el's comments:

3. While Peter usually sets the boost as Wa-el describes, the way you change boost is to use menu 4(00) and adjust your primary turbo boost to be one psi less than your secondary boost. Menu 9(00) lets you set the max boost for the car under any circumstances.

4. The reason that your readings will fluctuate over a wide range is because you're in closed loop mode and the air pump at idle is injecting a lot of air when the O2 sensor tells the stock ecu to add air.

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