Need advice on basic exhaust system

The shape

X pipe the two parts of the system merge into each other and then away at a point that makes a junction, and that is about the same bore as 1 pipe. the pipes in this area are cut and welded to allow both pipes to communicate with each other. the arangement looks like a cursive writing or Algebra x
to remove the trans you will have in most cases to remove the X section

H pipe the 2 sides of the exhaust follow their own route and are joined by a link between the 2, looks like an H. if you get the link made with slip fit connectors or flanges so you can unbolt it there is a chance that the trans can come out without the exhuast system being completely removed.

the aim here allows pulses from 1 bank of cylniders to influence those on the other bank

the X or H is put at a sweet spot far enough back to allow good extraction of exhaust gas from each cylinder (decent length of none varying bore pipe from port to the X or H but not so close as to disrupt pulses and casue a reversion of exhaust gas back into an apposing cylinder.


on the whole if done right you usually find an increase in torque mid range, which makes the car feel a bit more peppy on the street

and the exhausut note, can make it have less crack to it...

too close to the heads and it wil help with all out power but you will loose some of that mid range torque that you use when street driving

in general the further back you merge the more the torque cuve is biased towards lower RPMs but this only works if the pipe bore is correct

too fat a pipe and the effect is negated

you will gain by the fact that you intend to use cast iron manifolds they hold heat longer and can promote fast gas flow the key here is making sure the pipes from the manifolds to the main system are of appropriate bore to take advantage

for a street car a system too big is worse than one a little too small

drag race and it a whole different kettle of fish

Dave