911SC 83 Bosch Coil

[greg bradbury]

My 83 SC conked out the other day. I found the coil was s/c primary (0.9 ohms) I have ordered a replacement but this is a long time coming. In the interim I have put in a Bosch GT40 oil filled coil that I had in the shed. The car goes well but I am a bit worried about going too far from home in case it goes again. My question- is there anything special about the original coil. As the car has a CDI I thought that it may need a special coil to handle higher voltages. The GT40 does not seem to get hot.

[Kirk911SC]

Use an MSD Hi-Vibration Blaster coil. I went through 3 Bosch coils (made in Brazil) in under a year. All leaked out the top. No problems with the MSD and a stock CDI box.

Kirk

[KNS]

Anyone else had long term success with the MSD Hi-vibration coil?

[RANDY P]

Bosch Blue coil works perfect with CDI as well. Another choice.

rjp

[Groesbeck Hurricane]

Just one more item, what type of CDI do you have?

[greg bradbury]

Originally posted by Groesbeck Hurricane
Just one more item, what type of CDI do you have?

the CDI is the stock one

[blue82coupe]

I also went thru (2) of the silver with brown top coils in 1 year. I switched to MSD cdi and Hi -Vibration coil.. no problems. Dan

[rfuerst911sc]

I have wondered the following: if you move the location of the coil so it is in the upright position does that change the type of coil you can use? It seems to me that the upside down position of the coil limits the type of replacement coils that are available?

[Groesbeck Hurricane]

Stock = Bosche

Sorry to be a-retentive here. The PermaTune is silver also but is not stock. When a PermaTune goes bad it tends to send the coil over the edge also. They can be returned to PermaTune for a "free" checkup, but that usually turns up no issues. Replacement is the generally suggested option.

[greg bradbury]

Originally posted by Kirk911SC
Use an MSD Hi-Vibration Blaster coil. I went through 3 Bosch coils (made in Brazil) in under a year. All leaked out the top. No problems with the MSD and a stock CDI box.

Kirk

Thanks Kirk, this may be the way to go. My coil also leaked the oil out on a hot day. The MSD has no oil so this wont be a problem. The standard CDI would probably give the MSD coil less of a work out seeing as how the MSD ignition has multiple sparking. I think I will order one and give it a try. regards greg.

[greg bradbury]

Originally posted by rfuerst911sc
I have wondered the following: if you move the location of the coil so it is in the upright position does that change the type of coil you can use? It seems to me that the upside down position of the coil limits the type of replacement coils that are available?

I think that the reason they mount the coil facing down it that the engine gets a lot of rain water on it during wet weather. With the coil facing down the water just drips off and doesn't sit near the HV output which would cause a misfire.

regards,
greg.

[greg bradbury]

Originally posted by Groesbeck Hurricane
Stock = Bosche

Sorry to be a-retentive here. The PermaTune is silver also but is not stock. When a PermaTune goes bad it tends to send the coil over the edge also. They can be returned to PermaTune for a "free" checkup, but that usually turns up no issues. Replacement is the generally suggested option.

yes it is a bosch stock ignition.

[rfuerst911sc]

Greg your answer makes sense but when I said move the location of the coil I meant maybe closer to the fuse box in the engine compartment therefore not in the path of rainwater? I have seen pics of 911 engine compartments where the coil was over on the drivers side in the upright position just wondering if under those conditions does that open the window of additional coils that could be used? For me it doesn't matter because I hope to convert to EDIS ignition in the future.