924Board.org

[Kenodog]

Hey all,

So I'm gearing up to put on my big boy pants and getting the cars sorted out come spring. In the meantime it's inventory time and ordering what i need so there are no delays in getting these old ladies operational.

One thing I wanted to do to the '79 was a programmable distributor. There was a company in Germany that made these but I don't recall it being names 123 Ignition. Is this it or am I high :

https://www.classicautoelec.com/en/electronic-ignition-porsche/11377-electronic-ignition-programmable-engine-1600-r16tx-ts.html

??

Any help is as always appreciated. The grey matter is trying to rehash the finer details....


Me
_________________
1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140

[morghen]

Here it is

https://www.mittelmotor.de/racing/de/webshop/17887/6557/924-944/4-10-rennsport/4-09/2-4-09103t-neu-detail
_________________
https://www.the924.com

[Carrera RSR]

This dizzy has been on my car for near 10yrs.
_________________
1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
Now www.924board.org/viewtopic.php?t=34690
Then www.924board.org/viewtopic.php?t=31252

[Kenodog]

[Carrera RSR]

[Beartooth]

That's pretty pricey (the turbo version; the NA is reasonable, and I can't think of anything else that'd do the job at that price). Still, for someone wanting full control of timing without having to do a bunch of wiring to run an external ECU, I can't think of any other options. You could buy a Microsquirt and everything you'd need for less though. Then you could either wire in an ignition module to fire the coil and keep the look pretty close to stock, or you could convert to EDIS or coil-on-plug, plus you could run the frequency valve off it as well.

Different budgets and priorities are going to drive different choices, ultimately. Even though it's not cheap, it's great that there's an option like Mittlemotor's distributor. The cheapest thing would be to resort to old-school distributor tuning, although that's a steep learning curve, or you'd have to find a distributor guru (not many of them still around). Just to get more spark, coil and plug wire upgrades would help for relatively cheap. For an all-out effort, I'd lean towards going through the hassle of wiring up a Microsquirt or ignition controller. That'd give you finer control, assuming you went full-on with a TPS, CTS, and IAT. Of course, that begs the question of "why not EFI?" but I wonder, if you've got a good CIS setup, if there's much to gain unless you're aiming for big power numbers. I guess for me, if I'm going to spend big money, I'd like the most sophisticated and capable solution possible, but that's a big investment in time and energy - easier said than done.
_________________
1980 931 diamond in the rough

[924RACR]

I still contend that the only reasons the EFI conversion isn't more popular is because few have driven the car with it and experienced the difference.

Yes, it's a good bit of work, and yet perhaps the most challenging parts are simply sorting the fuel plumbing (which honestly isn't that hard) and making the wiring harness (takes a little time and diligence to do well, to ensure you have a solid, robust product).
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Kenodog]

The reason I'm thinking of it is simply because the motor it will go on is a bit different than a stock 931.

I forget the actual build spec but it's something like :

88mm flat hypertension flat tops
Knife edged crank
Teflon scraper
NOS hybrid turbo with the bearing housing from a 951 mated to a 6.10 NOS K26 from Germany
Factory Carrera GT intercooler
911 SC aluminum pressure plate
Euro Motor Werks (think that's the name) big valve kit and a custom ported head and springs etc. that our man Dan used to sell
Fast road cam from Elgin

Bunch of other things, can't remember actually since it's been about 7 years since it was built. Sounds horny as heck and she's going to be a ripper. The WUR is rebuilt as is the entire fuel system. It's as good as it can be with the stock electronics but I'm thinking that at least some form of control would be nice to help dial it in as best we can.
_________________
1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140

[morghen]

I’ll try to make a cis/efi video when i have the silver 924SC running.
Running my efi system on the 931 is possible, only challenge is the trigger wheel thing, i may have to make something custom there.
_________________
https://www.the924.com

[mattmax1981]

Is anyone familiar with danST Engineering in the UK?

I ran across them when looking for a crank trigger wheel for my project.
This kit is just ignition control for carbs/mechanical injection, but they also sell an EFI system.
They also sell the crank trigger kit by itself, which looks like it would work well with a megasquirt or other ECU.

https://danstengineering.co.uk/Porsche-924-EA831-NODIZ-ECU-Wasted-Spark-Management-Pack?search=924&page=3

[Beartooth]

Maybe I'm just lucky to have as good a CIS setup as I've got. I can't compare to one with EFI, but mine just works. I hadn't driven it in a few weeks (between having some things apart for the leak-down check and being out of town), but the weather was nice last week so I decided to get it all back together. I had to run some snowmobile parts down to Cody (close to a two-hour drive, one way, farthest afield I've taken it). It started after just a few turns, drove perfectly the whole way down and back, and the only issue was starting after sitting a couple hours took fifteen seconds or so of cranking. I'm not arguing there's nothing to be gained from EFI, just that maybe there's less for some of us than others. Maybe years of previous owners' questionable fuel and repairs, or even not-quite-so-perfect from the factory parts leaves some cars with a lot more to gain?

Anyway, I think you'd lose out on a lot with that much of a build without more control over fueling, in addition to spark. The distributor upgrade would help a lot, but the adjustments possible with a completely stock CIS setup seem too crude, and judging by jacobroufa's conversion, just a Microsquirt and a few added sensors would unlock a ton of tuning potential. That dizzy would be great for a stock setup, but it just seems like a waste to add an intercooler, upgrade the turbo, and then have that 40-year-old lambda control still in the loop. Could be a liability too. Nothing wrong with EFI either - I could see why somebody would go that way as a matter of course - but it sounds like you're more where I'm at in terms of having a CIS setup you've invested in, that's working well for you. What FrankenCIS came up with is pretty brilliant, and you don't even need to buy their stuff to get most of the benefit.
_________________
1980 931 diamond in the rough

[924RACR]

I actually just placed an order yesterday with Danst for their crank trigger kit. For my 931, I used Dan's crank trigger wheel and sensor setup... but their kit is maybe a little more complete anyway!

This is for converting the NA 924 racecar. Fiddled with the throttle body, looking at how to fit a TPS... will be a bit of a pain, but manageable I think. Just so much easier on the S2 931!! Note: rules require we keep stock throttle body, so the easy swaps aren't an option.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[morghen]

I also saw someone posting on the fb groups about an efi conversion kit for the 931 S2. They had a neat fuel rail concept to be able to tuck it under the charge tube.
I went for looking somewhat original by keeping the fuel distributor block and running individual fuel lines from it to each injector.
_________________
https://www.the924.com

[Cedric]

[Carrera RSR]