Steve Nagata

I have a 993.

If I went with the Electromotive DFI system would I never have to worry about rotor replacement, distributer etc etc?

Does a system like this last almost forever/mantainence free? I would just need to do the regular wire and plug replacement?

thanks

A930Rocket

Talk to Richard Clewett at: http://www.clewett.com/products/engnmgmt/emsys.htm

You might try the XDi system if you just want an ignition system.

You will not have your the cap and rotor like you did.

Geoffrey

I think the 964/993 distributor based system works fine, with the added benefit of being ECU controlled. If you replaced it with an XDI system, you would have a seperate EFI system and seperate ignition system. Further, you'd lose any knock control. The XDI system is not an improvement from what you have.

Yes, the XDI is maintenace free.

986Jim

Having used Electromotive units in the past they totally eliminate the distributor. If there is a block off in the head for it you can do that and physically remove it.

They are a direct fire crank trigger ignition. You put a 60+1 tooth on the crank with a sensor that reads back to the main unit so it knows the cranks position, then the 3 coils basically replace the job of the distributor. You will run plug leads from the coils to your spark plugs and it fires in a wasted spark system. It's fully programmable via laptop. You can get base maps but they suck in reality so your lookin at 5 hours for a race setup, and that plus day and days of other tuning for a street car. Getting cold start-up setup properly so the car idles like normal and stuff is hard... Setting up the system for a WOT only car like in drag racing is pretty easy but for part throttle and other various driving styles, a full stand alone system has some draw backs. A piggy back system suits a street car much better, that or you have lots of $$$'s for dyno tuning.

FotoVeloce

Wouldn't 993 users require 6 coil packs? I've helped tune an Electromotive system before. They are pretty trick, and pretty tricky to get right. Sounds like an interesting mod.

Steve Weiner-Rennsport Systems

Geoffrey is right,....The Motronic OEM ignition systems on the N/A 993's are much more capable than the Electromotive stuff and more than adequate for the "mission".

A.Wayne

Yes any direct fire coil pack DFI system would allow you to remove your factory distributors ...
I will have to disagree regarding the 993 stock distributor system , as i hate to deal with those WW2 distributors, the maintenance and the cost for replacement.

after saying that ,if your motor is stock and you do not intend to upgrade , modify etc, then i would stick with the stock system ....

986Jim

No because each coil pack has two leads on it. Thats what a wastespark system is..

You have 3 coils that run 6 spark plugs. The coil fires both plugs at a time. One spark is at just BTDC on the compression cycle, the other files at almost BDC on the exhaust cycle which is a "wasted" spark. It's a totally efficient system (other than a wasted spark which doens't matter) as it takes half the controls to run the system vs. 6 individual coils you have to controll sperately.



We get rid of distributors as often as we can. If you have a fully programmable ignition system on a race car, then due away with the WWII system (as A.Wayne said) when ever possible. It (hopefully) eliminates another possible failure.

Again for a street car, full stand alone is tough. My Talon makes 424whp and runs a full stand alone AEM ecu and to be honest, it's never right, and the car runs like crap overall unless your at WOT and the car is warm. Otherwise it's sputtering when it's cold started and part throttle the A/F goes all over the place and it couldn't pass emissions to save it's life. It's frickin fast tho... Went 11.7 @ 119mph on pump gas, street tires with A/C and a full leather interior

Geoffrey

"Having used Electromotive units in the past they totally eliminate the distributor. If there is a block off in the head for it you can do that and physically remove it"

In the 993 you cannot remove the distributor even if you are using an alternate ignition system. Inside is the hall sensor which detects cam position for full sequential injection. The engine will not run properly without the cam position sensor.


"They are a direct fire crank trigger ignition. You put a 60+1 tooth on the crank with a sensor that reads back to the main unit so it knows the cranks position"

The Electromotive system actually uses 60-2 invented by Bosch, not 60+1. So is the factory system, it too uses a 60-2 trigger wheel on the flywheel and has an ECU determining the proper time to send the spark (ignition timing).


