PMS Info thread for all PMS questions


New Member
Mar 14, 2004
Got PMS question ask in here? There seems to be a lot of interest in this so ask all questions in here and go to Troy's informative site @ :nice:

This is copy and paste from another thread I didn't want to hi-jack and overwhelm with Q&A on this subject. :D

BlueOvalStangGT said:
The PMS unit doesnt require a lap top does it? And doesnt one of the tweecer models let you datalog so you dont need a laptop?Im too poor to own one of those foldable computers.
You don't need a laptop with the O4 PMS but if you want to save data logging info you have to have one. Other than that it can be completely tuned by pushing a few buttons and you have realtime monitoring in your view. Here are a few screens that what it can do for you so you get the jist of it ..
This is an O4 AFM PMS by EFI Systems

Main Menu Options
(Each option has a table)

This is the Part Throttle table for fuel

This one is for timing

This is my Idle table

This is realtime moitoring of what I watch when driving

O4 PMS features

* Now comes with global fuel adjustments, which means you can offset the mass air for different sized injectors.

* Air charge temp and Water temp fuel and timing adjustments can now be made from -40 to +250 degrees

* TPS volts are now adjustable: What this means is if you want 1.05 to be idle you put that in. The same with W.O.T. - you tell the PMS what volts.

* NEW! Easier to use controller with adjustments down to 500 rpm increments starting at 2000 rpm

* NEW! for 2004 single data display screens let you monitor spark timing, injector function, oxygen sensor, water temp, air charge temp., mass air voltage and manifold pressure/vacuum

* Start fuel setting, which controls the injector when the starter is turning the motor over. This gets rid of the hard starting with 42 lb. injector or bigger.

* Air Fuel Mixture fully adjustable.

* Idle Mixture and Timing fully adjustable.

* Stand alone turn on is now adjustable: The stand alone is set up to turn on at 3500rpm, which can be adjusted from 2000 rpm to 5600 rpm. The factory EEC has no control in standalone mode. This gives us even better fuel and timing control and now the Rev limiter can be moved to as high as 9900 rpm with a faster processor.

* Total spark and rate-of-advance fully adjustable.

* Two step rev-limiter.

* Two programmable RPM/Throttle output accessory control switches.

* Tunable Nitrous Oxide Adjustment Table.

* Tunable Turbo or Supercharger timing and fuel adjustment up to 30lb of boost.

* Purple anodized, finned aluminum case resists corrosion, dirt and moisture!

* Easy installation in less than one hour.

* Plug in and Run” installations requires no programming—Just start it up and go!

* Increased RAM, EPROM, and EEPROM Internal Memory Capacity!

* Easy “User Friendly” operation—detailed owner’s manual explains all functions.
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New Member
Mar 14, 2004
I never used a twEEcer and was considering b/t the R/T and this PMS when I was shopping. So I can't honestly compare from exp but I know a few people with them and am familiar.

They cost more b/c of the handheld screen plus it's a complete stand alone computer that plugs into your EEC.

The O4 is $857 from AFM
The 3 bar map is $85 for boost table option
UEGO WB is around $550-600 for real time readings on the PMS monitor.


Advanced Member
Sep 28, 2003
Indianapolis, IN
Visit site
I talked to Troy and this is the email he sent me.....

The PMS and TwEECer do have their advantages over one
another, and they work in different ways. The PMS is
simple to use, it modifies the signals going to and
from the EEC with an inline 60pin harness. Your just
modifying what the EEC sees and what it is sending
out. The TwEECer you actually change the tables in
the EEC. The TwEECer you can upload many calibrations
at once. The PMS you just modify the tables in the
PMS. The PMS has Idle tables, 8 part throttle areas
(from low load to high load), WOT tables. This, to
me, is much more simple than changing different
functions, scalers, and tables in the
you need to know what those tables and functions do.
With the PMS you just add/subtract fuel or
timing...very simple and effective.
Things the PMS can do that the TwEECer can't...the PMS
has boost tables and nitrous tables. Using a MAP
sensor or wiring the nitrous solenoid wire to the PMS,
and when it sense boost (or nitrous) it will revert to
your nitrous/boost tables. With the TwEECer you have
to design a program for boost or nitrous, and then
swap to it. The PMS can also turn things
on/ water injection or nitrous. I'll be
using the PMS to act as a window switch for my nitrous
kit. I'll have the nitrous turn on at 4,000rpms and
turnoff at input a TPS percentage and
RPM as on/off points. The PMS also has a built in
Two-Step rev limiter...really nice for 5spd cars. The
best feature is Standalone. When standalone is used
the PMS bypasses the EEC, locks the timing at 25
degrees total and shoots for 12:1 a/f. You then add
in your timing/fuel into the WOT tables. The EEC is
not really consistent on timing as compared to the
Things the TwEECer can do that the PMS can't are turn
off sensors like EGR and smog pump, to help with Check
Engine can tell it where your O2 are
located. The PMS does not access all the scalars in
the EEC like the TwEECer can do.
The TwEECer is lower priced but requires a laptop.
The PMS does not require a laptop, but if you want the
optional software to have more tuning options and
datalogging then you need a laptop. You will see more
racers with a PMS and more street cars with a TwEECer.
Also on telling the EEC where the O2s are...I don't
have my O2s plugged in. I leave them unplugged, let
the EEC havee a default voltage, and then the EEC
can't learn around changes and I just use my wideband
to tune all areas.
Bottom line is they both work, and work well. Both
have good support. For me the PMS was more simple and
easy to use and does everything I need it to do. If
you have any more questions feel free to ask.


15 Year Member
Nov 29, 1999
Boca Raton, Florida
I've had both the Tweecer and PMS. Haven't used the PMS though. The Tweecer is great but I hated to lug a laptop around with it. Probably because at the time my laptop was like $1600. The datalogging was great. For you AOD or AODE guys the Tweecer is what you want. From what I've seen with the PMS in person on a dyno it's just much easier to use and many tuners know how to use them. You can't go wrong either way and saying one is better over the other is just stupid. What's ever easier for you to use then that's the one to get.

I don't have any PMS questions yet but when the car is running I'll have plenty.