Rob Edwards

Hmm. Any set of directions that start with destroying the LH harness in order to have a pigtail at the V and W plugs to connect the new harness to, isn't 'pretty close' to PnP.

As an electronics retard (in the intellectual sense, not the igintion timing sense), my hat is off to anyone that can get an aftermarket tuning system to work, let alone work well. And I certainly agree that there may be benefits to be had from a new aftermarket ECU. But for 99+% of 928 owners, even if you pay $~500 for an LH repair, $200 for a MAF recalibration and $1350 for a new LH harness, you're still way ahead of the costs and hassle of a 3rd party ECU, and good for another 25 years of motoring.

danglerb

Maybe we should hear from someone who has completely finished tuning their aftermarket fuel injection system? Must be one somewhere. Giving up does not count either.

BC

Todd.
The car Greg Built with the Link
Jake here in Socal


These people were successful and have not given up.

I would like to temper everything above my post with the statement that just because it looks unattainable or to difficult to you, does not make it fact.

Having a rational cost benefit discussion like Rob suggested, is correct.

L_perm

Thanks again for all the replies. Thanks to Carl for the information.

As for cost, I am replacing so many parts of the ignition and fuel systems (along with other stuff) that I am that person who can effectively buy the TEC GT system and end up spending about the same amount of money. This is why I started this thread in the first place.

However, my car is stock, except for an x-pipe and high flow cats. The x-pipe is from the PO, and I installed the cats because I don't believe in contributing to childhood asthma for a few HP. I've kept the x-pipe more for the easy access to the bell housing than anything else.

Carl enunciated my thinking once again--why not upgrade the computer and get rid of some parts that will no longer be needed, as well as gaining the benefits of newer engine management tech?

However, I am not a tuner. And, though I'm a quick study, I doubt I have anyone with the time or interest to help me. Hence, my desire for a PnP system. PnP in this context refers to the need, or lack thereof, for programming after physical installation. Clearly, the physical installation is not PnP.

I, too, was hoping to hear from someone who had successfully installed the TEC GT system--for some nitty gritty, so to speak. FLVMO has been helpful with his description of his Tec3r system(s), but I don't know how or if TEC GT might be more/less user-friendly. Other comments also suggest a long, perhaps endless, frustrating row to hoe.

At this point, it appears my best bet is to extensively refresh what I have and maybe ponder this question again in 20 years, God willing.

I have to admit that part of me would love to jump into tuning for the learning experience and gratification at the end. Unfortunately, my "Porsche hobby" aggravates people more than it conjures any interest.

Carl Fausett

Then you'll have to keep shopping Rob, until you find a after-market engine management that includes the V and W plugs for a Porsche 928 fuse panel within the items they supply. Otherwise, you do what we do, and just connect to them.

I think the problem may be in the term "Plug and Play". Our kit uses the stock 928 knock sensor, and the stock 928 crank reference sensor. No need to change them out. But, replacing a injector wiring harness - especially when we allow you to route and loom your wires as you like - is not "plug and play". You have to crimp the 2nd end on to the wires. (EXPLANATION - 1) if we put both ends on the injector wires for you you cannot pull the harness through the firewall grommet. 2) if we put both ends on the injector wires for you, you can only route the wiring one way - any other way and the wires will be either too long or too short. So - the injector wires we provide will have one end crimped for you (the ECU end) and a 6' or 10' tail. You can route your injector wires where you want, loom them the way you like, then cut to length and crimp on the end.

So that's why I said it was NOT "plug and play" - but it isn't too bad.

Rob Edwards

Oh, I know, I'm guilty of a little snark there.. I just think that there are no easy ways to go about implementing an aftermarket ECU, and my hat is sincerely tipped in your direction for having the successes you've had with your setups on track, salt, and street.

Watching Greg Brown and Neil Harvey (who between them have a little experience with tuning Porsche engines) make the Link system work on Andy G's ITBed stroker was enough to scare me back to the safe confines of 1986 technology, but as you say, when you have an application that the stock-ish stuff won't work, you have to make the leap.

Carl Fausett

L-Perm,

The TECGT EMS has 4 injector channels, and fires two injectors at a time on a V8. The TEC3R has 8 injector channels and can handle full-sequential injector timing.

As a result, the TEC3R is a more complicated install, and a more complicated tune, but it has greater tunability. It requires you also wire in a camshaft timing sensor, which the TecGT system does not require.

