[gtfpv]

Originally Posted by Chris

Firstly everyone, sorry about the late reply's, but bear with me, i will get to everyone.

The 1/78 difilippo is not a trick - just smart engineering. Modern engine building theory tells us to use the smallest primary to do the job, build up airspeed and increase scavenging.

So why go the 1 7/8??

Modern theory does go out the window when you have a unique, somewhat hybrid engine in a very narrow engine bay. The airspeed lost by going to a larger pipe is more than made up for by the larger cross sectional area at the head flange. If we were talking hot rods, where you could run a pipe straight off the head a few inches before it turns, you would be more confident with the smaller primary. However, the BA is very limited in its space, and loves the 1 7/8 pipe.

We notice that we run faster down the quarter than our closest rival in ET and MPH, and we run a 4:1 and they i believe are using a try y.

Thats good enough for me.

Editing the cars will make improvements over each mod, so it is recommended that a competent tuner aid you in editing each and every step of the way, to maximise efficiency.

thanks . that explains a lot now i understand , its not just try y's versus 4:1s but the right size as well . cheers.