Gus

Thanks Larry, are you on my payroll? LOL .

NineMeister

Install almost complete, preliminary dyno tests clearly show the 2500-5000rpm advantages of the Varioram conversion with Motec. More details when we are done.....

geordie

^ Subscribed!

Time to pull that engine sound though

Gus

9M -
Impressive numbers, your path follows mine pretty close but you have obtain more torque and HP.
Is that a stock 964 engine that you added the Vram to plus the MOTEC tune?
What is the red line rep of??? without the Vram???
Lots of questions on the set up, timing and fuel VE - but don't want to get personal.
Will be interested in what your final numbers are .

robt964

> What is the red line rep of???

According to the annotation lower down on the display it's 'pre motec conversion' power run.

Big hike in mid-range

Gus

I'm not sure if that is correct. If I look at my dyno charts the red line on 9m's chart is more reflective of my dyno pulls be for I installed the VRAM.
The VRAM gives you that significant torque increase that starts in the 3000 RPM range.
With out the VRAM you don't have that radical climb in torque.
9M, your charts so call the shot.

axl911

9M,

Do you really need the Motec for the Vram? OR can you just get by with adding a set of RPM switches to control the vram flap?

NineMeister

The red line on the graph is indeed the pre-Motec pre-Varioram result for the standard 964 engine which had been remapped, the blue line is the result from the first dyno pull with the intake and Motec. I should stress that the engine is completely standard and not rebuilt so we will be expecting a little more should we rebuild the top end.

NineMeister

The car was initially scheduled for the Motec conversion only, then following discussion with the owner he found a Varioram manifold for sale and the rest, as they say, is history. We simply re-manufactured the 9m Motec wiring harness to include the Varioram and Resonance flap functions, hence no switch required. My opinion is that fitting VR to a 964 with a stock ecu is a pointless exercise since the ecu and injectors will not fully support the increased airflow of the VR manifold.

ras62

Previous 9M results without VRam using Motec seem to produce much higher torque and power? Am I reading this correctly?

https://rennlist.com/forums/964-foru...version-2.html

NineMeister

If you read through the posts on the thread you will see that the 964 engine in question had a top end rebuild due to a bent intake valve. Naturally at 9m that would involve a fresh valve job and optimisation of the camshaft timing......

NineMeister

Here is the dyno graph showing the increase in torque right across the board from the Varioram/Motec combination.

ras62

It seems the earlier non VRam conversion on Motec still produced quite a lot more torque / power. Is that because the VRAM is not optimised to the 964 heads or does this recent engine need a refresh?

kos11-12

does the VRM engine give best torque at all RPM, as it decreases/ increases the length of the trumpets automaticly inside the plenum.
is this set up heavier, (at the back)....
are 993 heads better than the 964s, port and valve size, this is why the 993 engine give more power to start with, regardless of the VRM, injectors size, ECU or mapping ?
are the late 993 engine cams different ?

NineMeister

The non-Varioram plastic intake system makes more torque at exactly 5000rpm whereas the Varioram makes more torque everywhere else in the rpm range.

Heavier, yes slightly, less so compared to the alloy 964 manifold of course.

No, in my opinion the 964 heads have superior port characteristics than the 993 head in spite of the larger valves of the 993 heads. In otherwise identical engines the one with the 964 heads will make more torque. To date we have not managed to measure a meaningful performance increase from the 993 exhaust either....

The 993 and 964 cam have very similar lift curves and performance, the main difference between the two are the longer opening ramps of the hydraulic 993 camshaft.