Hello Guys,
I would like to measure the back pressure before my turbocharger (between cylinder head outlet and turbine inlet).

My question is, if I know the back pressure and I know also the boost, what can I do with this information and what could result out of this information (conclusion) ?

I imagining that I could see, that it's not worth to run more boost, because my back pressure is getting to high.

I would like to know your thoughts and ideas regarding this topic.

Bye,
Cali

 

Me personally I like to run no more than 1 to 1 on back pressure. When you push the turbine wheel beyond its most efficient range you may run more boost but it may actually produce less HP . Just my experiance.

 

You could use the info to optimize the setup, you would need to set some goals for what you want to do with the info. If your exhaust pressure is low and you want it to spool faster go to a smaller turbine or A/R. If you want to turn up the boost and get it to top end better you would want to reduce the pressure, but you have to look at the combo holistically.

You could also use it for cam tuning or diagnostics, for instance if the engine is falling on its face the pressure reading will help you determine if you are floating valves or if the turbine side is just too small.

It is useful in diesel compound applications, measuring the pressure before the pair, then between gives an idea of drive pressure, it can help with sizing and setting the gates.

Just another tool in the toolbox. I reckon most people never measure it unless they are trying to set the world on fire with their combo, EG class racing or have a problem.

 

Most consider a "decent" setup to be less than 2:1, but will vary depending on your goals. 1:1 or better is great, but is typically race territory, especially with a journal bearing turbo. Spooling techniques, tuning, and turbo tech is advancing, and is allowing the ratio to be much better, even on street orientated builds.