944 Remap: Chip tuning the 944 & 924S

This engine was rebuild 10 yrs ago, aluminium flywheel and balance shafts deleted. All standard spec’s.

Original 944NA has 205Nm 163Hp

This engine made up to 242 Nm 170 Hp, all real data.

 The Benefits

• Better running engine, more smooth
• Pulls better from 1000 rpm to 6000 rpm
• Better economy
• Higher torque and power output
• Gives you more smiles on your face
• Aside from spending money on more power you also did perform maintenance on your car
  as injectors will fail over time.

So I actually cannot find a reason for not doing this maintenance upgrade.

We look forward to your visit.

The set includes 4 modern 4 hole injectors from Bosch completely refurbushed, cleaned and tested for fuel delivery and spray patern. And a completely remapped chip tuned eprom for your ecu.

How we achieved this – the long story

We are very happy with this result, let me tell you how we did this.
When it comes to tuning an engine there are many variables that need to be controlled, otherwise the result might not be repeatable and trustworthy.

Engine
So we started with a totally rebuild engine with all stock internals and factory measurements. The rebuild was about 10 years ago so the engine has had quite a bit of lifetime, probably just like yours.

Reason to start with this engine for base tuning was that it has high compression (a bit over 10.6) so any other engine won’t suffer pre-ignition (engine knock) because of our remap of ignition timing.

Alu flywheel and race headers were added, balance shafts deleted, well yeah it is was a race car.

At the start we made a measurement and it was about 220Nm of torque. Just like it had in the past when I was racing the car.

Dyno measurement
Most dyno’s are wheel based dyno’s. Tire wear and resistance and even differences in strapping down the car can make differences over 10Hp.

Dynopack has wheel hubs so the wheels have to be removed and axles are bolted directly to the dynamometer, the accuracy and repeatability of these hub dyno's are unquestionable. (figure 3)

These dyno’s do not wear so accuracy stay’s constant.

^The dyno pack at DP engineering   ^The wheelhubs connected to the dyno

The Tuner
Well I have met a few tuners, every tuner has it’s own way of working to the result. Pieter from DP engineering is by my opinion the most accurate and sharp observing professional I met.

The facility at Dp-engineering is a very well cooled dyno chamber, it storms with about 150 km/h.

Tuning program
An eprom is written in bits and bytes, 16K eprom, all just numbers with no layout for what the reason is for these bytes.

^ bites en bytes written on a eprom

We now know every table  (Idle, part throttle and full throtte) both timing and fuelling maps. Even injector characteristics can be altered.

Other eproms

For years there have been other remapped eproms for sale for the 944. But they were all for low octane (92) fuel and mostly written for performance only. So I felt it was time for a European version of this eprom. Since our cars have higher compression the output can be higher also. Fuel economy can be better in the midrange. And furthermore we wanted to change the mapping in the future when doing more upgrades to the engine like camshaft, MAF conversion etc.

 No other available eprom has been adjusted for modern injectors !

Variables on your 944 NA

So the goal was to rewrite the complete mapping, write it down on an EPROM, and sell this product to other 944 lovers.  But how can we assure the result is going to be a success on your car?

Well first of all, your car needs to be in good condition of course. Ignition wires, spark plugs, fuel pressure, compression.

But what we experienced over the years is that fuel injectors often fail in giving precise the same volume of fuel. We have tested many Porsche injectors over the past and experienced that spray pattern and volume both can be different between the 4 injectors. (see figure 6). Aside of that changing injectors is usually done in case of a problem and not as part of a maintenance plan.

Almost from every car that we test the injectors do have differences over 5 %, and even upto 20% and still running okay.

So I would highly recommend changing these 40 years old electronic injectors. Just imagin how many clicks they have made over the years.

^ an example of difference in volume of four different 944 injectors

In order to make this a success we went for sourcing a good replacement for these expensive and NLA injectors.

We succeeded in finding a set of modern 4  hole injectors that have slightly higher flow rate (but close to original) that we adjusted for mounting exactly in the fuel rails of your Porsche 944. ( see figure 7) The difference in flow rate is adjusted in our eprom.

 < a four hole injector 

These injectors can still be obtained new but are quite pricey. So to keep cost down we have sourced a professional company that can supply us of many of these injectors. The injectors are ultrasonic cleaned, backflushed, rebuild and tested for spray pattern and flow matched.

The remapping

We spent a whole day on the dyno to prepare, getting the hardware to work and tune all original mappings.

^ the Porsche 944 on the dyno

The result:

The result is what I expect to be the best and easiest solution for tuning a standard 944 2.5 L NA engine.

Extra torque from 1000 rpm up to 6000 rpm. That means you have benefit of the extra power over the whole rpm range! Upto 20Nm can be expected.

Better mileage

Yes, we even achieved that, when driving / cruising your Porsche 944 the mileages will be higher because we have tuned the part throttle map  for economy. You will feel the engine runs smoother in low and higher ranges, And at full throttle the difference in power will be revealed.

Future plans

Yes we have plan’s to go a few steps beyond but that will take more time in developing and remapping and testing and will need more new parts. So for now, this is the best solution. For sure there’s more power in this engine.

• You can sent us your ECU and: 
• we test your ecu at our Porsche 944
• we make the nessecary adjustments for fitting the new eprom
• we test it again
• we sent it back to you including your old eprom seperately and including the 4 injectors

DIY replace injectors.
If you have the skills you can easily replace the injectors yourself.

Make sure you know how to work with leaking fuel.

If not, any garage in your neighbourhood is capable of replacing the injectors.

Driveby conversion.

In 3 hours you are ready to go with your tuned 944. Exchange service extra cost 150 euro incl VAT.
Just make sure you have filled up your fueltank with only octane 98 or higher. If not we can offer you a bottle of octane booster.

Applicable Porsche’s

All 944 8V 2.5 ltr from 1985 / 2 , so called type 2. All 924S with 2.5 ltr engine.

Bosch ECU numbers

The early ECU in 944 is different and cannot be adapted. There is a solution although, contact us for information.

Got excited? Order the part here!