RAdkins

Does anyone have any experience in the AiM PDM system? I'm thinking about using this system in my 1978 911 IROC build. Also, what are the basic set of sensors that I should have for data acquisition?

Thanks,
Ryan

ProCoach

The AiM PDM is a great combination of power distribution and data collection, along with a powerful display.

The sensor suite should include at a minimum those measurements you need to evaluate the health of the car. RPM is included, but oil pressure, oil temperature should be added at a minimum, possibly fuel pressure, fuel level, the latter depending on your fuel tank/cell situation.

For driving, throttle position, brake pressure (x2 only if you have a balance bar) and perhaps steering wheel (which allows you to also measure steered at-the-tire) angle are the minimum.

Lots of other things that are powered will need to have a button box connected to the PDM to control them, wipers, ignition, fuel pumps, DME, lights, brake lights and others. It’s not a project for the faint of heart, but now is the time if you’re doing a bare tub rebuild.

Recommend you source and work with the shop that will be doing (or locally assisting with) the work. That way fewer calls, less finger pointing and better outcome when it’s all done.

I no longer sell the hardware, but I can recommend several folks if you want to PM me.

RAdkins

Thank you Peter for the information. I was planning on using AiM for the data acquisition system and I saw the PDM. It will make the wiring a lot easier. What data would you want for helping a student?

Thanks,
Ryan

dgmark

Is it going to be a race car or a street car,. The first decision is a PDM 32 or 8, If you need more than 6 circuits get the PDM32 the circuits get used up quickly I did a PDM 32 on my 996 race car over the winter and used 2 High power circuits for the wipers. Lots of time in the setup but I have Antilock brakes and lots of other electrical loads., unless your are extremely OCD about the wire color get the premade harness, The unit is extremely flexible, If you can think of something you want it to do you can most likely program it to do it.

RAdkins

@dgmark It will be a dedicated race car.

ProCoach

I’ll be the first to say that unless you are willing to learn and invest in the significant amount of time to collect and interpret chassis data (suspension travel, ride height, rake, roll stiffness, tire pressure, tire temperature and brake temperature), I don’t recommend you start with those, as they can always be added.

You and I would want to look together at throttle pedal position, brake pressure (again, x2 ONLY if you have two master cylinders and a balance bar, possibly if you have a manual, driver operable bias reduction on the rear brake hydraulic circuit) and steering angle. I think wheel speeds might be the next thing, but those are valuable mainly for honing your maximum, threshold braking technique.

You MUST get a camera with this setup, for sure. Proper coaching and self-coaching requires this.

Youll find that the PDM (or any current AIM logger) will break up and present the information in such a way to give you plenty to work on with those three sensors, engine speed and GPS speed.

Simple is better, most of the time.

ProCoach

Without a doubt, I recommend the PDM32. I’m partial to the 10” display, but the 6” would work fine in an older car.

RAdkins

@ProCoach Thank you once again! Yes, I just want to focus on the basics at first.

Matt Romanowski

I might be considered biased, but it's a solid product and a great choice With the exception of a few specific ways people look to do things, it's a great choice for older cars when you rewire. Having guided customers through a lot of installs, there are certainly some tricks to make things easier. The biggest has already been pointed out in the Plug and Play Harness. I developed it before the PDM came out and keep them in stock. I figure it saves the average user about 40 hours of work.

For sensors, I would want to discuss what you are going after and what you have planned. You will certainly end up with oil pressure, oil temp, RPM (different ways to do it), brake pressure, GPS measures, steering position, and throttle position. From there, you can choose what you want to add right away and what you might want to add in the future as it will determine how you lay the system out. While tire temps are not as inexpensive, I think it's almost a requirement to run my $225 TPMS system.

The PDM is a planning exercise. You are creating the car's electrical and data system. From things like if you are going to have a keypad, how you will turn the PDM on, and what you want for switches and controls. The better you plan, the cleaner the install and the better the outcome. The other part is availability of hardware. I have a PDM32 in stock along with all the dash options.

Even if you don't get your PDM from me, I would highly suggest you work with someone that will support you and has done a few. There are a lot of small things that will make a big difference.

Frank 993 C4S

Regardless of what system you decide to purchase, what you will want is

RPM
Oil Pressure
Oil Temperature
Barke Pressure
Throttle Position

That will get you pretty far.

grega99

I'm currently running the AiM PDM 32 system on BMW E46. I love it. Super clean install, expandable and currently working great. It was involved to install but worth the effort. A couple pics during the build below-

8 button keypad in front of shifter. 6" Display.


PDM32 with the orange power connector.

RobT 394

Since you are in N Alabama, you might take a day trip to see the Goldcrest crew and check out the 87 they built for me. 100% of the stock electrics were pulled and replaced with PDM and C127 dash. We used Motec as opposed to Aim, the result should be the same. While expensive, the PDM was worth the money as we have never had an electrical gremlin other than water in the ECU which we had to keep to be class legal. I wish I could say the same for my air cooled street car! Getting rid of all the relays was priceless.

lowside67

There is no question the AiM PDM offering is great value compared to a Motec system. But I think it's worth being aware that it's pretty new and from the looks of the online support groups on Facebook, in typical AiM fashion, there are many little bugs and kinks still being worked out. These may not affect you at all but conversely might be a frustrating part of teething. I'd echo strongly you need to buy it from a dealer who will sell you the hardware and configuration/wiring help - Matt (in this thread) has been active in supporting many PDM installs and would be a great choice.

You might also consider a Motec PDM offering - more money for sure, but once the harness is built, as a %, it's not that much more and is a much more mature and true top spec product.

-Mark

ProCoach

Having sold both, I’d agree!

Slow RSA

+1 on Rob's Motec set up...and the whole car in general. WOW. If you want to run modern electronics on an air cooled car, I'd second the guidance toward Goldcrest. They did my MXL2 for RPM, brake pressure and pots for throttle/steering on top of the normal internal capabilities on my RSA. It's a lot of good info. We run Aim PDM32's on our Honda Civics and like it was mentioned before... learn everything you can, what the rule book says you can/cant do, what you want now and what you want later, etc. You (to make life easier in the long run) have one shot at building a clean/complete harness upfront. Don't squander that opportunity while you have a bare tub.