- Joined
- Sep 26, 2020
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- Budapest, Hungary
- Website
- www.oemplusmods.com
- Car(s)
- 2020 GR Supra A90 Edition
- Thread starter
- #511
thank you for the details Alec! How do I pin this on the thread?Thanks Guys and thanks for extending me some grace! Well there is a lot to unpack. Maybe my guy Oli @stormgreysupra will consider pinning this post for anyone’s future reference.
The 65 OMEGA Turbo
First of all The 65 OMEGA isn’t really a “new” turbo. It’s utilizing our same OMEGA series dual ceramic ball bearing CHRA that’s designed to support high speed, high boost applications. We’ve been building these turbos for years and have customers with over 20,000 miles on their turbos daily driven.
All OMEGA series turbos have dual piston ring oil seals at both ends of the rotating shaft to fight the possibility of oil leaks at both the compressor wheel or turbine wheel sides. The thick rotating shaft allows for stability at high speed and we balance all completed rotating assemblies at a minimum of 120,000rpm to make sure they can consistently and reliably operate, especially at high boost. Finally we couple this with our standard 1 year warranty on the complete CHRA. IF you were ever to have a problem, we would send you an entirely new CHRA as a replacement.
The turbine wheel on the OMEGA series is a unique 9 blade design with a deep back cut on each of the fins. It allows the turbine wheel to flow much larger amounts of exhaust gases than would be expected in a given A/R turbine housing while keeping back-pressure in the turbine housing low. This allows the OMEGA series turbos to support high horsepower while keeping the A/R tighter for fast spool. For example, while testing the big brother 70 OMEGA on a MKV Supra, we were able to determine that the OMEGA series turbine wheels are capable of flowing well enough efficiently make ~1000whp in a ~0.82 A/R turbine housing while keeping back-pressure low.
Here is a look at the turbine wheel if you’re curious:
For the 65 OMEGA, we leveraged the existing CHRA technology and developed a new compressor and turbine wheel to allow us to achieve instantaneous spool while allowing for very high power potential. Here is where it sits in our entire lineup:
For the Supra, we started by scanning and modeling the stock turbine housing/exhaust manifold on the Supra. Then we cut the stock housing into 3 pieces using a waterjet so we could properly scan and model the twin scroll architecture. We then added 25.4mm to the runner length to simultaneously support higher HP in the upper RPM and move the CHRA off the block to support the larger and more efficient compressor housing. We then resized the turbine housing section from the ~0.57 A/R of stock to ~0.80-0.81A/R to also simultaneously support much better top end without sacrificing spool.
Due to the much larger compressor housing, We developed a custom extension arm complete with a built in ball joint to make sure it could never bind. This unit accomplished its task but came with the complication of finding the correct overall length.
We took it to the dyno the first time and these were the preliminary results:
PRELIMINARY TEST RESULTS (Conservative timing & low boost):
Let me preface these results by stating these are low boost and low timing. We COULD NOT turn it up because I was just running the stock low pressure fuel pump. We noticed right off the bat that something was up. We were missing all of our boost targets! I’ll tell you why in a second.
Dyno’s were done with 305/30R19 Continental Extreme Contact Sports on the 19x11.5 BCForgedNA LE53’s.
Green = 93 octane & Blue = E50. We threw some E in to help us figure out what was going on more safely. We were missing all out boost targets because the wastegate was open . We were commanding full closure but the gate was prevented from closing because the adjustable arm was too long
Stock arm was 81.6mm, our testing was done at 89.2mm haha. The next day after the dunk, we adjusted it down to 85.6mm and started hitting boost targets on the street!
Ok back to the results! We were excited to see that we were hitting over 400ftlbs of tq by 2,950rpms even with the open wastegate issue!
Someone asked how our turbo compares to the DAW, well I know we can’t talk about other offerings. But we are happy with this result so far:
400TQ
65 OMEGA with open wastegate - 2,950rpms
DAW - 3,450rpms
500TQ
65 OMEGA with open wastegate - 3,450rpms
DAW - 3,700rpms
Power fall off
65 OMEGA with open wastegate - 6,600rpms
DAW - 6,100rpms
Different dyno’s, different cars and different tuners but we are happy that we are doing so well with these both being dynojets with the same correction factor.
End of Part 1. I’ll come back with more information here shortly
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