I have been developing a new DME SSR (Solid State Relay) for the Porsche 944/968/924S/964/968/993, and now have prototypes ready for beta testing. Only four of these are in existence and I am looking for Porsche enthusiasts in the Phoenix area who drive one of these cars as their daily driver to test one. If you’re interested, please sent me a PM. Keep in mind, these are not production units, there are a few of changes that will be made on the final version. All of these changes are very minor, the most significant being the small green wire (look closely in the picture). Once production units are ready, I am going to need these prototypes back, but I will give you a shiny new one out of the first batch for helping me test.

Here is a picture on the new Solid-State DME relay next to a factory DME relay:



Some Information about the new Solid-State DME Relay

I think everyone is aware the OE relay suffers from various issues that cause no-starts and other erratic and shall we say “interesting” behavior. Lots of guys, including me, keep a spare relay in their glove box just in case. And I suppose I could have just bought a new OE relay form Porsche or one of the OEM or aftermarket options. But I am basically a 944 junkie with an engineering degree, so enviably I was going do a full redesign and make it better. The main issue with the OE relay, in my view, is cracked solder joints. The reason this happens is because the mechanical relays are made of metal which is heavy. Combine that with several amps of heat, constant engine vibration and one to three decades of driving… Yep, cracked solder joints. Even if the joints are re-soldered they will eventually crack again at some point in the future. But that’s assuming the relay armature and contact points don’t wear out first. In comparison, this new Solid-State DME relay is less than half the weight, which will preserve the solder joints indefinitely. Plus, it has no mechanical parts or contacts and therefore cannot “wear out”. And because I have way too much time on my hands, I went ahead and put in a timing circuit that primes the fuel pump for two to three seconds when the key it turned on. This is a standard feature on most modern cars because it helps bring the fuel pressure up before the DME/ECU starts firing injectors. It's a handy feature if you have opened you fuel system and want to bleed out the air without cranking the engine. And a nice no-start troubleshooting aid because you can faintly hear the fuel pump cycle on KOEO.

I welcome everyone input, so please don’t hold back with the question and/or comments.

 

if I was in USA I would be in there. keen to see how this pans out being a technology nut myself.

Keep up the good work.

 

I'll do it. I'm in Connecticut, but my C4 is my daily. So happy to help if you want to send one

 

I would be interested once finalized. Not local and engine is being rebuilt so would not be able to be a beta tester.

 

Would do it in a heartbeat but I'm in Canada.

 

Things like this is why I love this forum and the people on it. Not everyday can someone try and do something a little better than 25years ago.

 

Sign me up if you go into production.

 

I am in the us (Ann Arbor MI) and daily drive mine during the summer and can test if you'd like

 

I am in Nebraska if you need a tester in corn country ��

 

Same here. The fuel pump prime is absolutely brilliant.

 

I am in Canada (west coast), would be more than happy to help you out testing one of these, will even pay round trip shipping. :-))
Keep us in the loop, as I will buy one when ready for production.

 

in in for one once they go thru beta - nice effort, looks great!

 

Ftech9 - truly amazing, I echo the sentiment about rennlist having great people. Please include me in a final unit. My car is in San Diego but as it is a work in progress not much help with assisting in the prototype stage.

 

Very cool. I too drive my 964's daily if you still need a volunteer.

 

Also happy to test it on a 964. Also interested in production unit. (I have opened an old defective unit to do a modest failure analysis and indeed solder joints are the weak points - as expected.)