Hi Guys
I want to get a new coil for the bus 77 2ltr Kombi, what one do I need GT 40R or non resistor! Has any one got one of those new plastic or resin GT 40's are they better than the oil filled can, type? I also want to go with a petronix points eliminator ingnition system.
Any comments appreciated!
Rob.......

[Edited on 27-8-2003 by Robo]

GT40 not R
mixed feelings & opionions about new type they don't actually "work any better" as in you wont notice any difference, they are certainly a lot smaller, which can be an advantage, & lighter

Thanks Kim!
I have been thinking of mounting it off the engine, the smaller plastic one's would be better for this I would imagine! also do you have any knowlage of the breaker less points eliminator systems. will they work with a GT 40 coil?
Rob......

I would rather recomend a Bosh coil
Blue if points
Black if electronic

I "think" the model is SU12 or something

Micks or Volkspower

The breakerless point (Magfire etc) need 3.5 ohms to work. Low resistance (1 ohm) will burn it out.

the coil i had was a SU120... i think that is the one blue 74 is talking about. i had a pointless conversion but the two things were never on the engine at the same time....

my answer would be that the GT40 would be compatible with any "any"(most)breakerless bolt on, decide on a breakerless system (I will be getting a magfire) then get the coil, I guess

Have used countless numbers of Oil filled Bosch GT40 coils with both the Compufire and Petronix drop in point replacement electronic ignition kits. Both worked faultless. Do prefer the Petronix kit, little neater and fits slighlty better. As for the newer style resin filled transister sytle GT40 wouldn't touch them anymore. Can remember of at least 4 that I have taken of engines and replaced, one at least that I fitted, also know of one very well repected VW enthusist that works for the NRMA that has nothing good to say about the same sytle of coil. Can't go past the old Oil filled Bosch GT40 triggered by the simple and cost affective Petronix electronics.

I have had trouble with all the GT40 coils, I now use a oil filled Bosch, SU120 in the new style are good as well.

The GT40 coils all worked well on single carb stock motors, but not on any of my Twin carb motors.

personally I bought one when they first came out & it died, as in weak spark, within a year, & never bought another one
BUT I know people who have fitted them & had no trouble , it may be that initial teething problems have been sorted - because of my bad experience I am loathe to risk geting another one

which one did you buy ?

?????????????????????????????????????
Thinking of what could make a difference spark wise between a motor with single carb and that with twin carb's. Nothing springs to mind except the twin carb's were feeding the engine too much fuel wetting down the plugs causing the electrode to become soaked with fuel and resulting in a misfire. Ar just a thought.

Thanks guys
looks like the petronix is the go as for the points replacement! whats the difference between a Bosch Blue and Black coil?
Rob......

There was a post on the old forum about some one who worked at Bosch supposedly

Blue.. standard points
Black.. electronic ignition

and i think there is a red as well

This is an extract from an 80s Bosch catalogue about vw ignition parts;

http://www.type2.com/library/electrip/boignp.htm

At the bottom of this page are Bob Hoover's comments about black and blue coils:

http://www.geocities.com/vwresource/tune_up

Quote:

Originally posted by FirstName V LastName W ????????????????????????????????????? Thinking of what could make a difference spark wise between a motor with single carb and that with twin carb's. Nothing springs to mind except the twin carb's were feeding the engine too much fuel wetting down the plugs causing the electrode to become soaked with fuel and resulting in a misfire. Ar just a thought.

Quote:

Originally posted by Craig Torrens I have had trouble with all the GT40 coils, I now use a oil filled Bosch, SU120 in the new style are good as well. The GT40 coils all worked well on single carb stock motors, but not on any of my Twin carb motors.

not too sure ! most auto shops sell them.

I managed to get a stock Bosch coil from a Repco store, about $40....I think, a few years ago now !

Cool.... thanks for that. might call round in the morning see whats in store....

I've been using the same GT40 (red) oil filled coil with a Pertronix ignitor module & twin carbies for about 6 years now.
I might have just got lucky it seems.?

regards
Jak

I think things are getting a little confused with the "red coil" bit.

The classic GT40 "red coil" has been around for 30 years and has been used with great success by many VW owners. The "40" part refers to it's output of 40kV peak in comparison to a stock coil's 20 or so. Sorry, mnsKmobi, but your guy doesn't seem to know much about electrical theory - "the amount of energy going into your coil is determined by the points." I think he's getting confused by the extra energy available with the "dwell extension" provided by most electronic ignitions. The red coil has slightly less turns on the primary and more turns on the secondary. This produces a spark of faster rise time, higher peak voltage and higher energy, but with some loss in the length (time-wise) of the spark. This is great for firing leaner mixtures, fouled plugs or at higher revs.

In more recent times, Bosch have brought out an epoxy-type coil, also red and also called a GT40, which does not have any advatages I can see except it looks a bit trendier. Oil-filled coils have a "self-healing" property (to cope with inevitable spikes through the insulating material, usually a kind of paper,) whereas epoxy does not. This, combined with their inferior ability to dissipate and cope with heat, may be why these latter types have developed a reputation for unreliability. They are also not compatible with many "pointless" ignitions due to their lower primary resistance.

Finally, I don't think anyone answered one of the original questions: A non-resistor type coil should always be used with VWs, they never used a starter resistor.

I believe the "starter resistor" coils such as the GT40R was used in 6 & 8 cylinder cars to help them have enough spark when winding the Larger engines over. There is no reason why a resistor type coil couldn't be used (with a Resistor) on a VW engine. Its just that they never were, and I have never seen one on a VW personally. I have read where the GT40 Bosch coils shouldn't be used with Electronic or CDI Ignition systems. I am installing a DSE High Energy Ignition in My 68 AutoBug and the instructions say NOT to use the "High Output" type coils like the GT40.
CDI = Capacitor Discharge Ignition
DSE = Dick Smith Electronics

Thanks for that info, as I said I haven't had anything to do with the external resistor coils but it would take a bit to use them correctly on a VW.... unless it was just connected via the resistor all the time, whether the engine would start is another question...
I have a couple of these so I'll give them to My Son who is a VW & Ford enthusist.
thanks again.... I love learning.... Lee