" Setting up the system for a WOT only car like in drag racing is pretty easy but for part throttle and other various driving styles, a full stand alone system has some draw backs."

How so? What are the specific drawbacks of a standalone system from a technical perspective other than requiring knowledge in how to tune them? The same can be said for the Electromotive system, you had better know how to use a dyno to find the proper ignition timing for each cell in the table. Street tuning will not yield you a package that is better than even the factory conservative setup. You need a dyno or in-cylinder pressure equipement to properly set up ignition timing. A standalone is far superior to a piggy back or separate ignition system. It sounds like you weren't using the proper tools to tune the engine.


"Wouldn't 993 users require 6 coil packs?"
Yes, the 993 requires 6 coil packs when used with waste spark mode.


"Again for a street car, full stand alone is tough. My Talon makes 424whp and runs a full stand alone AEM ecu and to be honest, it's never right, and the car runs like crap overall unless your at WOT and the car is warm. Otherwise it's sputtering when it's cold started and part throttle the A/F goes all over the place and it couldn't pass emissions to save it's life."

I guess you probably need to have it properly tuned on a dyno. All of my racing and street cars start by reaching in the window and turning the key, idle and drive through the paddock with ease. All you need are the right tools.


"We get rid of distributors as often as we can. If you have a fully programmable ignition system on a race car, then due away with the WWII system (as A.Wayne said) when ever possible."

I would agree that in general that is true, however, I avoid installing a wasted spark system in a car wherever possible. FWIW, I chose the factory distributor on my 8100rpm 3.8RSR engine with 12:1 compression and 93 octane fuel. I have THAT much confidence in it. It also allows me to run a digital CDI system and a spark plug gap of .060" (I'd like to go .080" but haven't found correct plugs that will allow that). There is nothing wrong with a distributor based system if properly integrated into an EFI system.

fast951

If you want to lose the Distributor Cap & Rotor and leave the control to the DME, take a look at the Wasted Spark system we offer for the Motronic equipped cars. The 964/993 system should be released early 07.

Full timing control is left to the DME, we run the car in wasted spark mode, you can use 2 coil packs or COP. No need to add any external hardware, we use the signals from the DME.


Take a look at the system we have for the 944/951 and 3.2L 911. Similar system will be released for the 964/993.

http://www.vitesseracing.com/html/wa..._ignition.html

986Jim

If your running the electromotive you can use all their sensors and ignore the Porsche based sensors built into the engine. They sell a hall sensor if you need, make a mount. The TEC 3 is not an alternate ignition system, maybe you mis understand what it is. It's a full stand alone computer.. You pitch your stock computer and wiring and fully wire the car with the TEC 3 only and all realated sensors. Your stock sensors could be totally removed if you buy the parts needed with the TEC 3. This is not a CDI...

Sorry. You are correct.

Electromotive TEC3 being a full standalong computer system takes a lot of time to setup for a street car so it's drivable. I tune cars on the dyno and tune multiple different systems. AEM on my personal car is full stand alone and the car never runs as good as it ever did with the stock computer and a piggy back. It never made as much power, but the stock computer is ohh so smooth in all situations. TEC3 having to be fully programmed in every way from scratch is never as soom as the OEM ecu. They spend months and millions of dollars to make a stock engine run the way it does. One guy and a dyno with 6 hours will never accomplish that level of tuning.

How so? If each coil has two leads on it and wasted spark means your firing two spark plugs from one coil then 3 x 2 = 6 cylinders. The 6 coil system is for Ferrari and Lambo etc.. cause they have 12 cylinders.. You need 3 coils to fire 6 cylinders in wasted spark. That little picture I posted above is from a 6 cylinder TEC 3 system. I have used them on a lot of 6 cylinder cars, (VR6 turbo setups mostly) in wasted spark. It has 3 coils. This system would be used exactly the same on a P car.

Is it warm all the time where you live? As soon as you introduce cold weather, cars with stand alone never start up nicely. Mainly because nobody ever sets up the cold startup configuration because the car is never cold, on a dyno in cold weather to do it. Tuning on the street in 500hp cars can easily get you into trouble.

