Hi All..

What is the standard boost pressure and what is a resonable pressure on a standard engine with an exhaust upgrade. Going to the exhaust place tomorrow...Any suggestions?? besides bigger is better. I was thinking 3" with a straight thru muffler

Stock setup is controlled by the PCM.

If the system is operating properly you are going to see what it wants as a maximum on your boost gauge.

11 to 12 psi should be OK but it depends on the exhaust temperature. If you see the exhaust temperature going toward 1200 F with pyro installed preturbo it's time to back out.

If you install the pyro post turbo it's going to read a lot lower and that will need to be taken into consideration. Could be 200 to 300 F difference in the downpipe. That would be 900F max.

With an Intercooler you could lower the intake air temperature and the exhaust temperature by up to 100F on a hot day or maybe more.


Gauges are required because all vehicles are different. With the stock system the PCM has sensors to monitor boost, intake air, coolant temperature, etc, etc.

If you modify the vehicle you take over the job of the PCM.

for the best flow rate, use 3 1/2" without a muffler, or 4" with a muffler.

Get gauges.

Hi All..

What is the standard boost pressure and what is a resonable pressure on a standard engine with an exhaust upgrade. Going to the exhaust place tomorrow...Any suggestions?? besides bigger is better. I was thinking 3" with a straight thru muffler

3" is bare minimum, your #1 enemy is the squashed turbo downpipe, replace that with a smooth mandrel bent one 3" tube for that not much more clearance room than that, then have a look through the more performance thread in FAQ for more ideas

Don't be surprised if you only see 5-7 psi of boost on a stock engine. Some of the boost foolers and the Turbo Master can help you increase the boost to 10-12 psi (that's a safe level). I've used both to good advantage. The engine loves to have more air, more boost!

I use a 3" mandrel bent downpipe and a 4" exhaust w/straight thru muffler. I could have skipped the muffler. It doesn't change the sound much at all.

Jake

I am getting a max boost of 15 psi and a normal run of 11-12 psi out my 1995 GMC 2500. I have many extras, as you can see on my signature.