Back Pressure on the 3B-II (1 Viewer)

[LeftHandRev]

I put a Turbo Glide kit with a Garrett GT25 onto my '88 BJ70 with a 3B-II engine. TG's instructions stated that the best option is to have a 2.5" straight pipe with no muffler... but I'm a skeptical motherfxxxer, so I would like some more input.

I've been running this setup for a while. I plan to put an intercooler in as well so I can increase my boost above 9.5lbs. My EGTs are running just above 800 degrees F when going full bore uphill.

I'm asking about back pressure because I don't know if I'm really getting all the power I should be from this setup.

My other concern is that I'm running too lean.

I'm open to any suggestions or advice. Let me know!

 

[Mudder]

If you think you may be running lean I'd install an AFR gauge in the exhaust.

 

[Tapage]

too lean ain't gonna be a problem .. your pyro gauge probe it's pre turbo ..?

your turbo it's your best muffler .. so feel free to run a straight pipe with no problem ..

 

[LeftHandRev]

too lean ain't gonna be a problem .. your pyro gauge probe it's pre turbo ..?

your turbo it's your best muffler .. so feel free to run a straight pipe with no problem ..

The pyro is pre-turbo.

As for your second sentence, I'm not exactly certain that it's answering my question directly.

I'll try to ask it another way: Do turbos benefit from a little back pressure?

Edit - Never mind, I think I've found my answer. Engine Exhaust Back Pressure

"At increased back pressure levels, the engine has to compress the exhaust gases to a higher pressure which involves additional mechanical work and/or less energy extracted by the exhaust turbine which can affect intake manifold boost pressure. This can lead to an increase in fuel consumption, PM and CO emissions and exhaust temperature. The increased exhaust temperature can result in overheating of exhaust valves and the turbine. An increase in NOx emissions is also possible due to the increase of engine load."

 

[LeftHandRev]

If you think you may be running lean I'd install an AFR gauge in the exhaust.

I'm going to order an AFR, but this then makes me ask, what's the correct AFR reading for this setup?