kuwona

Brian G - I hadn't heard the 86.5 being preffered to the S4 before. You said "hotter" engine. What does that mean? Does an 86.5 5-speed have any advantage over an 87 5-speed? Or how about an 86.5 auto compared to a 91 S4 auto? I guess the weight difference is something. Anything else?

touque

I think he was referring to the 'hotter' 32-valve 85/86 928S engines vs the 16-valve 83/84 928S (288HP vs 234HP), not to the 316HP S4 engine...

BrianG

What do you mean that you haven't heard that the '86.5 car is the "much preferred" car?? I thought that everyone knew this!

Thanks, Troy... Yes, I meant that it has the benefits of the 32 V engine. IIRC, I am given to understand that the '85-'86 cars had a hotter cam profile than the later S4's as well, and that this is the major reason that they benefit so much more from "chips" than the S4 does.

Jfrahm

I think the reason they benefit more from chips is due to the lack of a knock sensor. The 85-86 has a less agressive timing map and no knock sensor while the later cars use a knock sensor to run at the edge of knock for the best power from the fuel and conditions. If you chip the 85-86, you can get more HP but with more risk of damage from detonation.

I would be curious which motor has more potential with and X pipe and dual exhaust, a chipped 85-86 with the bigger cams or the S4 with the better engine management?

The 85-86 are somewhat overlooked great Porsches. I was next to one in traffic the other day and I must admit I really like the small rear spoiler and rear lights. The side exhaust is cool too. Even the 85-86.0 is a great car, the single pot brakes are fine on the street and better for autoX. The only downside on the street really is uneven pad/rotor wear.

-Joel.