slowrollin93

iTrader: (7)

I was getting currious if I actually have enough back pressure. I will be running a LS1, with stock 241s, and a MS3. I have all the bolt ons also. The exhaust is currently pacesetters 1 3/4" primaries and 3" collectors. There is only about 18" of 3in pipe on each side goin to Spintech prostreet mufflers, 3in 3out, and dumped after that, there is no x or h pipe, really is no room for one right there. Is that setup making enough backpressure for the motor is what i am wandering. Any help or advice would be great.

ringram

What are you talking about?
Zero back pressure is always best. Just maintain velocity through good header and collector design. Forget backpressure its for retards who have no clue.

Silver Metal

iTrader: (1)

Thats not true some engines will run lean due to reduction in backpressure causing more air to be drawn into the combustion chamber than before.

DaddySS

The idea of all of these mods we do is to increase flow in and out. Whether or not the mixture needs to be adjusted has nothing to do with whether back pressure is good or bad. For performance, you don't want back pressure, you want good velocity. If you think your pipes are too big, it's not because you want backpressure, it's because you may be losing velocity and scavenging. H pipes and X pipes help with scavenging and velocity. For the LS1, the x gives better results, so if you can work one into your setup, do it.

mchdg86

iTrader: (3)

Ummm..... There is a thing called a mass air sensor that reads how much air is being drawn in and it sends a signal to the computer and the proper adjustments are made to keep a desired air/fuel ratio. I ran cutouts on the header colectors on my old car and it was faster with them open so the less backpressure the better.

Grimes

iTrader: (3)

You don't want backpressure, you want an exhaust that flows well, but has small enough primaries to keep up exhaust gas velocity.

The whole backpressure thing is a myth, and should be shot to death every time it is brought up.

1989GTA

"The whole backpressure thing is a myth, and should be shot to death every time it is brought up."

Hehehe. So true. However there is such a thing as over scavenging. However it is unlikely we are going to run into that problem with our motors and exhaust systems.