Homemade header

[Losiracer2]

Does anyone even have a sound clip of this? or even of the Bisi header? I've never seen an actual vid. to listen to how it changes the exhaust note of this engine.

[wed3k]

I remember that header. Pretty cool to see the numbers it managed, I hope it hasn't given you too much trouble

yea it leaks like crazy, im going to get some springs to hold the collectors together and fix the down pipe.

with the cutout you can really hear the rumble at a cruising speed. right now i have the stock header and it doesnt sound anything like this so im assuming the header has everything to do with the sound and power. Only have an A6 cam too.

[loud92CB7]

sounds very throaty ... i like it....

[James Matteu]

Exhaust Pulsation

I thought the audible pulsation of exhaust gases indicated asynchronous collector design. I also thought this was undesirable as exhaust gasses rushing by through the collector are able to draw out gasses from subsequent exhaust cycles. Spacing them out like that loses some of the efficiency gained by what I would characterize a "Bernouli Effect" in the exhaust stream. I don't have any numbers on this, but given the OEM design synchronizes the exhaust strokes, I imagine an asynchronous design would either cluster the exhaust note (pulsing) or prevent a complete evacuation of the cylinder on the exhaust cycle. Removing such technology from your exhaust system takes you back to 1920's technology, when each cylinder had a dedicated exhaust pipe and/or collectors were placed far from the motor.

Just food for thought.

[wed3k]

I thought the audible pulsation of exhaust gases indicated asynchronous collector design. I also thought this was undesirable as exhaust gasses rushing by through the collector are able to draw out gasses from subsequent exhaust cycles. Spacing them out like that loses some of the efficiency gained by what I would characterize a "Bernouli Effect" in the exhaust stream. I don't have any numbers on this, but given the OEM design synchronizes the exhaust strokes, I imagine an asynchronous design would either cluster the exhaust note (pulsing) or prevent a complete evacuation of the cylinder on the exhaust cycle. Removing such technology from your exhaust system takes you back to 1920's technology, when each cylinder had a dedicated exhaust pipe and/or collectors were placed far from the motor.

Just food for thought.

i know, which is why my dyno chart has waves in it, LOL.