LHD AE86 headers and exhaust

[jondee86]

(05-23-2017 08:39 PM)zenki Wrote:  So 50mm or 63mm? Which one is the best performance wise?

When I installed a stock smallport in my car I used the factory cast AE86
exhaust manifold and 2>1 section mated to a custom 50mm over axle
exhaust. The fabricator said the 50mm was better for torque as it kept
the gas velocity higher. The system worked very well and continued to
work well with 272 cams and ITB's and the limiter raised to 8200rpm

It is possible that the engine was restricted a little at the very top end of
the rev range (>7500rpm), but considering how little time the engine would
spend at that rpm, it was not a problem in a road car.

For a highly modified N.A. or a GZE you might use a 63mm exhaust, but in
general it is considered to be too big for a N.A. 4AGE. 57mm diameter is
the recommended maximum for cars with medium modifications (cams, carbs
headers and a compression bump). I once put a 57mm exhaust and 4>2>1
headers onto a stock 4AGE and it did nothing except make more noise

So I recommend going with the 50mm exhaust for a DD/road car.

Cheers... jondee86