964 Engine W/993 Intake ECU etc

[jamesjedi]

Hi,

This is a cross post from the 993/964 forum. Did not get much response.

Hope fully someone can help me here.

Can I run a 964 (M64-01) engine with 993 ecu and intake (throttle-body etc) with 964 injectors?? Or, If you have a better idea, please let me know (cost is a factor).


Here is what I have;

- M64-01 964 long block.
- 993 plastic intake (with throttle body)from another project
- 964 aluminum intake, with 964 throttle body
- 993 wiring harness
- 964 injectors
- engine Group B Super Cup (964.246.071.2) cams installed w/0.57 overlap
- 993 headers w/flipped flange

Any help would be greatly appreciated. I really want to get this thing running!

[jamesjedi]

Just for fun....a picture;

[Trophy]

Most people believe that the 964 Injectors are HP restricted.

Although the car will run, the best injectors to run with the ECU would be 993 Injectors.

[jamesjedi]

What is max hp for 964 injector?

There seem to be diiferent flow rate numbers on this site.

Came across a Ren. post stating that the 964 injector could be good for 305 hp with increased fuel pressure?

[Trophy]

The 964 Injectors flow 194cc/min (18.48 lb/hr) The fuel pressure for 964/993 engines is 3.8 bar or 55.1 psi.

If you plug these figures into most injector calculators you get a max HP of approx 212, which falls well below a 964's 250hp.

If you plug in a HP goal of 250 hp with 55 psi fuel pressure and 85% duty cycle the calculators call for 229 cc/min or 22 lb/hr injectors which are well above what the stock ones are.

993 Injectors are rated at 233 cc/min (22.17 lb/hr) @ 43.5psi or 261 cc/min (24.9lb/hr) @ 55 psi

[Steve@Rennsport]

Originally Posted by Trophy

The 964 Injectors flow 194cc/min (18.48 lb/hr) The fuel pressure for 964/993 engines is 3.8 bar or 55.1 psi.

If you plug these figures into most injector calculators you get a max HP of approx 212, which falls well below a 964's 250hp.

If you plug in a HP goal of 250 hp with 55 psi fuel pressure and 85% duty cycle the calculators call for 229 cc/min or 22 lb/hr injectors which are well above what the stock ones are.

993 Injectors are rated at 233 cc/min (22.17 lb/hr) @ 43.5psi or 261 cc/min (24.9lb/hr) @ 55 psi

Just remember, if you swap injectors without adjusting duty cycles, you'll have a very rich running engine. The vast majority of 964 software was tuned for OEM injectors so 993 injectors requires either custom software or converting to Motec and mapping the engine.

[Trophy]

Absolutely. The dead times can be very different even between injectors of the same or similar capacity.

I think in this case since he is looking at running a 993 ecu, the best simplest option is to run a 993 Injector as well.

[jamesjedi]

Thank you to everyone who has replied.

- I will use 993 injectors. Great.


Ok... does this mean I can run 993 ECU/injectors with a 1995 993 intake on the 964 engine? or, should I use an aftermarket ECU? Remember that i have the cam as well.

This is beyond my knowledge, so help would be greatly appreciated.

[Trophy]

Steve would be best on this regarding the cam choice and the compatibility.

For stock or mild cams the setup should work fine.

To get the most out of your setup of course an Aftermarket ECU would be the best option, however if you are on a budget this may not be a good option.

[jamesjedi]

Does anyone know if the 993 injector stack will fit a 964 cylinder head? are the 964 for and 993 injector holders the same? Thanks again for any help.

[RSstop]

The 993 and 964 intake manifolds have the same bolt pattern. The 993 are slightly larger bore at the base, so you will need to open the 964 intake port to match. The fuel rail mounting is different, but as long as you are using the 993 fuel rails with the 993 manifolds, it will bolt right on.
This 964 engine has 993 manifolds and fuel rails. I did this so I could install an adjustable 993 style pressure regulator.

[jamesjedi]

Thank you for the explanation and pictures. I really appreciate it.

If I use the 964 injector holders, will the 993 injector fit in it? I want to avoid taking a cylinder head off and getting it machined to have the 993 injector holder fit.

[RSstop]

Yes, 964 and 993 injectors are dimensionally the same. You will need to use the 964 fuel rails with the 964 base manifolds. The stand-offs are shorter. You could try to use spacers and longer bolts with the 993 fuel rail. I haven't experimented with that.
The 993 fuel plumbing is much cleaner with less flex hoses.

Here is a photo of the 964 plumbing:

[jamesjedi]

I just bought 993 injectors (thanks Trophy).

Thanks to everyone for the input and pictures. Engine management is a steep learning curve for me.

I just measured my intake port. They are 43 mm. Previous owner had them enlarged for TWW ITB'S. I can now use the 993 intake manifold with my 993 injectors and runners.

I understand that the aftermarket ECU (Motec, or more cost effective DTA) will get a little more out of the engine, but can I use the 993 ECU and have a chip ordered from either Wiener or Steve Wong and have it run well?

Engine has;

- Group B Super Cup (964.246.071.2) cams installed w/0.57 overlap
- 993 headers, Valves are stock 964 but have a three angled seat, with slightly enlarged intake port. lightly polished. Stock springs.
- The rod bolts and head studs are Raceware


At a certain point there are diminishing returns. However...I really would like a 300 hp motor.

[Sboxin]

Looking very good !!

IMHO --- you might want to call and talk to Steve W about the 993 engine
management system on your engine.

Long PM sent . . .

Regards,

[Deadeye]

I also would recommend Steve W for ECU alterations. ECU Doctor in FL is another resource, but not as specific as Steve will be.

[jamesjedi]

I spent acouple of hours yesterday (on vacation w/very slow internet) reading about chips. Very entertaining and only somewhat educational. Lorenfb and the Steve Wong supporters. Summed up....a lot of opinions. However, a very important observation - is that Porsche engineers were smart people, did they leave that much room for improvent? They spent millions on the development of their ECU.

My engine will not be OEM...will benifit from custom chip.

[mreid]

Porsche engineers also had to deal with emissions and sound control. You do not. That's HP, baby!

[Spenny_b]

Originally Posted by jamesjedi

I spent acouple of hours yesterday (on vacation w/very slow internet) reading about chips. Very entertaining and only somewhat educational. Lorenfb and the Steve Wong supporters. Summed up....a lot of opinions. However, a very important observation - is that Porsche engineers were smart people, did they leave that much room for improvent? They spent millions on the development of their ECU.

My engine will not be OEM...will benifit from custom chip.

Funnily enough, I've just been reading the exact same (somewhat tedious) Rennlist thread...talk about gloves off, haha!

Good job that there's no fear of the fight continuing on this forum, according to "that certain somebody" (no prizes for guessing), us Pelicanites are just a bunch of car polishing technical numpties

[jamesjedi]

Contacted Steve Wong...$675 for chip. It is a simple and proven method. Expensive.

He was not sure that the 1995 993 had 43 mm intake port. I see that Bill V has it on one of his posts - but it was far vario ram motor.