NineMeister

Yes, you read it right. We have just completed our first Varioram to Non-Varioram conversion on a late 993 engine. Obviously there is some logic to the tale:

Our customer had just purchased an old 1989 RHD 964 race car which had fitted a late model 993 Varioram engine, but in the course of looking for this car he also had the pleasure of driving a similar 911SC race car that in the past we had fitted with a 993 NVR engine on Motec. Since he was looking for an exciting road/trackday car he decided that he much preferred the throttle response and torque characteristics of the Motec NVR to the Motronic VR in the car he bought, but wanted the more modern 964 chassis, hence he commissioned us to converrt the engine to exactly the same specifications.

Things are never as straightforward as they seem and we had some fun & games along the way. Making the adapter loom from the 993VR to the M48 ecu was a brainache as I had to wire in an additional control relay; had to change the idle valve to a 964 version due to control output limitations of the M48 ecu - which meant that I had to turn up a pipe reducer for the intake elbow; also found that the resonance flap control state is reversed in comparison to the 964 system.

The final discovery on the dyno (at 11pm last night) after strangely having to add 5 degrees extra ignition advance in order to get optimum power was that one of the ignition coils had failed. Since I had a spare coil from my RS engine available, I stayed late into the night to fit it and re-run the full throttle mapping pulls. Here are the results we achieved:

Graph 1 = Car as arrived (VR Motronic) to now (NVR Motec)
Graph 2 = Comparison of final power on 2 coils against best on 1 coil (lower plugs working)
Graph 3 = Comparison of 964 to "Gilbert" - the 911SC with 993NVR Motec

I'm sure you will find the results as interesting as I did....

NP993

Amazing. I assume that when you mention the Motec setup, you're talking about ITB's?

NineMeister

No Noah, this conversion uses a stock 993 non-varioram manifold.

The complete Motec conversion on this car is just an ecu, adapter loom, MAP sensor, AT sensor, intake pipe & K&N filter and a set of injectors - plus the dyno time & knowledge to set it up.

NP993

Okay, now that's really amazing. But I don't get it.

If you're keeping the same intake and engine internals, how do you get so much more power? Without major physical changes, all you have to work with is AFR's and ignition timing. Is the stock Varioram setup so far off that you can get 50 horsepower just by setting things up correctly?

NineMeister

The manifold choice is probably irrelevant on this engine. In my experience the varioram would probably make more power from peak to redline and more low end torque from 2500 to 4000, but the non-varioram would have better peak torque at 5000rpm. With respect to physical changes which yield more performance, clearly by using larger multi-pintle injectors fired sequentially we have better atomisation & full control of the fuel delivery event in addition to the volume of fuel supplied and the timing of the spark. A less restrictive intake (although not a lot less than a MAF) also helps the cause.

I would have expected the varioram engine to make nearer 300hp in standard form, so the coil was probably down when the car came in for the work, hence the low starting numbers. From a 300hp starting point we found 10% by giving the engine a more productive burn event, which is roughly what I would expect from a similar 964 Motec conversion.

bart1

I about broke my left mouse button when I saw this topic.

I love seeing continually impressive results from 9M!

BTW, how far are you guys from Melksham, England?

NineMeister

Cheers, good to know my posts are appreciated.

We're 80 miles north of Birmingham & 200 miles from London, slap bang inbetween Liverpool & Manchester.

Incidentally the car is currently having a 3:32 R&P fitted in the workshop and is planned to be on its way to its new home in France on Friday.

bart1

My company has a plant over there and it looks lie you are 2.5 hours away or so. If I ever make it over, I will try to visit.

JM993

[QUOTE=NineMeister;6770407]Cheers, good to know my posts are appreciated.[QUOTE]

An understatement to be sure

NineMeister

Of course, I meant 8:32 R&P.....

If I get the chance I'll post a couple of photos of the car before it leaves us.

Stealth 993

WOW!
Ok, stock 993 NVR engine conversion, with stock intake & exhaust? You just added the MoTec with new injectors? Then tuned?

That is very, very impressive! It's amazing what a quality stand alone (with proper tuning) can do!! The power under the curve, is amazing, that late torque drop is very impressive. Is that in part to the injectors not falling off, &/or keeping the timing more precise in the higher revs?

NineMeister

It's effectively a stock 993NVR but with the larger intake valves of the VR engine, stock Gillet heat exchangers (I prefer Bischoff) with a custom made cross-over pair of pre-silencers and 993 style side silencers - i.e. no cat(s). Just added a 9m Motec package & around 10 hours of dyno time, resulting in engine performance a fraction below the numbers we normally achieve with a 9m Motec conversion of the 964RS. This is probably to be expected since the heat exchangers offer superior flow in comparison to the 964, whereas the large port 993 heads are not as well optimised as the 964, so one balances out the other.

The torque characteristics of the engine are pretty much down to the design of the cam and non-Varioram resonance flap manifold, all we have done with the Motec & injectors is given the engine what it needs to optimise what it's got.

trophy

Hey Colin,

Looks like a great setup, I have always been a fan of Motec products. Can you give us an indication of the cost of the Motec, Loom etc upgrade? (Not including Dyno time)

Regards

JoeMag

is that little dip at ~5.6k rpm the res flap opening?

haygeebaby

That's heavy duty - impressive. Like +50bhp and +50tq.
What do I need to do to get this upgrade Colin ?