docmirror

Actually, IIRC there are two drivers, and they fire in two batches of 4 cylinders.

victor25

In other words... at idle lets just say the LH fires the injectors for 1ms and those fires are 400 ms apart... (not actual numbers obviously) so then the adapter just fires the individual injectors in order for 1ms, but at 50ms apart. The 400ms divided by 8.

victor25

I originally thought that too, but after looking at the schematics I only see one out connection from the LH. That splits into 2 which splits into 4 per side. The power comes from the one relay and splits down in the same manner.

svpmx83

current duration and frequency divided by 8 is not what you need
it's a little complicated and this may help you visualise the differences

Lizard928

Do you know where in the harness it splits from 1 output to 8 running to each injector? I will give you a hint, it isnt in the cabin.....
Also all the wires running to each injector are the same color.

In order to change to sequential, or even bank firing, you would need to pair the cylinders correctly. Lets say you split into two banks, you want to do 1,4,6,7 on one, then 2,3,5,8 on the other.
Now in order to not make the car run really bad, you must have an RPM signal input. If you want to do full sequential, then you MUST have a cam sensor input, if you do not, then the car will likely run worse believe it or not.

However, the other thing that the standalone systems do is instead of squirting once per revolution, they fire up to 8 times per revolution. 19 and 24# injectors you can run 4 squirts per cycle and the PW time is still long enough to be able to run the engine. If you switch to 40-60# injectors you can only run 2 squirts per cycle (batch and bank fire), or the inj PW becomes too short and the injectors cannot be accurately controlled.

I have converted a half a dozen 928s to standalone, as well as helped a number of others convert. I have extensively thought about this. I have also seriously considered trying to get the EZK to fire COP or CNP units so as to be able to get a stronger ign system while retaining the individual knock control. It always comes back to the same thing, it is much more cost effective to fully convert the entire car to a standalone system and obtain many more features, and benefits to go along with it.

One of the large benefits that I see to converting to standalone is ditching the MAF and going to MAP. With MAP if you pop a vacuum line, or a boost pipe comes off, the car runs the same, albeit without boost pressure, or at a higher idle. But you can still drive home!

One of our very respected members on this board will be coming out with a plug and play harness for an entry level (but still very good) standalone system hopefully sooner rather than later. When this happens, I expect a number more will convert.

Lizard928

Also,
the pulse effect as far as I know is limited to the dead ended fuel rails.
I ran 60# injectors on the LH2.3 (87+) with no issues what so ever, no random spikes, or changes of fuel pressure, or AFR at any RPM.

svpmx83

just to add to my previous post.

The only hardware I'm aware of that would have a chance running as an interceptor in the way you are describing is Pro-Sequential
I had one on a Lexus V8 powered toy I used to have and its quite a capable bit of kit as it directly feeds from and regenerates the ignition and injector signals. And syncs itself to cam/crank timing and has an internal map sensor.

http://www.powermod.com.au/index-2.html
and
http://www.moristech.com.au/pro-sequ...nterceptor.php

both companies listed manufacture them (a partnership that split up)
It would be worth asking if they have any interest in altering the software to run an extrapolated full sequential or semi-sequential

Milorad at Powermod
and
Daniel at Moristech
were to go to guys

928mac

Like docmirror says you can get rid of the two old ECMs that may fail at any time, get rid of the distributors, you get 2 dual coil packs so no more expensive wires ~ well I dont know as I have not compared those to the originals. No more MAF to restrict your Super Charger.
I dont know, as I have never got my car set up right but IMO there were a lot of plusses and OH the big plus was I got to build a new wiring harness with all new connectors so I did not have to spend $1200 from Porsche.

Each to there own I guess but I was thinking of what I would spend in the future on plug wires, LH&EZK rebuild, full engine harness, MAF rebuild or replace and the cost was the same if not more.
It also opened the door to future mods like the SC, Turbo or NOS

Hilton

I can't see any plusses in having a car that doesn't run right, and spending north of $3k to get there, compared to spending only $1200 for a new factory harness and having a car that just runs right.

Victor, I'd have thought that non-destructive is the only sensible approach, so a car can be returned to stock easily, which means completely supplanting the injection harness (which includes all the intake sensor connectors) to support sequential injection.

If thats the case it seems that fixing the fuel rail and dampener setup would be inherently cheaper for a customer to do than a complete new standalone ECU setup.

Do any of the other boost kits suffer from this resonance? I haven't seen any posts about it with respect to the Murf kit which uses stock ECU's (with custom EPROMs) and 42lb injectors.

Ducman82

i am running Mega Squirt 3X. unit plus harness and sensors was around 800. i had to fab up a cam sensor and trigger wheel as well.

AO

The harness has been one of the key things stopping me from doing a conversion to an aftermarket ECU setup. I'm very interested. If you know anymore, I would be interested in being a beta tester...

hacker-pschorr

Not that I know of.

Murf928, 928 Motorsports, ptuomov's turbo, 928 Specialists, Greg Brown's strokers (the ones with the original ECU) etc.... do not suffer from any fuel line resonance that I've ever heard about.

I can only speak in greater detail about the Murf928 setup since I'm a bit familiar with it's design.
The Murf928 Supercharger system was designed from the start to retain as many stock parts as possible. This makes everyday use (like idling, cruising around in traffic) much easier to tune for.
The Murf928 tune has very few modifications to the fuel and ignition map off boost. It simply wasn't needed.

DR's setup from 928 Specialists also uses 100% stock fueling (dampeners, rails, FPR's etc...) With zero resonance issues with 42# injectors.

Reading all the posts trying to tune Victor's setup on and off boost really had me scratching my head until I learned how flawed the fuel system is.

This fuel resonance is a problem unique to a setup that removed dampeners under the assumption they were "not needed". I'm sure a lot of testing went into determining that......

As for the dead-ended fuel rail, I have been speechless on ever since I learned about it. I simply cannot believe such a setup was brought to market and sold to customers.

Not only is the dead-ended fuel rail a major mistake, having the #5 injector so close to this "dead end" pretty much guarantees the fuel flow to that one injector will be different form the rest.

Trying to go batch fire just to fix an obvious design flaw such as this, is like using a tourniquet to stop a nose bleed.

jcorenman

Doing this as an add-on box for the LH is not simple at all. There is one injector-driver and the harness connects all injectors in parallel (two separate power feeds on the 89+ cars to accommodate the ignition protection relay). So you would need to design the magic box what would measure the injector pulse-width from the LH, compute the correct timing delay for eight cylinders, and then open each injector separately via eight drivers. This would introduce a one-revolution delay, I suspect there will be detrimental effects from that. You would then need to hack the injector harness to install it, etc. As others have said, if this is the goal then

But isn't your real goal to overcome the problems caused by ditching the front damper and dead-ending the fuel rails? Wouldn't it be simpler to solve this with fuel plumbing that retains the front damper and feeds the rails from the front?

AO

Didn't David Caradine try a neck tourniquet? Sorry, in medical terms it was "Auto-erotoic Asphyxiation." Same difference... same result.

AO

Jim, the title of the thread explains it all... he wants a WIZARD! You know, Magic, Sorcery, Illusions, Paranormal, Witchcraft, Conjuring, etc...

If it were that easy, he'd hire a mechanic.