icemans2k02

rmerchant3

For a track build, I'd go for reliability. Garrett or Borg. Depending on your power goals, the new G series (G25-660) from Garrett look really promising. I've mapped a few out if you are interested.

DavidNJ

What is the application and power level? The log manifold doesn't seem like you are going for power which brings the V-mount radiator/intercooler into question. There are 850hp E85 street-driven S2000s on this forum that needs big intercoolers to handle the hot air from 3+:1 pressure ratios. If you are at 12 psi for 500hp that is probably overkill. If you are going for 800+ a single EFR is probably not your turbo.

The EFR turbos have titanium aluminide turbine wheels; half the mass of Inconel or Mar-M (same density as Iconel) in other turbos. The G25 series is about to be joined by the G30 and G35 this fall. It is better than the old Garrett turbos; IMHO the EFR is probably better if big enough to meet your airflow needs.

The star of the EFR line is the small frame 7163. Good for over 500hp. at most boost levels. The EFRs are all come with recirculating BOVs and a 3-port boost control solenoid on the compressor housing and are available with internal wastegates. There is also a 90° compressor housing available. They have a T2.5 undivided and V-band and T4 twin scroll with internal wastegates. Turbosmart makes a popular iWG actuator for them and a nicer BOV that plugs into the existing slot. Full Race makes an aluminum top to the OEM BOV. I'm hoping BW gets around to offering an electronic actuator like the one on OEM turbos. So far, no. Ditto the built-in quick spool valve they showed at SEMA in 2014. There are videos on YouTube of a compound turbo S2000...he used 2 EFR turbos and discussed why at the beginning of one of his videos.

https://www.full-race.com/store/borg...fr-7163-turbo/

Mrsideways

My G25-660 is ready to go in the car. I'll have updates in hopefully a week or two.

spdracerut

Have any data you can share on the G25-660? It's hard to come by..... G25-660 will be the most robust turbo option out there as it's basically a Motorsports turbo with the highest quality/most durable materials.

DavidNJ

Performance Turbos | BorgWarner Turbo Systems

https://www.indycar.com/News/2017/09...ocharger-plant

https://www.indycar.com/Fan-Info/INDYCAR-101/The-Car-Dallara/IndyCar-Series-Chassis-Specifications


http://www.youtube.com/watch?v=-0iD6D8zZ0U

spdracerut

Ferrari F1 - Garrett
All WRC rally cars - Garrett
Every winner of the 24 hour of Le Mans since 2000 - Garrett
CART/Champ Car - Garrett
GRC - Garrett
All FIA Touring Cars - Garrett
Ford GT and BMW GTLM cars - Garrett
Most if not all Japan Super GT cars - Garrett

FACT: TiAl has a temperature operating limit of at the very most, 980C though 950C is probably safer. Garrett Motorsports and the G25 series turbos use MarM with a limit of 1050C. The GT30-35 use inconel713 IIRC, good for 980C.

DavidNJ

TiAl was used by MHI with the Evo IX, and has the same temperature range as Inconel 713C which is used in pretty much every other aftermarket turbo.

In the end, this isn't going to be in a competition where 10ths or 100ths of a second count. Any of these turbos will be fine. And if someone wants to run a lean mixture in a fuel economy race, the Mar-M will allow a higher temperature if the housing also supports that temperature range.

spdracerut

Slight correction, MHI used TiAl on the Evo 6.5 TME. I've seen a LOT of turbos come off cars that were used on track with inconel tubine wheels showing over-temp of the inducers. Reason being the vast majority of cars getting tuned don't use EGT measurement. Tuners just crank up the boost, lean out the A/F. That's fine for street use and drag racing, but road course cars should use a bit more care. Of course, turbos become wear items at a high enough performance level.

So yes, you can get away with inconel and TiAl turbine wheels with careful tuning in a road course type of environment. Same with ni-resist vs stainless steel turbine housings. SS is more durable but ni-resist can hold up at a lower performance level. But if one is looking for maximum durability, MarM and SS are the way to go. Maybe an interesting tidbit, the BMW GTLM cars use the OEM turbos as used on the M5/M6 you can buy from the dealer. They already come with MarM turbine wheels and SS turbine housings, but use journal bearings instead of ball bearing.

DavidNJ

Why would they lean out the A/F? How far do they lean it out? If anything, I would have thought anti-lag would have been the temperature culprit. But then, the anti-lag is only for a few seconds at a time and the goal isn't to see how much flame shoots out the exhaust.