Bill Verburg

Undiagnosed leaks, yes

no egg carton but I do have 2 brand new oem '95 993 cans

If I remember correctly most of the vac fittings are NLA from Porsche, I had to use aftermarkets

Gus

Guess I will start looking for the egg carton canister -
Here are some pic's of the Vram I have - you can see what is missing -
So I have a few pieces to obtain before I can install -
Right now the issue I have to solve is - at what RPM does the resonance flap control on the 964 (wired to #23 on DME ) activate. Then at what RPM do the Solenoids and the resonance flap activate on the 993. IF these are not in the same ball park I may have to set up an after market RPM activation switch for the Vram system.

North Coast Cab

I can take some pictures tonight of mine if you want me too. It is basically complete and not yet installed.

Gus

NCCab - Yes, that would be helpful in looking at what I maybe missing a little more in detail verses comparing what I have to the parts manual drawings. Trying to figure out what I have and what I need and where it all goes is interesting to say the least. Appreciate the offer -

North Coast Cab

Gus,
I opened up my box and unfortunately it doesn't look much different. Most of the parts are ther, but they are not assembled. If I get it togetehr I will shoot you a shot of it.

NineMeister

964 & 993NVR activate the resonance flap somewhere around 5500-5700rpm.

From what I remember when I played around with one on Motec, the VR operates the tubes first at 5100 and the flap at 5900. You could compromise and try both on the same signal, it won't be perfect but it will work.

Gus

NC Cab - Send pics when you get a chance - would be nice to compare -

Colin - what is important - The range difference between opening points or when the tubes and flap are opened - You think the tubes open at 5100 RPM and then the flap at 5900. Is this 800 RPM difference what is important - So using two (2) RPM activated switches set at 5000 and 5800 RPM would have the same effect. But, using one switch for both - that say opened both around 5600 RPM would not have the same effect. I the dyno of the 2 993's, the Vram car hit a flat spot in the 5000 RPM range ( appears as the tubes are opening ) but the flap doesn't seem to have that impact - ( Don't have the chart in front of me ) Is that the case -After the tubes are opened the car or the power line settles back down and runs along with the NON Vram car - If I recall there doesn't seem to be much impact when the flap opens -Does this make sense?? _ I need to go look at that Dyno chart again and compare RPM values for the tubes and flap to the Vram performance graph.

JM993

Hey Guys,

As you both know and I am a little farther along on my v-ram conversion. Hopefully some of the attached pics of my parts will help. As I said earlier, there are a helluva lot of small items (including some you wouldn't normally think of) you need for the conversion. Of particular note, you will need to source pins for the ECU connector and bullet connectors for the chassis to engine harness. Hint: these connectors can be found in the 964 section of the PET. I just ordered mine and a lot of other things from Sunset.

Gus, since you have a 964 you will need to modify your engine harness to accept the extra leads from the ECU. For those who have the updated (post recall) 993 engine harness, you engine harness will not need any modification.

Like Tal, I recommend using the later vacuum tank. It's cheap ($17) and designed to do the job. You will also need to source the vacuum tank connector and appropriate vacuum hose.

Please feel free to PM me with any questions you have along the way.

JM993

More pics

NineMeister

You need to set the switch points of the varioram tubes and resonance flap independently according to the requirements of your engine. The very best method is to tune the engine on a dyno in three modes:
1. ram pipes long (off), resonance flap closed (off)
2. ram pipes short (on), resonance flap closed (off)
3. ram pipes short (on), resonance flap open (on)
Do this and you will end up with three dyno graphs, as in the example below. All you do then is set the on points to the rpm at the intersection of the lines.

FYI this dyno plot came from a customer's modified 3.8 litre 964RS on Motec (motec +2) who was interested in increasing top end power to match the GT3's and came up with the idea of running a 993RS intake manifold. Rather than let him spend his money unwisely, I dusted my RS manifold down from the loft and fitted it to make these runs. As expected, the car made lots more torque low down out of the power band but had less torque at peak and with a little more power at the top, unfortunately not enough to make it worthwhile. In the end we fitted ITB's with race cams and added 40hp.....

Gus

Colin - chart shows great info - thanks for the print out - Looks like 5200+ RPM is a good number for the tubes and then 6000 RPM for the flap are the points on your graph - Since my engine will have all stock cams/ internals - my max RPM will be much lower than this graphs max - I will really need to do the dyno runs to plot the graph as you mentioned - Thanks for the feed back, as I had not even considered doing a dyno run to plot the different points - GREAT INFO

Gus

Joe - thanks for the pictures - great info - You got a lot more stuff than I did - Right now it is loking like I may go with stand alone RPM switches to activate the tubes ad the flap in the Vram - can get set up to come on at 200 RPM intervals at any range - this may be easier than trying to track all the wires in the DME - Although Colin talks about using the existing "resonance flap" wiring to activate both - (It looks better on the graph if both tubes and flap are activated separately) I have the resonance wire located - just need to identify what RPM range the DME sends signal to activate -

NineMeister

Don't forget that there is a slight signal lag between the ecu switching the output, the solenoid valve opening and the vacuum actuator reaching full movement - therefore always choose a switch on point slightly lower than the graph says to allow for the acceleration rate of the engine in gear.