We chose the TecGT system for its easier installation and tuning for our customers. The performance gains from full sequential injector firing compared to paired injector firing are pretty small, (often reported at about 2%) and not worth the headache for most customers.

However, if you would like the Tec3R, I can get it for you.

sny928

Two months ago I finished my installation of a VEMS system on my Euro 928 -81. I've spent the last 12 months replacing my broken -81 engine with an -84 engine and the installation process maybe accounted for 4 months of that time (working mostly evenings). I chose the VEMS system cause it was fairly cheap (~$900) and it supported the 100-1 trigger wheel that the -84 engine has. I had to make a new engine harness and make a few other modifications (install a resistor TPS a MAP sensor and a wideband lambda) as well. Apart from beeing cheap the VEMS is a far from PnP as you can get and I scratched my head many times in combination with endless google searches to find the answers to all the questions popping up along the way. The support is all on the couldbeawholelotbetterorganized VEMS webpage and you can always email questions but all that takes a lot of time. I'm quite used to electronics but this was my first ECU job and knowing what I know now I'd probably chosen a more "complete" (i.e. expensive) system as a first project. It's a real joy however when everything finally works and you know you've done it all by yourself, not to mention that you can just hook up the laptop to it and change whichever parameter while running (I'm not that skilled in tuning yet though). I had the car professionaly tuned on a dyno ($550) after I was done and so far it's been running without a problem. I'm running wasted spark ignition with two dual Ford coils. I've saved all the original stuff, LH, MAF, distributors etc. so that some future owner can convert it back to stock should he want to.

/Sverker

GregBBRD

Leave it stock....fix what is currently wrong and drive it for the next 20 years.....unless you have endless hours of idle, worthless time on your hands.

The amount of tuning required, even after you learn all the "ins and outs" of any aftermarket ECU system (hours and hours of learning curve) is absolutely crazy.

People don't realize the amount of time that car makers spend tuning and refining the maps on their vehicles. I have a friend that worked for BMW on tuning their new cars. They would literally send out a "fleet" of cars, two people in each car, each day, driving and tuning....come back to the shop, compare notes with the rest of the "fleet" and do the same thing the next day. For months on end! And this happened in multiple spots across the entire world, so that they could get tuning for different temperatures, elevations, etc.

Cold start, cold running. Warm start, warm running....and everything between the two.

It's a crazy investment in time.

On the Link system I installed, I paid Neil Harvey to come and tune it on the dyno (which was terribly cumbersome....you could actually wear an engine out on the dyno doing this.) Once we put the engine into the car....it ran....but not good. Neil then told me that it was going to take another 10K or so to tune it in the car. Andy took the car, running OK....but not what I would call good....and has greatly improved the tune....but only because he found a guy that knew a whole bunch about it.

I'd never do it again, if I could use an existing system.

Never.

Ever.

I'm undertaking a "crazy" 928 16 valve project for a '83 car.

I'm smarter now. I'm going to use a S-4 injection with John's "Alpha N" pieces. Only because it's basically stock stuff and easy to tune with Corenman's Sharkplotter system.....plus all the little tiny details that make the car start and run smoothly are still there.

Lizard928

To date, I have installed 3 megasquirt systems, and 3 VEMS systems. All are running well to this day.

The VEMS unit is far superior to the megasquirt with regards to features and quality.

However the VEMS has a ton more wires, and takes much longer to build.

If you have a bad fuel injection harness, along with a bad LH, and a failed EZK, bad caps and rotors, and ignition leads. Then you might be equal on cost to convert.
But unless you get someone who knows what they are doing to tune it, you will be spending months if not years completing the tune.
I've spend a good number of hours helping others like Jake (Ducman), and Bart-Jan, perfect their tunes, and eliminate problems.

If your car is functioning properly and is not being heavily modified, stay stock. Also a standalone EFI will likely reduce the resale value of the car, even if running.
If you have a 78-84 928, and want more power, then convert and add forced induction. But with 85-95 cars being tunable thanks to JDS Porsche and all behind the scenes people. There is no need to convert.

L_perm

Thanks for all the thoughts guys.

I've decided to leave well-enough alone and stay with the 1991 version of "engine management." This thread was very helpful, as I had a somewhat skewed view of the work required. My only experience with tunes is with my 997 TT, where I just added the hardware, and FVD provided the program, which I load through the OBDII. With the 997.1 TT, it seemed natural to tune it, as it basically came detuned from the factory. I don't expect I'll be messing with the 928 from a power standpoint.

I'm having fun, by the way--both discussing with you guys and doing the work.

Thanks,
Louis