Data logging exhaust to intake pressure ratio

[Paul Lohr]

I've read that the newer design turbochargers produce more intake pressure with less exhaust pressure when compared to some of the older turbos. I think older turbos would run at 2:1 exhaust:intake pressure ratio and the newer ones run closer to 1.5:1 (maybe less?). Does anyone have data logging results to compare a newer design turbo with an older one? By newer design, I am thinking of turbos with billet wheels, ball bearings and other recent enhancements.

 

[TTipe]

Billet wheels and ball bearings are the tip of the iceberg

 

[toomanymodz]

I didn't data-log it, but rather temporarily plumbed a pressure gauge to the exhaust side. At 21 psi boost, my exhaust pressure is about 30 psi. The turbo is the 6466CEA dbb with a .63 A/R. I may try a .85 A/R housing to see if it improves anything, especially since the current setup spools a bit too quick at the track and blows the tires off.

 

[bison]

I didn't data-log it, but rather temporarily plumbed a pressure gauge to the exhaust side. At 21 psi boost, my exhaust pressure is about 30 psi. The turbo is the 6466CEA dbb with a .63 A/R. I may try a .85 A/R housing to see if it improves anything, especially since the current setup spools a bit too quick at the track and blows the tires off.

You would need to know more information to be able to asses the next move. The mass flow the engine is using is a key component. If you're at 21psi and the engine is consuming 65lbs/ min of air and back pressure is only 30psi you are in a really good position to pick up a lot of flow by increasing boost. I wouldn't expect much drop in backpressure by switching.

 

[toomanymodz]

You would need to know more information to be able to asses the next move. The mass flow the engine is using is a key component. If you're at 21psi and the engine is consuming 65lbs/ min of air and back pressure is only 30psi you are in a really good position to pick up a lot of flow by increasing boost. I wouldn't expect much drop in backpressure by switching.

I would have thought so too, but when I switched to a race chip and increased boost to 25, I only saw a 2 mph gain at the track. Something is holding back this combo. Wish I knew what it was.

 

[bison]

I would have thought so too, but when I switched to a race chip and increased boost to 25, I only saw a 2 mph gain at the track. Something is holding back this combo. Wish I knew what it was.

It's not the turbo.