Curious about running a turndown on track days on my red and if the lack of back pressure would do more harm than good. Thoughts?

 

And I did search but came up empty handed

 

Turbo cars do not need back pressure your fine. The stock turbo will make enough pressure for it to be ok.

 

subscribed.

good question. I would also be interested in seeing if that hot exhaust gas causes any other issue with things under the car. Lots of guys run open dumps/turn downs for 1/4mile stuff, but what would happen if you did 5 - 30min sessions on a road course with either one of those dumping under the car???

 

Not entirely true. Some perform better with back pressure but it mostly relates to smaller turbos so I was curious if that applied to stock framed setups

 

Run a turndown, you will be fine...I have a QTP cutout downpipe on my car & it performs great with it...

 

No problems with carbon/soot covering everything?

 

No sir...I don't keep it open for long periods of time but you still shouldn't have a problem...I've run cutouts on my GSX & now my Evo...

 

99% of the turbos I have seen and have used perform better without back pressure. The turbos create enough back pressure to be run that way. These aren't v8 cars. The turbos are designed to run that way. If they weren't people wouldn't run them with no exhaust and side dumping exhaust.

 

Back pressure behind the turbo is never beneficial to creating power under boost. The turbine relies on delta pressure from one side of the wheel to the other to spin. The higher the delta pressure, the faster it spins. If your exhaust creates, say, 1 PSI of back pressure at the turbine exit, you need to make the pressure entering the turbine proportionally higher to spin the same speed (make the same boost)
Whether an engine wants back pressure when it's not using a turbo is up to cam specs. However, under boost, the pressure inside the manifold, and thus the back pressure the engine sees, is usually around 1.5 to 2 times boost pressure depending on how efficient the turbo setup is. Plenty for any engine's potential need for backpressure.

 

I have the highest WHP stock appearing turbo car in the world to my knowledge. I try to eliminate as much back pressure as possible! Running a turn down will produce quicker spool and more power throughtout the entire powerband. I have a Single Scroll Black for that reason

Mikey

 

I agree with Mikey^ but I will give you an explanation I got regarding the same question. You have a turbine wheel in the middle of the way of the exhaust flow... how much more back pressure do you need? Eliminating back pressure after the turbine wheel is essential to making the most power, and doing so efficiently.