Raceboy

I performed a VEMS standalone ECU install to my friends 1992 Porsche 964 C2.

As the car has around 100 000 km's , the wiring was perfect and the Plug'n'Play version of VEMS was the way to got (with Motronic 55pin connector). I also changed the injectors to 993 units because stock ones are very small and barely capable of handling stock power.
I ditched dual ign. dizzies and went to two Bosch 3x2 coil-packs. To use these, I fabricated sort of adaptors for connecting stock ignition wires to coil-packs. They are shape of bullet, one end goes to coil-pack and then you just plug the wire to coil-pack. Rubber-part of the ign. wire fits fine to coil-pack.

I made additional wire harness for power grounds, Wbo2 and ignition outputs (stock system uses just one TTL level ign channel).

Removed stock AFM and filter housing and installed aluminium pipe and Apexi Power intake (on the dyno, removing air filter didn't add ANY power, not a single kW )

I set the resonance plate to open at 5500 rpm, earlier than that caused a small valley on the power curve.

Testing was done on Superflow chassis dyno.

Here's dyno chart. Lower values are with stock ECU (it produced 156 rwkW).
There are number of runs, I left the violet one to ECU as I made the ignition a little bit safer side. This car uses stock catalytic converters.

Gus

This looks really good - do you have any pictures of what you fabricated and the install -
VEMS is mostly a European - correct- Went to the VEMS site but only saw a VEMS v3.x ECU with Motronics55 -for Audi, BMW and Peugeot - They did have one line on Porsche which was
Porsche (usually with 60-2 crankwheel VR sensor) tested with harness-adapter loom (with standard Econoseal36+18 VEMS and adapter outside). If you have such an engine, make your project page(s) from wiki MembersPage so we can help verify the application, pinout and other aspects.
Is this along the lines you followed ?? Did you install wide ban O2 sensor? or did you even use?
I am interested as have been looking for an economical solution to current MAF issues -
What did project run -

RallyDogRacing

Check with Marc Swanson of EFIExpress.com - he's a USA based VEMS distributor and just delivered to me a VEMS converted Audi 200 20v Turbo that I'm going to use as a motor donor for my 85 Audi UrQuattro.

During that process he converted it to individual coil-fired vs. dizzy based and uses the entire stock engine harness so no need to create timing wheels. My first few uses of the VEMS software front-end are very acceptable to me. Previous experience with 034-EFI, and then ancient Autronic stuff. His harness wiring work is top-notch as is his customer service from my experience.

I personally think after I'm done with my UrQ update I'm going to be very, VERY tempted to do a VEMS 964C4 conversion and if possible use Turbo 3.6 exhaust manifolds to create a narrow-bodied C4 3.6 turbo albeit relatively low pressure on the turbo.

So if I interpret the results correctly the VEMS converted normally aspirated car is producing:
219 lb/ft of torque @ 5000'ish RPM
209 hp @ 6200'ish RPM
both of which are at-the-wheels.. Or do I have those numbers inverted?
What are non-tweak'd/converted numbers at the wheels other people are seeing?

Geoffrey

993 Injectors are marginally larger than 964 injectors, only about 2lb/hr larger.

Gus

In re-looking the graph it shows a down turn in power around 5200 RPM - the engine should still pull on out to 6400 -see graph - this a standard dyno run for the 964-
Sorry if it comes out side ways-

Raceboy

I'll ask the owner to take some pics of the setup.
Wideband was obviously used, can't tune without it, can you It is in place the original NB O2 sensor.
Since I'm VEMS distributor in Estonia, I performed the PnP job. It costs 888EUR as for any VEMS PnP ECU.

172 kW at the wheels equals 233 hp at the wheels, and 296 Nm at the wheels, with VEMS. With stock Motronic the car produced 156 kW at the wheels (212 whp).

I searched both using Bosch part numbers and I found a bit bigger difference. Since I had 993 injectors laying around anyway, it was a no brainer.

This was basically only a road tune and we measured on the dyno. We did only minor tuning fiddling with the resonace flap. It did like 5500 rpm as actuating it earlier made power come down for a few hundred rpm, then back up when it was engaged.
I think you misread the graph.

Violet lines are current tune lines, upper ones are torque, lower ones are power. Green and dark blue ones are with stock Motronic.

RallyDogRacing

Does anyone happen to know if the Turbo 3.6 manifolds are able to bolt-up to the standard 964 3.6 NA engine/heads/cyls? Meaning: are the manifold stud locations, exhaust port sizes similar enough to make my goof-idea even possible?

I suppose the el'cheap-o solution would be to put the turbo roughly where the catalytic is and move the cat to the center muffler and if needed re-install the secondary muffler... Might not be ideal exhaust pulse paths, but it would certainly be low-cost to get the hair-dryer bolted in...

What is the stock turbo on the 3.6? I'm thinking I need to go look at the compressor map...

Raceboy

Some pics:

Raceboy

IIRC stock turbo for 965 3.6 is K27 7200. There are map's for it floating around.

Sorry, can't help you with the manifold stuff but going 3.6 NA is really the correct way since it has twin-plug heads. And narrow-bodied turbos rule

Cheeksyboy

Hey Raceboy, what's with the unusual distributor setup? Is that part of VEMS?

Geoffrey

The 91/92 3.3 turbo is based on the older engine series, has 2 bolt intake manifold, has 32mm ports, so it won't be s bolt on. The 3.6 turbo is based on the same 3.6 block but the heads, ports, etc. are all different. It would require modification to make it all work. A 3.6l engine makes a good twin turbo conversion. There is enough baterial on the piston to mill the compression down to a reasonable level for a turbo application. The only thing that might become a problem is the material the heads are made from. It wasn't until 993 model that the N/A heads used the RR350 aluminum alloy like the turbo heads. However, I haven't seen problems when used moderately.

That isn't a distributor in the picture that is a wasted spark ignition module. You'd probably see the other one on the other side of the engine.

Gus

He did away with the dizzies and replace with coil pac's linked to the VEMS system - re read first post

Raceboy

Yes, those are Bosch coil-packs and both of them are at the same place were distributors used to be. If you look closely you can see the second one on first photo also.

N51

Why the Bosch coil-packs? The dual distributors work well.
Was the exhaust the same in both tests? If so, was it stock or modified?

Thanks,

Raceboy

Bosch coil-packs were the choice because they are cheap, allow to get rid of moving parts and no, the stock distributors don't work well when something happens to the belt between two distributors.

Plus I have better control over spark with direct igntion.

Exaust was exactly the same stock and it still has factory fitted cat. That will be changed to sport cat soon.

As I mentioned, all engine hardware that affects engine breathing (sans AFM) is stock.