The S4 goes under the knife…
Monday the S4 went under the knife to receive the first round of performance modifications. Take a look at the OEM exhaust manifolds. Proceed to cringe.
To gain access the exhaust manifolds we had to lower the motor. Pictured below, the transmission has already been removed.
The motor is supported so it can be lowered down enough to gain access to the exhaust manifolds.
Here you can see the JHM longtube headers installed.
This version of the headers uses v-band clamps.
Ceramic coated longtube headers
My JHM longtube headers have made it back from Performance Coatings! They've recieved a satin black ceramic coating to dramatically reduce radient heat.
We're looking at a 110-120 degree temperature reduction in the engine bay; this should be good for a 11-12% increase in engine efficiency. Gotta love free horsepower!
For a 450-500HP motor we can expect a gain of 50-55HP. Show me a better mod for the money!
Thanks to Performance Coatings and JHM!
JHM longtube headers have shipped!
I received word from JHM that my longtube headers have shipped. The JHM longtube headers replace the OEM headers and downpipes; other cars have been seeing both 20-50 ft/lbs and 20-50 AWHP gains throughout the powerband. JHM reccomends wrapping the headers with an exhaust wrap, I choose another route.
Performance Coating in Auburn, WA will be coating the headers with their satin black ceramic coating; we expect to see a temperature drop of 110-120ºF.
Read more about the headers on JHM's site.
Stock B6/B7 headers:
JHM prototype headers:
034 Motorsport dyno of stock headers and JHM headers; note the vehicle dynoed was an auto. Click image for fullsize.