BP S256 10-1.75EFR 6758 10-1.75
GTX3071R_10-1.55Precision 5558 10-1.68

After lots of opinions and some youtube videos we re watching everyday on the web, when it’s time to choose the right turbo for your race car, the tuner or supplier or your closest friend will suggest his turbo because he is satisfied or getting the turbo cheaper or for some reason he is affected from other sources.
We made a deep search in many sites who testing lots of turbos and get the maps from them or the official site as they always cannot lie on the ratio of lbs/min and pressure as anyone can measure it with the right machine.
We choose models for 500+WHP support and 0.6-0.63A/R and T3 flanged for external wastegate use.
TO be honest, we couldn’t find a map from Precision as they don’t post anything, so we got a turbo map from a famous turbo lab.
If we take a starting point of 10lbs/min as most people like better spool up we saw that BorgWarner cores were much faster with Bullseye Power in the 1st place for higher boost in low RPM and Garrett GTX series last.
ADRL drag strips in USA using lots of those turbos as they see lower times in 1/4 mile races.
1. Bullseye Power S256 – 10lbs/min produces 1.76 bar pressure
2. EFR 6758 – 10lbs/min produces 1.74 bar pressure
3. Precision 5558BB(ceramic bearings) – 10lbs/min produces 1.68 bar pressure
4. Garrett GTX3071R(ceramic bearings) – 10lbs/min produces 1.55 bar pressure