Straight pipes or X pipe?
Straight pipes or X pipe? What are the benefits of each.... Would it be better for performance to just run true duals, straight pipes right off the headers, or to run the same but with an X pipe?
Does it mostly affect sound more and not performance at that point?
Does it mostly affect sound more and not performance at that point?
TECH Resident
Joined: Jan 2009
Posts: 869
Likes: 0
From: In the moment...
For a motor built more for the street, an x-pipe would be ideal because of something having to do with backpressure. For race motors, straight pipes would be ideal to allow bigger heads to flow better. As a rule of thumb, the more power you make, the less restriction you want.
SBC firing order:
1-8-4-3-6-5-7-2
This results in one cylinder bank exhausting spent combustion charge as the oposite bank is drawing air/fuel charge in. Scavenging is a phenomenon where the exhausting cylinder actually helps to draw the charge in on the opposite bank. The X pipe or a simple H pipe ("balance tube") creates a space near the collectors (the closer to the collectors the better) where scavenging takes place or is enhanced.
Restrictor plate tracks are where you'll see NASCAR teams using X pipes, wheras they'll go straight pipes on non-restrictor plate tracks. Essentially, NASCAR teams are using a lengthened, highly-tuned version of an open header at non-restrictor plate tracks.
For street, an X pipe is the way to go. Worth mentioning, you can actually over-scavenge in some cases and end up burning some of the air/fuel charge across the exhaust valve and into the primary on the header. Unusually high exhaust temps and even glowing headers are a result. That being said, the most common cause of over-scavenging is too much exhaust duration (cam) on an exhaust that flows freely enough where the extra exhaust duration is not needed. For example: a Comp 306 (230/244) coupled with a 3" system dumped in front of the axle. And even that will vary quite a bit depending on the restriction (or lack thereof) provided by the mufflers chosen. The 306 would probably do a lot beter in this case with a catback system... which would be a simple Y pipe system, not an X.
1-8-4-3-6-5-7-2
This results in one cylinder bank exhausting spent combustion charge as the oposite bank is drawing air/fuel charge in. Scavenging is a phenomenon where the exhausting cylinder actually helps to draw the charge in on the opposite bank. The X pipe or a simple H pipe ("balance tube") creates a space near the collectors (the closer to the collectors the better) where scavenging takes place or is enhanced.
Restrictor plate tracks are where you'll see NASCAR teams using X pipes, wheras they'll go straight pipes on non-restrictor plate tracks. Essentially, NASCAR teams are using a lengthened, highly-tuned version of an open header at non-restrictor plate tracks.
For street, an X pipe is the way to go. Worth mentioning, you can actually over-scavenge in some cases and end up burning some of the air/fuel charge across the exhaust valve and into the primary on the header. Unusually high exhaust temps and even glowing headers are a result. That being said, the most common cause of over-scavenging is too much exhaust duration (cam) on an exhaust that flows freely enough where the extra exhaust duration is not needed. For example: a Comp 306 (230/244) coupled with a 3" system dumped in front of the axle. And even that will vary quite a bit depending on the restriction (or lack thereof) provided by the mufflers chosen. The 306 would probably do a lot beter in this case with a catback system... which would be a simple Y pipe system, not an X.
Last edited by Gojira94; Oct 4, 2010 at 03:20 PM.
