84/85 coil vs. 86/87 coil - GN and T-Type Performance Enthusiasts (GNTTYPE) Forums

garrett · #1 07-24-2006, 01:01 AM

Are there any advantages in performance in the newer coils (86/87)? Other than they are cheaper, of course. I don't feel like replacing it if there are no performance gains to be had. I am lucky enough to have several 84/85 spares as well.

pfredricks · #2 07-24-2006, 12:43 PM

I don't know of any specific spark power or tests to compare the older versus newer, but I recall something like a marginal advantage with the newer coil packs. So for the guys looking for that extra 10th in the quarter mile they may be the ticket.

The main advantage is availablity. Back in the day, the 84-85 coil pack/ignition module was like $800 from GM when I priced it

. I doubt you can even buy them now from the General, and the aftermarket sources are not much better in availability and pricing

. Then and now the 86-87 coil pack/ignition modules are much easier to come by. And it is easy to change over.

You may notice a difference under higher boost, as in less knock for the same high boost level. I've run them both on the street at around 15 PSI and didn't notice any difference (I had about the same knock). Your performance will vary based on tune, fuel pressure, etc.

But if you have your own stock, they are worth something to the guys looking to stay original.

Keller · #3 07-24-2006, 02:33 PM

The 84/85 coil and module are both discontinued. So the main advantage of the newer units is that they can be obtained.

brad_padgett · #4 07-24-2006, 10:48 PM

PFREDRICKS has the correct answer. I only swithched to the 87 IGN after I really boosted the engine. I wanted a new IGN as opposed to my 21 year old 85 IGN. The change in performance to the 87 IGN was barely noticable. I sold my original 85 IGN to a guy who wants to stay original . Brad

garrett · #5 08-23-2006, 04:42 AM

I wish I had someway to test the coils I have. I would buy Casper's tester, but by the time I purchase the adaptor for the Hotair coil, it will cost me about $150-$160. It doesn't make economic sense, when a newer coil can be purchased for less. Does a place like Autozone test them?

pfredricks · #6 08-23-2006, 08:13 AM

Garrett,

You have some options. One is to measure the resistance (Ohms) across the coil posts. There should be archive posts that state what that resistance should be, but 12K to 14K sticks in my mind. I could be wrong on this. Brad?

Another option is to ask those in your local Buick car club if anyone purchased Casper's tester. I'm sure they'd help you out.

The last option is to try them out on your running car. A really bad one should be noticable.

Hope that helps.