Porsche Enthusiasts Club Forum

I've been reading that you can put a later ecu and afm in a sqaure dash to improve bhp.
I've got a 2.5 lux. What would I need for this?? Does it have to be certain year non turbo??

Thank for your help in advance.

sounds like rubbish to me.

the post 1985 ecus used a different air flow meter. I think there are other differences too.

AFAIK all 2.5 8v 944s were 163hp, the 924s was 150.

Yes, I've also read something along these lines - I think on an American site where they had produced a hybrid early 944 ECU which was based on the EURO ECU settings but improved with more modern electrickery to replicate some the later ECU benefits....if that makes sense.

This is understandable because early 944's in the US were significantly less popwerful than the ROW cars....can't remember the figures exactly but I think US cars were less than 150bhp v ROW at 163bhp.

Don't know if the fix is genuine or snake oil though.

Jon

If you can cope with reading this eye-straining website, it details the parts you can replace from a BMW ECU to make the early 944 chipable, and therefore tunable. The website is so horrible I can't work out how these two pages are linked, so I'll link them both separately:
BMW Logic Board
Chipping My Early 944?

Also, from a well respected TIPEC member, is AugTronic. His website is here:
AugTronic - New Porsche 924/944 Plug and Play ECU Upgrade

He clearly states on that site of currently supported vehicles:
Porsche 944 2.5 8V < 1985.5 (Requires > 1985.5 Control Unit)

You certainly CAN swap an early / series one ECU for a later series two plastic type, but you need to fit the matching airflow meter and injectors, too.

This is the only way to fit new lookup tables into a series one car, unless you have a very rare metal DME with a removable EEPROM: 'chipping' in common parlance.

That's the first time I've heard about injectors

http://www.944online.com/cgi-bin/forum/ ... 1294430855

I thought it was the cam offset that restricted the USA power out put.

I thought they had different compression ratio as well.

Still confused about the injectors I've read a lot now but nowhere have I seen
You need to use newer ones. Has anyone actually ever done this????

The part numbers are different for the later DME cars, however, the flow rate is very similar.

In the past when I have updated the DME on a pre 85 car I have just changed the DME and Airflow Meter, not the injectors and the result has been perfect.

The airflow meter is required to be changed because the relationship between air consumed and voltage output from the airflow meter is completely different for the pre 85 and post 85 cars.

It may be that the slight difference between the early injectors and the later injectors would result in a very slight improvement if both used from the later car, however it may be that the use of the airflow meter and DME alone with the older injectors is one of the contributing factors of why the early cars, with early injectors, seem to pull so well.. I had always put it down to it being a lighter car, however it could be a contributing factor that the dynamics of the later DME and AFM on early injectors actually produces more power.

No evidence either way I am afraid, but if my time was limitless I would investigate further.

In short, injectors for Lux cars are next to worthless, so if you buy a DME and airflow meter, get the vendor to include the injectors and do your own testing and let us know of any difference you notice... However if you already have the DME and AFM without the injectors, don't loose any sleep over it...

The DME and AFM was all I changed, not had it on the road yet but it seems ok

The injectors work at a different line pressure, so they have to open for a different amount of time to flow the same amount of fuel. Thinking on: the fuel pressure regulator should be changed too.

Details of the injectors can be found somewhere on F.R.Wilk's brilliant/terrible website.

It seems ok but I do have the parts mentioned above that match the later DME and AFM so might just fit them before the car goes back on the road.

I know the flow rate is very slightly different, but the fuel pressure regulators are both 2.5 Bar ones.

You have me thinking I am mad now...

Here is where the confusion comes from.. FRWilk lists on his site the pressures that Bosch rated the flow of the injectors at, not the pressure in which they are used on the car.

I will run some calculations on corrected flow to the pressures of the application and post them here