What are all the classes 914s race in?, Past and present. Options

[Mark Henry]

IMSA thread has me wondering. Does anyone want to take a stab at the list and a brief explanation on what's legal (stock, mods, engines, tires, etc) for each class.
Whenever I've built a race engine I just asked what pertained to the engine I was building and honestly I've never looked any further. For anyone thinking of going down this rabbit hole it might be nice to know the differences.

[brant]

I know some of them.. but depending on the level of detail. That’s a long document

[stownsen914]

I'll take a stab. No guarantees on accuracy though (IMG:style_emoticons/default/smile.gif)

SCCA classes:
Production classes - no full tube frames, more limitations in general on chassis mods:
C production for 914/6 in the 70s and until mid 80s or so. I think tire width and displacement varied over time, but got up to 2.5L by the early 80s. This class was ended in the mid 80's or so when the GT classes started.
E production for the 1.8L 4's from the 70s until 10-15 years ago when it got moved down to F prod. At some point they started allowing 914/6's in E prod with limited engine prep, not sure if they got moved to F prod.
I think the 914/6 GT was classified as B prod back when it first came out, which was a disadvantage. B prod also ended when GT classes started.

GT classes - full tube frames
GT3 for small bore 6's and 4's. Not sure of the rules differences, but I'd guess the 6's get more weight and/or more limitations on engine prep.
GT2 - I believe when the class started in the 1980s, the 914/6 was allowed to run a 2.8 or 2.9L engine at a little over 2000 lbs. 10 inch wide wheels I believe, first 15's, then 16's. Maybe 18's now? But that would be difficult for most 914's without a lot of work. I think displacement has probably grown over time too. Cup cars are allowed in GT2 these days!

In IMSA, the 914 ran mostly in GTU from the early 70s and did well. In the early/mid 70s it was basically the 914/6 GT. At some point 2.5L engines were allowed, then 2.8 by the 1980s. Around 1987, IMSA stopped allowing 914's to race because they were too old, even though there were a bunch of them still competing. There was one guy who built a 914 with turbos around 1980 and ran in GTX with the 935s. I don't think it raced much or did well.

PCA Club Racing classes:
Not sure which stock classes, and really no one races them anyway.
In the GT classes, which allow many mods but must keep the stock floorpan, I've seen 914s in GT3, GT4, and GT5. It's a sliding displacement to weight scale, but usually small bore cars run GT5, 2.7-3.0 in GT4, and big bore in GT3.
Now there are vintage classes in PCA CR, and I think most 914's will migrate to those. Rules are evolving, but for now I understand there are Vintage 4 cyl under 2.4L, Vintage 4 cyl over 2.4L, Vintage 6 cyl under/over 2.4L, and separate classes for cars with wings and aero mods under/over 3.0L.

That's what I know!

Scott