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Discussion Starter · #1 ·
I've read about the Compufire that RallyBob installed and I've talked to Bob Dennard about the Electromotive. I have the XR700 installed now.

My question:

I am running dual Webers that have no place for vacuum advance. I'd like to try to avoid a mechanical need for advance if possible. The Electromotive ($600) seems to solve this problem with a programmable advance curve, but it's not cheap and I can't get a hold of Bob D. right now. He said he might have an "Opel" kit ready. I'd be willing to purchace one if I can find him and has something ready...but....

Is there another CHEAPER option with the Compufire and say something like the Crane TCU-1 (timing control unit) to solve my possible future vacuum advance problem?

BTW: the Compufire system is $202 at Doghouse....

kyle
 

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I too have twin webers and the crane 700 on my car. The big difference is you have the DCOE and I have DCOM, the OMs have ports for vacuum advance. Just an idea for you to ponder would be getting your hands on a pair of OM bodies. I see them all the time on Ebay for around 100 each. It's a backwards way of fixing the problem, or maybe a better solutoin to it. Just an idea
 

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Kyle,

The cheapest option, and the one most people with performance motors go for, is to remove the vacuum advance and re-curve the mechanical advance in the distributor. This will cost you nothing but a little labor.

Another option for those slightly more adventerous is one of the many DIY projects based on the Ford EDIS module. Here's a link to one of the projects...

http://picasso.org/mjlj/index.jsp

-Travis
 

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I also have twin DCOMs, but I've plugged all the vacuum ports with caps. I am running the Compufire ignition with no vacuum advance and a mechanical distributor modified akin to what RallyBob has described elsewhere on this site.
 

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Propel, was it recurved or just limited to total advance?
 

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I have not had the chance to "recurve" it yet using different springs since I wanted to get the dual carb setup running well before finetuning it. I have limited the total advance and bolted the advance plates together. This has been sufficient for my needs so far, and the car runs well. But I understand that if you really want to control your advance over specific rpm points, you will need something more sophisticated.
 

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Travis said:
Kyle,

The cheapest option, and the one most people with performance motors go for, is to remove the vacuum advance and re-curve the mechanical advance in the distributor. This will cost you nothing but a little labor.

Another option for those slightly more adventerous is one of the many DIY projects based on the Ford EDIS module. Here's a link to one of the projects...

http://picasso.org/mjlj/index.jsp

-Travis
Hey ! Travis beat me to it. Check this thread to get a rough idea what the parts will cost...http://picasso.org/mjlj/?q=node/view/88

I have not gathered any of the parts for this or megasquirt, yet.

Garry
 

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Discussion Starter · #8 ·
I'll try a search on the mechanical advance and probably go with the Compufire ignition also.

I've never tried this before so if someone has pics of what they've done, that would be great too.

Thanks all!
 

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Discussion Starter · #9 ·
....I was reading some of the mech advance posts...

so..."locking" the 2 plates together (I don't have a distributor in front of me right now) in attempt to hold the advance at a fixed location?? Is this the idea?

I saw mention of springs (different weights) too, this is a 2nd way to do it also?
 

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Another alternative is the Megajolt Lite Jr or other similar variation. Its definitly cost effective. You'd need a ford edis setup with 36-1 trigger wheel (or some other crank position sensor) and a map sensor. But thoses bits are very affoardable. And its fully programable which is a nice way to sqeeze the extra bit of go from the engine. Note that this is DIY effort and experimental (just like the megasquirt I've also touted a few times).
Megajolt jr page
 

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Locking the plates together disables the vacuum advance only. Once this is done you'll need to make an adjustable stop for the mechanical advance. Both myself and Bob have posted pictures(two different methods). Once the mechanical advance is limited you'll want to change the rate at which the timing advances. This is done by changing springs and/or their mounting points.

-Travis
 

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Discussion Starter · #12 ·
I just received the compufire ignition from the Doghouse website. ($230 for everything including the tach adapter.)

Question is: What is the ignition setup on the module. I attached a photo. I think 3 and 4 are correct but not sure about 1 and 2.

Correct me if I'm wrong....
 

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Speaking of this mod, has anyone figured out a way to make a timing light work on this? How are others timing their engines with the DIS?
 

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PROPEL said:
Speaking of this mod, has anyone figured out a way to make a timing light work on this? How are others timing their engines with the DIS?
You can use a normal timing light, but not an adjustable 'dial' type light. You will need to have markings on your front pulley/timing cover to accurately set the timing if you are not running stock settings.

Bob
 

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Discussion Starter · #17 ·
Compufire

I'm starting to wire the engine back up and a few things came up in regards to the COMPUFIRE ignition:

1- The wire that went to the positive side of the coil, this goes to the single red wire on the Compufire module, right?

2- The wire that was on the negative side of the coil, this is the "tach" wire isn't it? ....And would obviously attach to the new tach converter wire from the compufire module.

3- As far as mech advancing the distributor...since there is nothing attached to the breaker plate now, do I just leave it alone? Can I take the vacuum advance chamber off now? And/or do I just bolt the breaker plate to the plate below it with some advance put in??

4- The Compufire cap doesn't really fit too well on the distributor. It's seems to be a little bit smaller diameter?!?!

TIA
 

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1- The wire that went to the positive side of the coil, this goes to the single red wire on the Compufire module, right?

You should run a full 12v to the Compufire, without a resistor.

2- The wire that was on the negative side of the coil, this is the "tach" wire isn't it? ....And would obviously attach to the new tach converter wire from the compufire module.

If you mean the green wire, yes this is the tachometer wire.

3- As far as mech advancing the distributor...since there is nothing attached to the breaker plate now, do I just leave it alone? Can I take the vacuum advance chamber off now? And/or do I just bolt the breaker plate to the plate below it with some advance put in??

The Compufire doesn't affect the vacuum or mechanical advance use, the rotor (trigger) still is affected by both advance mechanisms. Whether or not you need to change the advance curve depends on the camshaft and compression ratio you are running.

4- The Compufire cap doesn't really fit too well on the distributor. It's seems to be a little bit smaller diameter?!?!

What year distributor are you using? I admittedly have only used it on late model distributors ('71-'74 type), but it fits those very well. I haven't tried the early style, which do use a different style distributor cap.

Bob
 

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Distributor cap locator types

RallyBob said:
. . .

4- The Compufire cap doesn't really fit too well on the distributor. It's seems to be a little bit smaller diameter?!?!

What year distributor are you using? I admittedly have only used it on late model distributors ('71-'74 type), but it fits those very well. I haven't tried the early style, which do use a different style distributor cap.

Bob
Here's an illustration of the two types of distributor cap locators used:
 

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Discussion Starter · #20 ·
Yea, I have a 71' type. Pictured on the left of tekenaars pic.

I couldn't have possibly rec'd the wrong p/n Compufire?? There's is only one listed on the website (doghouse) I think.
 
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