Quote:
Originally Posted by Barbapapa
Hi B'.
I couldn't use the Cayenne coils with the Motec IEX. It's an issue with the Motec, it sends a super long dwell time during cranking and the Cayenne coils shut down upon seeing 20ms. I even sent one to Motec for bench testing but there's no fix.
I'm using Bosch coils as used in BMW Grand Am cars. They fit nicely, I found a couple of o-ring sizes that when slipped over the body allow them to be inserted in the 928 heads like a regular plug wire.
It's too bad about the Cayenne coils because I spent alot of time sourcing the oddball terminals. I do have a set of coils and connector parts to sell for cheap!  |
So did I. Todd and I have spoken for possibly hours on end about these coils. I am one of the first (with a few other's help of course) to get all the part numbers, and put together what is needed.
Upon further review, Todd (and I secondarily) have found out that the Cayenne coils are great - EXCEPT when you go too long on the dwell, OR (and this may be a big issue) if the falling signal has ANY noise at all. As in one nano-width size bobble on the down side of the 5v dwell signal.
The Coils, in these cases, or just the latter, seem to start to multi-spark. Obviously bad. Very bad infact, if it sparks something that was not to be sparked.
The concern was valid enough for Todd that he has veered away from the cayenne coils to the LS2 truck coils, which (ironically) are BETTER and MORE expensive than the Cayenne coils. They are 20 dollars compared to the 12-14 for the Porsche coils, and they can take huge amounts of dwell time - lastly - they do not seem at all to be very sensitive to the falling edge noise on the 5V signal that Todd and I believe may be inevitable in an open-world use cycle. Meaning - we have no idea if that 5V signal could get noise from simple things like driving under a high tension wire, etc.
I have not given up on their use as of yet, at least on the second engine - the 4V engine where they would fit perfectly. I always planned on using the LS2 truck coils on the 2V anyway.
Mike - Does your motec system give the 5V signal - I guess I would have to assume that it does? Do you have the part numbers for the coils? How did you source them?