Stock ECU's always run better in all situations than a stand alone does. You can never get a car as OEM drivable with full stand alone as you can with a stock Ecu and piggy backs etc...

So what stand alone system are you using that is not wasted spark on your car and how much HP are you making?

Attached is VR6 Turbo/Nitrous with TEC3. You can see 3 coils, wasted spark, two plug leads per coil for a 6 cylinder. Stock ECU totally removed. This system will run any 6 cylinder car.

Geoffrey

"The TEC 3 is not an alternate ignition system, maybe you mis understand what it is. It's a full stand alone computer"

The original poster was questing the Electromotive DFI system in place of the twin distributor therefore he was talking about the XDI setup, not the TEC 3 which I am also familiar with.


"I tune cars on the dyno and tune multiple different systems. AEM on my personal car is full stand alone and the car never runs as good as it ever did with the stock computer and a piggy back."

Well my cars run as well as OEM cars in all situations, but it does take datalogging and tuning after the dyno session, so, yes, it requires more than 6 hours of dyno time to get them running right in all conditions. Perhaps you were not using an ECU in full sequential mode and never took the time to get the injection timing table set, the air temp table set properly, the idle air control valve operating properly, etc.


"If each coil has two leads on it and wasted spark means your firing two spark plugs from one coil then 3 x 2 = 6 cylinders."

BECAUSE a 993 has TWO spark plugs per cylinder, so you essentially have 2 separate waste spark systems installed on the engine. One for the upper plugs, one for the lower plugs, each with 3 double ended coils. 3 coils x 2 sets of plugs = 6 coils total required.


"Is it warm all the time where you live? As soon as you introduce cold weather, cars with stand alone never start up nicely. Mainly because nobody ever sets up the cold startup configuration because the car is never cold, on a dyno in cold weather to do it. Tuning on the street in 500hp cars can easily get you into trouble.

Stock ECU's always run better in all situations than a stand alone does. You can never get a car as OEM drivable with full stand alone as you can with a stock Ecu and piggy backs etc..."

Well, of course, you need to take the time to tune it, there is no free lunch. Saying never means that you have not tried because it is possible, and I have done it. Even my full blown race car starts up when sitting outside in the cold weather. And it has a tiny Oddesy 680 battery so it needs to fire right up.


"So what stand alone system are you using that is not wasted spark on your car and how much HP are you making?"

I use and sell MoTeC ECUs and what car are you wanting to know, I've done quite a few? You can read about one of my personal cars here on Rennlist by searching the 964 Forum for "Racecar Project" and it is in Total 911 December 2006 - March 2007 issues out now. It makes enough HP to get the job done.

A930Rocket

Put that in your shorts and smoke it! LOL

Steve Nagata

Hi guys,

Thanks for all the input. Now i'm not sure if I want to go with the Clewett or Electromotive DFI.

Maybe some background about my car.

TPC supercharged lower compression, 2.5" pulley 9lbs boost, air to air intercooler. Pauter rods, RS ported and polished heads and valves, bronze maganese guides, eibach valve springs and titanium retianers. 6 larger 55lb injectors and UNICHIP.

Car is a Tiptronic

I hate worrying about the distributer belt braking and replacing rotors, caps etc.

I just want a system I can just put on and not worry about it ie: Tuning/dyno tuning. Just bolt on and smile.

On that note the Vitesse kit sems nice!

What do you gurus think?

986Jim

Not exactly..

The problem is when he said DFI in Electromotive terms from back in the days of Tec then TEC 2 and now TEC3 means Digital Fuel Injection. That is their TEC3 system.

He should have said XDI which is their ignition system, so no wonder we're talking about different things here.

You can also read about cars I have built in magazines dating back to 1998 like Sport Compact Car, Turbo Magazine and HCI. I have built everything from 300whp All motor 1.8L based cars, to 1000+hp Supras. But lets put those away, we don't need to swing them around anymore.

Unfortunately, my mistake was talking about the electomotive stuff which I know about, but on a setup that I dont... So I'll stop while I'm behind now...