Recommended Replacement Coil?

[Rumpith]

I'm looking to replace the coil on the TR7, and wondered if anyone has any recommendations? Looking on eBay there are loads available quite cheaply, but will ANY 12V coil do the job, or are there specific differences between makes/models? Anyone got a high-performance one for less than £20 they can recommend?

[thealligator]

The Lucas sports coil DLB 105 work ok and fairly cheap

Truthfully it was no better than the Metro one (Lucas high energy) one I took off

[32valves]

If you decide to fit an uprated coil make sure you get some uprated ignition leads too (magnecor or similar). The higher voltage of the uprated coil requires better insulated leads.

[Dale]

Most important thing is to ensure the coil you buy is of the correct resistance. The standard one is a 1.5 ohm unit, if you fit a 'standard' 12V one it could be a 3ohm unit. This will decrease the power available at the coil and defeat the object of a high power unit.
   It is also true to say that a higher output coil of itself will not give a bigger spark. The size of the spark is determined by a variety of factors including compression, mixture strength, valve timing, ignition timing etc but the biggest one, and the one you can change easiest is the plug gap.
   If you open up the plug gaps to say 28 thou instead of 25 you can utilise a more powerful coil, tho' to be honest it's probably not going to make much difference.
   If you still have points, don't open the plug gaps any more than that, if you have electronic ign. you can go further, say 30 thou or so, but beware - the bigger the gap beyond this, the more chance that you will get misfiring.
   The other point to bear in mind is that the spark is extinguished by being effectively 'blown out' by the compression and the bigger the gap the sooner the coil will 'run out of steam' to keep the spark on. This can lead to incomplete combustion causing not only high exhaust emmissions but also a slight power loss.
   Basically a normal coil in good nick with the right plug gaps etc etc is probably plenty good enough unless you've 'played a tune' on the motor.

[Deleted User]

The tr7 has a ballast resistance built into the loom, if you use a DLB 105 sports coil its a 12 v coil and needs an un-ballasted feed from the ignition switch, apart from that i'd recomend this coil as seems to work far better at high rpm with V8 conversions

hugh