Logging turbine back pressure

[fastblackracing]

Does any one sell a set up for measuring and logging back pressure? I want to add this to my fast system and if there is a kit with all the needed items I would like to check it out vs. having to piece it together. Advice from those who are doing this is welcomed.

 

[rag231]

I am sure Bison has this info.

 

[turbobitt]

It is just as easy to make it yourself. Just need to buy a 100 psi pressure transducer and make a hard line so the sensor can be mounted away from the header.
AG.

 

[bison]

You can use the open auxiliaries on the XFI for other sensors. The SSI pressure transducers are high quality and should be plumbed as turbobitt explained. You have to set the calibration values for the input signal for the auxiliary you are using


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[Mike Licht]

We usually drill and tap the header of turbine housing for a brass adapter to inverted flare and use a piece of brake line that you can get at any auto parts store to get the sensor away from the heat. Then and inverted flair to 1/8 pipe female on the other end for the sensor. Pretty easy and works well.

 

[pacecarta]

tap old o2 sensor plug for 1/8npt
go to parts store and get a copper oil line kit ..its 1/8" copper
should have the fittings you need to screw onto an 1/8npt 100psi sensor

 

[MCH86GN]

We usually drill and tap the header of turbine housing for a brass adapter to inverted flare and use a piece of brake line that you can get at any auto parts store to get the sensor away from the heat. Then and inverted flair to 1/8 pipe female on the other end for the sensor. Pretty easy and works well.

I work in Troy, MI. So I'm not too far from your shop. Is this something you would be willing to do? I don't have XFI, but I have PL and I believe it has a few spare analog inputs.

 

[NY Twin Turbo]

Not to highjack the thread, but what would be a good differential of back/intake pressure at the right turbo's sweet spot for a given combination?

For example, is it possible to have nothing more than 1 or 2 psi difference on a 49 with the perfect converter, cam, head, combo at 20 psi?

I'm assuming that with any combination of parts, it is at this point of least differential when you are running your most efficient boost. No?

 

[Boost231]

1:1 would be awesome. I believe some even hit crossover

 

[NY Twin Turbo]

1:1 would be awesome. I believe some even hit crossover

I would imagine this would be impossible. You mean more boost then back pressure? That would mean over 100 percent efficiency. No?

 

[Boost231]

Yes more boost then back pressure.

 

[Boost231]

http://www.turbobuick.com/forums/index.php?threads/144094/

 

[fastblackracing]

I would imagine this would be impossible. You mean more boost then back pressure? That would mean over 100 percent efficiency. No?

from what I have gathered research wise on our turbo buicks with a 3bolt housing 1 1/2 to 1 would be a decent number and anything much lower than that would be good. ........ So 30 # intake pressure would be 45# exhaust pressure. And you have to remember intake manifold pressure never sees the true output of the compressor due to the pressure drop across the inner-cooler.......... A twin setup would be different as would a 4 bolt housing......I am only interested in three bolt at this time.....I was one week away from logging my back pressure but now that the car is in the body shop hospital it will have to wait till next year........I have seen references to 1 to 1 ratio but I think the turbine housings are pretty big to make this happen and dont discount the fuel that is required to run a turbo so even at 1 to 1 I still dont see 100% efficiency....Input is welcomed on this....

 

[NY Twin Turbo]

from what I have gathered research wise on our turbo buicks with a 3bolt housing 1 1/2 to 1 would be a decent number and anything much lower than that would be good. ........ So 30 # intake pressure would be 45# exhaust pressure. And you have to remember intake manifold pressure never sees the true output of the compressor due to the pressure drop across the inner-cooler.......... A twin setup would be different as would a 4 bolt housing......I am only interested in three bolt at this time.....I was one week away from logging my back pressure but now that the car is in the body shop hospital it will have to wait till next year........I have seen references to 1 to 1 ratio but I think the turbine housings are pretty big to make this happen and dont discount the fuel that is required to run a turbo so even at 1 to 1 I still dont see 100% efficiency....Input is welcomed on this....

After looking at through the old thread link that Boost231 provided in post #12, I have come to the conclusion that the best way to tune for boost efficiency is to find the boost level you make the most power while having the least differential in back pressure to intake pressure.

Trying every turbo and intake combo on the market is not an option for most of us. Just use the turbo that is reasonably acceptable for your combination based on popular opinion. This doesn't mean you are making maximum power at this boost level. It just means you are making boost most efficiently.

After this, although gains are still made, you will begin to come upon the point of diminishing gains.