Anyone have experience with a Borg Warner EFR 7064 on an M20?

[cleanasse30]

Hey all,

I am new to the forum, but have eagerly begun planning my turbo build for my new to me 325i. I plan on using the car as a street-able track car mostly for road racing.

I am starting to research a turbo build and based on my calculations for required mass flow rate and pressure ratio I found a turbo sized around a GT3076R or GTX3076R would be good for about 350whp for my m20b25. I plan on building a custom twin scroll manifold and have heard good things about Borg Warner turbos in the past from my subaru days. I found that the EFR 7064 with a .92 A/R T4 twin scroll turbine housing has a similar compressor map to the GT30R but has an internal wastegate and BOV. The reason this is attractive to me is that it would make packaging a bit easier and may end up reducing the cost of my turbo build since I wouldn't have to buy 2 wastegates. This series of turbo also has the oil restrictor built into the cartridge so that is one less thing to worry about.

Does anyone have any experience with the Borg Warner EFR turbos or the EFR 7064 specifically?

Thanks,
Alex

[sayed ali]

Good luck choosing the correct turbo, but i prefer an external "good quality" waste gate for your power goals, since the internal waste gate may creep the boost over 1 bar <== that's what I've heard from some people

[jaywood]

Good luck choosing the correct turbo, but i prefer an external "good quality" waste gate for your power goals, since the internal waste gate may creep the boost over 1 bar <== that's what I've heard from some people

The Borg Warner's have very well designed internal w/g's. Subaru guys push well over 400 hp with the internal gates.

[wazzu70]

The Borg Warner's have very well designed internal w/g's. Subaru guys push well over 400 hp with the internal gates.

This. The Borg Warner IWG works very well because its actually designed for a petrol engine. To this day, most Garrett turbos are still based off diesel tractor housings which have completely different requirements. Also on a twin scroll housing the IWG is nice because it reduces manifold complexity and saves you the money of two external gates.

7064 would be perfect for a street/track car!

[cleanasse30]

This. The Borg Warner IWG works very well because its actually designed for a petrol engine. To this day, most Garrett turbos are still based off diesel tractor housings which have completely different requirements. Also on a twin scroll housing the IWG is nice because it reduces manifold complexity and saves you the money of two external gates.

7064 would be perfect for a street/track car!

I agree, the design of the IWG setup on the twin scroll turbine housing seems very well designed in terms of minimizing turbulence when the gate opens while maintaining a rather large IWG. It would also make manufacturing the twin scroll manifold a bit easier. Perrin also did a review of the EFR 7163 and 7064 series turbos and said that upgrading the WG actuator can fix boost creep in high boost applications.

I was looking some more at the EFR 7163 and it has a twin scroll .80 A/R T4 housing which I feel would be a better match for the 2.5L engine giving better drivability, any thoughts?

[bobross]

7064 would be perfect for a street/track car!

+1 on all accounts. EFR 7064 with proper TS manifold haunt my dreams on a weekly basis.

[cleanasse30]

+1 on all accounts. EFR 7064 with proper TS manifold haunt my dreams on a weekly basis.

After looking at the compressor maps some more I think I am going to go with the EFR 7163. A very similar turbo to the EFR7064 but it has a .80 A/R T4 Twin Scroll exhaust turbine housing which would better suit the 2.5L for power between 3500-7000 rpm.

I am excited to start piecing things together, but first I need to take care of my suspension, wheels, tires and brakes. :p

[wazzu70]

The 7163 also has the mixed flow turbine wheel design. Sechsy time!!

[cleanasse30]

Yes! The more research I do on the turbo the more I want it... I saw a dyno sheets of this turbo on mostly stock 08 STi (which also has a 2.5L) and it was making peak torque of 353ft/lbs at 3600 RPM with a .64 A/R single scroll T25 turbine housing.

http://forums.nasioc.com/forums/showthread.php?t=2394879

I am hoping to get something similar-ish with this turbo using a twin scroll manifold and the .80 A/R housing and lower boost. Should be interesting to see how it turns out! Hopefully the turbo isn't back ordered like crazy when I try to purchase one towards the end of this year.

The 7163 also has the mixed flow turbine wheel design. Sechsy time!!