Garrett & EFR Turbocharger Spool time 

My pleasure - thanks for the comment.

These two turbos are not really an apples with apples comparison - the diameter of the compressor and flow capabilities are totally different (even though the advertised HP is similar) the EFR will most definitely have a good response but will outflow the G25 in the higher engine RPM range due to the larger compressor exducer. We have seen that the EFR HP ratings are something you can expect to see made at the wheels on most cars, and not a rating found at the crank. The smaller compressor wheel in the G25 runs out of steam with engines that rev higher. The best housing option for the Honda motor is by far the Vband unit which is AR.85, making it much more stable at the higher engine RPM requirements. Power with both of these turbos will still fall away, BUT the EFR will most certainly hold the power for longer int he RPM range. I would use the EFR7670 on this application for power levels around the 600WHP anything more than this the EFR8474 Black series is a loaded gun!

Thank you for your thoughts. I re-ran thru the match bot with the efr7670. As you’ve said, it seems a better match for the high reving engine. Larger turbine and more efficient compressor as well. Results here: www.borgwarner.com/go/8T9KHO Forgot to mention I’m on ID1300 injectors and stock motor, so not going to get too wild with the build and I intentionally limited my Hp goals with the 1300s. 😇

@@michaellecompte1889 Glad i could help - let me know how the build goes -

The EFR would absolutely be the better choice especially when it comes to spool and linear response, purely because of the lightweight turbine combination together with the high flow compressor. The most underrated turbochargers out there!

@@TurboDirectSA Thank you, Sir! I appreciate that advice! Cheers

@@tallenmotorsport8416 Pleasure buddy, anytime!

@Heffalompen All turbochargers fail, but something causes the failure - the EFR turbochargers have been through a number of revisions since their inception in mid 2000's the initial turbine head problems were resolved very early in life of the series, so failures that are being experienced are not from defective manufacture of parts internal to the assembly.

@Heffalompen Whichever you decide on, you cannot go wrong

Its not something anyone can say for sure, you will have to do back to back testing - but the EFR is lightweight in terms of the Gamma TI materials used on the turbine head. Manifold choice makes a big difference with larger turbos when separated. These two turbos are far from apples with apples in terms of the physical size and the AR of the turbine housings you mentioned.

EFR Compressor Wheel OD (exducer): 91mm Compressor Wheel Inducer: 73.7mm Max Flow Rate: 110 lb/min

Garrett Compressor Wheel Exducer: 73mm Compressor Wheel Inducer: 91mm Compressor Wheel Trim: 65 Max Flow Rate: 115 lb/min

The two compressors are very similarly designed in terms of size and flow, however the Garrett compressor map is certainly short lived compared to the HP claimed. It seems that all of the newer Garrett turbochargers' compressor maps do not show (at X10) the same flow required to make the claimed HP -- I would choose the EFR in this specific case.